BEAMFORMING TRAINING

CROSS REFERENCE

[001] This application claims the benefit of and priority from US Provisional Patent Application No. 62/530,732 entitled "ENHANCED BEAMFORMING FOR WIRELESS COMMUNICATIONS", filed July 10, 2017, and US Provisional Patent Application No. 62/530,682 entitled "ASYMMETRIC BEAMFORMING", filed July 10, 2017, the entire disclosures of which are incorporated herein by reference.

TECHNICAL FIELD

[002] Embodiments described herein generally relate to asymmetric beamforming training.

BACKGROUND

[003] A wireless communication network in a millimeter- wave band may provide high-speed data access for users of wireless communication devices.

BRIEF DESCRIPTION OF THE DRAWINGS

[004] For simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity of presentation. Furthermore, reference numerals may be repeated among the figures to indicate corresponding or analogous elements. The figures are listed below.

[005] Fig. 1 is a schematic block diagram illustration of a system, in accordance with some demonstrative embodiments.

[006] Fig. 2 is a schematic illustration of an Enhanced Directional Multi-Gigabit (EDMG) Physical Layer Protocol Data Unit (PPDU) format, which may be implemented in accordance with some demonstrative embodiments.

[007] Fig. 3 is a schematic illustration of an asymmetric beamforming training, which may be implemented in accordance with some demonstrative embodiments.

[008] Fig. 4 is a schematic illustration of a format of a sector Acknowledgement (ACK) frame, in accordance with some demonstrative embodiments.

[009] Fig. 5 is a schematic illustration of a format of a format of a channel allocation field, in accordance with some demonstrative embodiments.

[0010] Fig. 6 is a schematic illustration of a format of a format of a channel allocation field, in accordance with some demonstrative embodiments. [0011] Fig. 7 is a schematic flow-chart illustration of a method of asymmetric beamforming training, in accordance with some demonstrative embodiments.

[0012] Fig. 8 is a schematic flow-chart illustration of a method of asymmetric beamforming training, in accordance with some demonstrative embodiments.

[0013] Fig. 9 is a schematic flow-chart illustration of a method of asymmetric beamforming training, in accordance with some demonstrative embodiments.

[0014] Fig. 10 is a schematic flow-chart illustration of a method of asymmetric beamforming training, in accordance with some demonstrative embodiments.

[0015] Fig. 11 is a schematic illustration of a product of manufacture, in accordance with some demonstrative embodiments. DETAILED DESCRIPTION

[0016] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of some embodiments. However, it will be understood by persons of ordinary skill in the art that some embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, units and/or circuits have not been described in detail so as not to obscure the discussion.

[0017] Discussions herein utilizing terms such as, for example, "processing", "computing", "calculating", "determining", "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulate and/or transform data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information storage medium that may store instructions to perform operations and/or processes.

[0018] The terms "plurality" and "a plurality", as used herein, include, for example, "multiple" or "two or more". For example, "a plurality of items" includes two or more items.

[0019] References to "one embodiment", "an embodiment", "demonstrative embodiment", "various embodiments" etc., indicate that the embodiment(s) so described may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it may. [0020] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third" etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner. [0021] Some embodiments may be used in conjunction with various devices and systems, for example, a User Equipment (UE), a Mobile Device (MD), a wireless station (STA), a Personal Computer (PC), a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, a wearable device, a sensor device, an Internet of Things (IoT) device, a Personal Digital Assistant (PDA) device, a handheld PDA device, an on-board device, an off-board device, a hybrid device, a vehicular device, a non-vehicular device, a mobile or portable device, a consumer device, a non-mobile or non-portable device, a wireless communication station, a wireless communication device, a wireless Access Point (AP), a wired or wireless router, a wired or wireless modem, a video device, an audio device, an audio-video (A/V) device, a wired or wireless network, a wireless area network, a Wireless Video Area Network (WVAN), a Local Area Network (LAN), a Wireless LAN (WLAN), a Personal Area Network (PAN), a Wireless PAN (WPAN), and the like.

[0022] Some embodiments may be used in conjunction with devices and/or networks operating in accordance with existing IEEE 802.11 standards (including IEEE 802.11- 2016 {IEEE 802.11-2016, IEEE Standard for Information technology— Telecommunications and information exchange between systems Local and metropolitan area networks— Specific requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications, December 7, 2016); and/or IEEE 802.1 lay (P802. llay/Dl.0 Draft Standard for Information Technology- Telecommunications and Information Exchange Between Systems— Local and Metropolitan Area Networks— Specific Requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications— Amendment 7: Enhanced Throughput for Operation in License -Exempt Bands Above 45 GHz, November 2017)) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing WFA Peer-to-Peer (P2P) specifications (WiFi P2P technical specification, version 1. 7, July 6, 2016) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing Wireless-Gigabit-Alliance (WGA) specifications (including Wireless Gigabit Alliance, Inc WiGig MAC and PHY Specification Version 1.1, April 2011, Final specification) and/or future versions and/or derivatives thereof, devices and/or networks operating in accordance with existing cellular specifications and/or protocols, e.g., 3rd Generation Partnership Project (3GPP), 3GPP Long Term Evolution (LTE) and/or future versions and/or derivatives thereof, units and/or devices which are part of the above networks, and the like. [0023] Some embodiments may be used in conjunction with one way and/or two-way radio communication systems, cellular radio-telephone communication systems, a mobile phone, a cellular telephone, a wireless telephone, a Personal Communication Systems (PCS) device, a PDA device which incorporates a wireless communication device, a mobile or portable Global Positioning System (GPS) device, a device which incorporates a GPS receiver or transceiver or chip, a device which incorporates an RFID element or chip, a Multiple Input Multiple Output (MIMO) transceiver or device, a Single Input Multiple Output (SIMO) transceiver or device, a Multiple Input Single Output (MISO) transceiver or device, a device having one or more internal antennas and/or external antennas, Digital Video Broadcast (DVB) devices or systems, multi- standard radio devices or systems, a wired or wireless handheld device, e.g., a Smartphone, a Wireless Application Protocol (WAP) device, or the like.

[0024] Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems, for example, Radio Frequency (RF), Infra Red (IR), Frequency-Division Multiplexing (FDM), Orthogonal FDM (OFDM), Orthogonal Frequency-Division Multiple Access (OFDMA), FDM Time-Division Multiplexing (TDM), Time-Division Multiple Access (TDMA), Multi-User MIMO (MU-MIMO), Spatial Division Multiple Access (SDMA), Extended TDMA (E- TDMA), General Packet Radio Service (GPRS), extended GPRS, Code-Division Multiple Access (CDMA), Wideband CDMA (WCDMA), CDMA 2000, single- carrier CDMA, multi-carrier CDMA, Multi-Carrier Modulation (MDM), Discrete Multi-Tone (DMT), Bluetooth®, Global Positioning System (GPS), Wi-Fi, Wi-Max, ZigBee™, Ultra-Wideband (UWB), Global System for Mobile communication (GSM), 2G, 2.5G, 3G, 3.5G, 4G, Fifth Generation (5G), or Sixth Generation (6G) mobile networks, 3 GPP, Long Term Evolution (LTE), LTE advanced, Enhanced Data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems and/or networks.

[0025] The term "wireless device", as used herein, includes, for example, a device capable of wireless communication, a communication device capable of wireless communication, a communication station capable of wireless communication, a portable or non-portable device capable of wireless communication, or the like. In some demonstrative embodiments, a wireless device may be or may include a peripheral that is integrated with a computer, or a peripheral that is attached to a computer. In some demonstrative embodiments, the term "wireless device" may optionally include a wireless service.

[0026] The term "communicating" as used herein with respect to a communication signal includes transmitting the communication signal and/or receiving the communication signal. For example, a communication unit, which is capable of communicating a communication signal, may include a transmitter to transmit the communication signal to at least one other communication unit, and/or a communication receiver to receive the communication signal from at least one other communication unit. The verb communicating may be used to refer to the action of transmitting or the action of receiving. In one example, the phrase "communicating a signal" may refer to the action of transmitting the signal by a first device, and may not necessarily include the action of receiving the signal by a second device. In another example, the phrase "communicating a signal" may refer to the action of receiving the signal by a first device, and may not necessarily include the action of transmitting the signal by a second device. The communication signal may be transmitted and/or received, for example, in the form of Radio Frequency (RF) communication signals, and/or any other type of signal.

[0027] As used herein, the term "circuitry" may refer to, be part of, or include, an Application Specific Integrated Circuit (ASIC), an integrated circuit, an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group), that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware.

[0028] The term "logic" may refer, for example, to computing logic embedded in circuitry of a computing apparatus and/or computing logic stored in a memory of a computing apparatus. For example, the logic may be accessible by a processor of the computing apparatus to execute the computing logic to perform computing functions and/or operations. In one example, logic may be embedded in various types of memory and/or firmware, e.g., silicon blocks of various chips and/or processors. Logic may be included in, and/or implemented as part of, various circuitry, e.g. radio circuitry, receiver circuitry, control circuitry, transmitter circuitry, transceiver circuitry, processor circuitry, and/or the like. In one example, logic may be embedded in volatile memory and/or non-volatile memory, including random access memory, read only memory, programmable memory, magnetic memory, flash memory, persistent memory, and the like. Logic may be executed by one or more processors using memory, e.g., registers, stuck, buffers, and/or the like, coupled to the one or more processors, e.g., as necessary to execute the logic.

[0029] Some demonstrative embodiments may be used in conjunction with a WLAN, e.g., a WiFi network. Other embodiments may be used in conjunction with any other suitable wireless communication network, for example, a wireless area network, a "piconet", a WPAN, a WVAN and the like.

[0030] Some demonstrative embodiments may be used in conjunction with a wireless communication network communicating over a frequency band above 45 Gigahertz (GHz), e.g., 60GHz. However, other embodiments may be implemented utilizing any other suitable wireless communication frequency bands, for example, an Extremely High Frequency (EHF) band (the millimeter wave (mmWave) frequency band), e.g., a frequency band within the frequency band of between 20Ghz and 300GHz, a frequency band above 45GHz, a 5G frequency band, a frequency band below 20GHz, e.g., a Sub 1 GHz (S1G) band, a 2.4GHz band, a 5GHz band, a WLAN frequency band, a WPAN frequency band, a frequency band according to the WGA specification, and the like.

[0031] The term "antenna", as used herein, may include any suitable configuration, structure and/or arrangement of one or more antenna elements, components, units, assemblies and/or arrays. In some embodiments, the antenna may implement transmit and receive functionalities using separate transmit and receive antenna elements. In some embodiments, the antenna may implement transmit and receive functionalities using common and/or integrated transmit/receive elements. The antenna may include, for example, a phased array antenna, a single element antenna, a set of switched beam antennas, and/or the like.

[0032] The phrases "directional multi-gigabit (DMG)" and "directional band" (DBand), as used herein, may relate to a frequency band wherein the Channel starting frequency is above 45 GHz. In one example, DMG communications may involve one or more directional links to communicate at a rate of multiple gigabits per second, for example, at least 1 Gigabit per second, e.g., at least 7 Gigabit per second, at least 30 Gigabit per second, or any other rate. [0033] Some demonstrative embodiments may be implemented by a DMG STA (also referred to as a "mmWave STA (mSTA)"), which may include for example, a STA having a radio transmitter, which is capable of operating on a channel that is within the DMG band. The DMG STA may perform other additional or alternative functionality. Other embodiments may be implemented by any other apparatus, device and/or station.

[0034] Reference is made to Fig. 1, which schematically illustrates a system 100, in accordance with some demonstrative embodiments.

[0035] As shown in Fig. 1, in some demonstrative embodiments, system 100 may include one or more wireless communication devices. For example, system 100 may include a wireless communication device 102, a wireless communication device 140, a wireless communication device 160, and/or one more other devices.

[0036] In some demonstrative embodiments, devices 102, 140 and/or 160 may include a mobile device or a non-mobile, e.g., a static, device.

[0037] For example, devices 102, 140 and/or 160 may include, for example, a UE, an MD, a STA, an AP, a PC, a desktop computer, a mobile computer, a laptop computer, an Ultrabook™ computer, a notebook computer, a tablet computer, a server computer, a handheld computer, an Internet of Things (IoT) device, a sensor device, a handheld device, a wearable device, a PDA device, a handheld PDA device, an on-board device, an off-board device, a hybrid device (e.g., combining cellular phone functionalities with PDA device functionalities), a consumer device, a vehicular device, a non-vehicular device, a mobile or portable device, a non-mobile or nonportable device, a mobile phone, a cellular telephone, a PCS device, a PDA device which incorporates a wireless communication device, a mobile or portable GPS device, a DVB device, a relatively small computing device, a non-desktop computer, a "Cany Small Live Large" (CSLL) device, an Ultra Mobile Device (UMD), an Ultra Mobile PC (UMPC), a Mobile Internet Device (MID), an "Origami" device or computing device, a device that supports Dynamically Composable Computing (DCC), a context-aware device, a video device, an audio device, an A/V device, a Set- Top-Box (STB), a Blu-ray disc (BD) player, a BD recorder, a Digital Video Disc (DVD) player, a High Definition (HD) DVD player, a DVD recorder, a HD DVD recorder, a Personal Video Recorder (PVR), a broadcast HD receiver, a video source, an audio source, a video sink, an audio sink, a stereo tuner, a broadcast radio receiver, a flat panel display, a Personal Media Player (PMP), a digital video camera (DVC), a digital audio player, a speaker, an audio receiver, an audio amplifier, a gaming device, a data source, a data sink, a Digital Still camera (DSC), a media player, a Smartphone, a television, a music player, or the like. [0038] In some demonstrative embodiments, device 102 may include, for example, one or more of a processor 191, an input unit 192, an output unit 193, a memory unit 194, and/or a storage unit 195; and/or devices 140 and/or 160 may include, for example, one or more of a processor 181, an input unit 182, an output unit 183, a memory unit 184, and/or a storage unit 185. Devices 102, 140 and/or 160 may optionally include other suitable hardware components and/or software components. In some demonstrative embodiments, some or all of the components of one or more of devices 102, 140 and/or 160 may be enclosed in a common housing or packaging, and may be interconnected or operably associated using one or more wired or wireless links. In other embodiments, components of one or more of devices 102, 140 and/or 160 may be distributed among multiple or separate devices.

