CROSS REFERENCES

[0001] The present Application for Patent claims priority to U.S. Provisional Patent Application No. 62/448,326 to Zhou, et.al., titled "Wi-Fi Multichannel Aggregation", filed January 19, 2017; and U.S. Patent Application No. 15/872,844 by Zhou, et al., entitled "Power Save Procedures for Multi-Link Aggregation," filed January 16, 2018; each of which is assigned to the assignee hereof.

BACKGROUND

[0002] The present disclosure relates generally to wireless communication, and more specifically to power save procedures for multi-link aggregation.

[0003] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). A wireless network, for example a wireless local area network (WLAN), such as a Wi-Fi (i.e., Institute of Electrical and Electronics Engineers (IEEE) 802.11) network may include an access point (AP) that may communicate with one or more stations (STAs) or mobile devices. The AP may be coupled to a network, such as the Internet, and may enable a mobile device to communicate via the network (or communicate with other devices coupled to the access point). A wireless device may communicate with a network device bi-directionally. For example, in a WLAN, a STA may communicate with an associated AP via downlink and uplink. The downlink (or forward link) may refer to the communication link from the AP to the station, and the uplink (or reverse link) may refer to the communication link from the station to the AP.

[0004] Devices in a WLAN may communicate over unlicensed spectrum, which may be a portion of spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 5 GHz band, the 2.4 GHz band, the 60 GHz band, the 3.6 GHz band, and/or the 900 MHz band. The unlicensed spectrum may also include other frequency bands. The wireless connection between an AP and STA may be referred to as a channel or link. Users may access these radio frequency spectrum bands using various contention-based protocols (e.g., as specified by one or more versions of IEEE 802.11). Each band (e.g., the 5 GHz band) may contain multiple channels (e.g., each spanning 20 MHz in frequency), each of which may be usable by an AP or STA. A channel may support multiple connections (e.g., between multiple STAs and the AP) in a multiple access configuration (e.g., code division multiple access (CDMA)). Some wireless communications systems may thus support multi-link aggregation, where signaling may be transmitted and/or received over two or more links between two wireless devices (e.g., an AP and a STA). Such multi-link operations may result in increased power consumption, for example when the AP and/or STA are monitoring the multiple links for control or management signaling. Improved techniques for power save procedures for multi-link aggregation in wireless communications systems supporting multi- link operation may thus be desired.

SUMMARY

[0005] The described techniques relate to improved methods, systems, devices, or apparatuses that support power save procedures for multi-link aggregation. Generally, the described techniques enable a wireless device to dynamically activate and/or inactivate wireless links for multi-link communications, allowing some of the wireless links used for multi-link communications to be inactive (e.g., during time periods of reduced traffic, when no data is pending, etc.) to reduce power consumption by wireless devices engaging in multi- link communications. For example, a transmitting wireless device (e.g., a wireless device with data to be transmitted to a second wireless device) may indicate one or more wireless links to be activated by the receiving wireless device to receive subsequent multi-link transmissions. The indication may be sent over an anchor wireless link, such that the receiving wireless device may monitor the anchor wireless link, with other wireless links in an inactive or low power state, until an indication is received to activate additional wireless links. The receiving wireless device may then activate wireless links identified by the received indication, and receive data from the transmitting device via the multiple links. The activated wireless links may be inactivated upon expiration of a time duration (e.g., assuming no additional or second indication indicating the active link is to remain active is received during the time duration) or upon receiving a second indication to inactivate the active links. That is, indications received over an anchor wireless channel may identify other wireless links to be activated, inactivated, or maintained in an active state. [0006] A method of wireless communication is described. The method may include establishing a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the first wireless device and the second wireless device, receiving, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, activating, based at least in part on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and receiving the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components.

[0007] An apparatus for wireless communication is described. The apparatus may include means for establishing a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for

communications in parallel between the first wireless device and the second wireless device, means for receiving, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, means for activating, based at least in part on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and means for receiving the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components.

[0008] Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and

instructions stored in the memory. The instructions may be operable to cause the processor to establish a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the first wireless device and the second wireless device, receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, activate, based at least in part on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and receive the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components.

[0009] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to establish a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the first wireless device and the second wireless device, receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, activate, based at least in part on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and receive the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components.

[0010] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving, over the anchor wireless link, a second indication that the second wireless device may have additional data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links in the active state. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying, based at least in part on receiving the second indication, that the plurality of links may be in the active state. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving the additional data from the second wireless device over the plurality of wireless links.

[0011] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, receiving the indication comprises: receiving, over the anchor wireless link, an identifier for the one or more wireless links, wherein the receiving components of the first wireless device may be activated based at least in part on receiving the identifier for the one or more wireless links. [0012] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving, over the anchor wireless link, an identifier for a subset of the plurality of wireless links. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying at least one remaining wireless link of the plurality of the wireless links not identified by the received identifier. Some examples of the method, apparatus, and non- transitory computer-readable medium described above may further include processes, features, means, or instructions for returning receiver components of the first wireless device to the inactive state for the at least one remaining wireless link.

[0013] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for monitoring the anchor wireless link for a subsequent indication that the second wireless device may have further data to be transmitted to the first wireless device, wherein the subset of the plurality of wireless links comprises the anchor wireless link.

[0014] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying a duration for the one or more wireless links to remain in the active state. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining whether to maintain the one or more wireless links in the active state or return the one or more wireless links to the inactive state based at least in part on the identified duration.

[0015] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the duration comprises a target beacon transmission time (TBTT), or a target wake time service period (TWT SP), or a physical layer convergence procedure (PLCP) protocol data unit (PPDU) duration, or a transmission opportunity, or a combination thereof.

[0016] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, receiving the indication comprises: receiving a beacon, or a receive operating mode indicator (ROMI) signal, or a channel reservation signal, or a combination thereof, indicating the plurality of wireless links. [0017] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the anchor link may be one of the plurality of wireless links.

[0018] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the anchor link may be a different wireless link than each wireless link of the plurality of wireless links.

[0019] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for monitoring continuously the anchor wireless link for one or more indications that the second wireless device may have data to be transmitted to the first wireless device.

[0020] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for exchanging control frames or management frames between the first wireless device and the second wireless device over the anchor wireless link.

[0021] A method of wireless communication is described. The method may include establishing a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the first wireless device and the second wireless device, transmitting, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, activating transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and transmitting the data to the second wireless device over the plurality of wireless links using at least a portion of the activated transmitter components.

[0022] An apparatus for wireless communication is described. The apparatus may include means for establishing a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for

communications in parallel between the first wireless device and the second wireless device, means for transmitting, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, means for activating transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and means for transmitting the data to the second wireless device over the plurality of wireless links using at least a portion of the activated transmitter components.

[0023] Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and

instructions stored in the memory. The instructions may be operable to cause the processor to establish a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the first wireless device and the second wireless device, transmit, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, activate transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and transmit the data to the second wireless device over the plurality of wireless links using at least a portion of the activated transmitter components.

[0024] A non-transitory computer-readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to establish a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the first wireless device and the second wireless device, transmit, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state, activate transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and transmit the data to the second wireless device over the plurality of wireless links using at least a portion of the activated transmitter components.

[0025] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting, over the anchor wireless link, an identifier for the one or more wireless links, or an identifier for the plurality of wireless links.

[0026] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining to inactivate a subset of the plurality of wireless links. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting, over the anchor wireless link, an identifier for the subset of the plurality of wireless links.

