BACKGROUND OF THE INVENTION Recent developments in telecommunication and semiconductor teclmologies facilitate the transfer of growing amounts of information over wireless networks.

The demand for short to medium range, high speed connectivity for multiple digital devices in a local environment continues to rise sharply. For example, many workplaces and households today have many digital computing or entertainment devices such as desktop and laptop computers, television sets and other audio and video devices, DVD players, cameras, camcorders, projectors, handhelds, and others.

Multiple computers and television sets, for instance, have become common in American households. In addition, the need for high speed connectivity with respect to such devices is becoming more and more important. These trends will inevitably increase even in the near future.

As the demand for high speed connectivity increases along with the number of digital devices in typical households and workplaces, the demand for wireless connectivity naturally grows commensurately. High-speed wiring running to many devices can be expensive, awkward, impractical and inconvenient. High speed wireless connectivity, on the other hand, offers many practical and aesthetic advantages, which accounts the great and increasing demand for it. Ideally, wireless connectivity in a local environment should provide high reliability, low cost, low interference caused by physical barriers such as walls or by co-existing wireless signals, security, and high speed data transfer for multiple digital devices. Existing narrowband wireless connectivity techniques do not provide such a solution, having problems such as high cost, unsatisfactory data transfer rates, unsatisfactory freedom

from signal and obstacle related interference, unsatisfactory security, and other shortcomings. In fact, the state of the art does not provide a sufficiently satisfactory solution for providing high speed wireless connectivity for multiple digital devices in a local environment.

The state of the art in wireless connectivity generally includes utilization of spread spectrum systems for various applications. Spread spectrum techniques, which spread a signal over a broad range of frequencies, are known to provide high resistance against signal blocking, or"jamming,"high security or resistance against "eavesdropping, "and high interference resistance. Spread Spectrum techniques have been used in systems in which high security and freedom from tampering is required.

Additionally, Code Division Multiple Access (CDMA), a spread spectrum, packet- based technique, is used in some cellular phone systems, providing increased capacity in part by allowing multiple simultaneous conversation signals to share the same frequencies at the same time.

Known spread spectrum and modulation techniques, including CDMA techniques, direct sequence spread spectrum (DSSS) techniques, time hopping spread spectrum (THSS) techniques, and pulse position modulation (PPM) techniques, do not satisfactorily provide wireless connectivity in a local environment, including high reliability, low cost, low interference, security, and high speed data transfer for multiple digital devices. In addition, known UWB transmission and communication methods and systems lack satisfactory quality in areas that can include flexibility, adaptivity and adaptive trade-off capabilities in areas such as power usage, range, and transfer rates, and low cost implementation.

A number of U. S. and non-U. S. patents and patent applications discuss spread spectrum or UWB related systems for various uses, but are nonetheless in accordance with the above described state of the art. The U. S. and non-U. S. patents and patent applications discussed below are hereby incorporated herein by reference in their entirety.

There are several Japanese patents and applications in some of these areas.

Japanese patent application JP 11284599, filed on March 31,1998 and published on October 15, 1999, discusses spread spectrum CDMA mobile communications.

Japanese patent application JP 11313005, filed on April 27,1998 and published on November 9,1999, discusses a system for rapid carrier synchronization in spread spectrum communication using an intermittently operative signal demodulation circuit. Japanese patent application JP 11027180, filed on July 2,1997 and published on January 29,1999, and counterpart European application EP 0889600 discuss a receiving apparatus for use in a mobile communications system, and particularly for use in spread spectrum Code Division Multiple Access comrnunications between a base station and a mobile station. Japanese patent application JP 21378533, filed on November 18, 1988 and published on May 25,1990, discusses a transmitter for spread spectrum communication.

A number of U. S. patents and published applications discuss spread spectrum or UWB in various contexts. U. S. Patent No. 6,026, 125, issued February 15,2000 to Larrick, Jr. et al. , relates to utilization of a carrier-controlled pulsed UWB signal having a controlled center frequency and an adjustable bandwidth. U. S. Patent No.

6,351, 652, issued February 6, 2002 to Finn et al. , discusses impulse UWB communication. U. S. Patent No. 6,031, 862, issued February 29,2000 to Fullerton et al. , and related patents including U. S. Patent Nos. 5,677, 927,5, 960, 031, 5,963, 581, and 5,995, 534, discuss a UWB communications system in which impulse derived signals are multiplied by a template signal, integrated, and then demodulated, to increase the usability if signals which would otherwise be obscured by noise. U. S.

Patent No. 6,075, 807, issued June 13,2000 to Warren et al. , relates to a spread spectrum digital matched filter. U. S. Patent No. 5,177, 767, issued January 5,1993 to Kato, discusses a"structurally simple"wireless spread spectrum transmitting or receiving apparatus which is described as eliminating the need for code synchronization. U. S. Patent No. 6,002, 707, issued December 14,1999 to Thue, relates to radar system using a wide frequency spectrum signal for radar transmission to eliminate the need for very high energy narrow pulse transmitter and receiver systems. U. S. Patent No. 5,347, 537, issued June 21,1994 to Mori, et al. , and related patents including U. S. Patent Nos. 5,323, 419 and 5,218, 620, discuss a direct sequence spread spectrum transmitter and receiver system. U. S. Patent No. 5,206, 881, issued

April 27,1993, discusses a spread spectrum communication system attempting to use rapid synchronization of pseudo-noise code signals with data packet signals.

A number of published PCT international applications also discuss spread spectrum or UWB in various contexts. PCT international application, publication number WO 01/39451 published on May 31,2001, discusses a waveform adaptive transmitter for use in radar or communications applications. PCT international application, publication number WO 01/93441, published on December 6,2001, discusses a UWB high-speed digital communication system using wavelets or impulses. PCT international application, publication number WO 01/99300, published on December 27, 2001, discusses wireless communications using UWB signaling.

PCT international application, publication number WO 01/11814, published on February 15,2001, discusses a transmission method for broadband wired or wireless transmission of information using spread spectrum technology.

Short-range ultra wide band wireless networks are being developed in order to allow wireless transmission of vast amounts of information between various devices.

U. S. patent application 2003/0063597 of Suzuki, titled"Wireless transmission system, wireless transmission method, wireless reception method, transmitting apparatus and receiving apparatus", which is incorporated herein by reference, described wireless networks that each includes a base station. U. S. patent application 2004/0170217 of Ho titled"Wireless personal area networks with rotation of frequency hopping sequences"describes a multiple piconets (personal network) environment in which each piconets is controlled by a piconets coordinator. Non-related and non- synchronized piconets use rotating frequency hopping sequences in order to avoid interferences.

Some of short-range ultra wide band wireless networks are characterized by a distributed architecture in which devices exchange information without being controlled by a central host or a base station.

Figure 1 is a schematic illustration of two ultra wide band wireless networks (also referred to as personal access networks) 10 and 20, each including multiple devices that wirelessly communicate with each other. First network 10 includes first

till third devices A-C 11-13 and the second network 20 includes forth till sixth devices D-F 24-26.

Figure 18 is a schematic illustration of two ultra wide band wireless networks (also referred to as personal access networks) 10 and 20, each including multiple devices that wirelessly communicate with each other. First network 10'includes first till fifth devices A-E 11-15 and the second network 20 includes sixth till eighth devices F-I 26-29.

Each of the ultra wide band wireless networks uses time division multiple access (TDMA) techniques in order to allow its devices to share a single channel.

Figure 2 illustrates a typical TDMA frame 30. TDMA frame 30 includes multiple time-slots, such as beacon slots 14 and media access slots. The media access slots include distributed reservation protocol (DRP) slots 36 and prioritized contention access (PCA) slots 38. PCA slots are also referred to as PCA periods. DRP slots are also referred to as DRP periods.

The beacon slots are used to synchronize devices to the TDMA frame 30. A typical beacon frame includes information that identifies the transmitting device. It also may include timing information representative of the start time of the TDMA frame 30.

The DRP slots 36 are coordinated between devices that belong to the same network and allow devices to reserve these slots in advance. During the PCA slots 38 devices that belong to the network compete for access based upon their transmission priority. It is noted that the allocation of media access time slots is dynamic and can change from one TDMA frame to another.

Typically, transmissions from devices during PCA slots are assigned by applying a carrier sense multiple access with collision avoidance (CSMA/CA) scheme If a device requests to transmit over a wireless medium it has to check if the wireless medium is idle. If the wireless medium is idle, the device has to wait a random backoff period. This random backoff time is selected from a contention window that has a length that is related to the priority of the device. For higher-priority devices the contention window is shorter.

The transmission process is usually quite complex and includes many operations such as but not limited to forward correction encoding, interleaving, modulating and the like. A receiver must reverse the procedures applied by the transmitter.

Various techniques are applied in order to increase the reliability of wireless telecommunications. A first technique includes sending acknowledgement messages to indicate a reception of a certain information frame when performing point-to-point transmission. These acknowledgement messages can be sent per frame (Immediate ACK scheme) or per a group of frames (Burst ACK scheme). The former decreases the communication channel utilization but reduces communication error penalty.

Burst ACK scheme is capable of keeping high throughput at the price of higher implementation complexity and higher memory requirements for a device. The acknowledgement transmission techniques (Imin-ACK and B-ACK) are not applied when performing multicast or broadcast transmission over ultra wide band wireless networks.

In some networks that include a central station and various clients or a master station and multiple slave stations various acknowledgment schemes were applied.

The following U. S. patent, U. S. patent applications and PCT patent application, all being incorporated herein by reference, provide an example of some prior art methods and systems: U. S. patent application 2001/0051529 of Davies titled"Radio system and apparatus for, and method of, multicast communication" ; U. S. patent 6122483 of Lo et al. titled"Method and apparatus for multicast messaging in a public satellite network" ; U. S. patent application 2003/0145102 of Keller-Tuberg, titled"Facilitating improved reliability of internet group management protocol through the use of acknowledgment massages" ; and PCT patent application W02004/084488 of Lynch et al, titled"Method and apparatus for reliable multicast".

Another technique involves introducing forward error correction encoding, such as convolutional encoding, that puts redundancies in the information that can be used to correct a limited amount of errors. Yet a further technique included only error detection, and not correction.

It is noted that in some applications (such as but not limited to streaming video, sound, and the like) the performance and the user experience deteriorate significantly when the non-acknowledgement schemes are used with nominal channel conditions (-1-8% Packet Error Ratio). Also, using acknowledge schemes in layers above the MAC layer (such as TCP/IP layers) increase significantly the latency and memory requirements and in some cases make the application impractical if not impossible from implementation standpoint.

There is a need to increase the reliability of ultra wide band transmission while keeping the throughput high and implementation requirements overhead low, reducing transmission or reception error penalty.

Transmission between devices that belong to the first network 10 can be subjected to interferences from devices of the second network. This can occur if, for example, a device of the second network is moved towards the devices of the first network, or if the wireless medium characteristics have changed such as to increase the transmission range of devices of the second network.

Figure 3 illustrates a TDMA frame 30 of first network 10 as well as a TDMA frame 40 of second network 20. TDMA frame 40 includes multiple time-slots, such as beacon slots 44, DRP slots 46 and PCA slots 48.

TDMA frame 30 and TDMA frame 40 are not aligned to each other. In addition, the partition between various slots differs from the TDMA frame 10 to TDMA frame 40.

The differences between the two TDMA frames can cause transmission failures. These failures can occur PCA slots and even during DRP slots..

The wireless medium can be utilized for transmission of variable-rate streaming applications. Application rates peaks can cause a reduction in the performance of the ultra wide band network, due to network congestion, buffers overflow, timing requirements violations and loss of packets.

There is a need to reduce the effects of inter-network interference. There is also a need to improve the utilization of the wireless medium.

There is a need to increase the reliability of ultra wide band transmission while keeping the throughput high and implementation requirements overhead low, reducing transmission or reception of error penalty.

Figure 26 illustrates a TDMA frame 3030 of first network 10 as well as a TDMA frame 3040 of second network 20. TDMA frame 3030 includes multiple time- slots, such as beacon slots 3014, DRP slots 3036 and PCA slots 3038. The TDMA frames do not overlap. TDMA frame 3040 includes multiple time-slots, such as beacon slots 3044, DRP slots 3046 and PCA slots 3048. The TDMA frames do not overlap. It is noted that the TDMA frame includes many fixed size slots. Usually, a number of contiguous slots allocated for DRP (or PCA) ARE regarded as a DRP slot (or PCA slot).

The range of ultra wide band wireless networks is limited. This limitation can reduce the utilization of the network. There in a need to expand the range of ultra wide band wireless networks.

A typical network includes multiple communication layers. In a network that includes various devices each device can be capable of receiving certain information streams or frames. For example, Ethernet protocol allows to define multiple virtual local networks, and each device has a unique MAC. Yet for another example, in a Internet Protocol network each device has a unique IP address. Yet for a further example, some devices can receive certain information types (such as but not limited MPEG compliant video streams), while other are not capable of receiving these information types. Thus, each device can be characterized by one or more application parameters.

In order to send the proper information frames to the proper devices there is a need to map application parameters to devices. More specially, in a network that applies a media access control scheme there is a need to direct information frames that include various application parameter to the proper MAC layer queues.

It is noted that the MAC layer queues can be associated with different applications. In some cases a single device that supports multiple applications, can be associated with multiple MAC queues. On the other hand information streams can also be multi-cast or broadcast, thus the amount of MAQ layer queues can differ than the

amount of devices. Furthermore, a certain MAC layer queue is not necessarily associated with a certain device.

Typical networks are characterized by a relative fixed configuration and also include a central controller (also termed master device, host, and the like) that determine the mapping scheme. In various networks, such as ultra wide band networks the network configuration can alter rapidly due to various reasons including a temporary change in the channel, a movement of a person carrying a mobile device and the like.

There is a need to provide a method and device that can allow an efficient alteration of mapping between application parameters and MAC layer queues.

Figure 39 illustrates a parent network 5100 and a child network 5200. Each of these networks is also referred to as a piconet. The parent network 5100 includes a first group of ultra wide band devices 5102-5120. The parent network 5100 includes a management device 5110 that controls the exchange of information between the devices of the parent network, by applying a time division multiplex access scheme.

