WO2014138523A1 - Range extension methods and procedures for future wifi - Google Patents

Abstract

A relay device may send an indication to a station relating to the ability of the relay device to act as a relay for the station. The relay device may determine an average priority associated with relay traffic. The relay device may transmit the average priority, e.g., transmit a beacon that includes the average priority. The relay device may receive a probe request from a station. The relay device may transmit a probe response with an allocated priority for the station. The relay device may receive relay traffic from the station. The relay device may transmit the relay traffic based on a priority allocated to the station. The relay device may include the relay traffic in transmitted traffic that includes data associated with the relay itself. The transmitted traffic may include data associated with the station aggregated with device data that is associated with relay device traffic itself.

Description

RANGE EXTENSION METHODS AND PROCEDURES FOR FUTURE WIFi

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61 /774,475 filed March 7, 2013, the contents of which are incorporated by reference herein.

BACKGROUND

[0002] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more STAs (stations) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired'Vireless network that carries traffic in and out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to the respective destinations. Traffic between STAs within the BSS may be sent through the AP where the source STA may- send traffic to the AP and the AP may deliver the traffic to the destination STA. Such traffic between STAs within a BSS may be peer-to-peer traffic. Such peer-to-peer traffic may be sent between the source and destination STAs with a direct link setup (DLS) using an 802.1 le DLS or an 802. i Iz tunneled DLS (TDLS). STAs may communicate with each other in a WLAN in independent BSS mode.

SUMMARY

[0003] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential featitres of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

- i - [0004] Systems, methods, and instrumentalities are disclosed for a relay device to send traffic (e.g., the relay device may prioritize traffic). A relay device (e.g., a WTRU) may be a dedicated relay or other device (e.g., a station acting as a relay, an AP acting as a relay, or a non-station such as a siation acting as an AP acting as a relay). The relay device may send an indication to a station relating to the ability of the relay device to act as a relay for the station. The rel ay device may determine an average priority associated with relay traffic (e.g., relay traffic being sent by the relay device). The average priority may provide an indication of average latency associated with traffic being sent by the relay device. The relay device may transmit the average priority, e.g., transmit a beacon that includes the average priority (e.g., an indication of the average priority). The relay device may transmit the beacon, including the average priority, periodically (e.g., the relay device may periodically determine a current average priority and include the current average priority in the currently transmitted beacon). The relay device may receive a probe request from a station (e.g., from a station evaluating whether to associate with the relay- device). The relay device may transmit a probe response with an allocated priorit for the station. The relay device may receive relay traffic from the station (e.g., traffic to be relayed by the relay device). The relay device may transmit the relay traffic based on a priority allocated to the station. The relay device may include the relay traffic in transmitted traffic that includes data associated with the relay itself (e.g., device traffic, non-relay traffic). That is, the transmitted traffic may include data associated with the station (e.g., relay traffic) aggregated with device data that is associated with relay device traffic itself (e.g., non-relay traffic).

[0005] A relay device may be a non-dedicated relay, such as a station acting as a relay. Such a relay device may have its own data to send (e.g., device traffic), which may be in addition to relay traffic. The relay device may determine that the relay device has device traffic to send. The relay device may determine to transmit the device traffic based on one or more of the allocated priority, existing traffic in a buffer, or the device traffic. The relay device may transmit the device traffic (e.g., according to the determination).

[0006] The station may have a deferral period. For example, the deferral period may indicate a period for the station to wait until accessing a channel. The relay device may determine a priority factor associated with ihe station and send the priority factor to the siation. The priority factor may increase or decrease the deferral period, which may increase or decrease the time that the station waits to access the channel.

[0007] The relay device may have a deferral period. For example, the deferral period may indicate a period for the relay device to wait until accessing a channel. The relay device may determine a priority factor for the relay device. The relay device priority may increase or decrease the deferral period, which may increase or decrease the time that the relay device waits to access the channel. The relay device may determine one or more conditions that may be associated with the relay device needing priority to access the channel. For example, the relay device may determine that an uplink buffer associated with the relay device is full or that the relay device has an amount of data to send that is above a threshold. The relay device may, e.g., in response to the determination, set a priority factor associated with the relay device to a value that gives priority to the relay device to access a channel (e.g., the priority factor may reduce the deferral time for the relay device).

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 A is a system diagram of an example communications system in which one or more disclosed embodiments may be implemented;

[0009] FIG. IB is a system diagram of an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A;

[0010] FIG. 1C is a system diagram of an example radio access network and an example core network that may be used within (he communications system illustrated in FIG. 1A;

[001 1] FIG. ID is a system diagram of an another example radio access network and another example core network that may be used within the communications system illustrated in FIG.

1A;

[0012] FIG. IE is a system diagram of an another example radio access network and another example core network that may be used within the communications system illustrated in FIG. 1 A;

[0013] FIG. IF illustrates exemplary 802.1 1 relay operation;

[0014] FIG. 2 illustrates an exemplary downlink relay from AP to STA through a relay node;

[0015] FIG. 3 illustrates an exemplary uplink relay from STA to AP through a relay node;

[0016] FIG. 4 illustrates an exemplary 1 -hop and 2-hop transmissions;

[0017] FIG. 5 illustrates exemplary- uplink transmissions;

[0018] FIG. 6 illustrates exemplary uplink transmissions;

[0019] FIG. 7 illustrates an exemplar '- source directed dynamic relay transmission in an uplink case;

[0020] FIG. 8 illustrates an exemplary relay device directed dynamic relay;

[0021 ] FIG. 9 illustrates exemplary relay transmissions with multiple relays;

[0022] FIG. 10 illustrates exemplary multiple relays with conditional relay repetition; [0023] FIG. 1 1 exemplary multiple relays with simultaneous transmission for coherent combining;

[0024] FIG. 12 illustrates exemplary multiple relays with selective transmission;

[0025] FIG. 13 illustrates an example of multiple STAs in communication with a relay node;

[0026] FIG. 14 illustrates an example where multiple relay nodes may communicate with an AP;

[0027] FIG. 15 illustrates an exemplary differential primary channel setting in relay systems;

[0028] FIG. 16 illustrates an example of a relay system operating on two frequency bands;

[0029] FIG. 17 illustrates examples of a downlink multiband relay system;

[0030] FIG. 1 8 illustrates an example of downlink multiband relay operation with contention free transmission;

[0031] FIG. 19 illustrates an exemplary multiple user aggregated PPDU transmitted between a relay node and a root AP;

[0032] FIG. 20 illustrates an example of a multi-user aggregated MPDU frame format;

[0033] FIG. 21 illustrates an exemplary R-STA and R-AP with separate RF chain;

[0034] FIG. 22 illustrates an exemplary R-STA and R-AP sharing an RF chain:

[0035] FIG. 2.3 illustrates exemplary poll based simultaneous transmission;

[0036] FIG. 24 illustrates an exemplary predetermined schedule based simultaneous transmission:

[0037] FIG. 25 illustrates exemplary poll based sequential transmission;

[0038] FIG. 26 illustrates an exemplary predetermined schedule based sequential transmission;

[0039] FIG. 27 illustrates an example of an AP broadcasting information to multiple relays;

[0040] FIG. 28 illustrates an example of simultaneous spatial orthogonal transmissions from multiple sectorized relays;

[0041] FIG. 29 illustrates an example of multiple sectorized relaying in the downlink;

[0042] FIG. 30 illustrates example simultaneous spatial orthogonal transmissions from multiple sectorized relays;

[0043] FIG. 31 illustrates an example of data forwarding from multiple relays to the AP;

[0044] FIG. 32 illustrates an example of data forwarding;

[0045] FIG. 33 illustrates an example OBSS with STA1/BSS 1 transmitting;

[0046] FIG. 34 illustrates exemplary OBSS transmission with Relay and TPC;

[0047] A detailed description of illustrative embodiments may now be described with reference to the various figures. Although this description provides a detailed example of possible implementations, it should be noted that the details are intended to be exemplary and in no way limit the scope of the application. In addition, the figures may illustrate message charts, which are meant to be exemplary. Other embodiments may be used. The order of the messages may be varied where appropriate. Messages may be omitted if not needed, and, additional flo ws may be added.

[0048] FIG. 1A is a diagram of an example communications system 100 in which one or more disclosed embodiments may be implemented. For example, a wireless network (e.g., a wireless network comprising one or more components of the communications system 100) may be configured such that bearers that extend beyond the wireless network (e.g., beyond a walled garden associated with the wireless network) may be assigned QoS characteristics.