[0027] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting an indication of a duration for the one or more wireless links to remain in the active state. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining whether to maintain the one or more wireless links in the active state or return the one or more wireless links to the inactive state based at least in part on the duration.

[0028] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, transmitting the indication of the duration comprises: transmitting a beacon, or a ROMI signal, or a channel reservation signal, or a combination thereof, indicating the duration.

[0029] In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the duration comprises a TBTT, or a TWT SP, or a PPDU duration, or a transmission opportunity, or a combination thereof.

[0030] Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for identifying channel conditions for a wireless link of the plurality of wireless links. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining whether to maintain the wireless link in the active state or return the wireless link to the inactive state based at least in part on the identified channel conditions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 illustrates an example of a system for wireless communication that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. [0032] FIG. 2 illustrates an example of a wireless communication system that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure.

[0033] FIGs. 3 and 4 illustrate example of a process flows that support power save procedures for multi-link aggregation in accordance with aspects of the present disclosure.

[0034] FIGs. 5 through 7 show block diagrams of a device that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure.

[0035] FIG. 8 illustrates a block diagram of a system including a wireless device that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure.

[0036] FIGs. 9 through 13 illustrate methods for power save procedures for multi-link aggregation in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

[0037] Some wireless communications systems may support multiple parallel links between communicating devices, for example, to increase throughput, to improve link efficiency, to reduce latency, etc. A wireless link may refer to a communication path between devices, and each link may support one or more channels (e.g., logical entities) that support multiplexing of data, such that during at least some duration of time, transmissions or portions of transmissions may occur in parallel, for example over both links at the same time, either synchronously, or asynchronously. The wireless links may be in the same or different radio frequency (RF) spectrum bands. Each link of a multi-link session may be associated with respective physical components (e.g., antennas, amplifiers, including power amplifiers and low noise amplifiers, etc.) and/or logical processing components (e.g., physical (PHY) layers, media access control (MAC) layers, etc.) of a given wireless device, and these components may be configured to support multi-link communications. The multiple links may connect wireless devices at the MAC layer (e.g., each link may connect respective lower MAC components of communicating devices). The MAC layer may aggregate data packets from the multiple wireless links to provide to upper layers (if the wireless device is receiving) or receive from upper layers (if the wireless devices is transmitting) of the device (e.g., using multiple connections from the MAC layer to the PHY layer). [0038] Such parallel communications, while benefiting the system in terms of throughput and spectral utilization, may result in increased, and in some cases unnecessary, power utilization. For example, powering multiple logical entities (e.g., MAC entities) to maintain multiple links may result in additional power consumption (e.g., compared to single link, single MAC entity operation). Further, in cases where there is little or no communication over one or more of the multiple links, powering components to maintain those links (e.g., continuing to power MAC entities to monitor links for transmissions) may result in unnecessary power consumption.

[0039] As such, wireless communications systems supporting multi-link aggregation may employ power save procedures for multi-link aggregation techniques described herein. For example, a receiving wireless device may reserve a wireless link as an anchor channel or an anchor wireless link. When the receiving wireless device is in an idle or inactive mode (e.g., when the wireless device has one or more other links in an inactive state, idle state, sleep state, low power state, etc.), the receiving wireless device may monitor the anchor wireless link to determine when it may be desirable to activate additional wireless links by powering on one or more components used to transmit and/or received using the additional wireless links. That is, the receiving wireless device may monitor the anchor wireless link for indications identifying one or more inactive wireless links to be activated. Transmitting wireless devices may therefore use the anchor wireless link to signal to a receiving wireless device which other additional links may be used to serve the receiving wireless device for subsequent multi-link communications. As such, wireless devices may dynamically turn on links (e.g., MAC entities other than the one or more MAC entities associated with the anchor link) as desired, for example when multiple links are to be used for transmission or reception. Such techniques are described herein, including details relating to signaling for anchor channel establishment, determination of links to be powered, duration of powering, etc.

[0040] The described techniques relate to improved methods, systems, devices, or apparatuses that support techniques for such power saving techniques. Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are then described with reference to process flows implementing discussed multi-link power saving techniques. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to power save procedures for multi-link aggregation. [0041] FIG. 1 illustrates a WLAN 100 (also known as a Wi-Fi network) configured in accordance with various aspects of the present disclosure. The WLAN 100 may include an AP 105 and multiple associated STAs 115, which may represent devices such as wireless communication terminals, including mobile stations, phones, personal digital assistant (PDAs), other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (e.g., TVs, computer monitors, etc.), printers, etc. The AP 105 and the associated STAs 115 may represent a basic service set (BSS) or an extended service set (ESS). The various STAs 115 in the network are able to communicate with one another through the AP 105. Also shown is a coverage area 110 of the AP 105, which may represent a basic service area (BSA) of the WLAN 100. An extended network station associated with the WLAN 100 may be connected to a wired or wireless distribution system that may allow multiple APs 105 to be connected in an ESS.

[0042] A ST A 115 may be located in the intersection of more than one coverage area 110 and may associate with more than one AP 105. A single AP 105 and an associated set of STAs 115 may be referred to as a BSS. An ESS is a set of connected BSSs. A distribution system may be used to connect APs 105 in an ESS. In some cases, the coverage area 110 of an AP 105 may be divided into sectors. The WLAN 100 may include APs 105 of different types (e.g., metropolitan area, home network, etc.), with varying and overlapping coverage areas 110. Two STAs 115 may also communicate directly via a direct wireless link 125 regardless of whether both STAs 115 are in the same coverage area 110. Examples of direct wireless links 125 may include Wi-Fi Direct connections, Wi-Fi Tunneled Direct Link Setup (TDLS) links, and other group connections. STAs 115 and APs 105 may communicate according to the WLAN radio and baseband protocol for physical and MAC layers from IEEE 802. i l and versions including, but not limited to, 802.11b, 802. l lg, 802.11a, 802.11η, 802.1 lac, 802. Had, 802.11 ah, 802.1 lax, 802. Hay, 802.11ba, etc. In other implementations, peer-to-peer connections or ad hoc networks may be implemented within WLAN 100.

Devices in WLAN 100 may communicate over unlicensed spectrum, which may be a portion of spectrum that includes frequency bands traditionally used by Wi-Fi technology, such as the 5 GHz band, the 2.4 GHz band, the 60 GHz band, the 3.6 GHz band, and/or the 900 MHz band. The unlicensed spectrum may also include other frequency bands.

[0043] In some cases, a STA 115 (or an AP 105) may be detectable by a central AP 105, but not by other STAs 115 in the coverage area 110 of the central AP 105. For example, one STA 115 may be at one end of the coverage area 110 of the central AP 105 while another STA 115 may be at the other end. Thus, both STAs 115 may communicate with the AP 105, but may not receive the transmissions of the other. This may result in colliding transmissions for the two STAs 115 in a contention based environment (e.g., carrier-sense multiple access (CSMA)/collision avoidance (CA)) because the STAs 115 may not refrain from transmitting on top of each other. A STA 115 whose transmissions are not identifiable, but that is within the same coverage area 110 may be known as a hidden node. CSMA/CA may be

supplemented by the exchange of a request-to-send (RTS) packet transmitted by a sending STA 115 (or AP 105) and a clear-to-send (CTS) packet transmitted by the receiving STA 115 (or AP 105). This exchange may alert other devices within range of the sender and receiver not to transmit for the duration of the primary transmission. Thus, RTS/CTS handshake may help mitigate a hidden node problem.