The child network includes a second group of devices 5120 and 5202-5206. Device 5120 belongs to both the parent and child networks 5100 and 5200 respectively. It controls the exchange of information between the devices of the second network 5200.

Transmission between devices that belong to the parent network 5100 can be subjected to interferences from devices of the child network 5200 and vice versa.

There is a need to provide an efficient manner for solving this interference issue.

SUMMARY OF THE INVENTION A method for ultra wide band wireless medium access control in which information frames that were assigned to DRP queues are re-assigned to PCA queues.

A method and device for ultra wide band wireless medium access control, the method includes: (i) assigning a plurality of information frames to one or more DRP queue and to one or more PCA queues; (ii) determining whether to re-assign at least one information frame previously assigned to at least one DRP queue to a PCA queue ; and (iii) re-assigning at least one information frame in response to the determination.

A device that includes an ultra wide band wireless medium access control circuitry, whereas the circuitry includes at least one PCA queue, at least one DRP queue, and a controller, adapted to: (i) assign a plurality of information frames to at least one DRP queue and to at least one PCA queues; (ii) determine whether to re- assign at least one information frame previously assigned to at least one DRP queue to a PCA queue; and (iii) re-assign at least one information frame in response to the determination.

A device and method for ultra wide band wireless medium access control, the method includes: (i) assigning a plurality of information frames to at least one DRP queue and to at least one PCA queues; and (ii) scheduling a transmission of at least one information frame assigned to at least one DRP queue during at least one PCA transmission period.

A computer readable medium having code embodied therein for causing an electronic device to perform the stages of : assigning a plurality of information frames to at least one DRP queue and to at least one PCA queues; determining whether to re- assign at least one information frame previously assigned to at least one DRP queue to a PCA queue; and re-assigning at least one information frame in response to the determination.

A computer readable medium having code embodied therein for causing an electronic device to perform the stages of : assigning a plurality of information frames to at least one DRP queue and to at least one PCA queues; and scheduling a transmission of at least one information frame assigned to at least one DRP queue during at least one PCA transmission period.

A device for transmission. The device includes: (i) an interface for receiving at least multiple information signals; and (ii) circuitry adapted to process the at least multiple information signals to provide an information frame that includes a PHY layer header, multiple payload fragments, multiple fragmentation control fields and multiple payload fragment check sequence fields. The circuitry is further adapted to transmit the information frame over a network that utilized a distributed media access control scheme. The multiple payload fragments are associated with the multiple

fragmentation control fields and with the multiple payload fragment check sequence fields.

A method for transmission includes: (i) receiving at least multiple information signals; (ii) processing the at least information signals to provide an information frame that includes a PHY layer header, multiple payload fragments, multiple fragmentation control fields and multiple payload fragment check sequence fields; and (iii) transmitting the information frame over a network that utilizes a distributed media access control scheme; whereas the multiple payload fragments are associated with the multiple fragmentation control fields and with the multiple payload fragment check sequence fields.

A method for reception, the method includes: (i) receiving, an information frame that was transmitted over a network that utilizes a distributed media access control scheme, the information frame includes a PHY layer header, multiple payload fragments, multiple fragmentation control fields and multiple payload fragment check sequence fields; whereas the multiple payload fragments are associated with the multiple fragmentation control fields and with the multiple payload fragment check sequence fields; and (ii) processing the information frame to provide a payload that includes multiple information signals.

A method for multicasting information over a network that utilizes a distributed media access control scheme, the method includes: (i) utilizing a distributed media access control scheme for allocating at least one timeslot for a transmission of information from a first device to a group of peer devices and for a transmission of acknowledgement massages from the peer devices of the group; and (ii) transmitting the information in response to the allocation.

A device that includes (i) a medium access controller adapted to participate in a distributed media access control scheme that allocates at least one timeslot for a transmission of information from the device to a group of peer devices and for a transmission of acknowledgement massages from the peer devices of the group; and (ii) transmission circuitry adapted to transmit the information in response to the allocation.

A computer readable medium having code embodied therein for causing an electronic device to perform the stages of : utilizing a distributed media access control scheme for allocating at least one timeslot for a transmission of information from a first device to a group of peer devices and for a transmission of acknowledgement massages from the peer devices of the group; and transmitting the information in response to the allocation.

A method for expanding a range of an ultra wide band wireless network, the method includes: (i) providing a first network and an external device, the first network includes multiple devices that receive ultra wide band wireless transmissions from each other, the external device is capable of receiving a transmission from a first device of the first network but not capable of receiving a transmission from a second device of the first network; and (ii) allowing the first device to relay transmissions between the external device and the second device.

An ultra wide band device that includes: (i) a receiver, adapted to receive transmissions from members of a first network and from an external device not capable of receiving transmissions from a second device of the first network, and (ii) a transmitter, adapted to transmit information to members of the first network and to the external device; wherein the device is adapted to relay transmission from the second device of the first network to the external device.

A method for expanding a range of first network, the method includes: providing a first network and an external device, the first network includes multiple devices that participate in a first distributed media access control scheme, whereas the external device participates in a second distributed media access control scheme and is capable of receiving a transmission from a first device of the first network but not capable of receiving a transmission from a second device of the first network; and relaying, by the first device, transmissions between the external device and the second device.

A method for mapping information streams to MAC layer queues, the method includes: utilizing a distributed media access control scheme to determine a configuration of the network; and adjusting an adjustable filter such as to map

application parameters to the MAC layer queues, in response to the configuration of the network.

A device, including: MAC layer entity including multiple MAC layer queues, the MAC layer entity is adapted to participate in a distributed media access control scheme to determine a configuration of the network; and an adjustable filter adapted to map application parameters to the MAC layer queues, in response to the configuration of the network.

A computer readable medium having code embodied therein for causing an electronic device to perform the stages of : utilizing a distributed media access control scheme to determine a configuration of the network; and adjusting an adjustable filter such as to map application parameters to the MAC layer queues, in response to the configuration of the network.

A computer readable medium having code embodied therein for causing an electronic device to perform the stages of : (a) allowing a first group of ultra wide band devices to exchange information using a first frequency hopping sequence; and (b) allowing at least one certain device that is responsive to at least one transmission of information from a device of the first group to exchange information using the first frequency hopping sequence during at least one time period and allowing devices that belong to the second group to exchange information using a second frequency hopping sequence during at least one other time period.

An ultra wide band device that includes: a receiver adapted to receive information from at least one device of a first group of ultra wide band devices, using a first frequency hopping sequence; and a transmitter, adapted to transmit information to at least one device of the first group of ultra wide band devices, using the first frequency hopping sequence during at least one time period and further adapted to transmit information to at least one device of a second group of ultra wide band devices, using a second frequency hopping sequence, during at least one other time period.

A method for ultra wide band transmission, the method includes: (a) allowing a first group of ultra wide band devices to exchange information using a first frequency hopping sequence; and (b) allowing at least one certain device that is

responsive to at least one transmission of information from a device of the first group to exchange information using the first frequency hopping sequence during at least one time period and allowing devices that belong to the second group to exchange information using a second frequency hopping sequence during at least one other time period.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: Figure 1 is a schematic illustration of two networks (also referred to as personal access networks), each including multiple devices that wirelessly communicate with each other; Figure 2 illustrates a typical TDMA frame; Figure 3 illustrates a TDMA frame of first network as well as a TDMA frame of a second network; Figures 4-5 illustrate a device capable of wireless transmission, and some of its components, according to an embodiment of the invention;.

Figures 6-9 illustrate media access control queues management circuitries, according to various embodiments of the invention; Figures 10-11 are flow charts of methods of ultra wide band wireless medium access control, according to various embodiments of the invention; Figure 12 illustrates a proposed MBOA information frame ; Figure 13 illustrates an information frame, according to an embodiment of the invention; Figure 14 illustrates the throughput achieved when using different information frames; Figures 15 and 16 are flow charts that illustrate methods for transmission, according to various embodiments of the invention; and Figure 17 is an information frame, according to an embodiment of the invention.

Figure 18 is a schematic illustration of two networks (also referred to as personal access networks), each including multiple devices that wirelessly communicate with each other; Figures 19-22 illustrate an information frame as well as various portions of information frame, according to various embodiments of the invention; Figures 23-24 are illustrate timing diagrams of a multicast transmission of an information frame and a transmission of acknowledgment messages, according to various embodiments of the invention; Figure 25 is a flow chart of a method for multicasting information over an ultra wide band wireless medium, according to an embodiment of the invention.

Figure 26 illustrates a TDMA frame of a first network as well as a TDMA frame of a second network; Figure 27 illustrates a beacon frame, according to an embodiment of the invention.

Figures 28-29 illustrate various information frames, according to various embodiments of the invention; Figures 30-31 are flow charts of methods for expanding a range of a network, according to various embodiments of the invention; Figure 32 illustrates various communication layers and also service access points (SAPs) that illustrates the interaction between layers of a device of a first network; Figure 33 illustrates an environment that includes some of the components that allow to communicate over the ultra wide band wireless medium on one side and also with other wired or wireless components on the other side; Figures 34 and 37 illustrate an adjustable filter according to various embodiments of the invention; Figure 35 illustrates a two-dimensional virtual table according to an embodiment of the invention; Figure 36 illustrates a format of an instruction, according to an embodiment of the invention;

Figure 38 is a flow chart of a method according to an embodiment of the invention; Figure 40 illustrates a parent network TDMA frame and a neighbor TDMA frame ; Figure 41 illustrates a parent network TDMA frame and a child TDMA frame ; Figure 42 illustrates the multiple band groups allocated for ultra wide band transmission; Figure 43 illustrates a first frequency hopping sequence; Figure 44 illustrates a parent network TDMA frame and an affected network TDMA frame according to an embodiment of the invention; Figure 45 illustrates a first frequency hopping sequence and a second frequency hopping sequence, according to an embodiment of the invention; Figure 46 illustrates a first frequency hopping sequence and a second frequency hopping sequence, according to another embodiment of the invention; Figure 47 is a flow chart of a method for ultra wide band transmission, according to an embodiment of the invention; and Figure 48 illustrates a ultra wide band (UWB) device according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS Some portions of the following description relates to wireless ultra wide band networks that utilize a distributed media access control scheme. In these networks there is no central media access controller, but rather various devices of the network participate in determining how to share a common wireless medium. It is noted that according to various embodiments of the invention the disclosed methods and devices can be applied in networks that utilize a distributed media access control scheme but differ from ultra wide band wireless networks. It is further noted that according to some embodiments of the invention networks other than ultra wide band network can apply some of the suggested methods.

Various operations such as transmissions utilize the distributed media access control scheme in the sense that the access to a shared medium is governed by a distributed media access control scheme.

Some embodiments of the invention provide an ultra wide band wireless medium access control method and a device capable of performing ultra wide band wireless medium access control schemes.

Conveniently, the device is a part of a ultra wideband wireless network and has a communication protocol stack that includes at least a PHY layer and a MAC layer.

The MAC layer of such devices controls the access to ultra wide band wireless medium and is referred to ultra wide band wireless medium access control.

Examples of devices that have a PHY layer are illustrated in the following U. S. patent applications, all being incorporated herein by reference: U. S. patent application serial number 10/389789 filed on March 10 2003 and U. S. patent application serial number 10/603,372 filed on June 25 2003.

The receiver can include various components that are arranged in multiple layers. A first configuration includes a frame convergence sub-layer, a MAC layer, a PHY layer as well as MAC SAP, PHY SAP, frame convergence sub-layer SAP and a device management entity can also be utilized. Another configuration is described at Figures 4 and 5.

Wisair Inc. of Tel Aviv Israel manufactures a chip set that includes a Radio Frequency PHY layer chip and a Base-Band PHY layer chip. These chips can be connected in one end to a RF antenna and on the other hand be connected or may include a MAC layer circuitry.

Figure 4 illustrates a device 60 that is capable of wireless transmission, according to an embodiment of the invention.

Device 60 includes antenna 61 that is connected to a RF chip 62. RF chip 62 is connected to a MAC/PHY layers chip 63 that includes a PHY layer block 63 and a MAC layer block 64. The MAC/PHY layers chip 63 is connected to an application entity 66 that provides it with information to be eventually transmitted (TX) and also provides the application 66 with information received (RX) by antenna 61 and processed by PHY and MAC layers blocks 68 and 69 of Figure 5.

Typically, the MAC layer block 64 controls the PHY layer block using a PHY status and control interface. The MAC and PHY layers exchange information (denoted TX and RX) using PHY-MAC interface 90. The RF chip 62 provides to the PHY layer block 63 received information that is conveniently down-converted to base band frequency. The RF chip 62 receives from the PHY layer block 63 information to be transmitted as well as RF control signals. The application 66 is connected to the MAC/PHY layers chip 63 by a high speed I/O interface.

Figure 5 illustrates various hardware and software components of the MAC/PHY layers chip 63, according to an embodiment of the invention.

The Upper Layer IF block 64 of the MAC/PHY layers chip 63 includes hardware components (collectively denoted 69) and software components (collectively denoted 68). These components include interfaces to the PHY layer (MAC-PHY interface 90) and to the application (or higher layer components).

The hardware components 69 include configuration and status registers 81, Direct Memory Access controller 82, First In First Out (FIFO) stacks 83 and frame validation and filtering components 84, DRP and PCA slots schedulers 85, ACK processors 86, and MAC-PHY internal interface 87.

The software components 68 include a management module 72, transmit module 73, receive module 74m hardware adaptation layer 75, DMA drivers 76, MAC layer management entity (MLME) service access point (SAP) 71, MACS API 70 and the like.

These software and hardware components are capable of performing various operations and provide various services such as: providing an interface to various layers, filtering and routing of specific application packets sent to MAC data queues or provided by these queues, performing information and/or frame processing, and the like.

The routing can be responsive to various parameters such as the destinations of the packets, the Quality of Service characteristics associated with the packets, and the like.

The processing of information along a transmission path may include: forming the MAC packet itself, including MAC header formation, aggregation of packets into

a bigger PHY PDU for better efficiency, fragmentation of packets for better error rate performance, PHY rate adaptation, implementation of Acknowledgements policies, and the like.

The processing of information along a reception path may include de- aggregation and/or de-fragmentation of incoming packets, implementation of acknowledgment and the like.