[0049] The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the

communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (QFDMA), single-carrier FDMA (SC-FDMA), and the like.

[0050] As shown in FIG. 1A, the communications system 100 may include at least one wireless transmit/receive unit (WTRIJ), such as a plurality of WTRUs, for instance WTRUs 102a, 102b, 102c, and 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 1 10, and other networks 1 12, though it should be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and'or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d may be configured to transmit and/or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, consumer electronics, and the like.

[0051] The communications systems 100 may also include a base station 1 14a and a base station 1 14b. Each of the base stations 1 14a, 1 14b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the core network 106, the Internet 1 10, and/or the networks 1 12. By way of example, the base stations 1 14a, 1 14b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Mode B, a Home eNode B, a site controller, an access point (AP), a wireless router, and the hke. While the base stations 1 14a, 1 4b are each depicted as a single element, it should be appreciated that the base stations 1 14a, 1 14b may include any number of interconnected base stations and/or network elements.

[0052] The base station 1 14a may be part of the RAN 104, which may also include other base stations and/or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 1 14a and/or the base station i 14b may be configured to transmit and/or receive wireless signals within a particular geographic region, which may be referred to as a cell (not shown). The cell may further be divided into cell sectors. For example, the cell associated with the base station 1 14a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In another embodiment, the base station 1 14a may employ multiple- input multiple output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell.

[0053] The base stations 1 14a, 1 14b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 1 16, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 1 16 may be established using any suitable radio access technology (RAT).

[0054] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 1 14a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile ^'! eJecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 1 16 using wideband CDMA (WCDMA). WC-DMA may include

communication protocols such as High- Speed Packet Access (HSPA) and/or E volved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High- Speed Uplink Packet Access (HSUPA).

[0055] In another embodiment, the base station i 14a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 1 16 using Long Term Evolution (L^'T^'E) and/or LTE- Advanced (LTE-A).

[0056] In other embodiments, the base station 1 14a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA200G IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0057] The base station 1 14b in FIG. 1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a focalized area, such as a place of business, a home, a vehicle, a campus, and the like. In one embodiment, the base station 1 14b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.1 1 to establish a wireless local area network (WLAN). In another embodiment, the base station 1 14b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 1 14b and the WTRUs 102c, 102d may utilize a cellular - based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. IA, the base station 1 14b may have a direct connection to the Internet 1 10. Thus, the base station 1 14b may not be required to access the Internet 1 10 via the core network 106.

[0058] The RAN 104 may be in communication with the core network 106, which may be any type of network configured to provide voice, data, applications, and/or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. For example, the core network 106 may provide call control, billing se dees, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high-level security functions, such as user authentication. Although not shown in FIG. 1 A, it should be appreciated that the RAN 104 and/ or the core network 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RA 104, which may be utilizing an E-UTRA radio technology, the core network 106 may also be in communication with another RAN (not shown) employing a GSM radio technology.

[0059] The core network 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, i02d to access the PSTN 108, the Internet 1 10, and/or other networks 1 12. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 1 10 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and the internet protocol (IP) in the TCP/IP internet protocol suite. The networks 1 12. may include wired or wireless communications networks owned and/or operated by other service providers. For example, the networks 1 12 may include another core network connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT,

[0060] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities, i.e., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links. For example, the WTRIJ 102c shown in FIG. 1 A may be configured to communicate with the base station 1 14a, which may employ a cellular-based radio technology, and with the base station 1 14b, which may employ an IEEE 802 radio technology.

[0061] FIG. I B is a system diagram of an example WTRIJ 102. As shown in FIG. I B, the WTRIJ 102 may include a processor 1 18, a transceiver 120, a transmit/receive element 122, a speaker/microphone 124, a keypad 126, a display/touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and other peripherals 138. It should be appreci ted that the WTRIJ 102 may include any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0062] The processor 1 18 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller,

Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit fiC), a state machine, and the like. The processor 1 18 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRIJ 102 to operate in a wireless environment. The processor 1 18 may be coupled to the transceiver 120, which may be coupled to the

transmit/receive element 122. While FIG. IB depicts the processor 1 18 and the transceiver 12.0 as separate components, it should be appreciated that the processor 1 1 8 and the transceiver 120 may be integrated together in an electronic package or chip.

[0063] The transmit receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 1 14a) over the air interface 1 16. For example, in one embodiment, the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals. In another embodiment, the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive TR-, UV, or visible light signals, for example. In yet another embodiment, the transmit/receive element 122 may be configured to transmit and receive both RF and light signals. It should be appreciated that the transmit/receive el ement 122 may be configured to transmit and/or receive any combination of wireless signals. [0064] In addition, although the transmit/receive element 122 is depicted in FIG, IB as a single element, the WTRU 102 may include any number of transmit/receive elements 122, More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit/receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 1 16.

[0065] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 122 and to demodulate the signals that are received by the transmit/receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.1 1 , for example.

[0066] The processor 1 18 of the WTRU 102. may be coupled to, and may receive user input data from, the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 1 18 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128. In addition, the processor 1 18 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and/or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other ty pe of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 1 18 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0067] The processor 1 18 may receive power from the power source 134, and may be configured to distribute and/or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry ceil batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0068] The processor 1 18 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 1 02. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 1 16 from a base station (e.g., base stations 1 14a, 1 14b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It should be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0069] The processor 1 18 may further be coupled to other peripherals 138, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands tree headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like.

[0070] FIG. IC is a system diagram of an embodiment of the communications system 100 that includes a RAN 104a and a core network 106a that comprise example implementations of the RAN 104 and the core network 106, respectively. As noted above, the RAN 104, for instance the RA 104a, may employ a UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 1 16. The RAN 104a may also be in communication with the core network 106a. As shown in FIG, IC, the RAN 104a may include Node-Bs 140a, 140b, 140c, which may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 1 16. The Node-Bs 140a, 140b, 140c may each be associated with a particular cell (not shown) within the RAN 104a. The RAN 104a may also include RNCs 142a, 142b. It should be appreciated that the RAN 104a may include any number of Node-Bs and RN Cs while remaining consistent with an embodiment,

[0071] As shown in FIG. IC, the Node-Bs 140a, 140b may be in communication with the RNC 142a. Additionally, the Node-B 140c may be in communication with the RNC 142b. The Node- Bs 140a, 140b, 140c may communicate with the respective RNCs 142a, 142b via an lub interface. The RNCs 142a, 142b may be in communication with one another via an lur interface. Each of the RNCs 142a, 142b may be configured to control the respective Node-Bs 140a, 140b, 140c to which it is connected. In addition, each of the RNCs 142a, 142b may be configured to carry out or support other functionality, such as outer loop power control, load control, admission control, packet scheduling, handover control, macrodiversity, security functions, data encryption, and the like.

[0072] The core network 106a shown in FIG. IC may include a media gateway (MOW) 144, a mobile switching center (MSC) 146, a serving GPRS support node (SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each of the foregoing elements is depicted as part of the core network 106a, it should be appreciated that any one of these el ements may be owned and/or operated by an entity other than the core network operator. [0073] The RNC 142a in the RAN 104a may be connected to the MSG 146 in the core network 106a via an IuCS interface. The MSG 146 may be connected to the MOW 144. The MSG 146 and the MGW 144 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land- line communications devices.

[0074] The RNC 142a in the RAN 104a may also be connected to the SGSN 148 in the core network 106a via an IuPS interface. The SGSN 148 may be connected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 1 10, to facilitate communications between and the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0075] As noted above, the core network 106a may also be connected to the networks 1 12, which may include other wired or wireless networks that are owned and/ or operated by other sendee providers.

[0076] FIG. ID is a system diagram of an embodiment of the communications system 100 that includes a RAN 104b and a core network 106b that comprise example implementations of the RAN 104 and the core network 106, respectively. As noted above, the RAN 104, for instance the RAN 104b, may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 1 16, The RA 104b may also be in communication with the core network 106b.

[0077] The RAN 104b may include eNode-Bs 140d, 140e, 140f, though it should be appreciated that the RAN 104b may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 140d, 140e, 140f may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 1 16. In one embodiment, the eNode-Bs 140d, I40e, 140f may implement MIMO technology. Thus, the eNode-B 140d, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a.

[0078] Each of the eNode-Bs I40d, 140e, and 140f may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink and/or downlink, and the like. As shown in FIG. ID, the eNode-Bs 140d, 140e, 140f may communicate with one another over an X2 interface.