[0039] In some demonstrative embodiments, processor 191 and/or processor 181 may include, for example, a Central Processing Unit (CPU), a Digital Signal Processor (DSP), one or more processor cores, a single-core processor, a dual-core processor, a multiple-core processor, a microprocessor, a host processor, a controller, a plurality of processors or controllers, a chip, a microchip, one or more circuits, circuitry, a logic unit, an Integrated Circuit (IC), an Application-Specific IC (ASIC), or any other suitable multi-purpose or specific processor or controller. Processor 191 may execute instructions, for example, of an Operating System (OS) of device 102 and/or of one or more suitable applications. Processor 181 may execute instructions, for example, of an Operating System (OS) of device 140 and/or of one or more suitable applications.

[0040] In some demonstrative embodiments, input unit 192 and/or input unit 182 may include, for example, a keyboard, a keypad, a mouse, a touch-screen, a touch-pad, a track-ball, a stylus, a microphone, or other suitable pointing device or input device. Output unit 193 and/or output unit 183 may include, for example, a monitor, a screen, a touch- screen, a flat panel display, a Light Emitting Diode (LED) display unit, a Liquid Crystal Display (LCD) display unit, a plasma display unit, one or more audio speakers or earphones, or other suitable output devices. [0041] In some demonstrative embodiments, memory unit 194 and/or memory unit 184 includes, for example, a Random Access Memory (RAM), a Read Only Memory (ROM), a Dynamic RAM (DRAM), a Synchronous DRAM (SD-RAM), a flash memory, a volatile memory, a non-volatile memory, a cache memory, a buffer, a short term memory unit, a long term memory unit, or other suitable memory units. Storage unit 195 and/or storage unit 185 may include, for example, a hard disk drive, a floppy disk drive, a Compact Disk (CD) drive, a CD-ROM drive, a DVD drive, or other suitable removable or non-removable storage units. Memory unit 194 and/or storage unit 195, for example, may store data processed by device 102. Memory unit 184 and/or storage unit 185, for example, may store data processed by device 140. [0042] In some demonstrative embodiments, wireless communication devices 102, 140 and/or 160 may be capable of communicating content, data, information and/or signals via a wireless medium (WM) 103. In some demonstrative embodiments, wireless medium 103 may include, for example, a radio channel, a cellular channel, an RF channel, a WiFi channel, a 5G channel, an IR channel, a Bluetooth (BT) channel, a Global Navigation Satellite System (GNSS) Channel, and the like.

[0043] In some demonstrative embodiments, WM 103 may include one or more directional bands and/or channels. For example, WM 103 may include one or more millimeter-wave (mmWave) wireless communication bands and/or channels.

[0044] In some demonstrative embodiments, WM 103 may include one or more DMG channels. In other embodiments WM 103 may include any other directional channels.

[0045] In other embodiments, WM 103 may include any other type of channel over any other frequency band.

[0046] In some demonstrative embodiments, device 102, device 140 and/or device 160 may include one or more radios including circuitry and/or logic to perform wireless communication between devices 102, 140, 160 and/or one or more other wireless communication devices. For example, device 102 may include at least one radio 114, and/or device 140 may include at least one radio 144.

[0047] In some demonstrative embodiments, radio 114 and/or radio 144 may include one or more wireless receivers (Rx) including circuitry and/or logic to receive wireless communication signals, RF signals, frames, blocks, transmission streams, packets, messages, data items, and/or data. For example, radio 114 may include at least one receiver 116, and/or radio 144 may include at least one receiver 146.

[0048] In some demonstrative embodiments, radio 114 and/or radio 144 may include one or more wireless transmitters (Tx) including circuitry and/or logic to transmit wireless communication signals, RF signals, frames, blocks, transmission streams, packets, messages, data items, and/or data. For example, radio 114 may include at least one transmitter 118, and/or radio 144 may include at least one transmitter 148.

[0049] In some demonstrative embodiments, radio 114 and/or radio 144, transmitters 118 and/or 148, and/or receivers 116 and/or 146 may include circuitry; logic; Radio Frequency (RF) elements, circuitry and/or logic; baseband elements, circuitry and/or logic; modulation elements, circuitry and/or logic; demodulation elements, circuitry and/or logic; amplifiers; analog to digital and/or digital to analog converters; filters; and/or the like. For example, radio 114 and/or radio 144 may include or may be implemented as part of a wireless Network Interface Card (NIC), and the like. [0050] In some demonstrative embodiments, radios 114 and/or 144 may be configured to communicate over a directional band, for example, an mmWave band, a 5G band, and/or any other band, for example, a 2.4GHz band, a 5GHz band, a SIG band, and/or any other band.

[0051] In some demonstrative embodiments, radios 114 and/or 144 may include, or may be associated with one or more, e.g., a plurality of, directional antennas.

[0052] In some demonstrative embodiments, device 102 may include one or more, e.g., a plurality of, directional antennas 107, and/or device 140 may include on or more, e.g., a plurality of, directional antennas 147.

[0053] Antennas 107 and/or 147 may include any type of antennas suitable for transmitting and/or receiving wireless communication signals, blocks, frames, transmission streams, packets, messages and/or data. For example, antennas 107 and/or 147 may include any suitable configuration, structure and/or arrangement of one or more antenna elements, components, units, assemblies and/or arrays. Antennas 107 and/or 147 may include, for example, antennas suitable for directional communication, e.g., using beamforming techniques. For example, antennas 107 and/or 147 may include a phased array antenna, a multiple element antenna, a set of switched beam antennas, and/or the like. In some embodiments, antennas 107 and/or 147 may implement transmit and receive functionalities using separate transmit and receive antenna elements. In some embodiments, antennas 107 and/or 147 may implement transmit and receive functionalities using common and/or integrated transmit/receive elements. [0054] In some demonstrative embodiments, antennas 107 and/or 147 may include directional antennas, which may be steered to one or more beam directions. For example, antennas 107 may be steered to one or more beam directions 135, and/or antennas 147 may be steered to one or more beam directions 145.

[0055] In some demonstrative embodiments, antennas 107 and/or 147 may include and/or may be implemented as part of a single Phased Antenna Array (PAA).

[0056] In some demonstrative embodiments, antennas 107 and/or 147 may be implemented as part of a plurality of PAAs, for example, as a plurality of physically independent PAAs.

[0057] In some demonstrative embodiments, a PAA may include, for example, a rectangular geometry, e.g., including an integer number, denoted M, of rows, and an integer number, denoted N, of columns. In other embodiments, any other types of antennas and/or antenna arrays may be used.

[0058] In some demonstrative embodiments, antennas 107 and/or antennas 147 may be connected to, and/or associated with, one or more Radio Frequency (RF) chains. [0059] In some demonstrative embodiments, device 102 may include one or more, e.g., a plurality of, RF chains 109 connected to, and/or associated with, antennas 107.

[0060] In some demonstrative embodiments, one or more of RF chains 109 may be included as part of, and/or implemented as part of one or more elements of radio 114, e.g., as part of transmitter 118 and/or receiver 116. [0061] In some demonstrative embodiments, device 140 may include one or more, e.g., a plurality of, RF chains 149 connected to, and/or associated with, antennas 147. [0062] In some demonstrative embodiments, one or more of RF chains 149 may be included as part of, and/or implemented as part of one or more elements of radio 144, e.g., as part of transmitter 148 and/or receiver 146.

[0063] In some demonstrative embodiments, device 102 may include a controller 124, and/or device 140 may include a controller 154. Controller 124 may be configured to perform and/or to trigger, cause, instruct and/or control device 102 to perform, one or more communications, to generate and/or communicate one or more messages and/or transmissions, and/or to perform one or more functionalities, operations and/or procedures between devices 102, 140, 160 and/or one or more other devices; and/or controller 154 may be configured to perform, and/or to trigger, cause, instruct and/or control device 140 to perform, one or more communications, to generate and/or communicate one or more messages and/or transmissions, and/or to perform one or more functionalities, operations and/or procedures between devices 102, 140, 160 and/or one or more other devices, e.g., as described below. [0064] In some demonstrative embodiments, controllers 124 and/or 154 may include, or may be implemented, partially or entirely, by circuitry and/or logic, e.g., one or more processors including circuitry and/or logic, memory circuitry and/or logic, Media-Access Control (MAC) circuitry and/or logic, Physical Layer (PHY) circuitry and/or logic, baseband (BB) circuitry and/or logic, a BB processor, a BB memory, Application Processor (AP) circuitry and/or logic, an AP processor, an AP memory, and/or any other circuitry and/or logic, configured to perform the functionality of controllers 124 and/or 154, respectively. Additionally or alternatively, one or more functionalities of controllers 124 and/or 154 may be implemented by logic, which may be executed by a machine and/or one or more processors, e.g., as described below.

[0065] In one example, controller 124 may include circuitry and/or logic, for example, one or more processors including circuitry and/or logic, to cause, trigger and/or control a wireless device, e.g., device 102, and/or a wireless station, e.g., a wireless STA implemented by device 102, to perform one or more operations, communications and/or functionalities, e.g., as described herein. In one example, controller 124 may include at least one memory, e.g., coupled to the one or more processors, which may be configured, for example, to store, e.g., at least temporarily, at least some of the information processed by the one or more processors and/or circuitry, and/or which may be configured to store logic to be utilized by the processors and/or circuitry.

[0066] In one example, controller 154 may include circuitry and/or logic, for example, one or more processors including circuitry and/or logic, to cause, trigger and/or control a wireless device, e.g., device 140, and/or a wireless station, e.g., a wireless STA implemented by device 140, to perform one or more operations, communications and/or functionalities, e.g., as described herein. In one example, controller 154 may include at least one memory, e.g., coupled to the one or more processors, which may be configured, for example, to store, e.g., at least temporarily, at least some of the information processed by the one or more processors and/or circuitry, and/or which may be configured to store logic to be utilized by the processors and/or circuitry.

[0067] In some demonstrative embodiments, device 102 may include a message processor 128 configured to generate, process and/or access one or messages communicated by device 102.

[0068] In one example, message processor 128 may be configured to generate one or more messages to be transmitted by device 102, and/or message processor 128 may be configured to access and/or to process one or more messages received by device 102, e.g., as described below. [0069] In one example, message processor 128 may include at least one first component configured to generate a message, for example, in the form of a frame, field, information element and/or protocol data unit, for example, a MAC Protocol Data Unit (MPDU); at least one second component configured to convert the message into a PHY Protocol Data Unit (PPDU), for example, by processing the message generated by the at least one first component, e.g., by encoding the message, modulating the message and/or performing any other additional or alternative processing of the message; and/or at least one third component configured to cause transmission of the message over a wireless communication medium, e.g., over a wireless communication channel in a wireless communication frequency band, for example, by applying to one or more fields of the PPDU one or more transmit waveforms. In other embodiments, message processor 128 may be configured to perform any other additional or alternative functionality and/or may include any other additional or alternative components to generate and/or process a message to be transmitted.

[0070] In some demonstrative embodiments, device 140 may include a message processor 158 configured to generate, process and/or access one or messages communicated by device 140.

[0071] In one example, message processor 158 may be configured to generate one or more messages to be transmitted by device 140, and/or message processor 158 may be configured to access and/or to process one or more messages received by device 140, e.g., as described below. [0072] In one example, message processor 158 may include at least one first component configured to generate a message, for example, in the form of a frame, field, information element and/or protocol data unit, for example, a MAC Protocol Data Unit (MPDU); at least one second component configured to convert the message into a PHY Protocol Data Unit (PPDU), for example, by processing the message generated by the at least one first component, e.g., by encoding the message, modulating the message and/or performing any other additional or alternative processing of the message; and/or at least one third component configured to cause transmission of the message over a wireless communication medium, e.g., over a wireless communication channel in a wireless communication frequency band, for example, by applying to one or more fields of the PPDU one or more transmit waveforms. In other embodiments, message processor 158 may be configured to perform any other additional or alternative functionality and/or may include any other additional or alternative components to generate and/or process a message to be transmitted. [0073] In some demonstrative embodiments, message processors 128 and/or 158 may include, or may be implemented, partially or entirely, by circuitry and/or logic, e.g., one or more processors including circuitry and/or logic, memory circuitry and/or logic, Media-Access Control (MAC) circuitry and/or logic, Physical Layer (PHY) circuitry and/or logic, BB circuitry and/or logic, a BB processor, a BB memory, AP circuitry and/or logic, an AP processor, an AP memory, and/or any other circuitry and/or logic, configured to perform the functionality of message processors 128 and/or 158, respectively. Additionally or alternatively, one or more functionalities of message processors 128 and/or 158 may be implemented by logic, which may be executed by a machine and/or one or more processors, e.g., as described below.

[0074] In some demonstrative embodiments, at least part of the functionality of message processor 128 may be implemented as part of radio 114, and/or at least part of the functionality of message processor 158 may be implemented as part of radio 144.

[0075] In some demonstrative embodiments, at least part of the functionality of message processor 128 may be implemented as part of controller 124, and/or at least part of the functionality of message processor 158 may be implemented as part of controller 154.

[0076] In other embodiments, the functionality of message processor 128 may be implemented as part of any other element of device 102, and/or the functionality of message processor 158 may be implemented as part of any other element of device 140. [0077] In some demonstrative embodiments, at least part of the functionality of controller 124 and/or message processor 128 may be implemented by an integrated circuit, for example, a chip, e.g., a System on Chip (SoC). In one example, the chip or SoC may be configured to perform one or more functionalities of radio 114. For example, the chip or SoC may include one or more elements of controller 124, one or more elements of message processor 128, and/or one or more elements of radio 114. In one example, controller 124, message processor 128, and radio 114 may be implemented as part of the chip or SoC.