[0044] Multi-link aggregation may yield multiplicative gains (e.g., increase network capacity due to the multi-link or parallel link operation). Such may result in improved channel utilization (e.g., offered load on one channel may be low, while demand may be high on other bands). Further, multi-link aggregation may improve user-perceived throughput (UPT) (e.g., by quickly flushing per-user transmit queues). Multi-link operation may further reduce latency and turnaround times.

[0045] In a system supporting multi-link aggregation (which may also be referred to as multi-channel aggregation), some of the traffic associated with a single STA 115 may be transmitted across multiple parallel communication links 120 (which may also be referred to as "links" or "wireless links" herein). Multi-link aggregation may thus provide a means to increase network capacity and maximize the utilization of available resources. In some cases, each communication link 120 for a given wireless device may be associated with a respective radio of the wireless device (e.g., where a radio comprises transmit/receive chains, physical antennas, signal processing components, etc.). Multi-link aggregation may be implemented in a number of ways. As a first example, the multi-link aggregation may be packet-based. In packet-based aggregation, frames of a single traffic flow (e.g., all traffic associated with a given TID) may be sent in parallel across multiple communication links 120 (e.g., on multiple channels). In some cases, the multiple communication links 120 may operate in the same RF spectrum band (e.g., each link may be in the 5 GHz band, and use channels in the 5 GHz band). In other cases, the multiple communication links 120 may be in different RF spectrum bands (e.g., one may be in the 2.4 GHz band while another is in the 5 GHz band). Each link may be associated with a different PHY layer and lower MAC layer as described with reference to FIG. 4. In such an implementation, management of the aggregation of the separate communication links 120 may be performed at a higher MAC layer. The multilink aggregation implemented at the lower MAC layers and PHY layers may be transparent to the upper layers of the wireless device.

[0046] As another example, the multi-link aggregation may be flow-based. In flow-based aggregation, each traffic flow (e.g., all traffic associated with a given TID) may be sent using one of multiple available communication links 120. As an example, a single STA 115 may access a web browser while streaming a video in parallel. The traffic associated with the web browser access may be communicated over a first channel of a first communication link 120 while the traffic associated with the video stream may be communicated over a second channel of a second communication link 120 in parallel (e.g., at least some of the data may be transmitted on the first channel concurrent with data transmitted on the second channel). In some examples, the transmissions on the first communication link 120 and the second communication link 120 may be synchronized. In other examples, the transmissions may be asynchronous. As described above, the channels may belong to the same RF band or to different RF bands. In the case of three communication links 120 (e.g., or other numbers of communication links greater than two), all three communication links 120 may support operation over the same RF band (e.g., all three in the 5 GHz RF band). In other cases, two communication links 120, but not the third, may support operation over the same RF band (e.g., two links in the 5 GHz RF band, and one link in the 2.4 GHz RF band). Or, in still other cases each of the three communication links 120 may support operation for a separate RF band. In some cases, flow-based aggregation may not use cross-link packet scheduling and reordering (e.g., which may be used to support packet-based aggregation). Alternatively, in the case of a single flow (e.g., in the case that the STA 115 simply attempts to access a web browser), aggregation gain may not be available.

[0047] In other embodiments, a hybrid of flow-based and packet-based aggregation may be employed. As an example, a device may employ flow-based aggregation in situations in which multiple traffic flows are created and may employ packet-based aggregation in other situations. The decision to switch between multi-link aggregation techniques (e.g., modes) may additionally or alternatively be based on other metrics (e.g., a time of day, traffic load within the network, available battery power for a wireless device, etc.). It is to be understood that while aspects of the preceding are described in the context of a multi-link session involving two (or more) communication links 120, the described concepts may be extended to a multi-link session involving multiple direct wireless links 125.

[0048] To support the described multi-link aggregation techniques, APs 105 and ST As 115 may exchange supported aggregation capability information (e.g. supported aggregation type, supported frequency bands, etc.). In some cases, the exchange of information may occur via a beacon signal, a probe association request or a probe association response, dedicated action frames, an operating mode indicator (OMI), etc. In some cases, an AP 105 may designate a given channel in a given band as an anchor link (e.g., the wireless link on which it transmits beacons and other management frames), which may also be referred to as an anchor channel in some instances. In this case, the AP 105 may transmit beacons (e.g., which may contain less information) on other channels or links for discovery purposes. Although described as being frequency -based, the anchor link could additionally or alternatively be time based, and refer to a point in time (e.g., an AP 105 may transmit its beacon during a predetermined time interval on one or more links).

[0049] In some examples, in multi-link aggregation, each link may use its own transmit queue. In other examples, a common transmit queue may be used across the links. In some examples, each link may have a unique TA and RA. In other examples, the TA and RA may be common across the multiple links used for multi-link aggregation. In other examples, one or more of a sequence number (SN), frame number (FN), and/or packet number (PN) may be common across the communication links. Other items that may be common (or different) across two or more of the links include encryption keys, MPDU generation, aggregated MAC service data unit (AMSDU) constraints, fragment size, reordering, replay check, and/or de- fragmentation techniques. In other examples, encryption keys may be per-link.

[0050] In some examples, block acknowledgements (BAs) may be sent in response to multi-link transmissions. A BA may refer to an acknowledgment (ACK) for multiple MPDUs sent together (e.g., an ACK for a block of MPDUs). The transmitting device (e.g., the device requesting the BA) and the receiving device (e.g., the device transmitting the BA) may establish a BA session (also known as a BA agreement) during a setup phase, negotiating an agreement regarding the terms and capabilities for the BA session (e.g., using an ADDBA request and response procedure). The transmitting device and receiving device may exchange capability information such as BA size, buffer size, window size (e.g., a sliding window), and/or policy, and then agree on the common parameters for each of the receiving device and the transmitter device to use. The BA agreement may be later torn down (e.g., using a delete BA (DELBA) request).

[0051] WLAN 100 may employ multi-link aggregation (e.g., flow-based and/or packet- based) to increase network capacity by efficiently allocating utilization of multiple links (and multiple channels). Further, WLAN 100 may utilize power save techniques discussed herein to reduce power consumption by wireless devices engaging in such multi-link

communications.

[0052] FIG. 2 illustrates an example of a WLAN 200 that supports power save procedures for multi-link aggregation in accordance with various aspects of the present disclosure. In some examples, WLAN 200 may implement aspects of WLAN 100. A wireless connection between AP 105-a and STA 115-a may be referred to as a wireless link 205 or a communication link, and each wireless link 205 may include one or more channels. As an example, WLAN 200 may support multi-link aggregation such that AP 105-a and STA 115-a may communicate in parallel over two or more links (e.g., wireless link 205-a and wireless link 205-b). STA 115-a may thus receive packets (e.g., MPDUs) over both wireless link 205- a and wireless link 205-b from AP 105-a. Such parallel communications 210-a and 210-b over the two or more links may be synchronized or asynchronous, and may be uplink, or downlink, or a combination of uplink and downlink during a particular duration of time. In some cases, the parallel communications 210-a and 210-b over the two or more wireless links 205-a and 205-b may occur between two STAs 115 (e.g., which may be referred to as sidelink communication) without deviating from the scope of the present disclosure.

[0053] Such multi-link aggregation may provide multiple benefits to WLAN 200. For example, multi-link aggregation may improve user-perceived throughput (UPT) (e.g., by quickly flushing per-user transmit queues). Similarly, multi-link aggregation may improve throughput for WLAN 200 by improving utilization of available channels (e.g., by increasing trunking gains). That is, multi-link aggregation may increase spectral utilization and may increase the bandwidth-time product. Networks that do not support multi-link aggregation may experience under-utilization of spectrum in non-uniform (e.g., bursty) traffic conditions. For example the communication load over a given wireless link 205 (e.g., wireless link 205- a) may be low at any particular instant, whereas the demand may be high for another wireless link 205 (e.g., wireless link 205-b). By allowing a single traffic flow (e.g., a single internet protocol (IP) flow) to span across different wireless links 205, the overall network capacity may be increased.