[0079] The core network 106b shown in FIG. I D may include a mobility management gateway (MME) 143, a serving gateway 145, and a packet data network (PDN) gateway 147. While each of the foregoing elements is depicted as part of the core network 106b, it should be appreciated that any one of these elements may be owned and/or operated by an entity other than the core network operator.

[0080] The MME 143 may be connected to each of the eNode-Bs 14()d, 140e, and 140f in the RAN 104b via an S I interface and may serve as a control node. For example, the MME 143 may be responsible for authenticating users of the WTR Us 102a, 102b, 102c, bearer activation/deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 143 may also provide a control plane function for switching between the RAN 104b and other RANs (not shown) that employ other radio technologies, such as GSM or WCDMA.

[0081] The serving gateway 145 may be connected to each of the eNodeBs 140d, 140e, 140f in the RAN 104b via (he SI interface. The serving gateway 145 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c. The serving gateway 145 may also perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when downlink data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like,

[0082] The serving gateway 145 may also be connected to the PDN gateway 147, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 1 10, to facilitate communications between the WTRUs 102 a, 102b, 102c and IP -enabled devices,

[0083] The core network 106b may facilitate communications with other networks. For example, the core network 106b may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the core network 106b may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) thai serves as an interface between the core network 106b and the PSTN 108, In addition, the core network 106b may provide the WTRUs 102a, 102b, 102c with access to the networks 1 12, which may include other wired or wireless networks that are owned and/or operated by other service providers.

[0084] FIG. IE is a system diagram of an embodiment of the communications system 100 ihai includes a RAN 104c and a core network 106c that comprise example implementations of the RAN 104 and the core network 106, respectively. The RAN 104, for instance the RAN 104c, may be an access service network (ASN) that employs IEEE 802.16 radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 116. As described herein, the communication links between the different functional entities of the WTRU s 02a, 102h, 102c, the RAN 104c, and the core network 106c may he defined as reference points.

[0085] As shown in FIG. IE, the RAN 104c may include base stations 102a, 102b, 102c, and an ASN gateway 141, though it should be appreciated that the RAN 104c may include any number of base stations and ASN gateways while remaining consistent with an embodiment. The base stations 102a, 102b, 102c may each be associated with a particular cell (not shown) in the RA 104c and may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 1 16. In one embodiment, the base stations 140g, 140h, 140i may implement MIMO technology. Thus, the base station 140g, for example, may use multiple antennas to transmit wireless signals to, and receive wireless signals from, the WTRU 102a. The base stations 140g, 140h, 140i may also provide mobility management functions, such as handoff triggering, tunnel establishment, radio resource management, traffic classification, quality of sendee (QoS) policy enforcement, and the like. The ASN Gateway 141 may serve as a traffic aggregation point and may be responsible for paging, caching of subscriber profiles, routing to the core network 106c, and the like,

[0086] The air interface 1 16 between the WTRUs 102a, 102b, 102c and the RAN 104c may be defined as an Rl reference point that implements the IEEE 802.16 specification. In addition, each of the WTRUs 102a, 102b, and 102c may establish a logical interface (not sho wn) with the core network 106c. The logical interface between the WTRUs 102a, 102b, 102c and the core network 106c may be defined as an R2 reference point, which may be used for authentication, authorization, IP host configuration management, and/or mobility management.

[0087] The communication link between each of the base stations 140g, 140h, 140i may be defined as an R8 reference point that includes protocols for facilitating WTRU handovers and the transfer of data between base stations. The communication fink between the base stations 140g, 140h, 140i and the ASN gateway 141 may be defined as an R6 reference point. The R6 reference point may include protocols for facilitating mobility management based on mobility events associated with each of the WTRUs 102a, 102b, 102c.

[0088] As shown in FIG. IE, the RAN 104c may be connected to the core network 106c. The communication link between the RAN 104c and the core network 106c may defined as an R3 reference point that includes protocols for facilitating data transfer and mobility management capabilities, for example. The core network 106c may include a mobile IP home agent (MIP- HA) 144, an authentication, authorization, accounting (AAA) server 156, and a gateway 158. While each of the foregoing elements is depicted as part of the core network 106c, it should be appreciated that any one of these elements may he owned and/or operated by an entity other than the core network operator.

[0089] The MIP-HA may be responsible for IP address management, and may enable the WTRUs 102a, 102b, and 102c to roam between different ASNs and/or different core networks. The MIP-HA 154 may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 1 10, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The AAA server 156 may be responsible for user authentication and for supporting user services. The gateway 158 may facilitate mterworking with other networks. For example, the gateway 158 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional landline communications devices. In addition, the gateway 158 may provide the WTRUs 102a, 102b, 102c with access to the networks 1 12, which may include other wired or wireless networks that are owned and/or operated by other service providers.

[0090] Although not shown in FIG. IE, it should be appreciated that the RAN 104c may be connected to other ASNs and the core network 106c may be connected to other core networks. The communication link between the RAN 104c the other ASNs may be defined as an R4 reference point, which may include protocols for coordinating the mobility of the WTRUs 102a, 102b, 102c between the RAN 104c and the other ASNs. The communication link between the core network 106c and the other core networks may be defined as an R5 reference point, which may include protocols for facilitating interworking between home core networks and visited core networks.

[0091] The 802.11 standards body has defined a High Throughput (HT) standard (802.1 In) and a Very High Throughput (VHT) standard (802.1 1 ac). In an infrastructure mode of operation, the AP may transmit a beacon on a fixed channel, which may be the primary channel. This channel may be 20 MHz wide, and may be the operating channel of the BSS. This channel may be used by the STAs to establish a connection with the AP. The fundamental channel access mechanism in an 802.1 1 system may be Carrier Sense Multiple Access with Collision Avoidance

(CSMA/CA). In this mode of operation, each STA, including the AP, may sense ihe primary channel. If the channel is detected to be busy, the STA may back off. One STA may transmit at any given time in a given BSS,

[0092] In 802.1 In, High Throughput (HT) STAs may use a 40 MHz wide channel for communication. This may be achieved by combining the primary 20 MHz channel, with an adjacent 20 MHz channel to form a 40 MHz wide contiguous channel. They may use multiple antennas at both the transmitter and receiver to increase the spectral efficiency (e.g., by sending up to four spatial streams simultaneously) or to increase the reliability of the transmission.

[0093] In 802.1 lac. Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and 160 MHz wide channels. The 40 MHz, and 80 MHz, channels may be formed by combining contiguous 20 MHz channels (e.g., similar to 802.1 In described herein). A 160 MHz channel may be formedeither by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, this may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that divides it into two streams. IFFT, and time domain processing may be done on each stream separately. The streams may be mapped on to the two channels, and the data may be transmitted. At the receiver, this mechanism may be reversed, and the combined data may be sent to the MAC, 802.1 1 ac may support up to 8 spatial streams and may support simultaneous transmission to multiple STAs, e.g., by using downlink Multi-user M l MO (MU-MIMO).

[0094] Range extension may be provided, e.g., in 802.1 In and 802.1 1 ac. In 802.1 1 n or 802.1 1 ac, the technology may be used to increase the rate at a desired range (e.g., improving the throughput) or, improve the range or reliability of a transmission at a desired rate (e.g., extending the range or improving the coverage). Range extension may be obtained by via one or more of the following: improved receiver architectures, such as receive diversity, selection diversity, or iterative receivers; transmit diversity (e.g., an STBC) where there may be no channel knowledge at the transmitter; LDPC channel codes; spatial expansion that may convert spatial diversity to temporal diversity that may be extracted by the channel code; or transmit beamforming, e.g., for where the transmitter may know the channel These may be used to ensure that the SNR or SINR required to achieve a desired performance of a given MCS mode is reduced and may translate to an extension of the range over which the WLAN is able to send information.