[0078] In other embodiments, controller 124, message processor 128 and/or radio 114 may be implemented by one or more additional or alternative elements of device 102. [0079] In some demonstrative embodiments, at least part of the functionality of controller 154 and/or message processor 158 may be implemented by an integrated circuit, for example, a chip, e.g., a System on Chip (SoC). In one example, the chip or SoC may be configured to perform one or more functionalities of radio 144. For example, the chip or SoC may include one or more elements of controller 154, one or more elements of message processor 158, and/or one or more elements of radio 144. In one example, controller 154, message processor 158, and radio 144 may be implemented as part of the chip or SoC. [0080] In other embodiments, controller 154, message processor 158 and/or radio 144 may be implemented by one or more additional or alternative elements of device 140.

[0081] In some demonstrative embodiments, device 102, device 140 and/or device 160 may include, operate as, perform the role of, and/or perform one or more functionalities of, one or more ST As. For example, device 102 may include at least one STA, and/or device 140 may include at least one STA.

[0082] In some demonstrative embodiments, device 102, device 140 and/or device 160 may include, operate as, perform the role of, and/or perform one or more functionalities of, one or more DMG ST As. For example, device 102 may include, operate as, perform the role of, and/or perform one or more functionalities of, at least one DMG STA, and/or device 140 may include, operate as, perform the role of, and/or perform one or more functionalities of, at least one DMG STA.

[0083] In other embodiments, devices 102, 140 and/or 160 may include, operate as, perform the role of, and/or perform one or more functionalities of, any other wireless device and/or station, e.g., a WLAN STA, a WiFi STA, and the like.

[0084] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured operate as, perform the role of, and/or perform one or more functionalities of, an access point (AP), e.g., a DMG AP, and/or a personal basic service set (PBSS) control point (PCP), e.g., a DMG PCP, for example, an AP/PCP STA, e.g., a DMG AP/PCP STA.

[0085] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured to operate as, perform the role of, and/or perform one or more functionalities of, a non-AP STA, e.g., a DMG non-AP STA, and/or a non-PCP STA, e.g., a DMG non-PCP STA, for example, a non-AP/PCP STA, e.g., a DMG non- AP/PCP STA.

[0086] In other embodiments, device 102, device 140 and/or device 160 may operate as, perform the role of, and/or perform one or more functionalities of, any other additional or alternative device and/or station.

[0087] In one example, a station (STA) may include a logical entity that is a singly addressable instance of a medium access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The STA may perform any other additional or alternative functionality. [0088] In one example, an AP may include an entity that contains a station (STA), e.g., one STA, and provides access to distribution services, via the wireless medium (WM) for associated STAs. The AP may perform any other additional or alternative functionality. [0089] In one example, a personal basic service set (PBSS) control point (PCP) may include an entity that contains a STA, e.g., one station (STA), and coordinates access to the wireless medium (WM) by STAs that are members of a PBSS. The PCP may perform any other additional or alternative functionality.

[0090] In one example, a PBSS may include a directional multi-gigabit (DMG) basic service set (BSS) that includes, for example, one PBSS control point (PCP). For example, access to a distribution system (DS) may not be present, but, for example, an intra-PBSS forwarding service may optionally be present.

[0091] In one example, a PCP/AP STA may include a station (STA) that is at least one of a PCP or an AP. The PCP/AP STA may perform any other additional or alternative functionality.

[0092] In one example, a non-AP STA may include a STA that is not contained within an AP. The non-AP STA may perform any other additional or alternative functionality.

[0093] In one example, a non-PCP STA may include a STA that is not a PCP. The non-PCP STA may perform any other additional or alternative functionality.

[0094] In one example, a non PCP/AP STA may include a STA that is not a PCP and that is not an AP. The non-PCP/AP STA may perform any other additional or alternative functionality.

[0095] In some demonstrative embodiments devices 102, 140 and/or 160 may be configured to communicate over a Next Generation 60 GHz (NG60) network, an Enhanced DMG (EDMG) network, and/or any other network. For example, devices 102, 140 and/or 160 may perform Multiple-Input-Multiple-Output (MFMO) communication, for example, for communicating over the NG60 and/or EDMG networks, e.g., over an NG60 or an EDMG frequency band. [0096] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to operate in accordance with one or more Specifications, for example, including one or more IEEE 802.11 Specifications, e.g., an IEEE 802.11-2016 Specification, an IEEE 802.1 lay Specification, and/or any other specification and/or protocol.

[0097] Some demonstrative embodiments may be implemented, for example, as part of a new standard in an mmWave band, e.g., a 60GHz frequency band and/or any other directional band, for example, as an evolution of an IEEE 802.11-2016 Specification and/or an IEEE 802.1 lad Specification.

[0098] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured according to one or more standards, for example, in accordance with an IEEE 802. Hay Standard, which may be, for example, configured to enhance the efficiency and/or performance of an IEEE 802. Had Specification, which may be configured to provide Wi-Fi connectivity in a 60 GHz band.

[0099] Some demonstrative embodiments may enable, for example, to significantly increase the data transmission rates defined in the IEEE 802.1 lad Specification, for example, from 7 Gigabit per second (Gbps), e.g., up to 30 Gbps, or to any other data rate, which may, for example, satisfy growing demand in network capacity for new coming applications.

[00100] Some demonstrative embodiments may be implemented, for example, to allow increasing a transmission data rate, for example, by applying MIMO and/or channel bonding techniques.

[00101] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to communicate MIMO communications over the mmWave wireless communication band.

[00102] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured to support one or more mechanisms and/or features, for example, channel bonding, Single User (SU) MFMO, and/or Multi-User (MU) MIMO, for example, in accordance with an IEEE 802. Hay Standard and/or any other standard and/or protocol.

[00103] In some demonstrative embodiments, device 102, device 140 and/or device 160 may include, operate as, perform a role of, and/or perform the functionality of, one or more EDMG STAs. For example, device 102 may include, operate as, perform a role of, and/or perform the functionality of, at least one EDMG STA, and/or device 140 may include, operate as, perform a role of, and/or perform the functionality of, at least one EDMG STA.

[00104] In some demonstrative embodiments, devices 102, 140 and/or 160 may implement a communication scheme, which may include Physical layer (PHY) and/or Media Access Control (MAC) layer schemes, for example, to support one or more applications, and/or increased transmission data rates, e.g., data rates of up to 30 Gbps, or any other data rate.

[00105] In some demonstrative embodiments, the PHY and/or MAC layer schemes may be configured to support frequency channel bonding over a mmWave band, e.g., over a 60 GHz band, SU MEVIO techniques, and/or MU-MIMO techniques.

[00106] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to implement one or more mechanisms, which may be configured to enable SU and/or MU communication of Downlink (DL) and/or Uplink frames (UL) using a MIMO scheme. [00107] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured to implement one or more MU communication mechanisms. For example, devices 102, 140 and/or 160 may be configured to implement one or more MU mechanisms, which may be configured to enable MU communication of DL frames using a MIMO scheme, for example, between a device, e.g., device 102, and a plurality of devices, e.g., including device 140, device 160, and/or one or more other devices.

[00108] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to communicate over an NG60 network, an EDMG network, and/or any other network and/or any other frequency band. For example, devices 102, 140 and/or 160 may be configured to communicate DL MIMO transmissions and/or UL MIMO transmissions, for example, for communicating over the NG60 and/or EDMG networks.

[00109] Some wireless communication Specifications, for example, the IEEE 802.1 lad-2012 Specification, may be configured to support a SU system, in which a STA may transmit frames to a single STA at a time. Such Specifications may not be able, for example, to support a STA transmitting to multiple STAs simultaneously, for example, using a MU-MIMO scheme, e.g., a DL MU-MEVIO, or any other MU scheme.

[00110] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to communicate over a channel bandwidth, e.g., of at least 2.16GHz, in a frequency band above 45GHz.

[00111] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to implement one or more mechanisms, which may, for example, enable to extend a single-channel BW scheme, e.g., a scheme in accordance with the IEEE 802. Had Specification or any other scheme, for higher data rates and/or increased capabilities, e.g., as described below.

[00112] In one example, the single-channel BW scheme may include communication over a 2.16 GHz channel (also referred to as a "single-channel" or a "DMG channel").

[00113] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to implement one or more channel bonding mechanisms, which may, for example, support communication over a channel BW (also referred to as a "wide channel", an "EDMG channel", or a "bonded channel") including two or more channels, e.g., two or more 2.16 GHz channels, e.g., as described below.

[00114] In some demonstrative embodiments, the channel bonding mechanisms may include, for example, a mechanism and/or an operation whereby two or more channels, e.g., 2.16 GHz channels, can be combined, e.g., for a higher bandwidth of packet transmission, for example, to enable achieving higher data rates, e.g., when compared to transmissions over a single channel. Some demonstrative embodiments are described herein with respect to communication over a channel BW including two or more 2.16 GHz channels, however other embodiments may be implemented with respect to communications over a channel bandwidth, e.g., a "wide" channel, including or formed by any other number of two or more channels, for example, an aggregated channel including an aggregation of two or more channels.

[00115] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured to implement one or more channel bonding mechanisms, which may, for example, support an increased channel bandwidth, for example, a channel BW of 4.32 GHz, a channel BW of 6.48 GHz, a channel BW of 8.64 GHz, and/or any other additional or alternative channel BW, e.g., as described below. [00116] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured to implement one or more channel bonding mechanisms, which may, for example, support an increased channel bandwidth, for example, a channel BW of 4.32 GHz, e.g., including two 2.16Ghz channels according to a channel bonding factor of two, a channel BW of 6.48 GHz, e.g., including three 2.16Ghz channels according to a channel bonding factor of three, a channel BW of 8.64 GHz, e.g., including four 2.16Ghz channels according to a channel bonding factor of four, and/or any other additional or alternative channel BW, e.g., including any other number of 2.16Ghz channels and/or according to any other channel bonding factor.

[00117] In some demonstrative embodiments, device 102, device 140 and/or device 160 may be configured to communicate one or more transmissions over one or more channel BWs, for example, including a channel BW of 2.16GHz, a channel BW of 4.32GHz, a channel BW of 6.48GHz, a channel BW of 8.64GHz and/or any other channel BW.

[00118] In some demonstrative embodiments, introduction of MEVIO may be based, for example, on implementing robust transmission modes and/or enhancing the reliability of data transmission, e.g., rather than the transmission rate, compared to a Single Input Single Output (SISO) case. For example, one or more Space Time Block Coding (STBC) schemes utilizing a space-time channel diversity property may be implemented to achieve one or more enhancements for the MEVIO transmission.

[00119] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to generate, process, transmit and/or receive a Physical Layer (PHY) Protocol Data Unit (PPDU) having a PPDU format (also referred to as "EDMG PPDU format"), which may be configured, for example, for communication between EDMG stations, e.g., as described below.

[00120] In some demonstrative embodiments, a PPDU, e.g., an EDMG PPDU, may include at least one non-EDMG fields, e.g., a legacy field, which may be identified, decodable, and/or processed by one or more devices ("non-EDMG devices", or "legacy devices"), which may not support one or more features and/or mechanisms ("non-legacy" mechanisms or "EDMG mechanisms"). For example, the legacy devices may include non-EDMG stations, which may be, for example, configured according to an IEEE 802.11-2016 Standard, and the like. For example, a non-EDMG station may include a DMG station, which is not an EDMG station.

[00121] Reference is made to Fig. 2, which schematically illustrates an EDMG PPDU format 200, which may be implemented in accordance with some demonstrative embodiments. In one example, device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1) may be configured to generate, transmit, receive and/or process one or more EDMG PPDUs having the structure and/or format of EDMG PPDU 200.

[00122] In one example, device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1) may communicate PPDU 200, for example, as part of a transmission over a channel, e.g., an EDMG channel, having a channel bandwidth including one or more 2.16GHz channels, for example, including a channel BW of 2.16GHz, a channel BW of 4.32GHz, a channel BW of 6.48GHz, a channel BW of 8.64GHz, and/or any other channel BW, e.g., as described below.

[00123] In some demonstrative embodiments, as shown in Fig. 2, EDMG PPDU 200 may include a non-EDMG portion 210 ("legacy portion"), e.g., as described below.

[00124] In some demonstrative embodiments, as shown in Fig. 2, non-EDMG portion 210 may include a non-EDMG (legacy) Short Training Field (STF) (L-STF) 202, a non-EDMG (Legacy) Channel Estimation Field (CEF) (L-CEF) 204, and/or a non- EDMG header (L-header) 206. [00125] In some demonstrative embodiments, as shown in Fig. 2, EDMG PPDU 200, may include an EDMG portion 220, for example, following non-EDMG portion 210, e.g., as described below.

[00126] In some demonstrative embodiments, as shown in Fig. 2, EDMG portion 220 may include a first EDMG header, e.g., an EDMG-Header-A 208, an EDMG- STF 212, an EDMG-CEF 214, a second EDMG header, e.g., an EDMG-Header-B 216, a Data field 218, and/or one or more beamforming training fields, e.g., a TRN field 224.

[00127] In some demonstrative embodiments, EDMG portion 220 may include some or all of the fields shown in Fig. 2 and/or one or more other additional or alternative fields. [00128] In some demonstrative embodiments, EDMG-Header-B field 216 may be included, for example, in EDMG MU PPDUs, for example, on a per STA basis.

[00129] In some demonstrative embodiments, EDMG-Header-B field 216 corresponding to a STA addressed by the EDMG MU PPDU may include, for example, information relating to a transmission of a data unit, for example, a PHY Service Data Unit (PSDU) to the STA.

[00130] In some demonstrative embodiments, EDMG Header B field 216 may include for example, 64 bits. In other embodiments, the EDMG Header B field 216 may include any other number of bits. [00131] In one example, EDMG Header B field 216 corresponding to the STA may include, for example, at least a scrambler seed field, a PSDU length field, e.g., to indicate a length of the PSDU to the STA, and/or one or more Modulation and Coding Scheme (MCS) fields to indicate one or more MCSs. For example, the Header B field may include first and second MCS fields to indicate MCSs for first and second respective spatial streams.