The hardware components are capable of transferring data between MAC software queues and MAC hardware (both TX and RX), scheduling of beacons slots, scheduling of DRP and PCA access slots, validation and filtering (according to destination address) of incoming frames, encryption/decryption operations, low-level acknowledgement processing (both in the TX path and in the RX path), Device 60 can be a simple device or even a complex device such as but not limited to a multimedia server that is adapted to transmit information frames of different types to multiple devices. It can, for example transmit Streaming data, like voice, Video, Game applications, etc. ) data files during DRP slots, and while PCA slots transmits video over IP frames, download MP3 files, download MPEG-2 files, and stream or download MPEG-4 streams.

Usually, voice frames are associated with higher quality of service requirements and accordingly are given higher transmission priorities. The voice frames QoS requirements are followed by video frames that in turn are followed by lower quality of service requirements (lower priority transmission) frames such as best effort frames and background frames.

Figure 6 illustrates a media access control circuitry 100, according to an embodiment of the invention.

The media access control circuitry 100 includes a controller (Also referred to as mapper) 102, four PCA queues PCAQA-PCAQD 110-116, four access units ACCESS UNIT A-ACCESS UNIT D 120-126 and a DRP queue DRPQA 130.

It is assumed that each of the four PCA queues has a different transmission priority, whereas PCA Q A 110 has the highest priority and PCAQD 116 has the lowest transmission priority. These priorities are referred to as PCA transmission priorities.

The controller 102 assigns information frames provided by various applications to the PCA and DRP queues 110-116 and 130, according to the type of application, and the like. Typically, DRP slots are used to convey isochronous traffic while PCA slots are used to convey asynchronous traffic.

The four PCA queues 110-116 are connected to four access units 120-126 that apply a CSMA/CA scheme to schedule the transmission of information frames from these queues. The information frames are sent to the PHY layer that in turn generates and transmits electromagnetic signals representative of these information frames.

The CSMA/CA scheme with differential access parameters is responsive for the PCA transmission priorities of the different PCA queues.

According to an embodiment of the invention, the DRP queue DRP_Q A 130 sends one or more information frames, such as IF 90, to one or more of the PCA queues, such as PCAQD 116. The receiving PCA queue can be selected in response to its PCA transmission priority, but this is not necessarily so. Conveniently, the selected PCA queue and the DRP queue have the same transmission priority.

By re-assigning a previously DRP assigned information packet to a PCA queue, the circuitry allows that information frame to be sent during a PCA periods.

According to an embodiment of the invention the information frame that was originally assigned to a DRP queue and then re-assigned to a PCA queue can be re- assigned to the DRP queue if certain conditions occur. For example-if it was not successfully transmitted prior to the next coming DRP period serving the specific DRP queue.

According to an embodiment of the invention the controller 102 or another component, such as a controller (not shown) can determine whether to re-assign a DRP packet to a PCA queue in response to various indications that can reflect a DRP transmission problem. These indications can include a predefined amount (or percentage) of failed transmissions (can be learnt when applying an Acknowledge- based transmission scheme), DRP queues fullness (for example-overflow), validity of queued information frames (for example-time stamps of time sensitive information frames are going to expire).

According to another embodiment of the invention the re-assignment is responsive to momentary peaks of a variable rate streaming application. In such a case the average rate traffic of such application can be sent during DRP slots while peak traffic is also conveyed during PCA slots. Conveniently, the re-assignment can be done before it causes a streaming data traffic hit.

The re-assignment of DRP packets can be applied during a limited amount of PCA periods, a limited amount of TDMA frames and the like. Conveniently, if DRP transmissions are interrupted during more than a predefined amount of TDMA frames or during more than a predefined amount of DRP slots, the device can initiate a listening sequence for determining the cause for transmission failures. Said sequence may cause the devices of a certain network to re-arrange and time-shift their TDMA frame.

Figure 6 illustrates a media access control circuitry 100', according to another embodiment of the invention.

Figure 6 illustrates a circuitry in which two DRP queues are defined, at least during one PCA period as PCA queues. In other words, DRP queues are assigned a certain priority and compete against/share with one or more PCA queues the right to send an information frame to the PHY layer.

Media access control circuitry 100'includes controller 102, four PCA queues PCAQA-PCAQD 110-116, four access units ACCESS UNIT A-ACCESS UNIT-D 120-126, DRP queues DRP QA 130 and DRPQB 132 and an arbitrator 140.

The two DRP queues 130 and 132 as well as the fourth PCA queue PCAQ D 116 are connected to the arbitrator 140. Arbitrator 140 arbitrates between these queues according to various well-known arbitration algorithms. The inventors used a round robin algorithm and alternatively used a weighted round robin algorithm, but other arbitration algorithms can be applied. Conveniently, the weight assigned to each queue reflects its transmission priority and/or the expected traffic throughput and/or buffer sizes of the respective queues.

The selected queue is connected to the fourth access unit 126 that competes with the other access units 120-124 to schedule the transmission of information frames by applying a well-known algorithm such as a CSMA/CA scheme.

Figure 8 illustrates a media access control circuitry 100", according to a further embodiment of the invention.

Circuitry 100"refers to each of the DRP queues as a PCA queue that has a certain PCA transmission priority. Each of the PCA and DRP queues participate in a CSMA/CA scheme that is responsive to the transmission priority associated with each PCA or DRP queue. The DRP queues can be assigned a PCA transmission priority that can reflect their DRP priority.

Circuitry 100"includes controller 102 that is connected to the PCA queues 110 - 116 and to DRP queues 130 and 132. Each of said queues is connected to an access unit out of access units 120-129. DRP queue 130 is connected to ACCESS_UNIT_E 128 and DRP queue 132 is connected to ACCESS_UNIT_F 129.

Figure 8 illustrates a media access control circuitry 101, according to another embodiment of the invention.

The media access circuitry 101 differs from the media access circuitry 100'of Figure 7 by having more queue and also includes multiple arbitrators for arbitrating between multiple queues that have the same transmission priority. Each arbitrator out of arbitrators 140-146 is connected to a corresponding access unit out of units 120- 126.

Arbitrator 146 is connected to three PCA queues 115-119 that have the same PCA transmission priority. Arbitrator 144 is connected to two PCA queues 112 and 113 and a DRP queue 136 that have the same PCA transmission priority. Arbitrator 142 is connected to two PCA queues 111 and 114 and DRP queue 134 that have the same PCA transmission priority. Arbitrator 140 is connected to PCA queue 116 and two DRR queues 130 and 132 that have the same PCA transmission priority. Each of the arbitrators can apply a well-known arbitration scheme. The four access units 120- 126 apply another well-known scheduling scheme such as CSMA/CA.

Figure 10 is a flow chart of method 200 of ultra wide band wireless medium access control, according to an embodiment of the invention.

Method 200 starts by stage 210 of assigning a plurality of information frames to at least one DRP queue and to at least one PCA queues. Referring to the example set forth in Figure 6, Controller 102 assigns multiple information frames to PCA queues 110-116 and to DRP queue 130 according to predefined rules.

Stage 210 is followed by stage 220 of determining whether to re-assign at least one information frame previously assigned to at least one DRP queue to a PCA queue.

Conveniently, the determining is responsive to transmission failures, to the status of one or more queue or even to a status of information frames within one or more queue, to a variable rate application and especially to transmission peaks of such an application, and the like.. Referring to the example set froth in Figure 5, controller 102 or another entity can determine to re-assign one or more information frames stored within a DRP queue 130 to one or more PCA queue.

Stage 220 is followed by stage 230 of re-assigning at least one information frame in response to the determination. According to an embodiment of the invention, the re-assigning comprises defining at least one DRP queue as a PCA queue..

Referring to the example set froth in Figure 5, the information packet IF 90 is sent to PCA queue 116.

Stage 230 is followed by stage 240 of scheduling a transmission of at least one information frame from the at least one PCA queue. Conveniently, each of the at least one PCA queue is associated with a PCA transmission priority, and the scheduling is responsive to the PCA transmission priority. Referring to the example set forth in Figure 6, the access units 120-126 apply a well-known scheduling scheme, such as CSMA/CA, to determine when information frames positioned at the bottom of each PCA queue is provided to the PHY layer.

According to an embodiment of the invention at least two PCA queue are associated with the same PCA transmission priority and whereas the scheduling comprises selecting between said at least two PCA queue. Conveniently, the selecting involves applying a round robin algorithm or a weighted round robin algorithm. For example, an arbitrator such as arbitrator 146 of Figure 8 can arbitrate between PCA queues of the same PCA transmission priority. It is noted that Figure 8 does not illustrate a provision of an information frame from a DRP queue to a PCA queue but it

can be modified to allow said provision. It is further noted that method 200 can be applied by a circuitry that includes multiple PCA queues, some having the same PCA transmission priority and which allows the transfer of one or more information queue from a DPR queue to one or more PCA queue.

Stage 240 may be followed by stage 250 of sending the selected one or more information frame to the PHY layer, during one or more PCA slots. This stage can include applying an acknowledge-based transmissions scheme in which the reception of one or more frames is followed by a transmission of an acknowledgement signal.

Stage 250 can be followed by various stages of transmitting information frames during DRP slots. During the DRP slots the DRP queues provide the PHY layer with information frames that are then wirelessly transmitted to other peer members of a wireless ultra wideband network. For simplicity of explanation these stages are not shown. Stage 250 can be followed by any of stages 210 (if new information frames are received), 230,240 or even stage 260.

Stage 260 includes determining whether to re-assign at least one previously re- assigned information frame to at least one DRP queue. Conveniently, the determination is responsive to time elapsed from stage 230 of re-assigning. According to another embodiment of the invention the determination is responsive to transmission scheduling of at least one re-assigned information frame.

Figure 11 illustrates method 300 for ultra wide band wireless medium access control, according to an embodiment of the invention.

Method 300 starts by stage 310 of assigning a plurality of information frames to at least one DRP queue and to at least one PCA queues. Referring to the example set forth in any of Figures 7-9, controller 102 or another entity assigns information packets to queues according to predefined rules.

Stage 310 is followed by stage 320 of scheduling a transmission of at least one information frame assigned to at least one DRP queue during at least one PCA transmission period. Referring to the examples set forth in any of Figures 6-8 the scheduling includes allowing at least one DRP queue to participate in an scheduling scheme and optionally also participate in an arbitration scheme that also involve PCA

queues. In other words, the DRP queues are at least temporarily treated as PCA queues.

According to various embodiments of the invention stage 320 includes one or more of stages 322,324 and 326.

Stage 322 includes assigning at least one PCA transmission priority to at least one DRP queue. Conveniently, the one or more assigned PCA transmission priority is responsive to one or more DRP transmission priorities of the one or more DRP queues.

Stage 324 includes selecting between said two or more PCA queues that have the same PCA transmission priority. Conveniently, the selection involves applying a round robin algorithm or a weighted round robin algorithm.

Stage 326 includes defining at least one DRP queue as a PCA queue.

Stage 320 is conveniently followed by stage 330 of determining whether to re- assign at least one information frame previously assigned to at least one DRP queue to a PCA queue.

Stage 330 is followed by stage 340 of re-assigning at least one information frame in response to the determination.

Stage 340 can be followed by stages such as stage 250 as well y various stages of transmitting information frames during DRP slots, transmitting beacon frames and also idle frames.

MBOA is a standard that is being developed by various vendors in the field of ultra wide band wireless communication. A MBOA transmitter has a PHY layer that is capable of performing multiple operations, such as but not limited to convolutional encoding, bit padding, time frequency code (TFC) interleaving, Quadrature Phase Shift Key (QPSK) modulation and Orthogonal Frequency Division Multiplexing (OFDM).

A typical transmitter includes a convolutional encoder, an interleaver and a OFDM modulator. An information sequence enters a convolutional encoder that adds redundant bits, the sequence is then interleaved in order to cope with burst errors, and then OFDM modulated. Said modulation includes mapping multiple signals to

multiple narrowband subcarriers and performing inverse Fourier transform to provide a sequence of OFDM symbols.

Figure 12 illustrates a proposed MBOAn information frame 1100. The information frame 1100 includes a physical layer convergence procedure (PLCP) preamble 1112, a PHY layer header 1114, a MAC layer header 1116, a header check sequence field (HCS) 1118, header tail bits 1120, header pad bits 1121, payload 1122, a frame check sequence field (FCS) 1124, frame tail bits 1126 and pad bits 1128.

The information frame 1100 includes MAC layer fields such as fields 1116, 1118,1122 and 1124. Information frame 1100 also includes various PHY layer fields, such as fields 1112,1114, 1120,1121, 1126 and 1128. The payload 1122 usually includes one or more MAC layer frames (also known as MSDU or MCDU) or frames of a upper communication protocol layer, such as an application layer. Typically information frame 1100 includes a single upper layer frame.

The PLCP preamble 1112 includes a packet and frame synchronization sequences that are followed by a channel estimation sequence. The PLCP preamble assists the receiver, among other things, to estimate the properties of the wireless medium. MBOA proposes two possible PLCP preambles-a short PLCP preamble and a long PLCP preamble. The long PLCP preamble is used at low bit rates. At high bit rates a first frame includes the long PLCP preamble while the remaining frames include the short PLCP preamble.

The PHY layer header 1114 includes information about the type of modulation, the coding rate and the spreading factor used during the transmission of the information, the length of the frame payload and scrambling information.

MAC layer header 1116 includes a frame control field, source and destination identification fields, sequence control fields 1117 and duration/access method fields.

The header tail bits 1120 as well as the frame tail bits 1126 are set to zero, thus allowing a convolutional encoder within the receiver to return to a"zero state"and improve its error probability. The header tail bits 1120 (the frame tail bits 1126) are followed by header pad bits 1121 (frame pad bits 1128) in order to align the information stream on an OFDM interleaver boundaries.

The payload is usually between one byte and 4096 bytes long. When a transmission or reception error occurs the whole frame is re-transmitted.

The mentioned below information frame is transmitted by a device that is a part of a wideband wireless network and has a communication protocol stack that includes at least a PHY layer and a MAC layer. The MAC layer of such devices controls the access to ultra wide band wireless medium and is referred to ultra wide band wireless medium access control.