[0095] A sub IGHz Wi-Fi system (e.g., 802.1 1 ah) may be provided. Spectrum is being allocated in various countries around the world for wireless communication systems such as WLANs. Such spectrum may be limited in the size and al so in the bandwidth of the channels they comprise. The spectrum may be fragmented in that available channels may not be adjacent and may not be combined for larger bandwidth transmissions. Such is the case, for example, in spectrum allocated below 1GHz in various countries. WLAN systems, for example built on the 802.1 1 standard, may be designed to operate in such spectrum. Given the limitations of such spectmm, WLAN systems may be limited to supporting smaller bandwidths and lower data rates, e.g., compared to HT/VHT WLAN systems for example based on 802.1 ln/802.1 lac. [0096] One or more of the following may be goals for 802.1 1 ah: OFDM PHY operating below I GHz in license-exempt bands excluding Television WbiteSpace (TVWS); enhancements to MAC to support PHY, coexistence with other systems (e.g. 802.15.4 and P802.15.4g);

Optimization of rate vs. range performance (e.g., range up to 1 km (outdoor) and data rates > 100 Kbit's). One or more of the following use cases may apply: Use Case 1 : Sensors and meters; Use Case 2 : Backhaul Sensor and meter data; or Use Case 3 : Extended range Wi-Fi for Cellular offloading.

[0097] Spectrum allocation in some countries may be limited, for example, in China the 470-566 and 614-787 MHz bands may be limited to IMHz bandwidth. There may be a need to support IMHz option as well as support for a 2MHz with an added IMHz mode. The 802.11 ah PHY may be required to support 1, 2, 4, 8, and 16 MHz bandwidths.

[0098] The 802.1 1 ah PHY may operate below 1 GHz and may be based on the 802.1 1 ac PHY. To accommodate narrow bandwidths that may be associated with 802, 1 lah, the 802.1 lac PHY may be down-clocked by a factor of 10. While support for 2, 4, 8, and 16 MHz may be achieved by the 1/10 down-clocking, support for the 1 MHz bandwidth may requires a new PHY definition with an FFT size of 32.

[0099] ΐη 802.1 lah, a use case is meters and sensors, in which up to 6000 STAs may need to be supported within one single BSS. The devices such as smart meters and sensors may have different requirements pertaining to the supported uplink and downlink traffic. For example, sensors and meters could be configured to periodically upload their data to a server which may be likely to be limited to uplink traffic. Sensors and meters may be queried or configured by the server. When the server queries or configures a sensor and meter, it may expect that the queried data may arrive within a setup interval. The server/application may expect a confirmation for configurations performed within a certain interval. These types of traffic patterns may be different than traditional traffic patterns assumed for WLAN systems.

[0100] In 802.11 ah , coverage may be limited by the uplink range because many STAs may be power saving single antenna devices (e.g., use case 3). Coverage may be limited by transmit power regulations across many countries. To improve the coverage, fixed repetition of the transmitted information may be used. Relays may be used.

[0101] Relays may be used in IEEE 802.11 s (e.g., mesh networks), IEEE 802.1 Id (e.g., 60 GHz WLA s) and IEEE 802.1 1 ah (e.g., sub 1 GHz transmission). Relays may provide one or more of the following: relay use may increase AP- STA link range and may improve uplink and downlink coverage; relay use may reduce power consumption at STAs; relay use may reduce the effect of high directivity and path loss in ram wave transmission; relay use may reduce the effect of high penetration loss in mm wave transmission; or relay use may improve connectivity in mesh networks (e.g., 802.1 1 mesh networks).

[0102] Relays may be dedicated relays or non-dedicated relays. Dedicated relays may be those where the relay's function may be limited to fonvarding traffic from the AP to the STAs or vice- versa. Non-dedicated relays may forward traffic from other STAs and may generate its own traffic (e.g., from a sensor attached to the relay).

[0103] 802.1 l ad may (e.g., currently) allow relaying with the relay operation limited to one relay node (e.g., two-hop relays). Two modes of relay operation may be illustrated in FIG. IF - a link switching mode and a link cooperating mode. In a link switching mode, the relay (R) may be used if a source (S)-Destination(D) link is disrupted. ^'This may improve performance degradation due to penetration loss, e.g., at 60 GHz frequencies, that may occur when an object (e.g., a human being) is between ihe S and D. In a link cooperating mode, the S-D frame may be simultaneously repeated by the R to improve signal quality at the D. This may improve performance degradation due to propagation loss, e.g., at 60 GHz frequencies, from the propagation characteristics of the channel.

[0104] An adaptation procedure for a Relay Operation-type Change (ROC) between the two relay operation types may be provided. Relay approaches may include one or more of the following: FD/AF: Full-duplex/amplify- and-forward; or HD/DF: Half-duplex/decode-and- forward. These may be provided in 802.1 1 ad.

[0105] Relays may be provided in IEEE 802.11 TGah. In order to serve STAs with poor wireless link conditions more efficiently with respect to power budget, relay functionality may be provided in the 802, 1 lah Specification Framework Document (SFD). This may extend AP coverage and may help to reduce power consumption on STAs with battery constraints and limited MCS range. A bidirectional two-hop relay function may be used that uses one relay node.

[0106] A relay node may be a device that may include two logical entities: a relay STA and a relay AP. The relay STA may associate with a parent node or AP. The relay AP may allow STAs to associate and obtain connectivity to the parent node/AP via the relay STA. A relay node may allow range extension and supports packet/frame forwarding between source and destination nodes.

[0107] To allo for relay channel access, there may be a sharing of one TXOP, e.g., for ihe source and relay transmission to reduce the number of contentions for channel access. A flow control mechanism at the relay may address the issue of buffer overflow at relay. The system may use a probe request for relay discovery and include information on AP-STA link budget (e.g., if available) to reduce number of responses.

[0108] An example of a downlink relay from AP (e.g., source) to STA (e.g., destination) through a relay node is shown in FIG. 2. This may include an explicit ACK.

[0109] An example of an uplink relay from STA (e.g., source) to AP (e.g., destination) through a relay node is shown in FIG. 3. This may include an explicit ACK.

[01 10] Systems, methods, and instrumentalities may be disclosed to share the medium using the spatial and/or frequency domains. These may include orthogonal transmission implementations. The orthogonal transmissions may include one or more of the following: DL and L^!L MU- MIMO, COBRA, or MU-PCA.

[01 1 1] Systems, methods, and instrumentalities may be disclosed for transmit power control (TPC) between devices in the network. TPC implentarions may include PcFi.

[01 12] Range extension for STAs, and non-STAs, in a WiFi network may be needed. Use cases may include one or more of the following.

[01 13] A high throughput, or data rate, may be required, e.g., wherein there may be up to 50 STAs per BSS. In this case, the radius of the BSS may be large, or the shadow fading pattern may be extreme and/or uneven. Due to the high throughput, the S R at the STA may be high. This may incur interference between STAs in a large network deployment. Mitigation of the interference that facilitates range extension may be needed.

[01 14] A dense AP network deployment may be implemented with overlapping BSS(s) (OBSS). Dedicated or non-dedicated relay/retransmission devices may facilitate range-extension for the STAs that are at the BSS edge or are subject to shadowing. This may relate to 802.1 lac+ or 802.1 lah for example (see below, for example, for WiFi overload).

[01 15] A number (e.g., significant number) of meter, or M2M, type devices may be implemented where the capability for high throughput may not be a priority. Where throughput is not a priority, the SNR for which a suitable data rate is achieved may be low, and, the radius of the BSS may be large. At the network/cell edge the shadow fading may be extreme and/or uneven.

[01 16] A mix of high throughput WiFi off-load devices (e.g., H-type devices) and low throughput, meter or M2M type devices (e.g., Z-type devices) may be implemented. In such a ease, there may be different requirements for the device types and the range over which they transmit. [0 17] Relays may be used for range extension. This may, as described herein, cause one or more of the following: increased traffic delay with two hop relay transmission; signal quality of direct vs. relay transmission may be different; non-dedicated relay operation may need prioritization: or a relay de vice may be a bottleneck.

[01 18] During the transmission of delay limited traffic, the additional time needed for an extra transmission hop may result in an unacceptable latency in data delivery. Adaptive switching between direct and relay transmissions based on the ability of the device to transmit directly to its receiver may be provided. This may reduce overall data transmission latency. Such cases may arise where the STA is in the AP coverage area but has a poor link budget due one or more of the following: being located at the coverage edges: shadowing based on mo vement of objects between the direct or relay links; or fast Rayleigh fading between the devices, e.g., due to channel variation.

[01 19] In environments where the channel is changing, the channel between the source-to-relay, relay-to-destination or source-to-destination may be compromised at different times. This may mean that the relay transmission may be contingent on the state of the different links. Systems, methods, and instrumentalities are disclosed that may limit relay use to times when such use is needed. This may arise where the STA. is in the AP coverage area but has a poor link budget due to one or more of the following: high penetration loss environments such as during mm Wave transmission; shadowing based on movement of objects between the direct or relay links; being located at the coverage edges; or fast Rayleigh fading between the devices, e.g., due to channel variation.