[00132] In other embodiments, EDMG Header B field 216 may include any other additional or alternative fields and/or information.

[00133] Referring back to Fig. 1, in some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to perform an asymmetric beamforming training procedure, e.g., as described below.

[00134] In some demonstrative embodiments, the asymmetric beamforming training procedure may be preformed between an EDMG initiator STA and one or more EDMG responder STAs, e.g., as described below.

[00135] In one example, device 102 may include, operate as, perform the role of, and/or perform one or more functionalities of, an EDMG initiator STA; and/or device 140 and/or device 160 may include, operate as, perform the role of, and/or perform one or more functionalities of an EDMG responder STA, e.g., as described below.

[00136] In some demonstrative embodiments, the asymmetric beamforming training procedure may be preformed, for example, to train an asymmetric communication link between the EDMG initiator STA and the one or more EDMG responder STAs, e.g., as described below. [00137] In one example, an asymmetric link may be present when a first STA, e.g., the EDMG initiator STA, is able to receive frames from a second STA, e.g., an EDMG responder STA, while frame transmissions from the first STA may not be received by the second STA, for example, due to a difference in a link budget between an uplink and a downlink between the first and second STAs. For example, the difference in the link budget may result from a difference in a number of antenna elements between the first and second STAs, for example, if the first STA may use a quasi-omni antenna configuration to communicate with the second STA.

[00138] In some demonstrative embodiments, the asymmetric beamforming training procedure may enable an EDMG initiator STA and one or more EDMG responder STAs to perform beamforming training, for example, even in case of an asymmetric link when a quasi-omni antenna configuration is used by one of the STAs when attempting communication with a peer STA, e.g., as described below.

[00139] In some demonstrative embodiments, an asymmetric beamforming training procedure, e.g., in accordance with an IEEE802.1 lay Specification, may be performed, for example, according to an allocation, e.g., a dedicated allocation, which may be scheduled, e.g., by an AP/PCP STA, for example, the EDMG initiator STA, e.g., as described below.

[00140] In some demonstrative embodiments, the asymmetric beamforming training procedure may include, for example, a first beamforming part and a second beamforming part, e.g., as described below.

[00141] In some demonstrative embodiments, during the first beamforming part an EDMG initiator STA may sequentially listen, for example, on each combination of sector and DMG antenna, which was used for DMG Beacon transmission during a last Beacon Transmission Interval (BTI). For example, a listening order of the EDMG initiator STA may be the same as a listening order that was used during the BTI.

[00142] In some demonstrative embodiments, an EDMG responder STA may transmit a sector sweep (SSW) frame or a short SSW frame, for example, during a directional listening slot, which corresponds to a best sector in the last BTI. [00143] In some demonstrative embodiments, the EDMG initiator STA may assign a plurality of space-time slots for one or more directional listening slots, for example, for each directional listening slot, e.g., for transmissions of the EDMG responder STAs.

[00144] In some demonstrative embodiments, during the second beamforming part, the EDMG initiator STA may transmit a sector Acknowledgement (ACK) frame, for example, on each sector, from which the EDMG initiator STA received an SSW frame and/or a short SSW frame, e.g., as described below.

[00145] In some demonstrative embodiments, device 102 may perform an asymmetric beamforming training with a one or more EDMG responder STAs, e.g., devices 104 and 160, e.g., as described below. [00146] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger an EDMG initiator STA implemented by device 102 to listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of device 102, e.g., as described below.

[00147] In some demonstrative embodiments, a listening period (also referred to as a "directional listening slot") of the plurality of listening periods may include one or more Space-Time Slots (STS), during which device 102 may be configured to listen on a sector of the plurality of sectors for one or more SSW frames, e.g., as described below.

[00148] In some demonstrative embodiments, device 140 may transmit an SSW frame to device 102, for example, during a listening period of device 102, e.g., as described below.

[00149] In some demonstrative embodiments, the SSW frame may include a short SSW frame.

[00150] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger an EDMG responder STA implemented by device 140 to determine a selected sector of an EDMG initiator STA, e.g., device 102, for example, based on a transmission from the EDMG initiator STA, e.g., as described below.

[00151] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to transmit a SSW frame to device 102 during a space-time slot of a listening period in the listening sequence of the plurality of listening periods, e.g., as described below. [00152] In some demonstrative embodiments, the listening period may correspond to the selected sector of device 102, e.g., as described below.

[00153] In some demonstrative embodiments, device 102 may be configured transmit a sector ACK frame via the sector of device 102, for example, in which the SSW frame is received from device 140.

[00154] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the STA implemented by device 102 to transmit the sector ACK frame via the sector in which the SSW frame is received from device 140, e.g., as described below. [00155] In some demonstrative embodiments, device 140 may be configured to receive the ACK frame from device 102, e.g., as described below.

[00156] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to receive the sector ACK frame from device 102, e.g., as described below. [00157] In some demonstrative embodiments, device 140 may not receive the sector ACK frame from device 102, e.g., as described below.

[00158] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to attempt another asymmetric beamforming training in a next beamforming training allocation, for example, when the sector ACK frame is not received from device 102, e.g., as described below.

[00159] Reference is made to Fig. 3, which schematically illustrates an asymmetric beamforming training 300, which may be implemented in accordance with some demonstrative embodiments. [00160] In some demonstrative embodiments, the asymmetric beamforming training 300 may be preformed between an EDMG initiator STA 302 and one or more EDMG responder STAs, e.g., including a first responder STA 340 and a second responder STA 360, e.g., as described below.

[00161] In one example, device 102 (Fig. 1) may include, operate as, perform the role of, and/or perform one or more functionalities of, EDMG initiator STA 302; and/or device 140 (Fig. 1) and/or device 160 (Fig. 1) may include, operate as, perform the role of, and/or perform one or more functionalities of EDMG responder STA 340 and/or EDMG responder STA 360, respectively.

[00162] In some demonstrative embodiments, as shown in Fig. 3, the asymmetric beamforming training 300 may be performed during an allocation period including a first part 320 and a second part 330.

[00163] In some demonstrative embodiments, as shown in Fig. 3, during first part 320, STA 302 may listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of device 302.

[00164] In one example, as shown in Fig. 3, STA 302 may include N sectors, e.g., identified by a plurality of respective sector identifier, e.g., a sector identifier (ID) "0", e.g., SectorID=0, to a sector ID N-l, e.g., SectorID=N-l . According to this example, STA 302 may listen for SSW transmissions during a listening sequence 311 corresponding to the sector ID "0" of device 302, STA 302 may listen for SSW transmissions during a listening sequence 312 corresponding to a sector ID "1" of device 302, and/or STA 302 may listen for (N-l) ^th SSW transmissions during a listening sequence 313 corresponding to the sector ID "N-l" of device 302.

[00165] In some demonstrative embodiments, a listening period (also referred to as "a directional listening slot"), e.g., listening period 311, may include one or more space- time slots 315, during which STA 102 is to listen for SSW frames on a sector 317, e.g., SectorID=0, of the N Sectors of STA 302.

[00166] In some demonstrative embodiments, STA 340 may determine sector 317 as the selected sector of STA 302, for example, based on a best sector in a last BTI.

[00167] In some demonstrative embodiments, as shown in Fig. 3, STA 340 may transmit an SSW frame 342 to STA 302 during a space-time slot 319, in listening period 311, which corresponds to the selected sector 317.

[00168] In some demonstrative embodiments, as shown in Fig. 3, during second part 330, STA 302 may transmit one or more ACK transmissions. For example, STA 302 may transmit a Sector ACK frame, for example, on each sector, on which STA 302 has received an SSW frame. [00169] In some demonstrative embodiments, STA 302 may transmit an ACK frame during a space-time slot 331, which corresponds to sector 317, for example, if STA 302 receives one or more SSW frames during listening period 311, which corresponds to sector 317.

[00170] Referring back to Fig. 1, in some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to support an acknowledgement protocol for asymmetric beamforming training, for example, asymmetric beamforming training 300 (Fig. 3), e.g., in which responder STAs with asymmetric link budget, e.g., with respect to the initiator STA, may be able to perform beamforming training with the initiator STA, e.g., using a dedicated allocation for the asymmetric beamforming training scheduled by the initiator STA, e.g., as described below [00171] In some demonstrative embodiments, the acknowledgement protocol for the asymmetric beamforming training may be configured to provide one or more technical solutions to support the second part of the asymmetric beamforming training, for example, second beamforming part 320 (Fig. 3), during which the initiator STA acknowledges the receipt of one or more SSW frames transmitted from the EDMG responder STAs e.g., as described below.

[00172] In one example, there may be a need to define one or more elements and/or fields of the Sector ACK frame, which may be used to acknowledge the receipt of one or more SSW frames transmitted from the EDMG responder STAs.

[00173] In another example, the acknowledgement protocol may be configured to define how to acknowledge the receipt of the (short) SSW frames, for example, when the initiator STA receives multiple (short) SSW frames from multiple EDMG responder STAs in the same sector.

[00174] In some demonstrative embodiments, the acknowledgement protocol for the asymmetric beamforming training may be configured to define a frame format of the sector ACK frame, for example, as a control frame, an Unprotected DMG Action frame, or any other frame format, e.g., as described below.

[00175] In some demonstrative embodiments, the acknowledgement protocol for the asymmetric beamforming training may be configured to define a frame format for the Sector ACK frame, which may be configured to support acknowledgement of multiple EDMG STAs, which may be transmitted to a same sector of the EDMG initiator STA in a preceding phase, e.g., as described below. [00176] In some demonstrative embodiments, devices 102, 140 and/or 160 may be configured to communicate the sector ACK frame, for example, according the acknowledgment protocol, e.g., as described below.

[00177] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the EDMG initiator STA implemented by device 102 to transmit a sector ACK frame via a sector, via which one or more SSW frames are received, the sector ACK frame including one or more sector feedback fields for one or more respective EDMG responder STAs, e.g., as described below.

[00178] In some demonstrative embodiments, a sector feedback field for an EDMG responder STA may include feedback for the EDMG responder STA, for example, based on a SSW frame received from the EDMG responder STA via the sector, e.g., as described below.

[00179] In some demonstrative embodiments, the sector ACK frame may include a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame, e.g., as described below.

[00180] In some demonstrative embodiments, the sector ACK frame via the sector may include a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period, e.g., as described below. [00181] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the STA implemented by device 102 to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period, e.g., as described below. [00182] In one example, device 102 may receive multiple SSW frames from multiple responder STAs in a same sector during a preceding asymmetric beamforming phase, e.g., the phase 320 (Fig. 3). According to this example, device 102 may transmit a single Sector ACK frame in that sector. For example, device 102 may include multiple Sector Feedback fields in the single Sector ACK frame, each of which may be used to provide acknowledgement and feedback to a STA that transmitted an SSW frame in the preceding phase, e.g., as described below. [00183] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the ST A implemented by device 102 to set a Receive Address (RA) field in the sector ACK frame, for example, based on a value in the number-of-sector-feedback field, e.g., as described below. [00184] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the STA implemented by device 102 to set the RA field in the sector ACK frame to a broadcast address, for example, when the number-of- sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame, e.g., as described below. [00185] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the STA implemented by device 102 to set the RA field in the sector ACK frame to an address of a single EDMG responder STA, for example, when the number-of-sector-feedback field is to indicate a single sector feedback field for the single EDMG responder STA, e.g., as described below. [00186] In some demonstrative embodiments, the sector feedback field may include an SSW field, a beam Refinement Protocol (BRP) field, a Beamformed link maintenance field, and/or any other field, e.g., as described below.

[00187] In some demonstrative embodiments, the sector ACK frame may include a duration field set to an end of a current allocation of the asymmetric beamforming training, e.g., as described below.

[00188] In some demonstrative embodiments, device 102 may transmit to device 140 the sector ACK frame including, for example, a sector feedback field for device 140 including feedback for device 140.

[00189] In some demonstrative embodiments, device 140 may receive the ACK frame from device 102, e.g., as described below.

[00190] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the EDMG responder STA implemented by device 140 to receive from device 102 the sector ACK frame including the one or more sector feedback fields for the one or more respective EDMG responder STAs, e.g., as described below. [00191] In some demonstrative embodiments, the one or more sector feedback fields may include at least a sector feedback field for device 140 including feedback for device 140, for example, based on the SSW frame from device 140.

[00192] In some demonstrative embodiments, the sector ACK frame may include the number-of-sector-feedback field to indicate the count of the one or more sector feedback fields in the sector ACK frame, the RA field, and/or the duration field, e.g., as set by device 102.

[00193] In some demonstrative embodiments, for example, if an EDMG initiator STA, for example, an AP/PCP STA, e.g., device 102, receives multiple (short) SSW frames in the same sector from multiple STAs in the preceding asymmetric beamforming phase, e.g., phase 320 (Fig. 3), the AP/PCP shall transmit a single Sector ACK frame in that sector, and include multiple Sector Feedback fields in the Sector ACK frame, each of which is used to provide acknowledgement and feedback to a STA that transmitted (short) SSW frame in the preceding phase. [00194] In some demonstrative embodiments, device 140 may communicate with device 102, for example, based on the feedback for device 140.

[00195] In some demonstrative embodiments, the sector ACK frame may include a control frame, e.g., as described below with reference to Fig. 4.

[00196] Reference is made to Fig. 4, which schematically illustrates a format of a sector ACK frame 400, in accordance with some demonstrative embodiments.

[00197] In one example, device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1) may be configured to generate, transmit, receive and/or process one or more sector ACK frames having the structure and/or format of sector ACK frame 400.

[00198] In some demonstrative embodiments, as shown in Fig. 4, sector ACK frame 400 may include an RA field 402, a Transmitter Address (TA) field 404, a number-of- sector-feedback field 406, a duration field 410, and/or one or more sector feedback fields 408, e.g., as described below.