[0054] Further, multi-link aggregation may enable smooth transitions between multi-band radios (e.g., where each radio may be associated with a given RF band) and/or enable a framework to setup separation of control channels and data channels. Other benefits of multi- link aggregation include reducing the ON time of a modem, which may reduce a power consumption of a wireless device, though the total power-savings gains (reduction in power consumption) may in some cases depend on other factors including processing requirements, RF bandwidth, etc. Multi-link aggregation additionally increases multiplexing opportunities in the case of a single BSS. That is, multi-link aggregation may increase the number of users per multiplexed transmission served by the multi-link AP 105-a. However, in some cases, monitoring for transmissions (e.g., beacons) on each link may unnecessarily waste power (e.g., in cases where data or communications intended for a receiving device is relatively low or manageable via one link).

[0055] WLAN 200 may employ multi-link power saving techniques described herein. A receiving wireless device may reserve a link as an anchor channel or anchor link. In the present example, STA 115-a may be referred to as a receiving device and AP 105-a may be referred to as a transmitting device. For communications between AP 105-a and STA 115-a, a wireless link 205 (e.g., wireless link 205-a) may be reserved as an anchor wireless link (e.g., an anchor channel). For example, a session for each wireless link 205 may be pre-established, but in the idle state only a MAC entity associated with the anchor wireless link 205-a may be powered to monitor the anchor channel. When STA 115-a is in an idle mode (e.g., when other links such as wireless link 205-b are in an inactive state or sleep state), the STA 115-a may monitor the anchor channel or anchor wireless link 205-a for transmissions (e.g., monitor for indications). Such transmissions may indicate when STA 115-a is to active or power additional links such as wireless link 205-b, such that when activity is low or nonexistent on wireless link 205-b, STA 115-a may conserve power by not powering logical entities associated with monitoring and maintaining wireless link 205-b.

[0056] Further, a transmitting device (e.g., AP 105-a) may use the anchor wireless link 205-a to signal to STA 115-a when other links will be used to serve STA 115-a for subsequent multi-link communications. For example, AP 105-a may transmit an indication to STA 115-a, over anchor wireless link 205-a, that the AP 105-a may use wireless link 205-b for upcoming communications. STA 115-a may receive the indication over the anchor wireless link, and accordingly activate or power on wireless link 205-b. Therefore, STA 115- a may dynamically turn on or power other links (e.g., such as wireless link 205-b) to receive data from AP 105-a, and may go back to an idle mode (e.g., go back to only monitoring the anchor channel via wireless link 205-a) when powering wireless link 205-b is no longer desirable. That is, a single wireless link 205-a (e.g., an anchor wireless link) may be used for control signaling, such that STA 115-a may turn off other links (e.g., wireless link 205-b) when the other bands are not desired or needed in order to save power.

[0057] In some cases, multi-link aggregation may be supported (including initiated) through signaling between STA 115-a and AP 105-a (or a peer STA 115). As an example, STA 115-a may indicate to AP 105-a (or the peer STA 115) whether it supports multi-link aggregation. For example, STA 115-a may indicate that it supports multi-link aggregation in general, for a particular RF spectrum band, for a wireless link 205 of a given RF spectrum band, etc. Such signaling could be static (e.g., in the form of beacons, probes, association or re-association frames, etc.), semi-static, or dynamic (e.g., via OMI or other similar operational parameters). In some cases, AP 105-a (e.g., or the peer STA 115) may decide whether to aggregate communications with STA 115-a based at least in part on the capabilities advertised by STA 115-a. Further, a wireless device may advertise which channel may be set up as an anchor channel. Either AP 105-a or STA 115-a may perform such advertising. In some cases, the anchor wireless link 205-a may be reserved for indications or non-data transmissions such as control frames, management frames, etc. In other cases, the anchor wireless link may additionally be used for data transmissions. In some cases, the anchor wireless link may be included in the wireless links identified (e.g., via the indication sent over wireless link 205-a) for subsequent multi-link communications.

[0058] Indications sent via anchor wireless link 205-a may identify links to be activated, inactivated, or maintained. For example, a transmitting device (e.g., AP 105-a) may indicate wireless link identifiers associated with one or more wireless links to be activated or inactivated. Such indications may be conveyed via a beacon, a receive operating mode indicator (ROMI) signaling, an extended request to send/clear to send (RTS/CTS), etc. For example, a ROMI may include wireless links or bands the STA 115 or AP 105 desires to activate. Such indications may be sent, for example, at the beginning of a target wake time service period (TWT SP). [0059] In some cases, the AP 105-a may determine which wireless links 205 should be active or inactive based on an amount of traffic (e.g., pending data to be transmitted, or data contained in a transmit buffer or queue). For example, AP 105-a may determine a number of additional wireless links to be activated based on how much data is to be sent, and how much benefit may be attained through use of additional wireless links for multi-link

communications. Additionally or alternatively, the AP 105-a may determine which wireless links 205 should be active or inactive based on channel conditions associated with the wireless links 205. For example, AP 105-a may identify channel conditions for particular wireless links 205 via a learning mechanism (e.g., via correlating channel conditions such as channel state information (CSI), signal-to-noise ratio (SNR), etc., associated with the wireless link from previous measurements). In other cases, channel conditions for the particular wireless links 205 may be determined from or configured by some central controller coordinating multiple APs 105. In yet other cases, channel conditions for the particular wireless links 205 may be determined by monitoring the traffic pattern, monitoring which STAs 115 are active, etc.

[0060] An active link may be inactivated via a subsequent (e.g., second) indication or, in other cases, upon expiration of a time duration. In some examples, the time duration a wireless link may remain active may be explicitly signaled by AP 105-a. For example, a message from AP 105-a (e.g., a beacon, OMI, etc.) may indicate that wireless link 205-b may be activated for some duration x. Such a duration may be indicated in terms of seconds, milliseconds, or some other defined interval such as a beacon interval, a target beacon transmission time (TBTT), a TWT SP, a physical layer convergence procedure (PLCP) protocol data unit (PPDU) duration, or a transmission opportunity (TxOP), etc. Such may be referred to as a lifetime of an active link. While a lifetime of a wireless link is valid, the STA 115-a and the AP 105-a may use the link for multi-link communications. When the lifetime expires, either the STA 115-a or the AP 105-a may extend the life time or stop using the wireless link. The lifetime may be defined or set for each individual wireless link, or may be for a group or set of wireless links. In some cases, the AP 105-a may advertise (e.g., via a beacon, etc.) the current value of the lifetime for one or more wireless links.

[0061] Therefore, if a second auxiliary link (e.g., wireless link 205-b) is available between AP 105-a and STA 115-a, AP 105-a may advertise a lifetime of 10 beacon intervals, then at every beacon, the AP 105-a may decrement the lifetime value by 1 until the 10th beacon where the lifetime value is 0. When the lifetime value is 0, the AP 105-a and STA 115-a may no longer use the wireless link 205-b, or the AP 105-a may start to advertise a new lifetime at the 10th beacon to extend the use of the wireless link 205-n. In another example, the AP 105-a may advertise a lifetime value of 10 beacon intervals and at the 5th beacon may decide to extend the link by another 10 beacon intervals. The AP 105-a may thus start advertising a lifetime value of 10 at the 5th beacon and continue to decrement the lifetime value by 1 in each subsequent beacon. In yet another example, the AP 105-a may advertise a lifetime value of 10 beacon intervals in each beacon repeatedly until sometime in the future when it decides to stop using the wireless link 205-b. That is, at any beacon, the AP 105-a may increment the lifetime value by any amount, but any decrement in lifetime value may be one unit at a time (e.g., the lifetime value may be decreased by 1 each beacon). The AP 105-a may maintain the same lifetime value since the STA 115-a know which beacon to monitor for any change.