[0120] A non-dedicated relay may send and receive its own information in addition to the information forwarded to and from the STA (e.g., source). Prioritization of the manner in which the non-dedicated relay handles its own traffic and the traffic of its associated source devices may be prov ided. This may be implemented, for example, where the volume and priority of the self-generated traffic may vary.

[0121] The relay device may be a bottleneck in the network due to one or more of the following: limited relay-to-receiver throughput; or the relay device buffer queues are full due to a large amount of traffic from its associated source device(s). Allowing association of the source device with multiple relays and cooperation or coordination between the multiple relays may be provided. This may allow for one or more of the following: increased relay-destination coverage; increased throughput; or seamless hand-o v er with no loss of transmission in the case of one relay buffer queue filling up. [0122] Transmission in wide area relay and heterogeneous networks may cause inefficiencies. A wide area relay network may be a network with multiple STAs and multiple relays transmitting to a root AP. A relay heterogeneous network may be a network with multiple STAs and multiple relays transmitting to a root AP; the STAs may be a mixture of low power, low throughput sensor STAs (e.g., z-type devices) and higher power, higher throughput WiFi offload STAs (e.g., H-type devices). Systems, methods, and instrumentalities are disclosed that may enable efficient data transmission in such specialized networks.

[0123] High density over-lapping BSS environments may cause inefficiencies. Transmission and interference mitigation may be disclosed. In high density over-lapping BSS environments, the introduction of relay nodes may exacerbate the interference environment ihe STAs and AP operate in. Sectorization and transmit power control may be provided, which may enable more efficient data transmission and mitigate the effect of interference in these environments.

[0124] Systems, methods, and instrumentalities are disclosed that may dynamically select between two hop relay transmission and single hop transmission. The STA, relay, and AP may decide (e.g., dynamically) on a direct transmission between the AP and STA or a two-hop relay transmission, e.g., between STA and relay and between relay and AP.

[0125] FIG. 4 illustrates exemplary 1 -hop and 2-hop transmissions and associated architectures, which may include one or more of the following: a STA; a relay, which may comprise a relay - AP (R-AP) and/or a relay-STA (R-STA); or a root AP. A relay device (e.g., a WTRU) may be a dedicated relay or other device (e.g., a station acting as a relay, an AP acting as a relay, or a non- station such as a station acting as an AP acting as a relay),

[0126] Destination directed dynamic relay transmission may be provided. This may initiate the relay transmission if the transmission to the destination device is not successful. The destination may control if the transmission is a 2-hop vs. 1 -hop transmission. The AP may be able to overhear and successfully decode the packet transmitted by the source STA. In such a case retransmission by the relay may waste resources. The receiver may send an ACK after transmission. The receiver may be the STA (e.g., in downlink transmission) or the AP (e.g., in uplink transmission). Where there is no ACK from the receiver, the relay may then transmit the information it has to the receiver.

[0127] FIG. 5 illustrates exemplary uplink transmissions (e.g., with relay behavior), which may include one or more of the following. The STA, relay, and AP may obtain shared TXOP for protected uplink transmission. The STA. may transmit data to Relay- P. If the AP overhears transmission and successfully decodes STA data (e.g., conditional one-hop transmission): in a RTFS (reduced interframe space) time, the AP may send an ACK to the relay-STA and STA, which may pre-empt the relay forwarding its data at a SIFS time; and/or the relay-AP may- forward ACK to STA. This may implicitly truncate the TXOP. If the AP does not overhear the transmission or does not successfully decode STA data (e.g., a two hop transmission): in a SIFS (short interframe space) time, the relay-STA may forward data to the AP, which may implicitly send an ACK to the STA; and/or on successful decoding, the AP may send an ACK to the R~ STA, and, the TXOP (e.g., entire TXOP) may be used. As illustrated in FIG. 5, this may reduce the time needed for a successful transmission and may improve the delay seen by the traffic.

[0128] Figure 6 illustrates exemplary downlink transmissions (e.g., with relay behavior), which may include one or more of the following. The STA, relay, and AP may obtain shared TXOP for protected downlink transmission. The AP may transmit data to the relay-STA. If the STA overhears transmission and successfully decodes the AP data (e.g., conditional one-hop transmission): in RIFS (reduced interframe space) time, the STA may send an ACK to the relay- AP and AP, which may pre-empt the relay-STA forwarding its data at a SIFS time: and/or the relay-STA may forward ACK to AP, which may be needed as the channel on the reverse link- may need the relay operation due to a different interference profile at the AP - the ACK may implicitly truncate the TXOP. If the STA does not o verhear transmission or does not successfully decode AP data (e.g., a typical two hop transmission): in SIFS (short interframe space) time, the relay-AP may forward data to STA, which may implicitly send an ACK to the AP; and/or on successful decoding, the STA may send an ACK to the R-AP. As illustrated in FIG. 6, this may- reduce the time needed for a successful transmission, and, may improve the delay seen by the traffic.

[0129] The relationship between the relay transmission and the receiver ACK may be regarded as a relative timing. For example, the receiver ACK may be sent within a SIFS and the relay- operation may be sent within a SIFS+timeslot delay.

[0130] Source directed dynamic relay transmission may be provided. The source transmitter (e.g., STA in the uplink or AP in the downlink) may decide on whether it initiates a two-hop transmission or a direct transmission to the receiver (e.g., root AP in the uplink or STA in the downlink). For a transmission failure in the one hop case, the relay may re-transmit the information to the relay as discussed herein; this may differ by allowing the transmitter to optimize the transmission parameters for the link it decides to send the information on. In this case, the relay operation may not be transparent. [0131] In this case, the STA may need to be able to compare the channel qualities of the channel between STA to relay-AP and STA to root AP. This may be implemented via one or more of the following.

[0132] Fast link adaptation may be used. The STA may transmit a link measurement request to the receiver and receive a link measurement response within a beam refinement protocol interframe space (BRPIFS). For non-802.1 lad transmissions, the fast link adaptation may be adopted with the link measurerneni response occurring within a subframe inierframe space (SIFS).

[0133] Traditional TPC request and response frames may be used to enable the STA to estimate the path loss between the desired receiver and the STA. The STA may use an estimate based on multiple requests and responses over time to make the decision.

[0134] The transmit power used may be incorporated into beacon/probe response frames for the root AP and relay AP, e.g., to enable the STA to estimate the path loss between the STA and desired AP (e.g., for uplink transmission). The STA may use an estimate based on multiple requests and responses over time to make the decision.

[0135] The STA MAC header may include a flag indicating relay transmission with 1 -hop iTansmission, which may be instantaneous. In the one-hop case, if an ACK is not received within a specified time, the relay may re-transmit the information, e.g., as disclosed herein.

[0136] FIG. 7 illustrates an exemplary source directed dynamic relay transmission in an uplink case. For the uplink case, one or more of the following may be used. The STA may transmit a fast link adaptation request to the AP and R-AP. The AP and R-AP may respond with link parameters, e.g., for optimal transmission. This may be a single request (e.g., with a flag or addressing to indicate that the request is meant for both devices). In this case, the AP may respond in a SIFS time after the link request and the R-AP may respond in a SIFS time after the AP response. The AP and the R-AP may be sent independent requests and may reply to the STA, e.g., independently. The STA may decide on one-hop vs. two-hop transmission. The AP, STA, and relay may obtain a transmit TXOP. The STA may transmit based on its decision. The transmission may include a flag indicating 1-hop vs. 2-hop transmission, e.g., to inform the relay of its decision. In a 1-hop transmission, if a relay does not overhear an ACK within SIFS timing, it may send an ACK to the STA and perform normal relay operations with the AP.

[0137] Relay-device directed dynamic relay transmission may be disclosed. The relay may decide on STAs that may initiate a two-hop relay transmission or a single-hop direct

transmission to the receiver in a dynamic manner. [0138] Based on criteria, the R-AP may dynamically signal STAs to stop transmitting or to initiate direct transmission going forward. Exemplary criteria may include one or more of the following: the amount of data in the relay device buffer waiting to be relayed; or the relative received signal strength at the relay when compared with the received signal strength at the receive device.

[0 39] The information that the source STA is initiating one-hop transmission may assist the source STA, e.g., in optimizing its transmission parameters for the added link. It may be necessary for the relay device to compare the relative quality of the S-R and S-D channels.