[00199] In some demonstrative embodiments, as shown in Fig. 4 a sector feedback field 408 may include an SSW feedback field 412, a beam Refinement Protocol (BRP) field 416, and/or a Beamformed link maintenance field 418, e.g., as described below. [00200] In some demonstrative embodiments, the SSW field 412, the BRP field 416, and/or the Beamformed link maintenance field 418 may be defined, for example, in accordance with an IEEE802.11ay specification and/or according to any other definition. [00201] In some demonstrative embodiments, the Duration field 408 may be set to an end of a current allocation, e.g., of the asymmetric beamforming training.

[00202] In some demonstrative embodiments, the RA field 402 may include a MAC address of a STA that is an intended destination of the sector ACK frame, for example, if a value of Number of Sector Feedback field 408 is 1. [00203] In some demonstrative embodiments, the RA field 402 may include a broadcast MAC address, for example, if a value of Number of Sector Feedback field 408 is more than 1.

[00204] In some demonstrative embodiments, the TA field 404 may include a MAC address of a STA transmitting the Sector ACK frame 400. [00205] In some demonstrative embodiments, a value in the Number of Sector Feedback Field 406 may indicates a number, e.g., N, of Sector Feedback fields 408 following the Number of Sector Feedback Field 406.

[00206] In one example, N may not be greater than eight. In another example, N may be any other number, e.g., less than or greater than eight. [00207] In one example, device 102 (Fig. 1) may receive a first SSW frame from device 140 (Fig. 1) via a sector of device 102, and a second SSW frame from device 160 (Fig. 1) via the same sector of device 102, for example, during a listening slot, e.g., listening slot 311 (Fig. 3). According to this example, device 102 (Fig. 1) may transmit a same, e.g., single, sector ACK frame 400 to both devices 140 and 160 (Fig. 1). For example, device 102 (Fig. 1) may set the RA field 402 to include the broadcast address, the transmitter address field 404 to include an address of device 102 (Fig. 1), and the number-of-sector-feedback field 406 to include the number two, e.g., for devices 140 and 160 (Fig. 1). Sector ACK frame 400 may include two sector feedback fields 408, e.g., one sector feedback field 408 including feedback for device 140 (Fig. l), and another sector feedback field 408 including feedback for device 160 (Fig l). [00208] Referring back to Fig. 1, in s some demonstrative embodiments, the sector ACK frame may include an Unprotected DMG Action frame, e.g., as described below.

[00209] In one example, device 102, device 140, and/or device 160 may be configured to generate, transmit, receive and/or process one or more sector ACK frames having the structure and/or format of the Unprotected DMG Action frame.

[00210] In some demonstrative embodiments, an action field of the Unprotected DMG Action frame may include a value to indicate that the Unprotected DMG Action frame is to be used as a sector ACK frame, e.g., as follows:

Table 1

[00211] In some demonstrative embodiments, a format of an action field may be configured to include one or more subfields, e.g. as follows:

Table 2

[00212] In some demonstrative embodiments, The Category field, and/or the Unprotected DMG Action field may be defined, for example, in accordance with an IEEE802. Hay specification. [00213] In some demonstrative embodiments, the Dialog Token field may be set to a value chosen by a STA sending the Unprotected DMG Action frame, for example, to uniquely identify a transaction.

[00214] In some demonstrative embodiments, the format of the action field may include one or more, e.g., up to N, sector feedback fields, which may be formed, for example, similar to sector feedback fields 408 (Fig. 4).

[00215] In some demonstrative embodiments, device 102, device 140, and/or device 160 may be configured to support an access and collision protocol for the asymmetric beamforming training, e.g., as described below.

[00216] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may be configured to address one or more technical problems in an asymmetric beamforming training, for example, which may be in accordance with an IEEE802.1 lay specification, e.g., as described below.

[00217] In one example, the access and collision protocol for the asymmetric beamforming training may be configured to provide a technical solution to support the EDMG initiator STA to signal a number of space-time slots assigned in a directional listening slot, e.g., in each directional listening slot, for example, to enable one or more responder STAs to determine in which space-time slot to transmit an SSW frame, e.g., as described below.

[00218] In one example, the access and collision protocol for the asymmetric beamforming training may be configured to define how multiple responder STAs, that want to transmit in a specific directional listening slot, access a channel and/or select one or more space-time slots in this a directional listening slot. According to this example, the access and collision protocol may define how multiple responder STAs should select multiple corresponding space-time slots for transmissions in the specific directional listening slot, e.g., as described below.

[00219] In one example, the access and collision protocol for the asymmetric beamforming training may be configured to address a technical problem in which multiple responder STAs select the same space-time slot in a specific directional listening slot. According to this example, SSW frame transmissions from multiple responder STAs may collide. The access and collision protocol may be configured to define how the responder STAs operate, for example, when a collision occurs during the asymmetric beamforming training, e.g., as described below. [00220] In one example, the access and collision protocol for the asymmetric beamforming training may be configured to provide a technical solution to support the EDMG initiator STA to sequentially listen on each combination of sector and DMG antenna which was used for a DMG Beacon transmission during a last BTI, for example, according to an order which is the same as an order that was used during the last BTI. According to this example, a number of directional listening slots may be the same as a value of a Count Down (CDOWN) field in a first DMG Beacon frame transmitted in the last BTI. However, if a responder STA misses the first DMG Beacon frame, the responder STA will not know the corresponding CDOWN value. As a result, the responder STA will not know a number of directional listening slots in an allocation for the asymmetric beamforming training. In this scenario the responder STA may be unable to locate an order of a directional listening slot to which the responder STA may be required to access.

[00221] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may be configured to define, for example, a way for the initiator STA to signal a number of space-time slots assigned in a directional listening slot, e.g., in each directional listening slot, and/or a number of directional listening slots for the responder STAs, e.g., as described below.

[00222] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may be configured to define, for example, how responder STAs should transmit in a directional listening slot and/or how the responder STAs may operate when a collision occurs within a directional listening slot, e.g., as described below. [00223] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may utilize a "Number of STS" subfield, which may be included, for example, in the EDMG Extended Schedule element and/or an other element, for example, to signal a number of space-time slots that may be assigned in each directional listening slot in the scheduled allocation for the asymmetric beamforming training, e.g., as described below.

[00224] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may utilize a collision and recovery protocol, for example, to configure how responder STAs should operate, for example, if a collision occurs within a space-time slot in a directional listening slot, e.g., as described below.

[00225] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may configure how responder STAs select a corresponding space-time slot(s) in a directional listening slot, e.g., as described below.

[00226] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may utilize a simple random access protocol, configured to regulate how responder STAs choose a corresponding space-time slot(s) in a specific directional listening slot. In other embodiments, any other access protocol may be implemented.

[00227] In some demonstrative embodiments, the access and collision protocol for the asymmetric beamforming training may utilize a "CDOWN" subfield, which may be included, for example, in a Channel Allocation field in an EDMG Extended Schedule element and/or any other element, for example, to signal a number of directional listening slots that may be present in a scheduled allocation for an asymmetric beamforming training, e.g., as described below.

[00228] In some demonstrative embodiments, device 102, device 140, and/or device 160 may be configured to support one or more aspects of the access and collision protocol for the asymmetric beamforming training, e.g., as described below. [00229] In some demonstrative embodiments, device 102 may be configured to signal to devices 140 and/or 160 a number of directional listening slots and/or a number of space-time slots assigned in a directional listening slot, e.g., in each directional listening slot, for devices 140 and/or 160, and/or, e.g., as described below.

[00230] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the EDMG initiator STA implemented by device 102 to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, e.g., as described below.

[00231] In some demonstrative embodiments, the EDMG schedule element may include a channel allocation field including a number-of-slots subfield including a count of one or more space-time slots, e.g., as described below. [00232] In one example, the number-of-slots subfield in the Channel Allocation field in the EDMG Extended Schedule element may signal the number of space- time slots that will be assigned in each directional listening slot in the scheduled allocation for the asymmetric beamforming training.

[00233] In some demonstrative embodiments, the number-of-slots subfield may include three bits. According to these embodiments, up to eight space-time slots may be assigned in each directional listening slot. In other embodiments, the number-of-slots subfield may include any other number of bits to support any other number of slots.

[00234] In one example, if the value of the number-of-slots subfield is set to 'm', for example, each directional listening slot may include (m+1) space-time slots in a corresponding allocation to be dedicated for the asymmetric beamforming training.

[00235] In some demonstrative embodiments, the channel allocation field may include a maximal-number-of-slots subfield to indicate a maximal number of space- time slots to be used by an EDMG responder STA in the listening period, e.g., as described below.

[00236] In some demonstrative embodiments, device 140 may receive the schedule element from device 102 including the channel allocation field including the number- of-slots subfield and the maximal-number-of-slots subfield, e.g., as described below. [00237] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the EDMG responder STA implemented by device 140 to receive from device 102 the EDMG schedule element to define an allocation of the asymmetric beamforming training. The EDMG schedule element may include the channel allocation field including the number-of-slots subfield including the count of one or more space-time slots. [00238] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to determine a selected sector of device 102, for example, based on a transmission from device 102, e.g., as described above.

[00239] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to determine a selected time slot, for example, based on the number-of-slots subfield, e.g., as described below.

[00240] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to transmit a SSW frame to device 102 during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, e.g., as described below.

[00241] In some demonstrative embodiments, the listening period may correspond to the selected sector of device 102, e.g., as described below.

[00242] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to attempt to receive a sector ACK frame from device 102, e.g., as described below.

[00243] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to attempt another asymmetric beamforming training in a next beamforming training allocation, for example, when the sector ACK frame is not received from the EDMG initiator STA.

[00244] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to randomly select the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield, e.g., as described below. [00245] In some demonstrative embodiments, controller 154 may be configured to control, cause and/or trigger the STA implemented by device 140 to determine the maximal number of space-time slots as 2 ^max , wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00246] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the STA implemented by device 102 to listen for transmissions, e.g., of SSW frames, during a listening sequence of a plurality of listening periods corresponding to the plurality of sectors of device 102, e.g., as described above.

[00247] In some demonstrative embodiments, a listening period of the plurality of listening periods may include one or more Space-Time Slots, during which device 102 may listen on a sector of the plurality of sectors for one or more SSW frames from one or more EDMG STAs, e.g., as described above.

[00248] In some demonstrative embodiments, controller 124 may be configured to control, cause and/or trigger the STA implemented by device 102 to transmit a sector ACK frame via the sector, for example, based on the one or more SSW frames, e.g., as described above.

[00249] In one example, device 102, device 140, and/or device 160 may be configured to support an access protocol, in which each responder STA may randomly select n space-time slots out of the total space-time slots in a corresponding directional listening slot, where m is the value in the field of Number of STS. For example, the value n shall be no larger than the value of 2 ^NmaxSTS , e.g., where NmaxSTS denotes the value of the maximal-number-of-slots subfield in the schedule element for the allocation.

[00250] In some demonstrative embodiments, device 102, device 140, and/or device 160 may be configured to support a collision protocol, for example, when a collision occurs during a space time slot, e.g., as described below.

[00251] In some demonstrative embodiments, the collision may be detected, for example, by a responder STA, e.g., if a responder STA does not receive a Sector ACK frame from the initiator STA in the second part of the asymmetric beamforming training, e.g., part 330 (Fig. 3). [00252] In some demonstrative embodiments, if the responder STA needs to transmit a SSW frame in the same direction, the responder STA may access one or more further space-time slots within the same directional listening slot, for example, during a next asymmetric beamforming training, e.g., scheduled by the initiator STA. For example, the responder STA may follow the access protocol described above to try to access one or more space-time slots in a corresponding directional listening slot again.

[00253] Reference is made to Fig. 5, which schematically illustrates a format of a channel allocation field 500, in accordance with some demonstrative embodiments.

[00254] In one example, device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1) may be configured to generate, transmit, receive and/or process one or more scheduling elements including the channel allocation field having the structure and/or the format of channel allocation field 500. [00255] In some demonstrative embodiments, channel allocation field 500 may be included as part of an EDMG Extended Schedule Element, for example, to signal a number of space-time slots that may be dedicated to an asymmetric beamforming training, e.g., as described below.

[00256] In other embodiments, channel allocation field 500 may be included as part of any other additional or alternative element and/or message.

[00257] In some demonstrative embodiments, channel allocation field 500 may include a scheduling type field 501 including a value of "0".

[00258] In some demonstrative embodiments, as shown in Fig. 5, channel allocation field 500 may include a number-of-slots field 502, denoted "Number of STS", and a maximal number of space-time slots field 504, denoted "Nmax STS".

[00259] In some demonstrative embodiments, number-of-slots field 502 may include a count of one or more space-time slots.

[00260] In some demonstrative embodiments, the number of STS field 502 may include three bits. According to these embodiments, up to eight space-time slots may be assigned in each directional listening slot. In other embodiments, the field 502 may include any other number of bits to support any other number of slots.

[00261] In one example, if the value of the number of STS field 502 is set to 'm', for example, each directional listening slot may include (m+1) space-time slots in a corresponding allocation to be dedicated for the asymmetric beamforming training. [00262] In some demonstrative embodiments, the maximal number of space-time slots field 504 may indicate a maximal number of space-time slots to be used by an EDMG responder STA in a listening period.

[00263] In one example, the maximal number of space-time slots may be determined, for example, as 2 ^NmaxSTS , wherein NmaxSTS denotes the value in the maximal number of space-time slots field 504.

[00264] In some demonstrative embodiments, as shown in Fig. 5, channel allocation field 500 may optionally include a CDOWN field 506.

[00265] In other embodiments, CDOWN field 506 may be optional or may be excluded from channel allocation field 500.

[00266] In one example, CDOWN field 506 may signal a number of directional listening slots that will be present in a scheduled allocation that will be dedicated for the asymmetric beamforming training. The "CDOWN" subfield may include 11 bits or any other number of bits. For example, if a value of CDOWN field 506 is n, the number of directional listening slots may include n directional listening slots. An order of the directional listening slots may be n-1, n-2, n-3, 0 or any other order.