MBOA is a standard that is being developed by various vendors in the field of ultra wide band wireless communication. A MBOA transmitter has a PHY layer that is capable of performing multiple operations, such as but not limited to convolutional encoding, bit padding, time frequency code (TFC) interleaving, Quadrature Phase Shift Key (QPSK) modulation and Orthogonal Frequency Division Multiplexing (OFDM).

A typical transmitter includes a convolutional encoder, an interleaver and a OFDM modulator. An information sequence enters a convolutional encoder that adds redundant bits, the sequence is then interleaved in order to cope with burst errors, and then OFDM modulated. Said modulation includes mapping multiple signals to multiple narrowband subcarriers and performing inverse Fourier transform to provide a sequence of OFDM symbols.

Figure 12 illustrates a proposed MBOAn information frame 1100. The information frame 1100 includes a physical layer convergence procedure (PLCP) preamble 1112, a PHY layer header 1114, a MAC layer header 1116, a header check sequence field (HCS) 1118, header tail bits 1120, header pad bits 1121, payload 1122, a frame check sequence field (FCS) 1124, frame tail bits 1126 and pad bits 1128.

The information frame 1100 includes MAC layer fields such as fields 1116, 1118, 1122 and 1124. Information frame 1100 also includes various PHY layer fields, such as fields 1112,1114, 1120,1121, 1126 and 1128. The payload 1122 usually includes one or more MAC layer frames (also known as MSDU or MCDU) or frames of a upper communication protocol layer, such as an application layer. Typically information frame 1100 includes a single upper layer frame.

The PLCP preamble 1112 includes a packet and frame synchronization sequences that are followed by a channel estimation sequence. The PLCP preamble assists the receiver, among other things, to estimate the properties of the wireless medium. MBOA proposes two possible PLCP preambles-a short PLCP preamble and a long PLCP preamble. The long PLCP preamble is used at low bit rates. At high bit rates a first frame includes the long PLCP preamble while the remaining frames include the short PLCP preamble.

The PHY layer header 1114 includes information about the type of modulation, the coding rate and the spreading factor used during the transmission of the information, the length of the frame payload and scrambling datan information.

MAC layer header 1116 includes a frame control field, source and destination identification fields, sequence control fields 1117 and duration/access method fields.

The header tail bits 1120 as well as the frame tail bits 1126 are set to zero, thus allowing a convolutional encoder within the receiver to return to a"zero state"and improve its error probability. The header tail bits 1120 (the frame tail bits 1126) are followed by header pad bits 1121 (frame pad bits 1128) in order to align the information stream on an OFDM interleaver boundaries.

The payload is usually between one byte and 4096 bytes long. When a transmission or reception error occurs the whole frame is re-transmitted.

The mentioned below information frame is transmitted by a device that is a part of a wideband wireless network and has a communication protocol stack that includes at least a PHY layer and a MAC layer. The MAC layer of such devices controls the access to ultra wide band wireless medium and is referred to ultra wide band wireless medium access control.

Figure 13 illustrates information frame 1200, according to an embodiment of the invention.

The information frame 1200 includes a PHY layer preamble, such as PLCP preamble 1112, a PHY layer header 1114, a MAC layer header 1116', HCS 1118, header tail bits 1120, header pad bits 1121. These are followed by a sequence 1210 of fragmentation control fields 1212 (1)-1212 (K), payload fragments 1214 (1)-1214 (K) and payload fragment check sequence field 1216 (1)-1216 (K). Whereas K is a

positive integer representing the amount of payload fragments per information frame 1200 and whereas each payload fragment is preceded by a corresponding fragmentation control field and is followed by a payload fragment check sequence field. Sequence 1210 is followed by a frame check sequence field (FCS) 1124, frame tail bits 1126 and pad bits 1128.

Most of the fragments, except the last fragment have the same size, thus information about their size is not transmitted. This is not necessarily so.

It is noted that the size of the fragment can be pre-negotiated or otherwise defined and transmitted to the receiver. Alternatively, part MAC header, like the Sequence Control field of the MAC header can be used to notify the size of the fragment in a particular aggregated frame.

It is noted that the information frame can include a long PLCP preamble, or a short PCLP preamble, according, for example to the bit rate and the order of an information frame within a series of information frames.

The inventors found that by using relatively short payload fragments and associating a payload fragment check sequence field and a fragmentation control field the penalty of errors is dramatically reduced from the size of a PHY frame to the size of a payload fragment.

Figure 14 illustrates the throughput achieved when using different information frames.

The X-axis represents the PHY layer data rate. The Y-axis represents the effective throughput at Million bits per second. The effective throughput is the rate of information payload.

The following curves were generated by simulating a transmission sequence of a first information frame that includes a long PCLP preamble, followed by five information frames that include a short PCLP preamble.

It is noted that these graphs were simulated under the assumption that no re- transmissions are required. It is noted that the low overhead associated with this scheme increases throughput.

Curve 1082 illustrates the transmission of information frame such as information frame 1200, while the other curves illustrate the transmission information frames such as information frame 1100, of various lengths.

The upper curve 1081 represents the effective throughput achieved when using information frames of four thousand bits. At a PHY data rate of about four hundred and eighty Mbps an effective throughput of four hundred Mbps was achieved.

The following curve 1082 represents the effective throughput achieved when using information frames of about four thousand bits that include multiple two hundred and fifty six bit fragments. At a PHY data rate of about four hundred and eighty Mbps an effective throughput of three hundred and ninety Mbps was achieved.

The four lower curves 1083-1086 represent the effective throughputs achieved when using information frames of two thousand, one thousand, five hundred and two hundred and fifty bits, accordingly. At a PHY data rate of about four hundred and eighty Mbps effective throughputs of three hundred and fifty, two hundred and eighty, one hundred and ninety and one hundred and ten Mbps respectively was achieved.

Figure 15 illustrates a method 1300 for transmission, according to an embodiment of the invention.

Method 1300 starts by stage 1310 of receiving at least multiple information signals. According to an embodiment of the invention the information signals can belong to multiple frames..

Stage 1310 is followed by stage 1320 of processing the at least multiple information signals to provide an information frame that includes a PHY layer header, multiple payload fragments, multiple fragmentation control fields and multiple payload fragment check sequence fields. Conveniently, the multiple payload fragments are associated with the multiple fragmentation control fields and with the multiple payload fragment check sequence fields. It is noted stage 1310 does not necessarily include processing all the received signals. It is also noted that during said processing some signals can be modified, other signals can be deleted and the like.

According to an embodiment of the invention stage 1310 includes aggregating signals from multiple payloads and/or frames. Conveniently, the control bits

associated with each received frame can be modified or remain unchanged. The control bits may include MAC header bits and the like.

Conveniently, after the fragments and other parts of the information frame are generated the processing continues to aggregate them into an information frame. Said aggregation involves an alteration of the information frame header, for example by adding an aggregate header or otherwise notifying that the information frame is an aggregated frame.

Conveniently, each payload fragments is associated with a fragmentation control field and with a payload fragment check sequence field.

Conveniently, a payload fragment is substantially smaller than the payload.

According to an embodiment of the invention stage 320 further includes providing a MAC layer header that includes fragmentation information representative of a structure of the information frame.

Conveniently, at least most payload fragments are of the same length.

Typically, the last fragment sizes differs from the size of other fragments.

Conveniently, the fragmentation control fields include a payload sequence serial number and also include a fragment serial number.

Stage 1320 is followed by stage 1330 of transmitting the information frame utilizing a distributed media access control scheme This stage can involve transmitting over a ultra wide band wireless medium.

Figure 16 illustrates a method 1400 for reception, according to an embodiment of the invention.

Conveniently, a receiver that executes the stages of method 1400 substantially reverses the stages applied by a transmitted applying method 1300.

Method 1400 starts by stage 1410 of receiving an information frame that was transmitted over a network that applied a distributed media access control scheme. The transmission can involve a transmission over an ultra wide band wireless medium.

The information frame includes a PHY layer header, a MAC header with notification of the type of frame (In-MPDU fragmented), multiple payload fragments, multiple fragmentation control fields and multiple payload fragment check sequence fields;

whereas the multiple payload fragments are associated with the multiple fragmentation control fields and with the multiple payload fragment check sequence fields.

Stage 1410 is followed by stage 1420 of processing the information frame to provide a payload that includes multiple information signals.

According to various embodiments of the invention the device is capable of aggregating multiple MAC layer frames to a single PHY frame. These MAC layer frames or MAC layer segments can be treated as information frame 1500 (of Figure 17) fragments. In such a case the information frame shall include an aggregation header or otherwise include aggregation information representative of the aggregation process that resulted in the generation of the information frame.

Figure 17 illustrates an information frame 1500 that includes a PHY layer preamble, such as PLCP preamble 1112, a PHY layer header 1114, a MAC layer header 1116", HCS 1118, header tail bits 1120, header pad bits 1121. These are followed by an aggregation header 502, and a sequence 510 of fragmentation control (FC) fields 512 (1)-512 (K), payload fragments 514 (1)-514 (K) and payload fragment check sequence (FCS) fields 516 (1)-516 (K). The FC fields can also indicate if a certain payload fragment is the last within the PHY frame. The last FCS field 516 (K) is followed by a frame check sequence field (FCS) 1124, frame tail bits 1126 and pad bits 1128.

The aggregation header 502 includes the following fields: amount of MAC layer frames 522, and for each payload fragment its length 524 (1)-524 (K), and a fragmentation control fields 526 (1)-526 (K) indicating whether this is a fragment of a MAC layer frame and if so whet is it's serial number. It is noted that at least some of the payload fragments can be MAC layer frames. In such a case the MAC layer frames are not necessarily fragmented in order to generate the information frame 1500.

It is assumed that the information frame 1500 is generated in response to a reception of one or more original frames. According to various embodiments of the invention the information frame can be generated in various manners. The information frame can include the payloads of more than one original frame but can also include portions of a single original frame. For example, the information frame can be generated by aggregating original frames that include their own frame check sequence

protection fields. Yet for another example, the information frames can be generated by fragmenting a single original frame and adding various fields..

According to another embodiment of the invention the information frame 500 does not include FGS or FC fields for each payload fragment, and the aggregation header is altered accordingly.

According to various embodiments of the invention the device can dynamically determines the configuration of a transmitted information frame in response to wireless medium quality and in response to a quality of service associated with certain applications. The wireless medium quality can be assessed by monitoring transmission successes and failures (for example monitoring acknowledge based transmissions), by performing an PHY layer SNR estimation, and the like. The quality of service can be represented by various parameters including, for example, packet error rate, latency, interval between channel reservation, and the like.

It is assumed, for simplicity of explanation, that the first device A 11 multicasts to other members B-E 12-15 of the first network. It is noted that other devices can also multicast, and that the multicasting can be applied to fewer members of the first network 20.

Figures 19-22 illustrate information frame 2200 as well as various portions of information frame 2200, according to various embodiments of the invention.

The information frame 2200 includes acknowledgment message information 160. This acknowledgement message information 1160 can be a part of the payload of information frame 2200 or a part of its header, or may be pre-negotiated.

According to another embodiment of the invention the order of acknowledgement message transmissions can be pre-determined such that there is no need in transmitting the acknowledgement message information 1160. For example, if the devices agree (or are pre-programmed or otherwise configures) to transmit the acknowledgement messages in response to the order of transmission of the devices beacon frames than there is no need in transmitting information 1160.

Figures 19-22 illustrate acknowledgment message information 1160 that is part of the information frame payload. The acknowledgment message information

1160 can merely specify the order of acknowledge message transmission but can also define the timing of the transmission.

Figure 19 illustrates an information frame 2200 according to an embodiment of the invention. The information frame 2200 includes a physical layer convergence procedure (PLCP) preamble 1112, a PHY layer header 1114, a MAC layer header 1116, a header check sequence field (HCS) 1118, header tail bits 1120, header pad bits 1121, payload 1210, a frame check sequence field (FCS) 1124, frame tail bits 1126 and pad bits 1128.

The payload 1210 includes acknowledgment message information 1160 and information 1162. The MAC layer header 1 116 includes information that identifies information frame 1122 as an acknowledge based. The destination address of this frame indicates multicast transmission. It is noted that some of the acknowledgment message information 1160 can also be includes within the MAC layer header 1116 or only within said header.

The MAC layer header 1116 includes a frame control field 2201, source and destination identification fields 2222 and 2223, sequence control fields 2224 and duration/access method fields 226. The frame control field 2201 includes a protocol version field 2202, a frame type field 2204 (indicates if a frame is a beacon frame, control frame, command frame, information frame and the like), a SEC field 2206 (indicated if the frame is encrypted), an acknowledge policy field 2208 (no acknowledge, immediate acknowledge, burst acknowledge or burst acknowledge request), a retry field 2210 (indicates if the frame is re-transmitted), and delivery ID field 2212. An immediate acknowledge requires to send an acknowledge frame response after the recipient of the information frame. The burst acknowledge indicates to store received frames and the burst acknowledge request indicates to send an acknowledgment message with information about success/failure of reception of individual frames in last bursts.

The destination identification field 2222 indicates the identity of intended receivers and may indicate that the transmission is multicast. In case of broadcast the identity of recipients is not necessarily known in advance.

According to an embodiment of the invention the acknowledgment message information 1160 can be a part of an information frame, as illustrated in Figure 19, or may be a part of a command frame.

Figure 20 illustrates acknowledgment message information 1160 that includes both order and timing information. The transmitter transmits the timing of acknowledgement messages transmission from the multicast receivers. Each of the devices of the first network 20'is represented by its DEVID (DEVID C 2262, DEVID B 2260, DEVID D 2264 and DEVIDE 2266) and a corresponding acknowledgement messages transmission time TAM 1-TAM 4 2270-2276. The acknowledgment message information can represent an offset from the beginning of the last multicast information frame, from the end of the last multicast information frame, or from a beginning of a TDMA super frame.

Figure 21-22 illustrate various formats of acknowledgment messages order information included within acknowledgment message information 1160. The order of the acknowledgment messages can be represented by a list of devices, sorted according to their acknowledgment messages transmission order: DEVIDC 2262, DEVID B 2260, DEVID D 2264 and DEVIDE 2266. Figure 22 illustrates a more efficient manner for transmitting the order of acknowledgment messages. Assuming that there are 2K possible orders than K bits (denoted code 2280) represent the selected order. In such a case the amount of devices that participate in the scheme should be transmitted.