[0140] To signal the two -hop/one- -hop status to the AP and the STA, the relay device may use direct signaling or adopt the Restricted Access Window/Target Wake Time mechanism.

Adopting the Restricted Access Window/Target Wake Time mechanism may comprise dynamically specifying the STAs associated with the relay-AP transmit access. The 802.1 1 ah TG may include scheduling mechanisms to allow STAs/APs to agree on intervals of time when operations are permitted, or preferred access is granted, for a subset of STAs using the Restricted Access Window/Target Wake Time (RAW/TWT). The relay-AP may dynamically change the members of the group; the relay- AP may exclude STAs it decides are candidates for one- hop transmission or is unable to service due to traffic considerations. A flag may be used to indicate the STAs eligible for one-hop transmission. The relay may be placed in sleep mode and STAs that are able may be directed to initiate single-hop transmission.

[01 1] The relay-device directed dynamic relay transmission may use one or more of the following.

[0142] The R-AP may initiate channel quality discovery, e.g., by sending out a frame to indicate that a set of source STAs perform a TPC request to the root AP. This set of source STAs may be a single STA, a group of STAs, or each of the STAs associated with the R-AP. A GroupID may be used to identify the set of STAs; each STA in the group may be assigned a specific index within the group.

[0143] The discovery may require a response (e.g., instantaneous) by the STAs and may result in a polled or scheduled TPC request transmission from each STA. The discovery may require that each STA send a TPC request to the root AP as it gains channel access in regular CSMA/CA. The request may be aggregated with normal data frames.

[0144] The AP may send out TPC responses to the TPC request(s). The responses may be sent individually or aggregated in a frame (e.g.,, the AP may wait until each of the STAs have sent in

- '? Ί - their request to send out the response). The relay-AP may estimate the path loss/received power between it and the STA based on the TPC request sent out.

[0145] The relay-AP may overhear the rooi -AP TPC response for each STA and compare the path loss/received power from the source STA at the root-A P with its own. estimate of the path loss/received power. The R-AP may decide on the subset of ST As that may need relay intervention and those that may perform direct transmission. The R-AP may signal its decisions to the source STAs by direct signaling. The relay may send out a. "relay-permitted" frame with addresses of STAs permitted to perform 2-hop transmission.

[0146] The R-AP may signal its decisions to the source STAs by using RAW/TWT. For example, one or more of the following may apply: the relay may define a periodic RAW/TWT that is valid for a given interval of time; the relay may specify a group of STAs that are permitted in the RAW; the members of the group may be dynamically updated based on relay decision; or to add or remove a member from the group, the information may be signaled by the STA address or some other S^'TA. identifier such as STA index within the group.

[0147] Where a STA is removed from the permitted group, flags may be used to trigger one or more of the following: initiate one-hop transmissions; stay silent; or look for another relay.

[0148] FIG. 8 illustrates an exemplary relay device directed dynamic relay, which may include explicit signaling,

[0149] Non-dedicated relay device usage and device traffic prioritization may be disclosed. A non-dedicated relay may be a relay that has its own information to transmit, which may be in addition to the information it has to relay. The implementations described herein may relate to how the relay aggregates the relay and self-traffic and/or how the relay prioritizes traffic from different source nodes and from itsself.

[0150] The relay may aggregate the traffic and may provide one or more of the following. The relay may ensure that the MSDUs for the relay traffic are separate from the MSDUs for the non- dedicated relay and combine both into an Aggregated MDSU (A-MSDU) for transmission. The relay may create separate MPDUs for the relay traffic and the non-dedicated relay traffic and aggregate them into an Aggregated MPDU (A-MPDU),

[0151] To prioritize traffic, QoS, e.g., as proposed in 802.1 le, may be extended to the traffic from the associated devices. In EDCA, the random delay may be calculated as

Total Deferral period = AIFS [Access __ciass]+Backoff[ Access class] where the Arbitration Interframes Space [AIFS], the contention windows, and the backoff calculated may depend on the access class of the data, e.g., background traffic (AC-BK), best effort traffic (AC BE), Video (AC VI), and Voice (AC Voice). A TXOP limit may be set based on the access class. A user priority factor may be used that may modify the Total Deferral period estimation within the relay to enable prioritization of the traffic from different source nodes and modify the upper limit of the TXOP needed for the relay transmission.

[0152] Examples may include one or more of the following.

Total Deferral period = <x{ AIFS [Access class]+Backoff[ Access class]}

In this case, the original deferral period for each user, and each traffic class for the user, may be scaled by a desired priority factor (a) that may be determined by the relay independently or by a handshake procedure between the relay and the source.

Total Deferral period = AlFS[Access_class]+Backoff[Access_class]-p,

p>0, Total Deferral period >0

In this case, the original deferral period for each user may be modified by a desired priority factor (p) that may be determined by the relay independently or by a handshake procedure between the relay and the source.

[0153] The values of the priority factors may be selected to influence behavior, e.g., as illustrated in the following exemplary cases: when the UL RS buffer is full and when the non- dedicated relay node has a lot of traffic to send (e.g., its own traffic). When the UL RS buffer is full, the priority factor (a or β) may be selected to ensure that the relay gains access to the channel. The TXOP limit may be set to the maximum allowable value. When the non-dedicated relay node has a lot of traffic to send (e.g., an amount of data above a threshold), the priority factor (a or β) may be set for the relay node traffic to ensure that the relay node information is transmitted. As an example, a-0, which may imply that its own traffic is mandatorily sent.

[0154] One or more of the following may be performed (e.g., in the case where non-dedicated relay device and device traffic prioritization may be implemented). The relay may broadcast a number of users and/or average priority (e.g. in beacon). The broadcast may be sent periodically. The average priority may be an integer that maps to a value of a or β. The source STA may- associate with the relay based on a probe request. The probe request m y include a requested priority value. The relay may respond with a probe response and/or allocated priority. The STA may evaluate the priority allocated and use the value as a possible factor in deciding to associate with the relay. The STA may start data transmission to/from the relay. The relay may use one or more of STA priority, existing traffic in the relay buffer, or traffic in its own buffer to decide on information relayed.

[0155] Multiple relay coordination and cooperation may be disclosed. A source device may be allowed to associate with multiple relays. The multiple relays may cooperate or coordinate to increase the relay-destination coverage, throughput, or enable seamless hand-over with no loss of transmission, e.g., in a case where one relay buffer fills up.

[0156] FIG. 9 illustrates exemplary relay transmissions with multiple relays. There may be a relay network with a source STA, two relays (e.g., Rl and R2) and a root AP (e.g., destination D), The architecture may relate to multiple relays with conditional relay repetition, multiple relays with simultaneous transmission for coherent combining, and/or multiple relays with selective transmission.

[0157] FIG. 10 illustrates exemplary multiple relays with conditional relay repetition. Relating to multiple relays with conditional relay repetition, conditional relay repetition may be used, e.g., the second relay may transmit if the first relay fails (e.g., the second relay may not transmit if the first relay is successful). One or more of the following may be implemented. The STA may associate with relays Rl and R2. The STA may associate with Rl and R2. independently. The STA may associate with relay Rl as the primary relay. Relay Rl may inform the STA that R2 (e.g., a secondary relay) is available. The STA may associate with relay Rl as the primary relay. The STA may inform relay Rl that R2 is a candidate. Rl and R2 may set up the coordination separately. For a specific uplink transmission, STA, Rl , R2, and AP may obtain a TXQP for transmission. The STA may send data, e.g., to Rl and R2. Rl may send data to the AP after SIFS timing. If there is no ACK, R2 may send data to the AP, e.g., after 2*SIFS + Datalength + slottime timing. The AP may combine information from Rl and R2 and send back an ACK. Primary Rl may send ACK back to the STA.