In one example, a sector ID and antenna ID for each directional listening slot may correspond to a same CDOWN value transmitted in the DMG Beacon frame during the last BTI. [00267] Reference is made to Fig. 6, which schematically illustrates a format of a channel allocation field 600, in accordance with some demonstrative embodiments.

[00268] In one example, device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1) may be configured to generate, transmit, receive and/or process one or more scheduling elements including the channel allocation field having the structure and/or the format of channel allocation field 600.

[00269] In some demonstrative embodiments, channel allocation field 600 may be included as part of an EDMG Extended Schedule Element, for example, to signal a number of space-time slots that may be dedicated to an asymmetric beamforming training, e.g., as described below. [00270] In other embodiments, channel allocation field 600 may be included as part of any other element. [00271] In some demonstrative embodiments, channel allocation field 600 may include a scheduling type field 601 including a value of "1".

[00272] In some demonstrative embodiments, as shown in Fig. 6, channel allocation field 600 may include a number-of-slots field 602, denoted "Number of STS", and a maximal number of space-time slots field 604, denoted "Nmax STS".

[00273] In some demonstrative embodiments, the number of STS field 602 may include a count of one or more space-time slots.

[00274] In some demonstrative embodiments, the maximal number of space-time slots field 604 may indicate a maximal number of space-time slots to be used by an EDMG responder STA in a listening period.

[00275] In one example, the maximal number of space-time slots may be determined, for example, as 2 ^NmaxSTS , wherein NmaxSTS denotes the value in the maximal number of space-time slots field 604.

[00276] In some demonstrative embodiments, as shown in Fig. 6, channel allocation field 600 may optionally include a CDOWN field 606.

[00277] In other embodiments, CDOWN field 606 may be optional or may be excluded from channel allocation field 600.

[00278] In one example, CDOWN field 606 may signal a number of directional listening slots that will be present in a scheduled allocation that will be dedicated for the asymmetric beamforming training, e.g., as described above.

[00279] Reference is made to Fig. 7, which schematically illustrates a method of asymmetric beamforming training, in accordance with some demonstrative embodiments. For example, one or more of the operations of the method of Fig. 7 may be performed by one or more elements of a system, e.g., system 100 (Fig. 1), for example, one or more wireless devices, e.g., device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1), a controller, e.g., controller 124 (Fig. 1) and/or controller 154 (Fig. 1), a radio, e.g., radio 114 (Fig. 1) and/or radio 144 (Fig. 1), and/or a message processor, e.g., message processor 128 (Fig. 1) and/or message processor 158 (Fig. 1). [00280] As indicated at block 702, the method may include listening at an EDMG initiator STA of an asymmetric beamforming training for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods including one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more SSW frames. For example, controller 124 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 102 (Fig. 1) to listen for transmissions during a listening sequence of a plurality of listening periods corresponding to the plurality of sectors of device 102 (Fig. 1), the listening period of the plurality of listening periods including the one or more space-time slots, during which device 102 (Fig. 1) is to listen on the sector of the plurality of sectors for the one or more SSW frames, e.g., as described above.

[00281] As indicated at block 704, the method may include transmitting a sector ACK frame via the sector, the sector ACK frame via the sector including one or more sector feedback fields for one or more respective EDMG responder STAs, a sector feedback field for an EDMG responder STA including feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame including a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. For example, controller 124 (Fig. 1) may be configured to cause, trigger, and/or control the EDMG STA implemented by device 102 (Fig. 1) to transmit the sector ACK frame via the sector, e.g., as described above.

[00282] Reference is made to Fig. 8, which schematically illustrates a method of asymmetric beamforming training, in accordance with some demonstrative embodiments. For example, one or more of the operations of the method of Fig. 8 may be performed by one or more elements of a system, e.g., system 100 (Fig. 1), for example, one or more wireless devices, e.g., device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1), a controller, e.g., controller 124 (Fig. 1) and/or controller 154 (Fig. 1), a radio, e.g., radio 114 (Fig. 1) and/or radio 144 (Fig. 1), and/or a message processor, e.g., message processor 128 (Fig. 1) and/or message processor 158 (Fig. 1).

[00283] As indicated at block 802, the method may include determining, at an EDMG responder STA of an asymmetric beamforming training, a selected sector of an EDMG initiator STA based on a transmission from the EDMG initiator STA. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 140 (Fig. 1) to determine the selected sector of device 102 (Fig. 1), for example, based on the transmission from device 102 (Fig. 1), e.g., as described above. [00284] As indicated at block 804, the method may include transmitting a SSW frame to the EDMG initiator STA during a space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control the EDMG STA implemented by device 140 (Fig. 1) to transmit the SSW frame to device 102 (Fig. 1) during the space- time slot of the listening period in the listening sequence of the plurality of listening periods, the listening period corresponding to the selected sector of device 102 (Fig. 1), e.g., as described above.

[00285] As indicated at block 806, the method may include receiving a sector ACK frame from the EDMG initiator STA, the sector ACK frame including one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields including at least a sector feedback field for the EDMG responder STA including feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame including a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control the EDMG STA implemented by device 140 (Fig. 1) to receive the sector ACK frame from device 102 (Fig. 1), the sector ACK frame including the one or more sector feedback fields for the one or more respective EDMG responder STAs, the one or more sector feedback fields including the sector feedback field for device 140 (Fig. 1) including feedback for device 140 (Fig. 1) based on the SSW frame, the sector ACK frame including the number-of-sector-feedback field to indicate the count of the one or more sector feedback fields in the sector ACK frame, e.g., as described above.

[00286] Reference is made to Fig. 9, which schematically illustrates a method of asymmetric beamforming training, in accordance with some demonstrative embodiments. For example, one or more of the operations of the method of Fig. 9 may be performed by one or more elements of a system, e.g., system 100 (Fig. 1), for example, one or more wireless devices, e.g., device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1), a controller, e.g., controller 124 (Fig. 1) and/or controller 154 (Fig. 1), a radio, e.g., radio 114 (Fig. 1) and/or radio 144 (Fig. 1), and/or a message processor, e.g., message processor 128 (Fig. 1) and/or message processor 158 (Fig. 1). [00287] As indicated at block 902, the method may include transmitting from an EDMG initiator STA of an asymmetric beamforming training an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element including a channel allocation field, the channel allocation field including a number-of-slots subfield including a count of one or more space-time slots. For example, controller 124 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 102 (Fig. 1) to transmit the EDMG schedule element to define the allocation of the asymmetric beamforming training, the EDMG schedule element including the channel allocation field including the number- of-slots subfield 502 (Fig. 5) including the count of one or more space-time slots 311 (Fig. 3), e.g., as described above.

[00288] As indicated at block 904, the method may include listening for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods including the one or more space-time slots indicated by the number-of-slots subfield, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more SSW frames from one or more EDMG responder STAs. For example, controller 124 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 102 (Fig. 1) to listen for transmissions during the listening sequence of the plurality of listening periods corresponding to the plurality of sectors of device 102 (Fig. 1), the listening period of the plurality of listening periods including the one or more space- time slots 311 (Fig. 3), indicated by the number-of-slots subfield 502 (Fig. 5), during which device 102 (Fig. 1) is to listen on a sector of the plurality of sectors for the one or more SSW from the one or more EDMG responder STAs, e.g., as described above. [00289] As indicated at block 906, the method may include transmitting a sector ACK frame via the sector based on the one or more SSW frames. For example, controller 124 (Fig. 1) may be configured to cause, trigger, and/or control the EDMG STA implemented by device 102 (Fig. 1) to transmit the sector ACK frame via the sector based on the one or more SSW frames, e.g., as described above.

[00290] Reference is made to Fig. 10, which schematically illustrates a method of asymmetric beamforming training, in accordance with some demonstrative embodiments. For example, one or more of the operations of the method of Fig. 10 may be performed by one or more elements of a system, e.g., system 100 (Fig. 1), for example, one or more wireless devices, e.g., device 102 (Fig. 1), device 140 (Fig. 1), and/or device 160 (Fig. 1), a controller, e.g., controller 124 (Fig. 1) and/or controller 154 (Fig. 1), a radio, e.g., radio 114 (Fig. 1) and/or radio 144 (Fig. 1), and/or a message processor, e.g., message processor 128 (Fig. 1) and/or message processor 158 (Fig. 1).

[00291] As indicated at block 1002, the method may include receiving from an EDMG initiator STA of an asymmetric beamforming training an EDMG schedule element to define an allocation of an asymmetric beamforming training, the EDMG schedule element including a channel allocation field, the channel allocation field including a number-of-slots subfield including a count of one or more space-time slots. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 140 (Fig. 1) to receive from device 102 (Fig. 1) the EDMG schedule element to define the allocation of the asymmetric beamforming training, the EDMG schedule element including the channel allocation field including the number-of-slots subfield including the count of the one or more space-time slots, e.g., as described above.

[00292] As indicated at block 1004, the method may include determining a selected sector of the EDMG initiator STA based on a transmission from the EDMG initiator STA. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 140 (Fig. 1) to determine the selected sector of device 102 (Fig. 1), for example, based on the transmission from device 102 (Fig. 1), e.g., as described above.

[00293] As indicated at block 1006, the method may include determining a selected time slot, based on the number-of-slots subfield. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control an EDMG STA implemented by device 140 (Fig. 1) to determine the selected time slot, for example, based on the number-of-slots subfield, e.g., as described above.

[00294] As indicated at block 1008, the method may include transmitting a SSW frame to the EDMG initiator STA during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control the EDMG STA implemented by device 140 (Fig. 1) to transmit the SSW frame to device 102 (Fig. 1) during the selected space-time slot of the listening period in the listening sequence of the plurality of listening periods, the listening period corresponding to the selected sector of device 102 (Fig. 1), e.g., as described above.

[00295] As indicated at block 1010, the method may include attempting to receive a sector ACK frame from the EDMG initiator STA. For example, controller 154 (Fig. 1) may be configured to cause, trigger, and/or control the EDMG STA implemented by device 140 (Fig. 1) to attempt to receive the sector ACK frame from device 102 (Fig. 1), e.g., as described above.

[00296] Reference is made to Fig. 11, which schematically illustrates a product of manufacture 1100, in accordance with some demonstrative embodiments. Product 1100 may include one or more tangible computer-readable ("machine-readable") non- transitory storage media 1102, which may include computer-executable instructions, e.g., implemented by logic 1104, operable to, when executed by at least one computer processor, enable the at least one computer processor to implement one or more operations at device 102 (Fig. 1), device 140 (Fig. 1), device 160 (Fig. 1), radio 114 (Fig. 1), radio 144 (Fig. 1), transmitter 118 (Fig. 1), transmitter 148 (Fig. 1), receiver 116 (Fig. 1), receiver 146 (Fig. 1), message processor 128 (Fig. 1), message processor 158 (Fig. 1), controller 124 (Fig. 1), and/or controller 154 (Fig. 1), to cause device 102 (Fig. 1), device 140 (Fig. 1), device 160 (Fig. 1), radio 114 (Fig. 1), radio 144 (Fig. 1), transmitter 118 (Fig. 1), transmitter 148 (Fig. 1), receiver 116 (Fig. 1), receiver 146 (Fig. 1), message processor 128 (Fig. 1), message processor 158 (Fig. 1), controller 124 (Fig. 1), and/or controller 154 (Fig. 1) to perform, trigger and/or implement one or more operations and/or functionalities, and/or to perform, trigger and/or implement one or more operations and/or functionalities described with reference to the Figs. 1, 2, 3, 5, 6, 7, 8, 9 and/or 10, and/or one or more operations described herein. The phrases "non-transitory machine-readable medium" and "computer-readable non-transitory storage media" may be directed to include all computer-readable media, with the sole exception being a transitory propagating signal. [00297] In some demonstrative embodiments, product 1100 and/or machine readable storage media 802 may include one or more types of computer-readable storage media capable of storing data, including volatile memory, non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re- writeable memory, and the like. For example, machine readable storage media 802 may include, RAM, DRAM, Double-Data-Rate DRAM (DDR-DRAM), SDRAM, static RAM (SRAM), ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), Compact Disk ROM (CD-ROM), Compact Disk Recordable (CD-R), Compact Disk Rewriteable (CD-RW), flash memory (e.g., NOR or NAND flash memory), content addressable memory (CAM), polymer memory, phase-change memory, ferroelectric memory, silicon-oxide-nitride-oxide-silicon (SONOS) memory, a disk, a floppy disk, a hard drive, an optical disk, a magnetic disk, a card, a magnetic card, an optical card, a tape, a cassette, and the like. The computer-readable storage media may include any suitable media involved with downloading or transferring a computer program from a remote computer to a requesting computer carried by data signals embodied in a carrier wave or other propagation medium through a communication link, e.g., a modem, radio or network connection.

[00298] In some demonstrative embodiments, logic 1104 may include instructions, data, and/or code, which, if executed by a machine, may cause the machine to perform a method, process and/or operations as described herein. The machine may include, for example, any suitable processing platform, computing platform, computing device, processing device, computing system, processing system, computer, processor, or the like, and may be implemented using any suitable combination of hardware, software, firmware, and the like. [00299] In some demonstrative embodiments, logic 1104 may include, or may be implemented as, software, a software module, an application, a program, a subroutine, instructions, an instruction set, computing code, words, values, symbols, and the like. The instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. The instructions may be implemented according to a predefined computer language, manner or syntax, for instructing a processor to perform a certain function. The instructions may be implemented using any suitable high-level, low-level, object- oriented, visual, compiled and/or interpreted programming language, such as C, C++, Java, BASIC, Matlab, Pascal, Visual BASIC, assembly language, machine code, and the like.