The transmission of only order information without exact timing is based upon the ability of the receiving devices to determine the end of the transmission Once a device receives an information frame that is multicast and requires acknowledgments it will search for acknowledgment message information 1160 within the information packet end of transmission.

Figure 23 is an exemplary timing diagram 2300 illustrating a multicast transmission of an information frame and a transmission of acknowledgment messages.

The timing diagram starts by a transmission of beacon frames (BF) 2301, 2303,2302, 2304 and 2305, from devices 11,13, 12,14 and 15 of first network 20'.

These beacon frames are followed by a point-to-point transmission, during two DRP timeslots 2321 and 2322, of two information frames 2306 and 2307.

It is noted that although this Figures illustrates a single frame per DRP slot this is not necessarily so. DRP slots are not necessarily limited to a single frame transfer.

They may include several frames, or, on other hand, a single frame may span a few DRP slots.

Information frames (IF) 2306 AND 2307 are followed by a multicast timeslot 2323 during which a multicast information frame (MIF) 2330 is transmitted from first device A 11 to devices B-E. During the multicast time slot 2323 devices B-E transmit acknowledgment messages (ACKMB 2332 from device B 12, ACKMC 2331 from device C, ACK-M-D 2333 from device D 14 and ACKME 2334 from device E 15) that are supposed to be received by first device A 11.

Figure 24 is an exemplary timing diagram that illustrates a multicast transmission of information during multiple time slots. The exemplary timing diagram illustrates a transmission of multiple multicast information frames MIF 2336 - 2340 during three DRP timeslots 2323-2325 wherein the last timeslot 2325 is also allocated for the transmission of acknowledgment messages. It is noted that the DRP slots as well as the PCA slots can be used for transmitting more that a single information frame or even only a frame portion. This scenario can be used when a fragmented information frame is transmitted during multiple timeslots and is also applicable when applying a burst acknowledgement scheme.

Figure 25 is a flow chart of method 2400 for multicasting information over an ultra wide band wireless medium, according to an embodiment of the invention.

Method 400 starts by optional stage 2410 of providing a distributed media access control scheme. Conveniently, stage 2410 includes scheduling a transmission and a reception of beacon frames, allocating PCA slots and DRP slots and the like.

Conveniently, the DRP slots are coordinated between devices that belong to the same network and allow devices to reserve these slots in advance. During the PCA slots devices that belong to the network compete for access based upon their transmission priority. It is noted that the allocation of media access time slots is dynamic and may change from one TDMA frame to another.

Stage 2410 can be repeated during the execution of the other stages of method 2400. Thus, various slots can be allocated before and after a multicast transmission is requested and scheduled. Typically, the ultra wide band wireless network does not include a central media access controller and the various peer devices that form this network exchange signals in order to allocate timeslots (grant access to the wireless medium).

According to various embodiments of the invention method 2400 can be applied by other networks, such as but not limited to networks that are not ultra wide band networks. These networks can apply a distributed media access control scheme.

Conveniently, stage 2410 includes determining an order of beacon frames that are transmitted by the peer devices. Typically, before a device joins a network is tries to detect existing beacon frames and if received it transmits its own beacon frame such as not to disrupt the existing beacon frames.

According to an embodiment of the invention timing or ordering information is sent only when a change occurs between a previous multicast transmission and a current multicast transmission.

According to an embodiment of the invention the temporary loss of one or more beacon frames, during one or more TDMA frame shall not alter the order of transmission of acknowledgment messages.

According to yet another embodiment of the invention the method is adapted to manage transmission of information bursts. Typically, the transmission of transmission bursts is coordinated between the transmitter and the intended receivers.

Said coordination is required in order to avoid receiver overflows. Thus, before transmitting an information burst to a certain receiver the transmitter has to know the receiving capabilities of the intended receiver.

The capabilities can include the amount of frames that the receiver can receive, the overall size of information frames that can be received by the receiver and can include the reception rate of the receiver. This rate can be influenced by the processing and buffering capabilities of the receiver.

Usually the transmitter will select a transmission that can be properly received by all the receivers, thus the transmission will be responsive to the slowest or least buffering receiver.

Stage 2410 is followed by stage 2420 of allocating at least one timeslot for a transmission of information from a first device to a group of peer devices and for a transmission of acknowledgement massages from the peer devices of the group; and transmitting the information in response to the allocation.

Conveniently, a transmission order of acknowledgement messages is responsive to the transmission order of beacon frames. According to an embodiment of the invention the transmission order of acknowledgement messages is substantially equal to the transmission order of beacon frames. In such a case there is no need in transmitting ordering information.

Conveniently, a first acknowledgment message and an end of information burst or frame are scheduled to be transmitted at a same timeslot or contiguous MAS slots belonging to the same DRP reservation or contiguous PCA MAS slots.

Conveniently, stage 2420 includes allocating the one or more timeslots such that a delay between a scheduled transmission of a beginning of the information and a scheduled transmission of a last acknowledgement message is responsive to the capabilities, such as buffering capabilities, of the first device. The transmitter has to be capable of re-transmitting information frames that were not received by one or more intended receivers. Thus, the transmitter has to buffer transmitted information frames during at least the mentioned above period.

According to an embodiment of the invention stage 420 further includes allocating a transmission of acknowledgment message information. Conveniently, the acknowledgment message information includes acknowledgment messages order information.

Conveniently, the order information includes information for selecting between a set of predefined options. The order of acknowledgment messages transmission can be selected between a set of predefined functions.

It is noted that the acknowledgement message information can be embodied in a certain information element (IE) within a beacon of the source of the source of

multicast transmission, specifying the sequence of the ACK frames to be transmitted.

In case a beacon is missed, the order of transmission of acknowledgement messages is conserved for a predefined amount of beacon frames (denoted MaxLostBeacons).

Notification about change in ACK frames sequence can be transmitted at least MaxLostBeacons before an actual change in the order of transmission occurs.

Assuming, for example that there are 2K possible relationships between the beacon transmission order and the transmission order of the acknowledgment messages then the selected relationship can be represented by K bits.

According to another embodiment of the invention the various peer devices can agree on a mapping between various acknowledgement transmission orders and order information codes.

Conveniently, the acknowledgment message information includes an identity of each peer device of the group and a time for transmitting its corresponding acknowledgement message.

Stage 2420 is followed by stage 2430 of transmitting the information in response to the allocation. The transmission is followed by a reception of acknowledgement messages.

Stage 2430 can be followed by stage 2420. Conveniently, stage 2430 can be followed of stage 2440 of evaluating a continuation of transmission of future frames or re-transmission in response of a reception or lack of reception of acknowledgement messages. Stage 2440 may include determining whether to re-transmit an information frame, and if so-whether to multicast it or transmit it using a point-to-point scheme it. It can also include altering acknowledgement schemes (for example-replacing burst acknowledgement to immediate acknowledgement, replacing immediate acknowledgement to burst acknowledgement, increasing or decreasing a size of a burst that is followed by an acknowledgement request), altering framing (by aggregation or fragmentation), changing the identity of recipients, and the like. It is noted that a change in the identity of recipients requires to update acknowledge messages timing information.

It is noted that method 2400 facilitates a transmission of multiple information frames during multiple time frames. The identity of the devices that belong to the

group can change over time, and stage 2420 is responsive to said change. Thus, the amount of acknowledgement messages and the identity of intended acknowledging devices may change.

Conveniently, an allocation of the one or more time slots for a transmission from the first device starts by a request to transmit said information and also to allow the transmission of acknowledgement messages.

According to an embodiment of the invention the requesting device announces which peer devices are to receive the multicast information. Conveniently, each device can respond by accepting the request and can also transmit his reception capabilities, so that the first device determines the amount, rate and/or timing of the transmission.

These capabilities usually include buffering capacity, reception rate and the like. In some cases the buffering capability is limited by the amount of frames that can be received, by the overall size of received information and the like.

The identity of the intended recipients as well as a need to re-transmit one or more information frames, either in a multicast manner or in a point-to-point manner can be responsive to various parameters including the reception or lack of reception of acknowledgment messages.

Conveniently, if the information is multicast during a DRP timeslot then that timeslot is also utilized for receiving acknowledgment messages from the intended recipients of the information. In cases where the information is transmitted during multiple time slots then the last timeslot can be allocated for the transmission of the acknowledgment messages..

According to an embodiment of the invention device 60 is adapted to inform the second device that device 60 is capable of relaying information to the external device. Conveniently, device 60 is adapted to receive information from the external device and transmit the information to the second device at a timing that corresponds to timing constraints of the first network.

Conveniently, the devices are adapted to perform a"peer discovery"stage. It is noted that a certain device can ask an adjacent device to relay information to another device (external device) if the certain device is aware that the external device is a potential peer device. This may involve an exchange of information between the

devices. According to various embodiments of the invention this can be implemented by a requesting from devices to transmit information about their neighbors, including their identity and optionally their capabilities. A request can be answered by a response from each receiving device. The exchange can be implemented by exchanging information Elements (IEs).

A request may include a the type of requested information-DAVID, MAC address, capabilities, and the like.

It is noted that this information exchange can occur in various timings and between various devices. This can occur during device initialization, during device operation, between devices that are adjacent to the same device, between devices that belong to the same network, between devices that do not belong to the same network, or between parts of one or more networks. The exchange can be initiated by certain devices or by any device.

According to an embodiment of the invention device 60 is further adapted to allocate a first destination identification value to transmissions destined to the device 60 and to allocate a second destination identification value to transmissions destined to be relayed by the device 60 to the external device. Conveniently, during a relay operation device 60 changes destination identification information.

According to another embodiment of the invention the destination identification can also represent a last destination of the information. Conveniently, such a field is not changed during the relay operation.

According to yet another embodiment of the invention the path (or a portion of said path) that should be passed by the information frame can be represented in various manners known in the art. The path includes at least the device that originated the information frame, the last destination device and can also include one or more intermediate (relaying) devices.

Conveniently, device 60 is further adapted to request the remote device to acknowledge a reception of at least one information frame from the second device.

According to various embodiments of the invention device 60 is able to relay the information at a MAC layer or at higher communication layers.

In case of a scheme where traffic is directed to the repeater with repeater's DEVID, the relaying device shall be able to distinguish between information frames that are intended to be relayed and between information frames that are aimed to it and are not supposed to be relayed to the external device. Conveniently, the information frame includes a destination source identification information (destination ID, or DEVID) and stream identification information (StreamID) that facilitates said distinction.

Alternatively, the traffic is marked as directed to the''final''destination, and the repeater is relaying this traffic to the intended recipient.

According to an embodiment of the invention distinct destination ID values are assigned to each device and to each relayed device. Thus, information frames aimed to device B 12 will include a certain destination ID value, while information frames that are destined to device F 26, are assigned with another destination ID value, although they are relayed via device B 12. If, for example, device B 12 also relays information frames to device D 24 then these information frames will include yet another destination ID value.

Conveniently, the relaying process includes replacing destination ID values.

For example, if device All sends an information frame to device F 26, via device B 12, then the information frame will include a first destination ID (F via B) indicating that B 12 should relay the information frame to F 26. This destination ID (via) is replaced, by device B, by another destination ID indicating that device B is sending an information frame to device F. The other destination ID can equal the destination ID (DEVID F) used by members of the second network 20 when sending information frames to device F 26.

Device B 12, which is capable of relaying information frames to certain external devices shall notify other members of the first network 10 that it is capable of relaying information frames to these external devices, and shall receive a unique destination ID value for each of said certain devices.

Conveniently, each device can select certain DEVID values from a predefined range of DEVID values. If a collision occurs it can be detected by transmission of said

DEVID values in beacon frames, and the collision can be resolved in various well known manners.

For example, if a device receives from another device an DEVID that equals one of its DEVIDs it will notify the other device about the collision and either determine by itself how to replace the common DEVID or cooperate with the other device in order to resolve the collision. It is noted that each device that detects a DEVID collision may alter his DEVID until the collision is resolved. Typically DEVID values are selected in a random or a pseudo random manner from a predefined range of DEVIDs but this is not necessarily so. It is further noted that a certain device can be aware of a DEVID conflict if he receives transmissions from two devices that use the same DEVID.

Figure 27 illustrates a beacon frame 3400, according to an embodiment of the invention.

Beacon frame 3400 is transmitted by a certain device, such as but not limited to device B 12. Beacon frame 3400 includes various fields such as beacon slot number field 3402, DEVID of the certain device 3404 (DEVID B), DEVID conflict field 3406, and a list 3408 of devices (represented by their DEVID) that are received by the certain device. Conveniently, the list 3408 includes a list of beacon frames received by the device and their timings.

It is assumed that device B 12 receives transmissions from devices All and C 13 of the first network 10 and form devices F 26 and D 24 of the second network 20.

Accordingly, list 3408 includes the following DEVIDs : DEVID A, DEVID-C, DEVID D and DEVID F. List 3408 may also include their beacon frame timing T1- T4. It is assumed that the times are aligned to TDMA frame 30, but this is not necessarily so.

It is noted that if the device is a relaying device than the various DEVIDs allocated for the relaying of information can appear within field 3404, or within a relay indication 3410. It is assumed that device B 12 can relay information from device A 11 and device C to devices F 26 and D 24 of the second network 20. Thus, relay information 3410 includes four DEVIDs : F via B, B via F, B via D and D via B.

According to another embodiment these relay information fields are not used, and the need to relay a certain information frame can be dictated by the reservation of a relay slot (being either DRP or PCA slot or slots).

These relay fields are not usually required when the information frame includes a"final"destination field or information defining the transmission path.

Conveniently, the beacon frame includes additional information (not shown) indicating the capability of the certain device to accept DRP or PCA traffic during future timeslots, the intended utilization of future TDMA frames by the certain device, types of DRP reservations, rate information and other capabilities of the device.

It is noted that the various DEVIDs allocated for relay transmission, indications about DEVID conflicts, a list of received devices and the like can be transmitted in other manners. For example at least some of said information can be included within various command frames and information frames.

According to various embodiments of the invention the transmission between the external device and the relaying device can occur according to timing constraints of the first network, according to timing constraints of a second network that includes the external device or according to both timing constraints.