[0062] As such, the STA 115-a may employ a deterministic method utilizing such lifetime values to determine how long to keep a particular wireless link 205 active. The STA 115-a may even skip one or more beacons without fear of losing any such information relating to the lifetime of the link (e.g., as the value may not be decreased by more than 1 each beacon). Therefore, warm-up times at the STA 115-a and any associated overheads (e.g., within a beacon period, if the AP asks the STA to turn ON or OFF a particular link, it can take some finite time and resources at the STA. Also, the response on the auxiliary link may not be instantaneous due to the finite time to warm-up (e.g., time to turn on or power up circuitry, etc.). Such signaling may be performed using a OMI (e.g., the epochs may be well defined, decrement every TBTT or x seconds from a current time, etc.).

[0063] In some cases, an indication may identify wireless links already active to remain active (e.g., the identification may identify wireless links to maintain as active). For example, AP 105-a and STA 115-a may establish a multi-link session utilizing two wireless links 205-a and 205-b. AP 105-a may indicate (e.g., via anchor wireless link 205-a) that STA 115-a may activate wireless link 205-b. While both wireless link 205-a and wireless link 205-b are active, AP 105-a may transmit another beacon indicating that more traffic is to be transmitted using both wireless links 205-a and 205-b.

[0064] FIG. 3 illustrates an example of a process flow 300 that supports power save procedures for multi-link aggregation in accordance with various aspects of the present disclosure. In some examples, process flow 300 may implement aspects of WLAN 100 and/or WLAN 200. Process flow 300 may include a wireless device 305-a (e.g., a receiving device) and a wireless device 305-b (e.g., a transmitting device), each of which may represent a STA 115 and/or an AP 105 as described with reference to FIGs. 1 and 2.

[0065] At 310, wireless device 305-a and wireless device 305-b may establish a multi- link session (e.g., establish a session for multiple links for parallel communications between the two devices). In some cases, the multi-link session may be established based on exchanged capability information (e.g., a number of links supported for multi-link

communications, wireless link identifiers, etc.).

[0066] At 315, wireless device 305-a may monitor an anchor channel (e.g., an anchor wireless link) for indications that a second wireless device (e.g., wireless device 305-b) has data to be transmitted to wireless device 305-a. In some cases, wireless device 305-a may continuously monitor the anchor wireless link for such indications automatically following multi-link session establishment or, in other cases, may continuously monitor the anchor wireless link upon receiving an explicit indication to do so from wireless device 305-b.

During the monitoring of the anchor wireless link, other wireless links (e.g., of the established multi-link session) may be in an idle mode or an inactive state to reduce power consumption until one or more of the other wireless links is desired for multi-link

communications. When continuously monitoring the anchor wireless link, the wireless device 305-a may periodically sleep and wake, waking according to a predefined schedule to listen for beacons or other control or management frames on the anchor wireless link indicating that data is available for transmission. However, the other wireless links of the multi-link session may nonetheless be inactive, such that no such listening may occur (e.g., for beacons or other management or control frames) on these other links when the wireless device 305-a periodically wakes to listen on the anchor wireless link.

[0067] At 320, wireless device 305-a may receive, over the anchor wireless link, an indication that wireless device 305-b has data to be transmitted to wireless device 305-a. The indication may identify one or more wireless links of wireless device 305-a that are in an inactive state and are to be activated for subsequent multi-link communications. For example, the indication may include wireless link identifiers of inactive wireless links to be used for transmission of pending data.

[0068] In some cases, wireless device 305-b may identify channel conditions for the wireless links of the multi-link session established at 310, and may determine whether or not to activate, inactivate, or maintain as active any of the wireless links based on the channel conditions. The indication may be transmitted via a beacon, a ROMI signal, a channel reservation signal, etc.

[0069] At 325, wireless device 305-a may activate receiver components associated with the one or more links identified by the indication received at 320. In some cases, activating receiver components may include powering additional receiver circuitry (e.g., supporting logical MAC layer entities) to enable reception over the one or more wireless links that were previously in an inactive state.

[0070] At 330, wireless device 305-a may receive data over multiple links. The multiple links may include the links activated at 325. Such data may be received by wireless device 305-a via multiple wireless links (e.g., using at least some of the receiver components activated at 325) and may employ multi-link aggregation techniques (e.g., techniques to process and order the data received over the multiple links). In some cases, the data may also be received over the anchor wireless link (e.g., in other cases the anchor channel may be reserved for non-data transmissions such as control frames, management frames, etc.).

[0071] In some cases (e.g., at 335), wireless device 305-b may transmit a second indication of additional data to be transmitted over some wireless links to wireless device 305-a. In cases where the second indication identifies wireless links that are already active, wireless device 305-a may identify such wireless links are already active, and may receive the additional data from wireless device 305-b over the wireless links. Further, if wireless device 305-a identifies active wireless links that are not identified by the second indication, the wireless device 305-a may return receiver components associated with such wireless links to an inactive state (e.g., to reduce power consumption associated with wireless links that will not be used to receive the additional data).

[0072] In other examples (e.g., at 335), wireless device 305-a may identify a duration (e.g., a time duration that may be predetermined and indicated in the link activation indication received at 320, etc.) for the one or more links activated at 325 to remain active. In such cases, the wireless device 305-a may continue to monitor the anchor wireless link, and if an indication identifying an active wireless link is not received prior to the duration expiring, the wireless device may return receiver components associated with the wireless link to an inactive state. The time duration may be indicated by one or more of a TBTT, a TWT SP, a PPDU duration, a TxOP, etc. [0073] Additionally or alternatively, wireless device 305-b may determine to inactivate a set of active wireless links, and may refrain from including such wireless links in a second indication. In other cases, wireless device 305-b may explicitly indicate in the second indication that the certain set of active wireless links are to be inactivated (e.g., indications sent over the anchor channel may include wireless link identifiers for wireless links to be inactivated).

[0074] FIG. 4 illustrates an example of a process flow 400 that supports power save procedures for multi-link aggregation in accordance with various aspects of the present disclosure. In some examples, process flow 400 may implement aspects of WLAN 100 and/or WLAN 200. Process flow 400 may include a wireless device 405-a (e.g., a receiving device) and a wireless device 405-b (e.g., a transmitting device), each of which may represent a STA 115 and/or an AP 105 as described with reference to FIGs. 1 and 2.

[0075] At 410, wireless device 405-b may transmit a ROMI to wireless device 405-a. The ROMI may indicate one or more wireless links to be activated, deactivated, or maintained as active. At 415, wireless device 405-a may acknowledge the received ROMI. At 420, wireless device 405-a may manage wireless link according to the ROMI received at 410. For example, the wireless device 405-a may supply power to receiver circuitry associated with a wireless link (e.g., if the ROMI identified the wireless link to be activated), reduce power to receiver circuitry associated with a wireless link (e.g., if the ROMI identified the wireless link to be inactivated), etc., based on the received ROMI. In some cases, the actions taken during the management of the wireless links at 420 may be maintained until another indication (e.g., ROMI) is received on the anchor wireless link. For example, a second ROMI may be received by wireless device 405-a at 425, and wireless device 405-a may send an

acknowledgment at 430, and update links accordingly.