EXAMPLES

[00300] The following examples pertain to further embodiments. [00301] Example 1 includes an apparatus comprising logic and circuitry configured to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training to listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames; and transmit a sector acknowledgement (ACK) frame via the sector, the sector ACK frame via the sector comprising one or more sector feedback fields for one or more respective EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00302] Example 2 includes the subject matter of Example 1, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00303] Example 3 includes the subject matter of Example 1 or 2, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period. [00304] Example 4 includes the subject matter of any one of Examples 1-3, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field. [00305] Example 5 includes the subject matter of any one of Examples 1-4, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame. [00306] Example 6 includes the subject matter of any one of Examples 1-5, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, set a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA. [00307] Example 7 includes the subject matter of any one of Examples 1-6, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00308] Example 8 includes the subject matter of any one of Examples 1-7, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00309] Example 9 includes the subject matter of any one of Examples 1-8, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period.

[00310] Example 10 includes the subject matter of Example 9, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00311] Example 11 includes the subject matter of any one of Examples 1-10, and optionally, comprising a radio. [00312] Example 12 includes the subject matter of any one of Examples 1-11, and optionally, comprising one or more antennas, a memory, and a processor.

[00313] Example 13 includes a system of wireless communication comprising an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training, the EDMG initiator STA comprising one or more antennas; a radio; a memory; a processor; and a controller configured to cause the EDMG initiator STA to listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames; and transmit a sector acknowledgement (ACK) frame via the sector, the sector ACK frame via the sector comprising one or more sector feedback fields for one or more respective EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00314] Example 14 includes the subject matter of Example 13, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00315] Example 15 includes the subject matter of Example 13 or 14, and optionally, wherein the controller is configured to cause the EDMG initiator STA to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period.

[00316] Example 16 includes the subject matter of any one of Examples 13-15, and optionally, wherein the controller is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field. [00317] Example 17 includes the subject matter of any one of Examples 13-16, and optionally, wherein the controller is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00318] Example 18 includes the subject matter of any one of Examples 13-17, and optionally, wherein the controller is configured to cause the EDMG initiator STA to, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, set a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00319] Example 19 includes the subject matter of any one of Examples 13-18, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00320] Example 20 includes the subject matter of any one of Examples 13-19, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00321] Example 21 includes the subject matter of any one of Examples 13-20, and optionally, wherein the controller is configured to cause the EDMG initiator STA to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period.

[00322] Example 22 includes the subject matter of Example 21, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00323] Example 23 includes a method to be performed at an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training, the method comprising listening for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames; and transmitting a sector acknowledgement (ACK) frame via the sector, the sector ACK frame via the sector comprising one or more sector feedback fields for one or more respective EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00324] Example 24 includes the subject matter of Example 23, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00325] Example 25 includes the subject matter of Example 23 or 24, and optionally, comprising transmitting a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period.

[00326] Example 26 includes the subject matter of any one of Examples 23-25, and optionally, comprising setting a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field. [00327] Example 27 includes the subject matter of any one of Examples 23-26, and optionally, comprising setting a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00328] Example 28 includes the subject matter of any one of Examples 23-27, and optionally, comprising, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, setting a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00329] Example 29 includes the subject matter of any one of Examples 23-28, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00330] Example 30 includes the subject matter of any one of Examples 23-29, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00331] Example 31 includes the subject matter of any one of Examples 23-30, and optionally, comprising transmitting an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period. [00332] Example 32 includes the subject matter of Example 31, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00333] Example 33 includes a product comprising one or more tangible computer- readable non-transitory storage media comprising computer-executable instructions operable to, when executed by at least one processor, enable the at least one processor to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training to listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames; and transmit a sector acknowledgement (ACK) frame via the sector, the sector ACK frame via the sector comprising one or more sector feedback fields for one or more respective EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. [00334] Example 34 includes the subject matter of Example 33, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00335] Example 35 includes the subject matter of Example 33 or 34, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period.

[00336] Example 36 includes the subject matter of any one of Examples 33-35, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field.

[00337] Example 37 includes the subject matter of any one of Examples 33-36, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00338] Example 38 includes the subject matter of any one of Examples 33-37, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, set a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00339] Example 39 includes the subject matter of any one of Examples 33-38, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00340] Example 40 includes the subject matter of any one of Examples 33-39, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00341] Example 41 includes the subject matter of any one of Examples 33-40, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period.

[00342] Example 42 includes the subject matter of Example 41, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00343] Example 43 includes an apparatus of wireless communication by an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training, the apparatus comprising means for listening for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames; and means for transmitting a sector acknowledgement (ACK) frame via the sector, the sector ACK frame via the sector comprising one or more sector feedback fields for one or more respective EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of- sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00344] Example 44 includes the subject matter of Example 43, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00345] Example 45 includes the subject matter of Example 43 or 44, and optionally, comprising means for transmitting a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period. [00346] Example 46 includes the subject matter of any one of Examples 43-45, and optionally, comprising means for setting a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field. [00347] Example 47 includes the subject matter of any one of Examples 43-46, and optionally, comprising means for setting a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame. [00348] Example 48 includes the subject matter of any one of Examples 43-47, and optionally, comprising means for, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, setting a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA. [00349] Example 49 includes the subject matter of any one of Examples 43-48, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00350] Example 50 includes the subject matter of any one of Examples 43-49, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00351] Example 51 includes the subject matter of any one of Examples 43-50, and optionally, comprising means for transmitting an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period.

[00352] Example 52 includes the subject matter of Example 51, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00353] Example 53 includes an apparatus comprising logic and circuitry configured to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training to determine a selected sector of an EDMG initiator STA based on a transmission from the EDMG initiator STA; transmit a Sector Sweep (SSW) frame to the EDMG initiator STA during a space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and receive a sector acknowledgement (ACK) frame from the EDMG initiator STA, the sector ACK frame comprising one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00354] Example 54 includes the subject matter of Example 53, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00355] Example 55 includes the subject matter of Example 53 or 54, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame. [00356] Example 56 includes the subject matter of any one of Examples 53-55, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA.

[00357] Example 57 includes the subject matter of any one of Examples 53-56, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00358] Example 58 includes the subject matter of any one of Examples 53-57, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training. [00359] Example 59 includes the subject matter of any one of Examples 53-58, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to receive from the EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period. [00360] Example 60 includes the subject matter of Example 59, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to randomly select the space-time slot for transmission of the SSW frame from a plurality of space- time slots indicated by the number-of-slots subfield. [00361] Example 61 includes the subject matter of Example 59 or 60, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00362] Example 62 includes the subject matter of Example 61, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to determine the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00363] Example 63 includes the subject matter of any one of Examples 53-62, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to attempt another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00364] Example 64 includes the subject matter of any one of Examples 53-63, and optionally, comprising a radio.

[00365] Example 65 includes the subject matter of any one of Examples 53-64, and optionally, comprising one or more antennas, a memory, and a processor.

[00366] Example 66 includes a system of wireless communication comprising an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training, the EDMG responder STA comprising one or more antennas; a radio; a memory; a processor; and a controller configured to cause the EDMG responder STA to determine a selected sector of an EDMG initiator STA based on a transmission from the EDMG initiator STA; transmit a Sector Sweep (SSW) frame to the EDMG initiator STA during a space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and receive a sector acknowledgement (ACK) frame from the EDMG initiator STA, the sector ACK frame comprising one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number- of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. [00367] Example 67 includes the subject matter of Example 66, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00368] Example 68 includes the subject matter of Example 66 or 67, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00369] Example 69 includes the subject matter of any one of Examples 66-68, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA.

[00370] Example 70 includes the subject matter of any one of Examples 66-69, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00371] Example 71 includes the subject matter of any one of Examples 66-70, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00372] Example 72 includes the subject matter of any one of Examples 66-71, and optionally, wherein the controller is configured to cause the EDMG responder STA to receive from the EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period.

[00373] Example 73 includes the subject matter of Example 72, and optionally, wherein the controller is configured to cause the EDMG responder STA to randomly select the space-time slot for transmission of the SSW frame from a plurality of space- time slots indicated by the number-of-slots subfield. [00374] Example 74 includes the subject matter of Example 72 or 73, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period. [00375] Example 75 includes the subject matter of Example 74, and optionally, wherein the controller is configured to cause the EDMG responder STA to determine the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00376] Example 76 includes the subject matter of any one of Examples 66-75, and optionally, wherein the controller is configured to cause the EDMG responder STA to attempt another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00377] Example 77 includes a method to be performed at an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training, the method comprising determining a selected sector of an EDMG initiator STA based on a transmission from the EDMG initiator STA; transmitting a Sector Sweep (SSW) frame to the EDMG initiator STA during a space- time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and receiving a sector acknowledgement (ACK) frame from the EDMG initiator STA, the sector ACK frame comprising one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00378] Example 78 includes the subject matter of Example 77, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field. [00379] Example 79 includes the subject matter of Example 77 or 78, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00380] Example 80 includes the subject matter of any one of Examples 77-79, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA.

[00381] Example 81 includes the subject matter of any one of Examples 77-80, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00382] Example 82 includes the subject matter of any one of Examples 77-81, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00383] Example 83 includes the subject matter of any one of Examples 77-82, and optionally, comprising receiving from the EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space- time slots for the listening period.

[00384] Example 84 includes the subject matter of Example 83, and optionally, comprising randomly selecting the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield.

[00385] Example 85 includes the subject matter of Example 83 or 84, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00386] Example 86 includes the subject matter of Example 85, and optionally, comprising determining the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00387] Example 87 includes the subject matter of any one of Examples 77-86, and optionally, comprising attempting another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00388] Example 88 includes a product comprising one or more tangible computer- readable non-transitory storage media comprising computer-executable instructions operable to, when executed by at least one processor, enable the at least one processor to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training to determine a selected sector of an EDMG initiator STA based on a transmission from the EDMG initiator STA; transmit a Sector Sweep (SSW) frame to the EDMG initiator STA during a space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and receive a sector acknowledgement (ACK) frame from the EDMG initiator STA, the sector ACK frame comprising one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00389] Example 89 includes the subject matter of Example 88, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00390] Example 90 includes the subject matter of Example 88 or 89, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00391] Example 91 includes the subject matter of any one of Examples 88-90, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA. [00392] Example 92 includes the subject matter of any one of Examples 88-91, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00393] Example 93 includes the subject matter of any one of Examples 88-92, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00394] Example 94 includes the subject matter of any one of Examples 88-93, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to receive from the EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period.

[00395] Example 95 includes the subject matter of Example 94, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to randomly select the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield. [00396] Example 96 includes the subject matter of Example 94 or 95, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00397] Example 97 includes the subject matter of Example 96, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to determine the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00398] Example 98 includes the subject matter of any one of Examples 88-97, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to attempt another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00399] Example 99 includes an apparatus of wireless communication by an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training, the apparatus comprising means for determining a selected sector of an EDMG initiator STA based on a transmission from the EDMG initiator STA; means for transmitting a Sector Sweep (SSW) frame to the EDMG initiator STA during a space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and means for receiving a sector acknowledgement (ACK) frame from the EDMG initiator STA, the sector ACK frame comprising one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00400] Example 100 includes the subject matter of Example 99, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00401] Example 101 includes the subject matter of Example 99 or 100, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00402] Example 102 includes the subject matter of any one of Examples 99-101, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA. [00403] Example 103 includes the subject matter of any one of Examples 99-102, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00404] Example 104 includes the subject matter of any one of Examples 99-103, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00405] Example 105 includes the subject matter of any one of Examples 99-104, and optionally, comprising means for receiving from the EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of the one or more space-time slots for the listening period. [00406] Example 106 includes the subject matter of Example 105, and optionally, comprising means for randomly selecting the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield. [00407] Example 107 includes the subject matter of Example 105 or 106, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00408] Example 108 includes the subject matter of Example 107, and optionally, comprising means for determining the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00409] Example 109 includes the subject matter of any one of Examples 99-108, and optionally, comprising means for attempting another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00410] Example 110 includes an apparatus comprising logic and circuitry configured to cause an Enhanced Directional Multi -Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising the one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames from one or more EDMG responder STAs; and transmit a sector acknowledgement (ACK) frame via the sector based on the one or more SSW frames. [00411] Example 111 includes the subject matter of Example 110, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by an EDMG responder STA in the listening period.

[00412] Example 112 includes the subject matter of Example 110 or 111, and optionally, wherein the sector ACK frame via the sector comprises one or more sector feedback fields for the one or more EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. [00413] Example 113 includes the subject matter of Example 112, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00414] Example 114 includes the subject matter of Example 112 or 113, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period.

[00415] Example 115 includes the subject matter of any one of Examples 112-114, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field.

[00416] Example 116 includes the subject matter of any one of Examples 112-115, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00417] Example 117 includes the subject matter of any one of Examples 112-116, and optionally, wherein the apparatus is configured to cause the EDMG initiator STA to, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, set a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA. [00418] Example 118 includes the subject matter of any one of Examples 112-117, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00419] Example 119 includes the subject matter of any one of Examples 110-118, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00420] Example 120 includes the subject matter of any one of Examples 110-119, and optionally, comprising a radio.

[00421] Example 121 includes the subject matter of any one of Examples 110-120, and optionally, comprising one or more antennas, a memory, and a processor.

[00422] Example 122 includes a system of wireless communication comprising an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training, the EDMG initiator STA comprising one or more antennas; a radio; a memory; a processor; and a controller configured to cause the EDMG initiator STA to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising the one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames from one or more EDMG responder ST As; and transmit a sector acknowledgement (ACK) frame via the sector based on the one or more SSW frames.

[00423] Example 123 includes the subject matter of Example 122, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by an EDMG responder STA in the listening period. [00424] Example 124 includes the subject matter of Example 122 or 123, and optionally, wherein the sector ACK frame via the sector comprises one or more sector feedback fields for the one or more EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. [00425] Example 125 includes the subject matter of Example 124, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00426] Example 126 includes the subject matter of Example 124 or 125, and optionally, wherein the controller is configured to cause the EDMG initiator STA to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder ST As from which SSW frames are received via the sector during the listening period.

[00427] Example 127 includes the subject matter of any one of Examples 124-126, and optionally, wherein the controller is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field.