For example, assuming that: (i) device B 12 relays information from device A 11 to device F 26. (ii) device B is aware of the TDMA frames of both first and second networks 10 and 20, (iii) TDMA frame 3030 that is used by the members of the first network 10 does not interfere with TDMA frame 3040 that is being used by the members of the second network 20. If these assumptions are satisfied then device B 12 can request to transmit information frames to device F 26 during various slots of TDMA frame 3040, assuming that the members of the second network 20 approve the request.

Device F 26 can transmit information frames to device B 12 during slots of TDMA frame 3040. Device B 12 can exchange information frames with device A 11 during slots of TDMA frame 3030. It is noted that if the transmissions of the various networks overlap then device B can initiate a channel change process that will lead the members of one of the networks to use another channel, or to"re-shuffle"its DRP

timing reservations. Re-shuffling does not require to perform a full DRP timing re- negotiation.

According to various embodiments of the invention the transmissions from the relaying device to the external device can be received by other members of the first network, but this is not necessarily so. For example, the relaying device can exchange information with the members of the first network using a first channel and use another channel for exchanging information with the external device. It is noted that the first and second channels have different transmission characteristics.

According to various embodiments of the invention the relaying device can transmit a single beacon frame, that is received by both members of the first network and also by the external device, but this is not necessarily so. For example, the first device can transmit a second beacon frame for communicating with the external device. Yet for another example, device B can use a single beacon frame in order to communicate with members of the first and second networks, but this is not necessarily so and it can transmit a first beacon frame to the members of the first network and transmit a second beacon frame to the members of the second network.

Figures 28-29 illustrate information frames 3100 and 3100', according to various embodiments of the invention.

Information frame 3100 of Figure 28 is transmitted from device A 11 to device B 12. Information frame 2100'of Figure 29 is transmitted from device B 11 to device F 26. The information frames differ by the destination ID values that are includes within.

Information frame 3100 includes a physical layer convergence procedure (PLCP) preamble 1112, a PHY layer header 1114, a MAC layer header 1116', a header check sequence field (HCS) 1118, header tail bits 1120, header pad bits 1121, payload 1122, a frame check sequence field (FCS) 1124, frame tail bits 1126 and pad bits 1128.

The MAC layer header 1116'includes a frame control field 2201, source and destination identification fields 2223 and 2222, sequence control fields 2224 and duration/access method fields 2226.

The destination identification field 2222 of information frame 100 indicates the identity of intended receivers and may indicate that the transmission is multicast or even broadcast transmission. The destination identification field 2222 includes a destination ID value (denoted F-via-B) indicating that the information frame 3100 is to be received by device B and then relayed to device F 26. The destination identification field 2222 of information frame 3100'includes a destination ID value (DEVID F) indicating that the information frame 3100'is to be sent to device F 26.

As previously mentioned, destination field 2222 can include a dedicated relay assigned information, a final destination field or another information describing the path of the information frame.

Figure 30 is a flow chart of method 3200 for expanding a range of an ultra wide band wireless network.

Method 3200 starts by stage 3210 of providing a first network and an external device, the first network includes multiple devices that receive ultra wide band wireless transmissions from each other, the external device is capable of receiving a transmission from a first device of the first network but is not capable of receiving a transmission from a second device of the first network. Referring to the example set forth in Figure 1 it is assumed that the external device is device F 24 and that device F 24 receives transmissions from device B 12 of first network 10 but not capable of receiving transmissions from device A 11.

According to an embodiment of the invention method 3200 also includes a "peer identification stage. For convenience of explanation this stage was not shown.

According to an embodiment of the invention stage 3210 is followed by stage 215 of informing the second device that the first device is capable of relaying information to the external device. Referring to the above mentioned example, device B 12 informs device A 11, conveniently by its beacon frame, that is receives transmissions from device F 26.

Stage 3215 is followed by stage 3220 of allowing the first device to relay transmissions between the external device and the second device. Stage 3220 may include assigning different destination ID to various devices and relayed devices, enabling the relaying device to transmit and receive to various devices. Said enabling

may include allocating time slots and DeliveryID for transmissions of information frames by the relaying device, transmitting one or more beacon frame by the relaying device, and the like. It is also noted that the transmission of the one or more beacon frames can occur during stage 3210.

Conveniently stage 3220 includes allocating a first destination identification value to transmissions destined to the first device and allocating a second destination identification value to transmissions destined to be relayed by the first device to the external device.

Conveniently, stage 3220 is followed by stage 3230 of receiving information from the external device and transmitting the information to the second device. The transmission occurs at a timing that corresponds to timing constraints of the first network.

Stage 3230 may also include receiving information from the second device and transmitting the information to the external device. The transmission occurs at a timing that corresponds to timing constraints of the external device or of a second network to which the external device belongs.

According to an embodiment of the invention stage 3230 includes changing destination identification information. Conveniently, stage 3230 includes requesting the remote device to acknowledge a reception of at least one information frame from the second device.

The stage of relaying can be applied in the MAC layer or may involve other upper layers. For example, the exchange of destination ID can be done at an application layer that is above the MAC layer. Referring to the example set forth in Figure 4a the relaying can be done by the application 66, or by the MAC layer block 64.

Figure 31 is a flow chart of method 2300 for expanding a range of an ultra wide band wireless network.

Method 3300 starts by stage 2310 includes providing a first network and an external device, the first network includes multiple devices that participate in a first distributed media access control scheme, whereas the external device participates in a second distributed media access control scheme and is capable of receiving a

transmission from a first device of the first network but not capable of receiving a transmission from a second device of the first network. The networks can be other than ultra wide band wireless networks.

Stage 3310 can be followed by stage 3320 of relaying, by the first device, transmissions between the external device and the second device.

Those of skill in the art will appreciate that the method can be easily modified to cases where the information is fragmented to multiple fragments and the acknowledgement messages should be sent after a transmission of at least one of said fragments.

According to other embodiments of the invention the acknowledgement messages can be sent during different timeslots. This can happen if a single timeslot is not long enough to encompass the transmission of all the expected acknowledgment messages. This can also happen if the method determines to transmit only some acknowledgment messages at a time.

Conveniently, if the information is scheduled be transmitted during one or more PCA timeslots then a transmission of acknowledgment messages from the group members are scheduled to be transmitted during a PCA timeslot in which at least an end of the information is scheduled to be transmitted.

According to an embodiment of the invention, the scheduling of a transmission of acknowledgment messages is responsive to a priority of the peer members. The priority can determine the order of transmission or can also be used a random or semi- random allocation schemes. In the latter, an acknowledgement message of a certain peer device is scheduled to be transmitted within a transmission window that is defined in response to the priority of the peer device.

According to an embodiment of the invention the transmitter can determine whether to re-transmit an information frame that was not acknowledged by a certain device in response to various parameters including the presence or absence of previous acknowledgments, the relevancy of the information frame and the like. The relevancy usually is reflected by an expiration period (also known as time of live) that can be associated with the information frame. The transmitter can re-transmit information frames in a multicast or point-to-point manner.

The devices of first network 10, as well as second network 20 of Figure 32 include multiple communication layer components. Figure 32 illustrates various communication layers and also service access points (SAPs) that illustrates the interaction between layers of a device of the first network 10.

The communication layers includes a PHY layer 4010, a MAC layer 4020, and a frame convergence sub-layer (FCSL) 4030. The interaction between the PHY layer 4010 and the MAC layer 4020 is represented by PHY SAP 4015. The interaction between the MAC layer 4020 and the FCSL 4030 is represented by MAC SAP 4025.

The interaction between FCSL 4030 and an upper layer (such as application layer) is represented by FCSL SAP 4035. Each layer includes a management entity. The PHY layer management entity (PLME) 4012 interacts with the MAC layer management entity (MLME) 4022 via MLME-PLME SAP 4017. MLME 4022 interacts with a device management entity (DME) 4040 via MLME SAP 4027. DME 4040 interacts with PLME 4012 via PLME SAP 4018.

It is noted that some of the management entities and SAPs of Figure 32 do not appear in Figure 5 or are not represented by dedicated corresponding components. It is noted that this for simplicity of explanation purposes. The device 60 illustrated in Figure 5 usually includes all the required components.

It is also noted that Figure 5 does not illustrate all the communication protocol stack and corresponding components that allow a reception and transmission and reception over the wired components that are connected to PHY/MAC layer chip 63, and especially does not illustrated the components that allow to exchange information with application 66 or other components connected to PHY/MAC layer chip 63.

Figure 33 illustrates an environment 4200 that includes some of the components that allow to communicate over the ultra wide band wireless medium on one side and also with other wired or wireless components on the other side. It is assumed that there is a USB PHY interface on one side and a Ethernet PHY interface on the other.

Environment 4200 includes an Ultra Wide Band (UWB) PHY layer component 4210 that is connected to a ultra wide band transmitter (not shown) such as but not limited to RF chip 62 and antenna 61 of Figure 4. The PHY UWB layer component

4210 is connected to a UWB MAC component 4220. The UWB MAC component 4220 is connected to a memory unit 4230, to a processor 4240 and to a direct memory access controller (DMA controller) 4250. The DMA controller 4250 is connected to a MAC Ethernet component 4260 that in turn is connected to a PHY Ethernet component 4270. The adjustable filter 4100 receives a byte stream from MAC Ethernet component 4260 and especially from a temporary storage unit within said MAC component, and is also connected to memory 4230.

The environment 4200 can include a device or be included within a device (such as device 60) that includes a MAC layer entity that in turn includes multiple MAC layer queues (such as but not limited to the queue illustrated in Figures 6-9).

This MAC layer entity is adapted to participate in a distributed media access control scheme to determine a configuration of the network ; and also includes adjustable filter 4100. The adjustable filter 4100 is adapted to map application parameters to the MAC layer queues, in response to the configuration of the network.

Figure 34 illustrates adjustable filter 4100 according to an embodiment of the invention.

Adjustable filter 4100 includes a controller 4310, program memory (also referred to as program RAM) 4320, key table memory unit (also referred to as key table RAM) 4330, result temporary storage unit (also referred to as result lock) 4340 and a comparator unit 4350. The controller is connected to components 4320-4350 and is adapted to execute programs stored within program memory unit 4320, and provide appropriate mapping between application parameters and devices. The mapping rules can include appropriate masks and comparisons.

The adjustable filter 4100 includes a two-dimensional virtual table (denoted 4332 in Figure 35). The first dimension is the key dimension and it can be altered according to various parameter including the application parameter associated with devices of a certain network, the applications supported by the devices of the network, the identity of devices that form a network, and the like.

The key's length can be changed in response to a various changes, such as but not limited to a change in the identity of devices that belong to the network an/or a change in the applications supported by the devices of the network. These changes can

occur quite rapidly, due to relative movement of one or more device in relation to other devices, due to temporal changes in the reception and transmission conditions and the like.

When there is a need to add more keys the length of each key (or at least of some of the keys) is usually decreased. The decrement is usually also responsive to the adjustable filter's storage capabilities. Thus, if there is enough storage space for storing more keys without a key length alteration, this alteration may not take place.

It is further noted that the mapping rules can change, even without changing the keys length, when there is a change in the applications supported by network devices or when there is a change in the devices that belong to a network. In some cases such a change will require to change the masks, as older masks do not necessarily provide a clear distinction between newly supported applications and older applications.

Conveniently, the adjustable filter 4100 performs multiple comparisons between selected portions of the received information stream and portions of the key.

The inventors used an adjustable filter that was able to perform two-bytes comparisons. Thus if the key was longer multiple comparisons were executed. The result of each two byte comparison was represented by two bits in a match result unit.

Once a comparison session ends multiple bits of the match result unit are examined to determine the overall success of the comparison process. It is further noted that when relevant fields are less than two bytes long the remaining bits can be masked during the comparison.

Referring to Figure 35, the virtual table 4332 has multiple entries, and each entry has two fields. The first fields are denoted 4334 (1, 1)-4334 (1, N) and are also referred to as the key fields. Each key field stores a single key. The second fields are denoted 4334 (2,1)-4334 (2, N) and are also referred to as the result (or destination) fields. They store the results of the filtering process-the destination of the received information stream from which various information fields were retrieved and processed.

The destination can be one of the MAC queues (such as but not limited to the various DRP or PCA queues illustrated in any of Figures 6-9), can be a processing

queue or a drop queue. The processing queue stores information frames that are not recognized or other information frames that ought to be processed by a processor (or a controller or a mapper) in order to determine their destination. The drop queue can be a virtual queue for information frames that are dropped.

Conveniently, the key fields length (also referred to as key dimension) can be adjusted. Conveniently it ranges between one byte and thirty two bytes, but other lengths can be appropriate. The result field is conveniently two bytes long, but this is not necessarily so.

It is noted that the result field length can be varied, although the inventors altered only the key field length.

The amount of keys is also referred to as the entry dimension, and represents the amount of different mapping rules. This dimension can reflect the amount of supported sessions.

Conveniently, the controller 4310 can execute simple commands (op-codes) such as set a register, reset s register, compare, compare using a mask, store to data RAM, load to a register, load offset, jump, end program and the like.

The adjustable filter 4100 can be easily adjusted to provide optimal solutions to a dynamic environment, and for supporting various applications (including media applications).

The mapping scheme is based upon a set of programmable instructions. The amount of streams supported by the adjustable filter is responsive to the storage capacity of the adjustable filter, and is characterized by a small silicon footprint.

Figure 37 illustrates adjustable filter 4100 in greater details, according to an embodiment of the invention.

Adjustable filter 4100 includes controller 4310 that is connected to a burst control unit 4430, a data address control unit 4410, program address control unit 4400, watchdog unit 4370, wait control unit 4380, comparator unit 4350, and register decoder unit 4440. The comparator unit 4350 is further connected to the frame key collect unit 4360 and to the match result unit 4340. The program RAM 4320 is further connected to a management access arbiter 4420 and to the program access control unit

4400. The key table RAM 4330 is also connected to the data address control unit 4410.

The watchdog unit 4370 monitors the cycle period and resets the controller if the execution of a single command is too lengthy. The register decoder unit 4440 is connected between controller 4310 and the comparator unit 4350 and allows the controller to access one of the registers of the comparator unit during a load register instruction. The wait control unit 4380 includes a counter that allows to execute commands that are triggered once a certain counter value is reached.