[0076] FIG. 5 shows a block diagram 500 of a wireless device 505 that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. Wireless device 505 may be an example of aspects of a STA 115 and/or an AP 105 as described herein. Wireless device 505 may include receiver 510, communications manager 515, and transmitter 520. Wireless device 505 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0077] Receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to power save procedures for multi-link aggregation, etc.). Information may be passed on to other components of the device. The receiver 510 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The receiver 510 may utilize a single antenna or a set of antennas.

[0078] Communications manager 515 may be an example of aspects of the

communications manager 815 described with reference to FIG. 8. Communications manager 515 and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the communications manager 515 and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an field- programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. The communications manager 515 and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some examples,

communications manager 515 and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other examples, communications manager 515 and/or at least some of its various subcomponents may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

[0079] Communications manager 515 may establish a multi-link session between the first wireless device and a second wireless device, the multi-link session including a set of wireless links for communications in parallel between the first wireless device and the second wireless device. Communications manager 515 may receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the set of wireless links, the set of wireless links including one or more wireless links that are in an inactive state. Communications manager 515 may activate, based on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and receive the data from the second wireless device over the set of wireless links using at least a portion of the activated receiver components. The communications manager 515 may also establish a multi-link session between the first wireless device and a second wireless device, the multi-link session including a set of wireless links for communications in parallel between the first wireless device and the second wireless device. The communications manager 515 may transmit, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the set of wireless links, the set of wireless links including one or more wireless links that are in an inactive state. The communications manager 515 may activate transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state, and transmit the data to the second wireless device over the set of wireless links using at least a portion of the activated transmitter components.

[0080] Transmitter 520 may transmit signals generated by other components of the device. In some examples, the transmitter 520 may be collocated with a receiver 510 in a transceiver module. For example, the transmitter 520 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The transmitter 520 may utilize a single antenna or a set of antennas.

[0081] FIG. 6 shows a block diagram 600 of a wireless device 605 that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. Wireless device 605 may be an example of aspects of a wireless device 505, a STA 115, or an AP 105 (e.g., as described with reference to FIGs. 1, 2, and 5). Wireless device 605 may include receiver 610, communications manager 615, and transmitter 620. Wireless device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0082] Receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to power save procedures for multi-link aggregation, etc.). Information may be passed on to other components of the device. The receiver 610 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The receiver 610 may utilize a single antenna or a set of antennas.

[0083] Communications manager 615 may be an example of aspects of the

communications manager 815 described with reference to FIG. 8. Communications manager 615 may also include multi-link session manager 625, anchor channel monitoring manager 630, receiver powering manager 635, multi-link manager 640, link indication manager 645, and transmitter powering manager 650.

[0084] Multi-link session manager 625 may establish a multi-link session between the first wireless device and a second wireless device, the multi-link session including a set of wireless links for communications in parallel between the first wireless device and the second wireless device.

[0085] Anchor channel monitoring manager 630 may receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the set of wireless links (e.g., the set of wireless links including one or more wireless links that are in an inactive state). Anchor channel monitoring manager 630 may receive, over the anchor wireless link, a second indication that the second wireless device has additional data to be transmitted to the first wireless device over the set of wireless links, the set of wireless links in the active state. Anchor channel monitoring manager 630 may receive, over the anchor wireless link, an identifier for a subset of the set of wireless links. Anchor channel monitoring manager 630 may monitor the anchor wireless link for a subsequent indication that the second wireless device has further data to be transmitted to the first wireless device, where the subset of the set of wireless links includes the anchor wireless link. Anchor channel monitoring manager 630 may monitor continuously the anchor wireless link for one or more indications that the second wireless device has data to be transmitted to the first wireless device, and exchange control frames or management frames between the first wireless device and the second wireless device over the anchor wireless link. In some cases, receiving the indication includes receiving, over the anchor wireless link, an identifier for the one or more wireless links, where the receiving components of the first wireless device are activated based on receiving the identifier for the one or more wireless links. In some cases, receiving the indication includes receiving a beacon, or a receive operating mode indicator (ROMI) signal, or a channel reservation signal, or a combination thereof, indicating the set of wireless links. In some cases, the anchor link is one of the set of wireless links. In some cases, the anchor link is a different wireless link than each wireless link of the set of wireless links.

[0086] Receiver powering manager 635 may activate, based on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state. Receiver powering manager 635 may identify, based on receiving the second indication, that the set of links are in the active state, return receiver components of the first wireless device to the inactive state for the at least one remaining wireless link. Receiver powering manager 635 may determine whether to maintain the one or more wireless links in the active state or return the one or more wireless links to the inactive state based on the identified duration.

[0087] Multi-link manager 640 may receive the data from the second wireless device over the set of wireless links using at least a portion of the activated receiver components. Further, Multi-link manager 640 may receive the additional data from the second wireless device over the set of wireless links and identify at least one remaining wireless link of the set of the wireless links not identified by the received identifier. The multi-link manager 640 may transmit the data to the second wireless device over the set of wireless links using at least a portion of the activated transmitter components, and determine whether to maintain the wireless link in the active state or return the wireless link to the inactive state based on the identified channel conditions.

[0088] Link indication manager 645 may transmit, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the set of wireless links, the set of wireless links including one or more wireless links that are in an inactive state. Link indication manager 645 may transmit, over the anchor wireless link, an identifier for the one or more wireless links, or an identifier for the set of wireless links. Link indication manager 645 may transmit, over the anchor wireless link, an identifier for the subset of the set of wireless links.

[0089] Transmitter powering manager 650 may activate transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state.

[0090] Transmitter 620 may transmit signals generated by other components of the device. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 835 described with reference to FIG. 8. The transmitter 620 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a communications manager 715 that power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. The communications manager 715 may be an example of aspects of a communications manager 515, a communications manager 615, or a communications manager 815 described with reference to FIGs. 5, 6, and 8. The communications manager 715 may include multi-link session manager 720, anchor channel monitoring manager 725, receiver powering manager 730, multi-link manager 735, link indication manager 740, transmitter powering manager 745, active link duration manager 750, active link manager 755, and channel conditions manager 760. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0092] Multi-link session manager 720 may establish a multi-link session between the first wireless device and a second wireless device, the multi-link session including a set of wireless links for communications in parallel between the first wireless device and the second wireless device.

[0093] Anchor channel monitoring manager 725 may receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the set of wireless links, the set of wireless links including one or more wireless links that are in an inactive state. Anchor channel monitoring manager 725 may receive, over the anchor wireless link, a second indication that the second wireless device has additional data to be transmitted to the first wireless device over the set of wireless links, the set of wireless links in the active state. Anchor channel monitoring manager 725 may receive, over the anchor wireless link, an identifier for a subset of the set of wireless links. Further, anchor channel monitoring manager 725 may monitor the anchor wireless link for a subsequent indication that the second wireless device has further data to be transmitted to the first wireless device, where the subset of the set of wireless links includes the anchor wireless link. Anchor channel monitoring manager 725 may monitor continuously the anchor wireless link for one or more indications that the second wireless device has data to be transmitted to the first wireless device, and exchange control frames or management frames between the first wireless device and the second wireless device over the anchor wireless link. In some cases, receiving the indication includes receiving, over the anchor wireless link, an identifier for the one or more wireless links, where the receiving components of the first wireless device are activated based on receiving the identifier for the one or more wireless links. In some cases, receiving the indication includes receiving a beacon, or a ROMI signal, or a channel reservation signal, or a combination thereof indicating the set of wireless links. In some cases, the anchor link is one of the set of wireless links. In some cases, the anchor link is a different wireless link than each wireless link of the set of wireless links.