[00428] Example 128 includes the subject matter of any one of Examples 124-127, and optionally, wherein the controller is configured to cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00429] Example 129 includes the subject matter of any one of Examples 124-128, and optionally, wherein the controller is configured to cause the EDMG initiator STA to, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, set a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00430] Example 130 includes the subject matter of any one of Examples 124-129, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00431] Example 131 includes the subject matter of any one of Examples 122-130, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00432] Example 132 includes a method to be performed at an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training, the method comprising transmitting an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; listening for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising the one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames from one or more EDMG responder STAs; and transmitting a sector acknowledgement (ACK) frame via the sector based on the one or more SSW frames.

[00433] Example 133 includes the subject matter of Example 132, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by an EDMG responder STA in the listening period.

[00434] Example 134 includes the subject matter of Example 132 or 133, and optionally, wherein the sector ACK frame via the sector comprises one or more sector feedback fields for the one or more EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00435] Example 135 includes the subject matter of Example 134, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period. [00436] Example 136 includes the subject matter of Example 134 or 135, and optionally, comprising transmitting a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period. [00437] Example 137 includes the subject matter of any one of Examples 134-136, and optionally, comprising setting a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field.

[00438] Example 138 includes the subject matter of any one of Examples 134-137, and optionally, comprising setting a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00439] Example 139 includes the subject matter of any one of Examples 134-138, and optionally, comprising, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, setting a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00440] Example 140 includes the subject matter of any one of Examples 134-139, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00441] Example 141 includes the subject matter of any one of Examples 132-140, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00442] Example 142 includes a product comprising one or more tangible computer- readable non-transitory storage media comprising computer-executable instructions operable to, when executed by at least one processor, enable the at least one processor to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training to transmit an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; listen for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising the one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames from one or more EDMG responder STAs; and transmit a sector acknowledgement (ACK) frame via the sector based on the one or more SSW frames.

[00443] Example 143 includes the subject matter of Example 142, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by an EDMG responder STA in the listening period. [00444] Example 144 includes the subject matter of Example 142 or 143, and optionally, wherein the sector ACK frame via the sector comprises one or more sector feedback fields for the one or more EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00445] Example 145 includes the subject matter of Example 144, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period.

[00446] Example 146 includes the subject matter of Example 144 or 145, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to transmit a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period.

[00447] Example 147 includes the subject matter of any one of Examples 144-146, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field. [00448] Example 148 includes the subject matter of any one of Examples 144-147, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to set a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00449] Example 149 includes the subject matter of any one of Examples 144-148, and optionally, wherein the instructions, when executed, cause the EDMG initiator STA to, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, set a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00450] Example 150 includes the subject matter of any one of Examples 144-149, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00451] Example 151 includes the subject matter of any one of Examples 142-150, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00452] Example 152 includes an apparatus of wireless communication by an Enhanced Directional Multi-Gigabit (DMG) (EDMG) initiator station (STA) of an asymmetric beamforming training, the apparatus comprising means for transmitting an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; means for listening for transmissions during a listening sequence of a plurality of listening periods corresponding to a plurality of sectors of the EDMG initiator STA, a listening period of the plurality of listening periods comprising the one or more space-time slots, during which the EDMG initiator STA is to listen on a sector of the plurality of sectors for one or more Sector Sweep (SSW) frames from one or more EDMG responder STAs; and means for transmitting a sector acknowledgement (ACK) frame via the sector based on the one or more SSW frames.

[00453] Example 153 includes the subject matter of Example 152, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by an EDMG responder STA in the listening period.

[00454] Example 154 includes the subject matter of Example 152 or 153, and optionally, wherein the sector ACK frame via the sector comprises one or more sector feedback fields for the one or more EDMG responder STAs, a sector feedback field for an EDMG responder STA comprising feedback for the EDMG responder STA based on a SSW frame received from the EDMG responder STA via the sector, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00455] Example 155 includes the subject matter of Example 154, and optionally, wherein the sector ACK frame via the sector comprises a sector feedback field for each EDMG responder STA from which a SSW frame is received via the sector during the listening period. [00456] Example 156 includes the subject matter of Example 154 or 155, and optionally, comprising means for transmitting a single sector ACK frame via the sector with sector feedback fields for all EDMG responder STAs from which SSW frames are received via the sector during the listening period.

[00457] Example 157 includes the subject matter of any one of Examples 154-156, and optionally, comprising means for setting a Receive Address (RA) field in the sector ACK frame based on a value in the number-of-sector-feedback field.

[00458] Example 158 includes the subject matter of any one of Examples 154-157, and optionally, comprising means for setting a Receive Address (RA) field in the sector ACK frame to a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00459] Example 159 includes the subject matter of any one of Examples 154-158, and optionally, comprising means for, when the number-of-sector-feedback field is to indicate a single sector feedback field for a single EDMG responder STA, setting a Receive Address (RA) field in the sector ACK frame to an address of the single EDMG responder STA.

[00460] Example 160 includes the subject matter of any one of Examples 154-159, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00461] Example 161 includes the subject matter of any one of Examples 152-160, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training. [00462] Example 162 includes an apparatus comprising logic and circuitry configured to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training to receive from an EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; determine a selected sector of the EDMG initiator STA based on a transmission from the EDMG initiator STA; determine a selected time slot based on the number-of-slots subfield; transmit a Sector Sweep (SSW) frame to the EDMG initiator STA during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and attempt to receive a sector acknowledgement (ACK) frame from the EDMG initiator STA. [00463] Example 163 includes the subject matter of Example 162, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to randomly select the space-time slot for transmission of the SSW frame from a plurality of space- time slots indicated by the number-of-slots subfield.

[00464] Example 164 includes the subject matter of Example 162 or 163, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00465] Example 165 includes the subject matter of Example 164, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to determine the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00466] Example 166 includes the subject matter of any one of Examples 162-165, and optionally, wherein the apparatus is configured to cause the EDMG responder STA to attempt another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA. [00467] Example 167 includes the subject matter of any one of Examples 162-166, and optionally, wherein the sector ACK frame comprises one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00468] Example 168 includes the subject matter of Example 167, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00469] Example 169 includes the subject matter of Example 167 or 168, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame. [00470] Example 170 includes the subject matter of any one of Examples 167-169, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA.

[00471] Example 171 includes the subject matter of any one of Examples 167-170, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00472] Example 172 includes the subject matter of any one of Examples 162-171, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training. [00473] Example 173 includes the subject matter of any one of Examples 162-172, and optionally, comprising a radio.

[00474] Example 174 includes the subject matter of any one of Examples 162-173, and optionally, comprising one or more antennas, a memory, and a processor.

[00475] Example 175 includes a system of wireless communication comprising an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training, the EDMG responder STA comprising one or more antennas; a radio; a memory; a processor; and a controller configured to cause the EDMG responder STA to receive from an EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space- time slots; determine a selected sector of the EDMG initiator STA based on a transmission from the EDMG initiator STA; determine a selected time slot based on the number-of-slots subfield; transmit a Sector Sweep (SSW) frame to the EDMG initiator STA during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and attempt to receive a sector acknowledgement (ACK) frame from the EDMG initiator STA.

[00476] Example 176 includes the subject matter of Example 175, and optionally, wherein the controller is configured to cause the EDMG responder STA to randomly select the space-time slot for transmission of the SSW frame from a plurality of space- time slots indicated by the number-of-slots subfield.

[00477] Example 177 includes the subject matter of Example 175 or 176, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00478] Example 178 includes the subject matter of Example 177, and optionally, wherein the controller is configured to cause the EDMG responder STA to determine the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield. [00479] Example 179 includes the subject matter of any one of Examples 175-178, and optionally, wherein the controller is configured to cause the EDMG responder STA to attempt another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA. [00480] Example 180 includes the subject matter of any one of Examples 175-179, and optionally, wherein the sector ACK frame comprises one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. [00481] Example 181 includes the subject matter of Example 180, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00482] Example 182 includes the subject matter of Example 180 or 181, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00483] Example 183 includes the subject matter of any one of Examples 180-182, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA.

[00484] Example 184 includes the subject matter of any one of Examples 180-183, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00485] Example 185 includes the subject matter of any one of Examples 175-184, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00486] Example 186 includes a method to be performed at an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training, the method comprising receiving from an EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; determining a selected sector of the EDMG initiator STA based on a transmission from the EDMG initiator STA; determining a selected time slot based on the number-of-slots subfield; transmitting a Sector Sweep (SSW) frame to the EDMG initiator STA during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and attempting to receive a sector acknowledgement (ACK) frame from the EDMG initiator STA.

[00487] Example 187 includes the subject matter of Example 186, and optionally, comprising randomly selecting the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield.

[00488] Example 188 includes the subject matter of Example 186 or 187, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period. [00489] Example 189 includes the subject matter of Example 188, and optionally, comprising determining the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00490] Example 190 includes the subject matter of any one of Examples 186-189, and optionally, comprising attempting another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00491] Example 191 includes the subject matter of any one of Examples 186-190, and optionally, wherein the sector ACK frame comprises one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00492] Example 192 includes the subject matter of Example 191, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00493] Example 193 includes the subject matter of Example 191 or 192, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame. [00494] Example 194 includes the subject matter of any one of Examples 191-193, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA. [00495] Example 195 includes the subject matter of any one of Examples 191-194, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00496] Example 196 includes the subject matter of any one of Examples 186-195, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00497] Example 197 includes a product comprising one or more tangible computer- readable non-transitory storage media comprising computer-executable instructions operable to, when executed by at least one processor, enable the at least one processor to cause an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training to receive from an EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; determine a selected sector of the EDMG initiator STA based on a transmission from the EDMG initiator STA; determine a selected time slot based on the number-of-slots subfield; transmit a Sector Sweep (SSW) frame to the EDMG initiator STA during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and attempt to receive a sector acknowledgement (ACK) frame from the EDMG initiator STA.

[00498] Example 198 includes the subject matter of Example 197, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to randomly select the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield. [00499] Example 199 includes the subject matter of Example 197 or 198, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00500] Example 200 includes the subject matter of Example 199, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to determine the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield.

[00501] Example 201 includes the subject matter of any one of Examples 197-200, and optionally, wherein the instructions, when executed, cause the EDMG responder STA to attempt another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00502] Example 202 includes the subject matter of any one of Examples 197-201, and optionally, wherein the sector ACK frame comprises one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame.

[00503] Example 203 includes the subject matter of Example 202, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00504] Example 204 includes the subject matter of Example 202 or 203, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00505] Example 205 includes the subject matter of any one of Examples 202-204, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA. [00506] Example 206 includes the subject matter of any one of Examples 202-205, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field. [00507] Example 207 includes the subject matter of any one of Examples 197-206, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00508] Example 208 includes an apparatus of wireless communication by an Enhanced Directional Multi-Gigabit (DMG) (EDMG) responder station (STA) of an asymmetric beamforming training, the apparatus comprising means for receiving from an EDMG initiator STA an EDMG schedule element to define an allocation of the asymmetric beamforming training, the EDMG schedule element comprising a channel allocation field, the channel allocation field comprising a number-of-slots subfield comprising a count of one or more space-time slots; means for determining a selected sector of the EDMG initiator STA based on a transmission from the EDMG initiator STA; means for determining a selected time slot based on the number-of-slots subfield; means for transmitting a Sector Sweep (SSW) frame to the EDMG initiator STA during the selected space-time slot of a listening period in a listening sequence of a plurality of listening periods, the listening period corresponding to the selected sector of the EDMG initiator STA; and means for attempting to receive a sector acknowledgement (ACK) frame from the EDMG initiator STA.

[00509] Example 209 includes the subject matter of Example 208, and optionally, comprising means for randomly selecting the space-time slot for transmission of the SSW frame from a plurality of space-time slots indicated by the number-of-slots subfield.

[00510] Example 210 includes the subject matter of Example 208 or 209, and optionally, wherein the channel allocation field comprises a maximal-number-of-slots subfield to indicate a maximal number of space-time slots to be used by the EDMG responder STA in the listening period.

[00511] Example 211 includes the subject matter of Example 210, and optionally, comprising means for determining the maximal number of space-time slots as 2NmaxSTS, wherein NmaxSTS denotes a value in the maximal-number-of-slots subfield. [00512] Example 212 includes the subject matter of any one of Examples 208-211, and optionally, comprising means for attempting another asymmetric beamforming training in a next beamforming training allocation when the sector ACK frame is not received from the EDMG initiator STA.

[00513] Example 213 includes the subject matter of any one of Examples 208-212, and optionally, wherein the sector ACK frame comprises one or more sector feedback fields for one or more respective EDMG responder STAs, the one or more sector feedback fields comprising at least a sector feedback field for the EDMG responder STA comprising feedback for the EDMG responder STA based on the SSW frame, the sector ACK frame comprising a number-of-sector-feedback field to indicate a count of the one or more sector feedback fields in the sector ACK frame. [00514] Example 214 includes the subject matter of Example 213, and optionally, wherein a Receive Address (RA) field in the sector ACK frame is based on a value in the number-of-sector-feedback field.

[00515] Example 215 includes the subject matter of Example 213 or 214, and optionally, wherein a Receive Address (RA) field in the sector ACK frame comprises a broadcast address, when the number-of-sector-feedback field indicates a count of two or more sector feedback fields in the sector ACK frame.

[00516] Example 216 includes the subject matter of any one of Examples 213-215, and optionally, wherein the number-of-sector-feedback field is to indicate a single sector feedback field, and a Receive Address (RA) field in the sector ACK frame comprises an address of the EDMG responder STA.

[00517] Example 217 includes the subject matter of any one of Examples 213-216, and optionally, wherein the sector feedback field comprises an SSW field, a beam Refinement Protocol (BRP) field, and a Beamformed link maintenance field.

[00518] Example 218 includes the subject matter of any one of Examples 208-217, and optionally, wherein the sector ACK frame comprises a duration field set to an end of a current allocation of the asymmetric beamforming training.

[00519] Functions, operations, components and/or features described herein with reference to one or more embodiments, may be combined with, or may be utilized in combination with, one or more other functions, operations, components and/or features described herein with reference to one or more other embodiments, or vice versa. [00520] While certain features have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.