[0158] FIG. 1 1 illustrates exemplary multiple relays with simultaneous transmission for coherent combining. In a case of multiple relays with simultaneous transmission for coherent combining, the data from each relay may be weighted in a manner as to ensure that it combines coherently with other relay(s) that may be transmitting simultaneously. One or more of the following may be implemented. The STA may associate with relays Rl and R2. The STA may associate with Rl and R2 independently. The STA may associate with relay Rl as the primary relay. Relay Rl may inform the STA that R2 (e.g., a secondary relay) is available. The STA may associate with relay Rl as the primary relay. The STA may inform Relay Rl that R2 is a candidate. Rl and R2 may set up coordination separately. For a specific uplink transmission. STA, Rl, R2, and AP may obtain a TXOP for transmission. The STA may send data, e.g., to Rl and R2. R elays Rl and R2 may send data to AP after a SIFS timing, where one or more of the following may apply: it may be assumed that the channel between Rl and AP is hi ; it may be assumed that the channel between R2 and AP is h2; or it may be assumed the information to be sent is s. Rl may send conj(hl)*s, and R2 sends conj(h2)*s, where conj(x) is the complex conjugate of subcarrier channels. The AP may combine information from Rl and R2. Given the transmission configuration where Relays Rl and R2 may send data to AP after a SIFS timing, the received signal may become (h l^A2 + h2^A2)*s. On successful decoding, the AP may send back an ACK to R l and R2. The primary Rl may send ACK back to STA.

[0159] In the multiple relays with simultaneous transmission for coherent combining ease, it may be necessary for both relays to be synchronized. This may be performed by timing advance/retard frames from the AP.

[0160] FIG. 12 illustrates exemplary multiple relays with selective transmission. In a ease of multiple relays with selective transmission, either of the two relays transmits (e.g., transmission during a relay operation may be limited toone relay transmiting ). One or more of the following may apply. The STA may associate with relays Rl and R2. The STA may associate with Rl and R2 independently. The STA may associate with relay Rl as the primary relay. Relay Rl may inform the STA that R2 (e.g., a secondary relay) is available. The STA may associate with relay Rl as the primary relay. The STA may inform relay Rl that R2 is a candidate. Rl and R2 may set up coordination separately . For a specific uplink transmission, STA, Rl, R2, and AP may obtain a TXOP for transmission. The STA may send data, e.g., to Rl and R2. Relay Rl or relay R2 may send data to AP. For example, Rl or R2 may send data to the AP based on a SIFS + random backoff timing. There may be a statistical selection between Rl and R2, For non- dedicated relays or relays with a queue overflow (e.g., due to much traffic), the state of the queue may dictate the relay that sends the information. The STA may indicate which relay should forward its packet. The decision may be influenced by one or more of: the reliability of the relay from the STAs point of v iew; or path loss estimates between 8-R1, S-R2, Rl-AP, and/or R2-AP. To enable this information to reach the STA, the STA may perform a TPC request to Rl and R2. Rl and R2 may perform a TPC request to the AP and tonvard the results to the STA. On successful decoding, the AP may send back an ACK to Rl and R2, The relaying device (e.g., Rl or R2) may send an ACK back to the STA.

[0161] Multi-user, multi-device, and/or multi-frequency type relays for uplink and downlink may be used. In such a case, one or more of the following may apply: multi-STA transmission to relay (e.g., multi-user relay); multi-relay transmission to the AP (e.g., multi-user relay); multiple z-type (low data rate) STAs to H-type (high data rate) relay (e.g., multi-device); STA-Relay frequency different from Relay-AP (e.g., multi-frequency); or multi-user aggregation, e.g., A- MPDU.

[0162] Multi-STA transmission to relay (e.g., multi-user relay) may be disclosed. In dense deployment, it may be likely that one relay node is associated with many end STAs (e.g., as illustrated in the example of FIG. 13). FIG. 13 illustrates an example of multiple STAs that may communicate with the relay node, e.g., simultaneously. The STAs may sense and acquire the media, e.g., using basic SCMA protocols. The STAs may share the medium using a TDD mode. Orthogonal transmissions may be used, e.g., as disclosed herein.

[0163] Multi-user orthogonal transmissions may be introduced between a relay node and STAs which are associated with it, which may improve the spectral efficiency. Non-relay STAs may perform UL orthogonal transmissions to the relay node. The relay node may perform DL orthogonal transmissions. Some DL orthogonal transmissions may be defined in IEEE 802.1 1 ac. The STAs may transmit to or receive from the relay node simultaneously. The relay node may distinguish the transmission from each STA by each STAs spatial signature, frequency band, or time slot,

[0164] A relay node may support one or more of the following transmission modes: diversity ; SLI-MIMO: or MU-MIMO DL. A relay node may choose to use a particular transmission mode independent of the mode of associated APs, non-STAs, and/or STAs. The implementation a relay node uses (e.g., for initiating a particular mode of operation) may be configured using a specific control channel, such as for example a primary channel. The control channel may be sent with or without the use of an associated relay node.

[0165] Some of the orthogonal transmissions may require know ledge of the channel state information at the transmitter. Channel sounding and feedback may utilize the NDP

announcement frame, NDP frame, and VHT compressed beamforming frame, e.g., defined in 802.1 l ac. It may be possible that the relay node and the AP may hear the compressed beamforming feedback frame which carries the compressed channel information from the STA. Distinguishing whether the destination is the relay node or the AP may be performed.

Transparent relay node to non relay STAs, e.g., the non relay STA does not know it

communicates with a relay node other than an AP, may be used. A four address-like implementation may be used, e.g., to identify the source, destination, and relay node. For beamforming training with relay, one or more of the following may be used: allowing MU- MlMO/beamforming training between a pair or set of non-AP STAs, e.g., as long as each of the non-AP STAs associate with one AP; or the NOP announcement frame and VHT compressed beamforming frame may include the MAC address of the STA , which may require the MU- MIMO/beamforniing training (for example, if the relay node requires the MU-- MJMO/beamforming training, then the MAC address of the relay node may be included in the frames).

[0166] If UL orthogonal transmission is considered, then the frames utilized for synchronization, power control, uplink orthogonal transmission management, etc., may need to be designed with the relay node MAC address.

[0167] Orthogonal transmissions that share the media in the spatial domain may be efficient to increase the system throughput. The spectrum may be shared orthogonally in the frequency domain. The relay node may operate on a wider bandwidth channel; the STAs may operate on the channels with bandwidth not in excess than that of the relay node. For example, ihe relay node and the AP may operate on an 8MHz bandwidth, while some of the STAs may be limited to supporting 2MHz, and other STAs may be able to support 4MHz and 8MHz. The STAs that support less bandwidth may operate on a portion of the wider channel (e.g., in 802.1 1). For example, the STAs supporting 2MHz transmission may operate on the 2MHz primary channel of the 8MHz wide band. Orthogonal implementations that share the media in the frequency domain may be utilized, which may improve spectral efficiency. Each user may be allocated to one or multiple sub -channels of the frequency band. Multiple users may share ihe frequency band, e.g., simultaneously, it may not be necessary for each of the transmissions to go through the primasy channel. The above implementations may be utilized for transmissions from relay node to STAs, and/or from STAs to relay nodes. Grouping, synchronization, power control, and/or management frames may be applied (e.g., as necessary). The MA C address of the relay node may be specified in some of the control frames and management frames.

[0168] For the orthogonal transmissions as decribed herein, a group ID may be utilized, e.g., to indicate a group of STAs that may share the media, e.g., simultaneously. The group IDs may be maintained and announced by the root AP. With a relay system, each relay node may maintain and announce its own group ID, e.g., more groups may be formed within one BSS. The chance that two different groups share the same group ID may be higher;the STAs may eventually need to check the MAC address to confirm whether it is in the group.

[0169] Multi-relay transmission to the AP may be disclosed (e.g., multi-user relays). Multiple relay nodes may communicate with the AP, e.g., simultaneously. FIG. 14 illustrates an example where multiple relay nodes may communicate with the AP, e.g., simultaneously. As shown in the example of FIG. 14, the AP may communicate with two relay nodes, and, each relay node may associate with several ST As. The relay nodes may follow CSMA/CA protocol to sense the channel and then acquire the media to transmit. The relay nodes may need to transmit one after another. Simultaneous transmission may be used, which may improve spectral efficiency. One or more of the following may apply.

[0170] The AP may perform orthogonal transmission in the spatial domain to communicate with multiple relay nodes, e.g., simultaneously, and, the multiple relay nodes may be distinguished by their spatial signature. The traffic load from relay node to the AP may be heavy, e.g., the relay node or the AP may aggregate several packets and then send them out, and, beamforming training may be performed, which may require accurate compressed beamforming feedback. Accurate compressed beamforming feedback may be performed by increasing the feedback resolution, using the history of previous feedback to help improve the feedback accuracy, etc. It may be assumed that the location of the relay node is relatively fixed, and, the channel between relay node and the AP does not change greatly.