[0094] Receiver powering manager 730 may activate, based on the received indication, receiver components of the first wireless device into an active state for the one or more wireless links that are in the inactive state. Receiver powering manager 730 may identify, based on receiving the second indication, that the set of links are in the active state, return receiver components of the first wireless device to the inactive state for the at least one remaining wireless link. Receiver powering manager 730 may determine whether to maintain the one or more wireless links in the active state or return the one or more wireless links to the inactive state based on the identified duration.

[0095] Multi-link manager 735 may receive the data from the second wireless device over the set of wireless links using at least a portion of the activated receiver components. Multi-link manager 735 may receive the additional data from the second wireless device over the set of wireless links. Multi-link manager 735 may identify at least one remaining wireless link of the set of the wireless links not identified by the received identifier. Multi-link manager 735 may transmit the data to the second wireless device over the set of wireless links using at least a portion of the activated transmitter components, and determine whether to maintain the wireless link in the active state or return the wireless link to the inactive state based on the identified channel conditions.

[0096] Link indication manager 740 may transmit, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the set of wireless links, the set of wireless links including one or more wireless links that are in an inactive state. Link indication manager 740 may transmit, over the anchor wireless link, an identifier for the one or more wireless links, or an identifier for the set of wireless links. Link indication manager 740 may transmit, over the anchor wireless link, an identifier for the subset of the set of wireless links.

[0097] Transmitter powering manager 745 may activate transmitter components of the first wireless device into an active state for the one or more wireless links that are in the inactive state.

[0098] Active link duration manager 750 may identify a duration for the one or more wireless links to remain in the active state. Active link duration manager 750 may transmit an indication of a duration for the one or more wireless links to remain in the active state, and determine whether to maintain the one or more wireless links in the active state or return the one or more wireless links to the inactive state based on the duration. In some cases, the duration includes a TBTT, or a TWT SP, or a PPDU duration, or a transmission opportunity, or a combination thereof. In some cases, transmitting the indication of the duration includes transmitting a beacon, or a ROMI signal, or a channel reservation signal, or a combination thereof, indicating the duration. In some cases, the duration includes a TBTT, or a TWT SP, or a PPDU duration, or a transmission opportunity, or a combination thereof.

[0099] Active link manager 755 may determine to inactivate a subset of the set of wireless links.

[0100] Channel conditions manager 760 may identify channel conditions for a wireless link of the set of wireless links.

[0101] FIG. 8 shows a diagram of a system 800 including a device 805 that supports power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. Device 805 may be an example of or include the components of wireless device 505, wireless device 605, a STA 115 or an AP 105 as described above, e.g., with reference to FIGs. 1, 2, 5, and 6. Device 805 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including communications manager 815, processor 820, memory 825, software 830, transceiver 835, antenna 840, and I/O controller 845. These components may be in electronic communication via one or more buses (e.g., bus 810).

[0102] Processor 820 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 820 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 820. Processor 820 may be configured to execute computer- readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting power save procedures for multi-link aggregation).

[0103] Memory 825 may include random access memory (RAM) and ROM. The memory 825 may store computer-readable, computer-executable software 830 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 825 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0104] Software 830 may include code to implement aspects of the present disclosure, including code to support power save procedures for multi-link aggregation. Software 830 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 830 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0105] Transceiver 835 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 835 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 835 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0106] In some cases, the wireless device may include a single antenna 840. However, in some cases the device may have more than one antenna 840, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0107] I/O controller 845 may manage input and output signals for device 805. I/O controller 845 may also manage peripherals not integrated into device 805. In some cases, I/O controller 845 may represent a physical connection or port to an external peripheral. In some cases, I/O controller 845 may utilize an operating system such as iOS®, ANDROID®, MS- DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, I/O controller 845 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, I/O controller 845 may be implemented as part of a processor. In some cases, a user may interact with device 805 via I/O controller 845 or via hardware components controlled by I/O controller 845.

[0108] FIG. 9 shows a flowchart illustrating a method 900 for power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. The operations of method 900 may be implemented by a first wireless device (e.g., a STA 115, an AP 105, or any of their components as described herein). For example, the operations of method 900 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, the first wireless device (e.g., a STA 115 and/or an AP 105) may execute a set of codes to control the functional elements of the first wireless device to perform the functions described below. Additionally or alternatively, the first wireless device may perform aspects of the functions described below using special-purpose hardware.

[0109] At 905 a first wireless device may establish a multi-link session with a second wireless device, the multi-link session comprising a plurality of wireless links for

communications in parallel between the two devices (e.g., between the first wireless device and the second wireless device). The operations of 905 may be performed according to the methods described herein. In certain examples, aspects of the operations of 905 may be performed by a multi-link session manager as described with reference to FIGs. 5 through 8.

[0110] At 910 the first wireless device may receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state. The operations of 910 may be performed according to the methods described herein. In certain examples, aspects of the operations of 910 may be performed by an anchor channel monitoring manager as described with reference to FIGs. 5 through 8.

[0111] At 915 the first wireless device may activate, based at least in part on the received indication, receiver components into an active state for the one or more wireless links that are in the inactive state. The operations of 915 may be performed according to the methods described herein. In certain examples, aspects of the operations of 915 may be performed by a receiver powering manager as described with reference to FIGs. 5 through 8.

[0112] At 920 the first wireless device may receive the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components. The operations of 920 may be performed according to the methods described herein. In certain examples, aspects of the operations of 920 may be performed by a multi- link manager as described with reference to FIGs. 5 through 8.

[0113] FIG. 10 shows a flowchart illustrating a method 1000 for power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. The operations of method 1000 may be implemented by a first wireless device (e.g., a STA 115, an AP 105, or any of their components as described herein). For example, the operations of method 1000 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, the first wireless device (e.g., a STA 115 and/or an AP 105) may execute a set of codes to control the functional elements of the first wireless device to perform the functions described below. Additionally or alternatively, the first wireless device may perform aspects of the functions described below using special-purpose hardware.

[0114] At 1005 the first wireless device may establish a multi-link session between the first wireless device and a second wireless device, the multi-link session comprising a plurality of wireless links for communications in parallel between the two devices (e.g., between the first wireless device and the second wireless device). The operations of 1005 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1005 may be performed by a multi-link session manager as described with reference to FIGs. 5 through 8.

[0115] At 1010 the first wireless device may receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the first wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state. The operations of 1010 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1010 may be performed by an anchor channel monitoring manager as described with reference to FIGs. 5 through 8.

[0116] At 1015 the first wireless device may activate, based at least in part on the received indication, receiver components into an active state for the one or more wireless links that are in the inactive state. The operations of 1015 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1015 may be performed by a receiver powering manager as described with reference to FIGs. 5 through 8.

[0117] At 1020 the first wireless device may receive the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components. The operations of 1020 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1020 may be performed by a multi- link manager as described with reference to FIGs. 5 through 8.

[0118] At 1025 the first wireless device may identify a duration for the one or more wireless links to remain in the active state. The operations of 1025 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1025 may be performed by an active link duration manager as described with reference to FIGs. 5 through 8.