The frame key collect unit 4360 includes a byte counter 4362, two match BE registers 4364 and 4665, as well as two match registers 5668 and 4669. The unit is adapted to strip certain bytes from a received information stream according to control information stored in one of its Match BE registers.

The comparator unit 4350 is adapted to compare the content of one of the match registers to information retrieved from the key table RAM, whereas the comparison can involve applying a mask on the compared information. The result of the comparison (failure/success) is sent to the match result unit 4340 The match result unit can set or reset an appropriate bit in response to a set/reset logic control field within an instruction.

Figure 36 illustrates a format of an instruction 4500, stored within the program RAM 4320, according to an embodiment of the invention. Instruction 4500 includes the following fields: Byte number field 4510, command field 4520, address field 4530, destination register field 4540, result bit mask field 4550, result set/reset field 4560 and burst size field 4570. The byte number field 4510 indicates the first relevant byte within a received information stream to be processed during the filtering process.

Table 1 illustrates exemplary values of the command field 4520 and the associated commands: Value Command Details 0000 Reset Reset the register defined in the destination Register register field 0001 Set Set the register defined in the destination Register register field 0010 Load Load the entry (within the key table RAM) indicated in the address field to the register defined in the destination register field 0011 Load Load the entry (within the key table RAM) Offset corresponding to (Address + Offset) to the register defined in the destination register field 0100 Comp Compare Matchl register (the bytes stripped are Match 1 from the information stream) to the entry (within the key table RAM) indicated in the address field. 0101 Comp Compare Match2 register (the bytes stripped are Match2 from the information stream) to the entry (within the key table RAM) indicated in the address field. 0110 Comp Compare Matchl register (the bytes stripped are Matchl from the information stream) to the entry & Mask (within the key table RAM) indicated in the address field, while applying a mask 0111 Comp Compare Match2 register (the bytes stripped are Match2 from the information stream) to the entry & Mask (within the key table RAM) indicated in the address field, while applying a mask 1000 Store Store the value from the register indicated by the destination register field to the entry (within the key table RAM) corresponding to the address filed. 1001 Jump Jump to instruction that is stored at the address indicated by the address field. 1111 End End the transaction after this current instruction and reset all registers. 1010-1110 NOP No operation

TABLE 1 The result bit mask field 4550 indicates which bit in the result register should represent (be either set or reset) the result of a single comparison. The result set/reset field 4560 indicates if that bit is set or rest when the comparison succeeds. The burst size field 4570 can indicate an amount of iterations a certain instruction should be continuously executed.

Tables 2 and 3 illustrate an exemplary mapping based upon various application parameters to devices and an exemplary mapping program. The application parameters include Ethernet Virtual LAN (VLAN) and destination address (DA) fields. The network is assumed to support twelve separate uni-cast addresses (usually corresponding to twelve possible devices) and two multi-cast addresses. The VLAN field is twelve bits long while the comparison is performed on a byte basis, thus a four bit mask should be applied.

Table 2 illustrates the format of an exemplary virtual table 4332'that is used during the mapping process: Entry Type KEY (8 bytes long) Result DA + VLAN [11 : 0]-8 bytes Stream-ID + Keyl Key2 Key3 Key4 others-2 Al-DA2 DA3-DA4 DA5-DA6 VLAN [11 : 0] bytes 2 =B3-B4 =B5-B6 =B15-B16 0 Multi EOKI EOK2 EOK3 EOK4 Stream-IDO Cast E1K1 E1K2 E1K3 E1K4 Stream-ID1 2 Uni-E2KI E2K2 E2K3 E2K4 Stream-ID2 3 cast E3Kl E3K2 E3K3 E3K4 Stream-ID3 4 E4K1 E4K2 E4K3 E4K4 Stream-ID4 5 E5K1 E5K2 E5K3 E5K4 Stream-ID5 6 E6K1 E6K2 E6K3 E6K4 Stream-ID6 7 E7K1 E7K2 E7K3 E7K4 Stream-ID7 8 E8K1 E8K2 E8K3 E8K4 Stream-ID8 | E9K1 E9K2 E9K3 E9K4 Stream-ID9 10 OK-1 ElOK2 EIOK3 EIOK4 Strearn- IDIO 11 E11K1 E11K2 E11K3 E11K4 Stream- DI11 12 E12K1 E12K2 E12K3 E12K4 Stream- In12 13 E13K1 E13K2 E13K3 E13K4 Stream- ID13

TABLE 2 The first comparison (denoted keyl) involves comparing between the first two bytes of the stored key (denoted B 1-B2) and the first two bytes of the DA field (denoted DA1-DA2). There are fourteen possible valid vales for these first two bytes, and they are denoted EOK1-E13K1. The second comparison (denoted key2) involves comparing between the third and fourth bytes of the stored key (denoted B3- B4) and the third and fourth bytes of the DA field (denoted DA3-DA4). There are fourteen possible valid vales for these bytes, and they are denoted EOK2-E13K2.

The third comparison (denoted key3) involves comparing between the fifth and sixth bytes of the stored key (denoted B5-B6) and the fifth and sixth bytes of the DA field (denoted DA5-DA6). There are fourteen possible valid vales for these bytes, and they are denoted EOK3-E13K3. The fourth comparison (denoted key4) involves comparing between the first twelve bits of the sixth and seventh bytes of the stored key (denoted B7-B8) and the first twelve bits of the VLAN field (denoted VLAN [11,0]. This comparison include masking the four remaining bits. There are fourteen possible valid vales for these bits, and they are denoted EOK4-E13K4. If the four comparisons are successful then result of the comparison is one of the results denoted Stream-IDO-Stream ID 13. Each of said results is associated with a single MAC layer queue.

Table 3 illustrates an exemplary program executed by the adjustable filter 4100 during a mapping process. Table 3 has three columns-an"Entry#"that represents the memory unit entry address in which an instruction is stored, the instruction column that represents the stored instruction and a comments column. Entry # Data content Comments 0 Keyl = B1-B2 1 Key2 = B3-B4 2 Key3 = B5-B6 Key4 = B14-B15 4 Mask for VLAN = 1111_00000000000 5 Mask for MC Keyl Other keys don't need mask 6 Mask for UC Keyl 7 Result Register initial value (for 14 entries) =0011111111111111 8 Lock Keyl Temporary entries to lock 9 Lock Key2 Key result from frame to be compared later in the program. 10-23 Keyl for 14 entries = EOKI-El3Kl Key Database 24-37 Key2 for 14 entries = E0K1-E13K2 38-51 Key3 for 14 entries = E0K3-E13K3 52-65 Key4 for 14 entries = E0K4-E13K4 66-79 Result for 14 entries = Result Database Stream-ID0-Stream-ID13 80-255 Not used

TABLE 3 These stored instructions are fetched by the controller 4310 that will execute the following program: Load Keyl (AO)- Matchl-BE register Load Key2 (Al) Match2-BE register Wait until B=2. Store Matchl register to Temp Lock A8.

Load Key3 (A2) o Matchl-BE register Wait until B=4. Store Match2 register to Temp Lock A9.

Load Key4 (A3) o Match2-BE register

Load initial value (A7) to Result-Lsb register Wait until B=6. Compare Matchl register to Key3-MC: A38, Burst =2.

Result (reset) from 0.

Compare Matchl register to Key3-UC : A40, Burst =12. Result (reset) from 2.

Load Lock-Keyl (A8 temp) o Matchl register.

Load Mask-MC (A5) i Mask register.

Compare-Mask Matchl register to Keyl-MC : A10, Burst =2.

Result (reset) from 0.

Load Mask-UC (A6) i Mask register.

Compare-Mask Matchl register to Keyl-UC : A12, Burst =12.

Result (reset) from 2.

Load Lock-Key2 (A9 temp) o Matchl register.

Compare Matchl register to Key2-MC&UC : A24, Burst =14.

Result (reset) from 0.

Load Mask-Vlan (A4)# Mask register.

Wait until B=16. Compare-Mask Match2 register to Key4-MC&UC : A66, Burst =14. Result (reset) from 0.

Load-Offset Result of the first Match entry (A66 + offset)- Output Register.

END! Tables 4 and 5 illustrate an exemplary mapping based upon various application parameters to devices and an exemplary mapping program. The application parameters include program identification field (PID) of an MPEG compliant media stream. The PID is thirteen bit long, thus a two-byte comparison and masking of three bits are required.

Table 4 illustrates the format of an exemplary virtual table 4332"that is used during the mapping process: Entry KEY Result # PID-2 bytes Stream-ID + others-2 bytes Key = B2-B3 0 EO Stream-IDO 1 E1 Stream-ID1 E2 Stream-ID2 3 E3 Stream-ID3 4 E4 Stream-ID4 5 E5 Stream-ID5 6 E6 Stream-ID6 7 E7 Stream-ID7 | E8 Stream-ID8 9 E9 Stream-ID9 10 E10 Stream-ID10 11 El l Stream-IDl l 12 E12 Stream-ID12 TABLE 4 Table 5 illustrates another exemplary program executed by the adjustable filter 4100 during a mapping process.

Entry # Data content Comments 0 Key = B2-B3 1 Mask = 111_0000000000000 2 Result Register initial value (for 13 entries) =0001111111111111 3-15 Key for 13 entries = EO-E13 Key Database 16-28 Result for 13 entries = Result Database Stream-IDO-Streanz-ID12 29-255 Not used TABLE 5 These stored instructions are fetched by the controller 4310 that will execute the following program: Load Key (AO) Matchl-BE Load Mask (Al)- Mask register

Load initial value (A2)# Result-Lsb Wait until B=3. Compare-Mask Matchl register to Key : A3, Burst =13.

Result (reset) from 0.

Load-Offset Result of the first Match entry (A16 + offset) Output Register.

END! Tables 6 and 7 illustrate an exemplary mapping based upon various application parameters to devices and an exemplary mapping program. The application parameters include an Internet Protocol (IP) field that four bytes long, thus two comparisons of two byte each were applied by the inventors.

Table 6 illustrates the format of an exemplary virtual table 4332"'that is used during the mapping process: Entry Type KEY Result # IP-Das-4-bytes Stream-ID + others-2 Keyl Key2 bytes IP1-IP2 DA3-DA4 =B39-B40 =B41-B42 0-9 MC EOKl-E9-Kl EOK2-E9-K2 Stream-IDO-Stream- ID9 10-31 UC ElOKl-E31-ElOK2-E31-K2 Stream-ID10-Stream- Kl ID31

TABLE 6 Table 7 illustrates another exemplary program executed by the adjustable filter 4100 during a mapping process. Entry # Data content Comments 0 Keyl = B39-B40 1 Key2 = B41-B42 2 Mask for MC Keyl Other keys don't need mask 8-17 Keyl for MC entries = EOKl-E9Kl Key Database 18-39 Keyl for UC entries = EIOKI-E31Kl 40-49 Key2 for MC entries = EOK2-E9K2 50-71 Key2 for UC entries = El OKl-E31K2 72-81 Result for MC entries = Result Database Stream-IDO-Stream-ID9 82-103 Result for UC entries = Stream-ID10-Stream-ID31 104-255 Not used

TABLE 7 These stored instructions are fetched by the controller 4310 that will execute the following program: Load Keyl (AO) Matchl-BE register Load Key2 (Al) Match2-BE register Load Mask (A2) Mask register Set Result-MSB register Set Result-LSB register Wait until B=40. Compare-Mask Matchl register to Keyl-MC : A8, Burst =10. Result (reset) from 0.

Compare Matchl register to Keyl-UC: A18, Burst =22. Result (reset) from 10.

Wait until B=42. Compare-Mask Match2 register to Key2-MC: A40, Burst =10. Result (reset) from 0.

Compare Match2 register to Key2-UC : A50, Burst =22. Result (reset) from 10.

Load-Offset Result of the first Match entry (A72 + offset)- Output Register.

END! Figure 38 illustrates a method 4600 for mapping information streams to MAC queues, according to an embodiment of the invention.

Method 4600 starts by stage 4610 of utilizing a distributed media access control scheme to determine a configuration of the network. Stage 4610 includes sending messages between devices of the network, whereas the messages indicate at

least some of the capabilities of the devices, such as their IP address, Ethernet address, MPEG related address, the applications each device supports and the like. The messages are sent over a shared medium, usually during PCA or DRP slot allocated to the transmitting device. It is noted that at least some of the information can be transmitted within a beacon frame.

Conveniently, a device that starts up or changes its environment uses the beacon frames to determine at least the identity of other devices that belong to the network.

Stage 4610 is followed by stage 4620 of adjusting an adjustable filter such as to map application parameters to devices of the networks, in response to the configuration. Stage 4620 can include determining a length of a key used to map an information stream that is characterized by one or more application parameters to a certain MAC layer queue.

Stage 4620 can include determining an amount of different application that should be supported by the adjustable filter and determining the length of the keys in response to said amount. The keys can differ from each other by length, and longer keys are provided when shorter keys can not distinguish between different applications. According to an embodiment of the invention stage 4620 can include providing a virtual table and changing at least its key dimension.

Conveniently, the adjustable filter can determine that it is not capable of supporting all the applications. In such a case some applications can be associated with a processing queue such that they are processed by a processor before being sent to the appropriate MAC layer queue. In such a case some application can be processed by fetching more information from an external memory, or by dropping them.

Stage 4620 is followed by stage 4630 of exchanging information frames between the devices while monitoring the configuration of the network. If the configuration has changed then stage 4630 is followed by stage 4620. Else, stage 4630 can be followed by stage 4630.

Referring to Figure 39, in order to prevent such interference the devices of the child network are allowed to exchange information during one time period, while the devices of the parent network are allowed to exchange information during another

time period. Device 5120 that belongs to both networks is able of exchanging information with devices of the parent group during the one time period or a portion of that one time period. Typically device 5120 is capable of receiving a beacon frame transmitted by the management device 5110 and accordingly to define the transmission window of the child network.

It is noted that the same inefficient use of the wireless medium can occur if the child device is replaced by a neighbor network. A neighbor network does not include a device that also belongs to the parent network, but the transmissions of devices of the neighbor network may interfere with the transmission of devices of the parent network.

Figure 40 illustrates a parent network TDMA frame 5300 and a neighbor TDMA frame 5400. The parent network TDMA frame 5300 starts by a beacon frame 5310 transmitted by the management device 5110. The beacon frame 5310 may include information that determines which device can transmit during various time slots of the TDMA frame 5300. The beacon frame 5310 is followed by a contention time slot 5312, that is followed by multiple slots CTA1-CTAn 5314-5330 that are allocated for a transmission of devices from the parent or neighbor networks.

The second slot CTA 2 is allocated for transmissions of devices of the neighbor network. During this time slot the devices of the parent network (except device 5120) are not allowed to transmit. The neighbor TDMA frame 5400 includes a neighbor beacon frame 5406 and multiple time slots (collectively denoted 5402) during which device of the neighbor network 5200 are allowed to transmit information. These time slots 5402 are followed by a silence period 5404 that starts when CITA 2 of certain parent network TDMA frame 5300 ends and ends when the CITA 2 of the next parent network TDMA frame 5300 starts.

It is noted that the mentioned above as well as the mentioned below TDMA frames are exemplary and that their content can vary from TDMA frame to TDMA frame.

Figure 41 illustrates a parent network TDMA frame 5300 and a child TDMA frame 5500. The child network TDMA frame 5500 starts by a child network beacon frame 5510 transmitted by device 5210 that acts like a child network management

device. The child network beacon frame 5510 may include information that determines which device of the child network can transmit during various time slots of the child network TDMA frame 5500. The child network beacon frame 5510 is followed by a contention time slot 5512, that is followed by multiple slots CCTA 1- CCTA_k 5514-5530 that are allocated for a transmission of devices from the child networks. The last slot CCTA_k 5530 is followed by a silence period.

The second slot CTA 2 is allocated for transmissions of devices of the child network. During this time slot the devices of the parent network (except device 5120) are not allowed to transmit. The child TDMA frame 5500 includes multiple time slots (collectively denoted 5502) during which device of the child network 5200 are allowed to transmit information. These time slots 5502 are followed by a silence period 5504 that starts when CITA 2 of certain parent network TDMA frame 5300 ends and ends when the CITA 2 of the next parent network TDMA frame 5300 starts.

Both child network and neighbor network, as well as other types of networks can be regarded as networks that are affected from the transmissions of the parent network. These transmissions result in a sub-optimal usage of the shared ultra wide band media.

There is a need to provide an efficient method for utilizing the shared ultra wide band media.

Figure 42 illustrates the multiple band groups 5615-5735 allocated for ultra wide band transmission. The first band group 5615 includes the first till third bands 5610-5630. The second band group 5645 includes the fourth till sixth bands 5640- 5660. The third band group 5675 includes the seventh till ninth bands 5670-5690. The fourth band group 5695 includes the tenth till twelfth bands 5700-5720. The fifth band group 5725 includes the thirteenth and the fourteenth bands 5730 and 5740. Each band is 528Mhz wide. The center frequencies of these bands are: 3432 Mhz, 3960 Mhz, 4488 Mhz, 5016 Mhz, 5544 Mhz, 6072 Mhz, 6600 Mhz, 7128 Mhz, 7656 Mhz, 8184 Mhz, 8712 Mhz, 9420 Mhz, 9768 Mhz and 10296 Mhz.

An ultra wide band device, such any of devices 5202-5206 or 5102-5120, can perform one out of several pre-defined frequency hopping sequences. Each frequency hopping sequence is limited to frequencies within a single band group. Each sequence

is associated with a unique Time frequency code. Some codes are allocated for frequency hopping sequences which include a frequency from each band. Other codes are allocated for fixed frequency sequences that include a single frequency.

Before initiating either one of the first or second frequency hopping sequences the receivers and transmitter that are going to use either of these hopping sequence is notified about it. There are various ways to perform such a notification, including sending dedicated messages, synchronization and the like. Conveniently, a transmitter includes information representative of the selected sequence within each information frame he sends. Conveniently, each time frequency code is associated with a unique base time domain sequence and a cover sequence that belong to a packet/frame synchronization sequence that in turn is a part of an information frame PLCP preamble, such as PLCP preamble 1112 of Figure 12.

Figure 43 illustrates a first frequency hopping sequence 6000. This frequency hopping sequence 6000 starts by transmitting a first symbol (represented by box 6002) using a carrier frequency from a first band of a certain band group (denoted by "band &num 1"). This transmission is followed by a guard period denoted 6004. Guard period 6004 is followed by a transmission of a second symbol (represented by box 6006) using a carrier frequency from a second band of a certain band group (denoted by"band #2"). This transmission is followed by a guard period denoted 6008. Guard period 6008 is followed by a transmission of a third symbol (represented by box 6010) using a carrier frequency from a third band of a certain band group (denoted by"band #3"). This transmission is followed by a guard period denoted 6012.

Guard period 6012 is followed by a transmission of a fourth symbol (represented by box 6014) using a carrier frequency from the first band. This transmission is followed by a guard period denoted 6016. Guard period 6016 is followed by a transmission of a fifth symbol (represented by box 6018) using a carrier frequency from the second band. This transmission is followed by a guard period denoted 6020. Guard period 6020 is followed by a transmission of a third symbol (represented by box 6022) using a carrier frequency from the third band. This transmission is followed by a guard period denoted 6024.

An inter-symbol period is defined by the transmission period of that symbol plus the guard time that follows this transmission. Each symbol is usually transmitted during a short time period that is conveniently three hundred nanoseconds long. The guard period is typically about sixty nanoseconds long. Thus an inter-symbol period is conveniently three hundred and sixty nanoseconds.

According to an embodiment of the invention the silence periods are replaced by periods in which the devices of both networks can operate in parallel, but using different frequency hopping sequences, such as not to interfere with each other.

According to an embodiment of the invention the frequency hopping sequences can be substantially the same but be time shifted in relation to each other.

According to another embodiment of the invention the first and second frequency hopping sequences differ from each other and are not just a time shifter version of each other.

Figure 44 illustrates a parent network TDMA frame 5300'and a affected network TDMA frame 6100 according to an embodiment of the invention.

The parent network TDMA frame 5300'does not include a silence period, as the transmission of parent network devices do not interfere the transmissions of the affected network devices. The affected network, or at least one device of the affected network is adapted to use the first frequency hopping sequence during a first period 6102 and use a second frequency hopping sequence during a second period 6104. The first period is used to exchange information with the parent network while the second period 6104 is used for exchanging information between devices of the affected network without interfering to the devices of the first network.

Figure 45 illustrates a first frequency hopping sequence 6000 and a second frequency hopping sequence 6100, according to an embodiment of the invention. The second frequency hopping sequence 6100 equals the first frequency sequence but is delayed by an inter-symbol period. The second frequency hopping sequence 6100 includes the transmissions of multiple symbols (denoted 6102-6122) and multiple guard periods (denoted 6104-6124).

Figure 46 illustrates a first frequency hopping sequence 6000 and a second frequency hopping sequence 6200, according to another embodiment of the invention.

The second frequency hopping sequence 6200 equals the first frequency sequence but is delayed by an half of an inter-symbol period. The second frequency hopping sequence 6200 includes the transmissions of multiple symbols (denoted 6202-6222) and multiple guard periods (denoted 6204-6224).

It is noted that the previous figures illustrate frequency hopping sequences that were limited to a single band group that includes three bands. It is noted that the amount of bands per band group, can be larger than three and that the frequency sequence does not necessarily be limited to frequencies within a single band group.

Those of skill in the art will appreciate that the second frequency hopping sequence can differ from the first frequency, and not just be being a delayed version.

It is noted that at least one device, such as certain device 5120, is capable of monitoring or controlling the second frequency hopping sequence to make sure that the transmissions of the second network devices do not interfere with the transmissions of the first network devices. For example if the frequency hopping sequences differ by a certain delay, that certain device can synchronize to the transmissions of the first network and then introduce a delay between the frequency hopping sequences.

Figure 47 is a flow chart of a method 6500 for ultra wide band transmission.

Method 6500 starts by stage 6510 of allowing a first group of ultra wide band devices to exchange information using a first frequency hopping sequence. Said allowing may include adjusting at least one device of the first group to perform such an exchange of information, informing one or more device that such a frequency hopping scheme should be implemented, and even when it should be implemented.

Stage 6510 is followed by stage 6520 of allowing at least one certain device that is responsive to at least one transmission of information from a device of the first group to exchange information using the first frequency hopping sequence during at least one time period and allowing devices that belong to the second group to exchange information using a second frequency hopping sequence during at least one other time period.

Conveniently, the at least one certain device belongs to the first and second groups of devices. Conveniently, the at least one certain device only belongs to the second group of devices.

Conveniently, the second frequency hopping sequence is substantially a delayed first frequency hopping sequence. Conveniently, the first and second frequency sequences include hopping between frequencies that belong to the same frequency band group. Conveniently, method 6500 involves controlling the exchange of information between members of the second group by the certain device.

Conveniently, method 6500 involves controlling the exchange of information between device of the second group by utilizing a distributed media access control scheme.

Conveniently, method 6500 includes transmitting information representative of the first and second frequency hopping sequences prior to utilizing the first and second frequency hopping sequences.

Conveniently, the first frequency hopping sequence comprises performing a frequency hopping between a transmission of each symbol. Conveniently, the second frequency hopping sequence is substantially a delayed first frequency hopping sequence and wherein the delay is a multiple integer of a inter-symbol period.

Conveniently, the second frequency hopping sequence is substantially a delayed first frequency hopping sequence and wherein the delay is fraction of an inter-symbol period.

Conveniently, stages 6510 and 6520 are repeated for allowing a repetition of multiple transmission sessions between members of the first network and multiple transmission sessions between members of the second network.

Conveniently, method 6500 includes synchronizing between the first and second frequency hopping sequences.

Conveniently, the at least one time period comprises a first set of time periods and the at least one other time period comprises a second set of time periods.

Conveniently, each time period of the first set is followed by a time period of the second set.

It is further noted that Figures 39-46 refer to a network that includes a management entity that applies a media access control scheme. It is noted that according to an embodiment of the invention at least one of the networks can apply a distributed media access control scheme.

Figure 48 illustrates a device 5555 according to an embodiment of the invention.

Device 5555 can be substantially similar to device 60 of Figures 4-5, or one of the devices of the first and second networks 10 and 20 of either Figure 1 or 26, or be similar to device 5555 of Figure 39. And can also be substantially similar to any combination of a receiver and a transmitter illustrated in either one of PCT applications, publication number WO 2004/017547A2 and publication number WO 2004/077684A2 of Wisair Ltd.

Device 5555 can include various components that are shared between its receiver and transmitter, but this is not necessarily so. It can utilize various UWB frequency hopping techniques known in the art.

Device 5555 is capable of exchanging information with ultra wide band devices that belong to a first group or to a second group of ultra wide band (UWB) devices. The first group of UWB devices can be equivalent to first network 10 or to parent network 5100. The second group of UWB devices can be equivalent to second network 20, to child network 5200 or to an neighbor network (not shown).

In order to exchange information device 5555 includes an UWB transmitter 5551 and an UWB receiver 5559. The receiver 5559 is adapted receive information from at least one device of a first group of ultra wide band devices, using a first frequency hopping sequence. Conveniently, the receiver 5559 is also adapted to receive information from at least one device of the first group of ultra wide band devices, using the first frequency hopping sequence during at least one time period and to receive information from at least one device of a second group of ultra wide band devices, using a second frequency hopping sequence, during at least one other time period.

The transmitter 5551 is adapted to transmit information to at least one device of the first group of ultra wide band devices, using the first frequency hopping

sequence during at least one time period and further adapted to transmit information to at least one device of a second group of ultra wide band devices, using a second frequency hopping sequence, during at least one other time period. Conveniently, the transmitted is also adapted to transmit information to at least one device of a first group of ultra wide band devices, using a first frequency hopping sequence.

The device 5555 can manage the access of device of the first and/or second group of UWB devices. Additionally or alternatively, device 5555 can also participate in a distributed media access control scheme in order to control the transmission of devices that belong to the first and/or second group of devices.

Conveniently, device 5555 belongs to the first and second groups of devices.

Conveniently, device 5555 only belongs to the second group of devices.

Conveniently, the second frequency hopping sequence is substantially a delayed first frequency hopping sequence. Conveniently, the first and second frequency sequences include hopping between frequencies that belong to the same frequency band group.

Conveniently, device 5555 is further adapted to transmit information representative of the first and second frequency hopping sequences prior to a utilization of the first and second frequency hopping sequences.

Conveniently, device 5555 is adapted to perform a frequency hopping between a transmission of each symbol. Conveniently, the second frequency hopping sequence is substantially a delayed first frequency hopping sequence and the delay is a multiple integer of a inter-symbol period. Conveniently, the second frequency hopping sequence is substantially a delayed first frequency hopping sequence and wherein the delay is fraction of an inter-symbol period.

Conveniently, device 5555 is further adapted to synchronize between the first and second frequency hopping sequences. Conveniently, the at least one time period comprises a first set of time periods and the at least one other time period comprises a second set of time periods. Conveniently, each time period of the first set is followed by a time period of the second set.

According to an embodiment of any of the mentioned above schemes can be applied by two networks that include at least one relaying device for relaying

information between at least one device of the first network and at least one device of the second network. By applying the frequency hopping scheme both networks can operate substantially seamlessly while the relaying device can exchange information, during at least one time period, with devices of the first network and exchange information, with device of the second network, during at least one other time period.

Whereas at least some of the information exchange includes relaying information.

It will be apparent to those skilled in the art that the disclosed subject matter may be modified in numerous ways and may assume many embodiments other then the preferred form specifically set out and described above. It is noted that each of the mentioned above circuitries can be applied by hardware, software, middleware or a combination of the above. The mentioned above methods can be stored in a computer readable medium, such as but not limited to tapes, disks, diskettes, compact discs, and other optical and/or magnetic medium.

Accordingly, the above disclosed subject matter is to be considered illustrative and not restrictive, and to the maximum extent allowed by law, it is intended by the appended claims to cover all such modifications and other embodiments, which fall within the true spirit and scope of the present invention.

The scope of the invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents rather then the foregoing detailed description.