[0119] At 1030 the first wireless device may determine whether to maintain the one or more wireless links in the active state or return the one or more wireless links to the inactive state based at least in part on the identified duration. The operations of 1030 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1030 may be performed by a receiver powering manager as described with reference to FIGs. 5 through 8.

[0120] FIG. 11 shows a flowchart illustrating a method 1100 for power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. The operations of method 1100 may be implemented by a first wireless device (e.g., a STA 115, an AP 105, or any of their components as described herein). For example, the operations of method 1100 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, the first wireless device (e.g., a STA 115 and/or an AP 105) may execute a set of codes to control the functional elements of the first wireless device to perform the functions described below. Additionally or alternatively, the first wireless device may perform aspects of the functions described below using special-purpose hardware.

[0121] At 1105 the first wireless device may establish a multi-link session with a second wireless device, the multi-link session comprising a plurality of wireless links for

communications in parallel between the two devices (e.g., between the first wireless device and the second wireless device). The operations of 1105 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1105 may be performed by a multi-link session manager as described with reference to FIGs. 5 through 8.

[0122] At 1110 the first wireless device may continuously monitor the anchor wireless link for one or more indications that the second wireless device has data to be transmitted to the first wireless device. The operations of 1110 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1110 may be performed by an anchor channel monitoring manager as described with reference to FIGs. 5 through 8.

[0123] At 1115 the first wireless device may exchange control frames or management frames with the second wireless device over the anchor wireless link. The operations of 1115 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1115 may be performed by an anchor channel monitoring manager as described with reference to FIGs. 5 through 8.

[0124] At 1120 the first wireless device may receive, over an anchor wireless link, an indication that the second wireless device has data to be transmitted to the wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state. The operations of 1120 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1120 may be performed by an anchor channel monitoring manager as described with reference to FIGs. 5 through 8.

[0125] At 1125 the first wireless device may activate, based at least in part on the received indication, receiver components into an active state for the one or more wireless links that are in the inactive state. The operations of 1125 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1125 may be performed by a receiver powering manager as described with reference to FIGs. 5 through 8.

[0126] At 1130 the first wireless device may receive the data from the second wireless device over the plurality of wireless links using at least a portion of the activated receiver components. The operations of 1130 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1130 may be performed by a multi- link manager as described with reference to FIGs. 5 through 8.

[0127] FIG. 12 shows a flowchart illustrating a method 1200 for power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. The operations of method 1200 may be implemented by a wireless device (e.g., a STA 115, an AP 105, or any of their components as described herein). For example, the operations of method 1200 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, a first wireless device (e.g., a STA 115 and/or an AP 105) may execute a set of codes to control the functional elements of the first wireless device to perform the functions described below. Additionally or alternatively, the first wireless device may perform aspects of the functions described below using special-purpose hardware.

[0128] At 1205 the first wireless device may establish a multi-link session with a second wireless device, the multi-link session comprising a plurality of wireless links for

communications in parallel between the two devices (e.g., between the first wireless device and the second wireless device). The operations of 1205 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1205 may be performed by a multi-link session manager as described with reference to FIGs. 5 through 8.

[0129] At 1210 the first wireless device may transmit, over an anchor wireless link, an indication that the wireless device has data to transmit to the second wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state. The operations of 1210 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1210 may be performed by a link indication manager as described with reference to FIGs. 5 through 8.

[0130] At 1215 the first wireless device may activate transmitter components into an active state for the one or more wireless links that are in the inactive state. The operations of 1215 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1215 may be performed by a transmitter powering manager as described with reference to FIGs. 5 through 8.

[0131] At 1220 the first wireless device may transmit the data to the second wireless device over the plurality of wireless links using at least a portion of the activated transmitter components. The operations of 1220 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1220 may be performed by a multi- link manager as described with reference to FIGs. 5 through 8.

[0132] FIG. 13 shows a flowchart illustrating a method 1300 for power save procedures for multi-link aggregation in accordance with aspects of the present disclosure. The operations of method 1300 may be implemented by a first wireless device (e.g., a STA 115, an AP 105, or any of their components as described herein). For example, the operations of method 1300 may be performed by a communications manager as described with reference to FIGs. 5 through 8. In some examples, the first wireless device (e.g., a STA 115 and/or an AP 105) may execute a set of codes to control the functional elements of the first wireless device to perform the functions described below. Additionally or alternatively, the wireless device may perform aspects of the functions described below using special-purpose hardware.

[0133] At 1305 the first wireless device may establish a multi-link session with a second wireless device, the multi-link session comprising a plurality of wireless links for

communications in parallel between the two devices (e.g., between the first wireless device and the second wireless device). The operations of 1305 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1305 may be performed by a multi-link session manager as described with reference to FIGs. 5 through 8.

[0134] At 1310 the first wireless device may transmit, over an anchor wireless link, an indication that the first wireless device has data to transmit to the second wireless device over the plurality of wireless links, the plurality of wireless links including one or more wireless links that are in an inactive state. The operations of 1310 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1310 may be performed by a link indication manager as described with reference to FIGs. 5 through 8.

[0135] At 1315 the first wireless device may activate transmitter components into an active state for the one or more wireless links that are in the inactive state. The operations of 1315 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1315 may be performed by a transmitter powering manager as described with reference to FIGs. 5 through 8.

[0136] At 1320 the first wireless device may transmit the data to the second wireless device over the plurality of wireless links using at least a portion of the activated transmitter components. The operations of 1320 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1320 may be performed by a multi- link manager as described with reference to FIGs. 5 through 8.

[0137] At 1325 the first wireless device may identify channel conditions for a wireless link of the plurality of wireless links. The operations of 1325 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1325 may be performed by a channel conditions manager as described with reference to FIGs. 5 through 8.

[0138] At 1330 the first wireless device may determine whether to maintain the wireless link in the active state or return the wireless link to the inactive state based at least in part on the identified channel conditions. The operations of 1330 may be performed according to the methods described herein. In certain examples, aspects of the operations of 1330 may be performed by a multi-link manager as described with reference to FIGs. 5 through 8.

[0139] It should be noted that the methods described above describe possible

implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects from two or more of the methods may be combined. [0140] Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), and other systems. The terms "system" and "network" are often used interchangeably. A code division multiple access (CDMA) system may implement a radio technology such as

CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may be commonly referred to as CDMA2000 IX, IX, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 lxEV-DO, High Rate Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A time division multiple access (TDMA) system may implement a radio technology such as Global System for Mobile Communications (GSM). An orthogonal frequency division multiple access (OFDMA) system may implement a radio technology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc.

[0141] The wireless communications system or systems described herein may support synchronous or asynchronous operation. For synchronous operation, the stations may have similar frame timing, and transmissions from different stations may be approximately aligned in time. For asynchronous operation, the stations may have different frame timing, and transmissions from different stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

[0142] The downlink transmissions described herein may also be called forward link transmissions while the uplink transmissions may also be called reverse link transmissions. Each communication link described herein— including, for example, WLAN 100 and WLAN 200 of FIGs. 1 and 2— may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies).

[0143] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term "exemplary" used herein means "serving as an example, instance, or illustration," and not "preferred" or

"advantageous over other examples." The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

[0144] In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

[0145] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0146] The various illustrative blocks and modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0147] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, "or" as used in a list of items (for example, a list of items prefaced by a phrase such as "at least one of or "one or more of) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase "based on" shall not be construed as a reference to a closed set of conditions. For example, an exemplary step that is described as "based on condition A" may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" shall be construed in the same manner as the phrase "based at least in part on."

[0148] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media can comprise RAM, ROM, electrically erasable programmable read only memory (EEPROM), compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general- purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0149] The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.