[0171] The AP may perform orthogonal transmission in the frequency domain to communicate with multiple relay nodes, e.g., simultaneously. Since the location of the relay nodes may be relatively fixed, the AP may save the timing and frequency synchronization parameters and power alignment parameters for each relay node utilized and may reuse them or update them based on their history, e.g., for additional orthogonal transmissions.

[0172] Multiple z-type (low data rate) STAs to H-type (high data rate) relay systems may be disclosed (e.g., multi-device type). This may include using one or more of a differential primary channel setting or a dedicated relay node.

[0173] A differential primary channel setting may be used. The device capability in one BSS may be different. For example, with 802.1 1 ah, the AP may be able to operate on an SMHz bandwidth channel, while the devices associated with it may be limited to supporting2MHz. The relay nodes may set the primary channel differently so that the 2MHz STAs may not operate on the same primary channel simultaneously, which may reduce interference between users. FIG. 15 illustrates an exemplary differential primary channel setting in relay systems. The root AP may operate on an 8 MHz channel, which may include four 2MHz channels. The root AP may set channel 1 as the primary channel. Relay node 1 may operate on the same frequency channel as the root AP. Relay node 1 may set channel 4 as the primar channel. Relay node 2. may set channel 2 as the primary channel. The root AP and relay nodes may transmit a beacon with a 2MHz duplicate mode, e.g., so that a 2Mhz STA may detect the beacon correctly.

[0174] A dedicated relay node may be used. There are other possible classifications of de vice types. For example, some devices may be limited to supporting simple operations. The devices may be power and data rate limited. ^'The number of these types of devices may be large. Other devices may support complex operations, e.g., which support a higher data rate. The AP may ask a relay node to serve certain type of devices dedicatediy, e.g., a relay node may service the former devices, but not the latter, or, vice-versa.

[0175] A dedicated relay node may be used in an operating frequenc band. For example, the root AP may operate on a wider bandwidth channel that aggregates narrow bandwidth channels. Some STAs may be limited to operation on certain bandwidth. The root AP may ask the relay node to operate on a narrower bandwidth, which may dedicatediy serve some of the STAs in the BSS.

[0176] A STA-Relay frequency that is different from Relay- AP may be used (e.g., multi- frequency). The links between relay node and root AP may operate on a different frequency band than the links between relay node and STAs. FIG. 16 illustrates an example of a relay system operating on two frequency bands. For example, the link between relay node and root AP is operating on 5GHz frequency band, while the links between relay node and STAs are on 2.4GHz frequency band. Other frequency bands may be possible. For example, the sub- 1 GHz frequency band may be utilized between STAs and a relay node. The usage of sub- 1 GHz may relate to sensor networks for example. The network may need to support a large number of devices in a relatively large range, and, the data rate may not be very high. The relay node may aggregate the traffic from multiple STAs and send to the root AP via a relay link, which may be operated on a different frequency band, e.g., 2.4GHz, and, with higher data rate. 60GHz transmission may be utilized for a relay link. The location of the relay node may be fixed, and, the link between root AP and relay node may be suitable for directional transmission.

[0177] With multiband relay operation, the root AP and relay node may be multiband capable. A multiband capable device may be able to operate on multiple frequency bands, e.g., simultaneously, or, may be able to operate on one frequency band at one time and switch to the other band, e.g., when a transmission is completed. The AP and relay node may broadcast the multiband capability in a beacon, probe request, and/or probe response frames.

[0178] F G. 17 illustrates examples of a downlink multiband relay system, e.g., with contention based transmission. Band 1 and band 2 may indicate two frequency bands. The relay node may be communicating with the STAs on band 1. The relay node may communicate with the AP on band 2.

[0179] FIG. 17(a) illustrates an example where the relay node may operate on band 1 and band 2 simultaneously. The root AP may transmit packet 1 (PI ) to the relay node over band 2. The relay node may reply with an ACK within SIFS time. The relay node may prepare to forward the packet to the destination STA over band 1 , e.g., once receiving the packet. The transmission from relay node to the destination STA may occur at a time SIFS away from the PI transmission. ^'The transmission on band 1 may follow the basic channel access protocol utilized on band 1 , e.g., the CSMA/CA protocol

[01 80] FIG. 17(a) illustrates an example where the relay node may operate on band 2 and then switch to band 1 , e.g., the relay node may operate on one band at a time and switch to another band, for example, after the completion of a transmission on the operating band. After the reception of PI on band 2, the relay node may wait for the transmission of the ACK frame and may prepare to switch to band 1. The relay node may broadcast to its associated STAs on band 2. and may transfer to band 1. After completion of the band transfer, the relay node may broadcast on band 1. The root AP that may be associated with the relay node on band 2, may hold the traffic until the relay node transfers back from band 1 to band 2. The root AP may communicate with the relay node on band 1, e.g., before transfer, if it can compete for the channel

successfully. Once the relay node operates on band 2, the STAs associated with the relay node may hold the traffic until detecting the broadcast frame transmitted from the relay node over band 1, which may indicate that the relay node is back to band 1 .

[0181] Some 802.11 specifications support contention free transmissions. In such a case, it may be possible to schedule the TXOPs on multiple bands, e.g., with good timing. FIG. 18 illustrates an example of downlink multiband relay operation with contention free transmission. It may be assumed that at least one band is in a contention free mode. FIG. 18(a) illustrates an example where the relay node may operate on the two bands simultaneously. FIG. 18(b) illustrates an example where the relay node may operate on band 2. and switch to band 1. The TXOP may be defined to cover the transmission on that band, e.g., enough to cover but not more or

substantially more. For example, the TXOP on band 1 may cover the transmission of PI and ACK on band 1, e.g., but not more or substantially more. The TXOP may be extended, and, the TXOP may be identical on both bands, which may cover the relay transmission, e.g., the entire relay transmission. [0 82] Multi-user aggregation e.g. A-MPDU, may be disclosed. A relay node may aggregate packets from multiple users and forward to the AP. A-MSDU aggregation may be utilized between the root AP and a relay. One or more of the following multi-user aggregation implementations may be used.

[01 83] FIG. 19 illustrates an exemplar}/ multiple user aggregated PPDU transmitted between a relay node and a root AP. A PPDU may include a preamble part and data part. Multi-user A- PPDU may aggregate the PPDUs from multiple users together to form a frame, e.g., in the example of FIG. 19, a frame for three users. Each PPDU may have a separate modulation and coding scheme. A separate preamble may be utilized. Since the transmission of this multi-user A-PPDU frame may be beiween a root AP and a relay node, ihe physical channel may be similar and it may be possible to have a common SIG field for each of the PPDUs. Examples of multiuser A-PPDU frame design may include one or more of the following. A full set of preamble, which may include STF, LTF, and/or SIG fields may be presented at the beginning of each PPDU, e.g., as shown in FIG. 19(a), A common SIG field may be utilized and repeated for each PPDU. A separate SIG field may be defined for each PPDU. A Preamble-Midamble format may^¬ be used. The preamble may be ittilized for the first PPDU. For the rest of PPDU(s), midambles may be inserted, which may be used to improve channel estimation and frequency offset estimation. FIG. 19(b) illustrates utilizing the preamble for the first PPDU. The SIG field may be repeated in the midambles; the SIG field may be limited to transmission in the preamble, etc. The SIG field may be repeated. A full set of preamble, including STF, LTF, and/or SIG field may be utilized for the first PPDU, and SIG fields may be inserted at the beginning of the rest of the PPDUs. A. common SIG field may be utilized. Different SIG fields may be defined for different PPDUs.

[01 84] A multi-user aggregated MPDU may be disclosed. An example of a multi-user aggregated MPDU frame format, e.g., transmitted between a relay node, is illustrated in FIG. 20. Each of the user packets may share the same preamble, which may include STF, LTF, and/or SIG fields. One set of modulation and coding parameters may be defined in the SIG field for the entire aggregated frame. The data payload for each non-relay STA user may be self-contained in an MPDU frame. An MPDU delimiter may be added in front of the MPDU frame. A pad maybe appendixed, e.g., if necessary. Each of the MPDUs within the multi-user A-MPDU may be addressed to the same receiver address, e.g., the root AP or the relay node depending on the direction of the transmission. Source address and destination address may be utilized to specify the source node and destination node for relay transmissions. A block ACK may be transmitted within a multi-user A-MPDU, Other management frames and control frames, e.g., such as a compressed beamforming feedback frame or management frames defined for multi-user enabling technologies such as disclosed herein, may be considered to transmit within the multiuser A-MPDU frame.

[01 85] Simultaneous transmission to or from a relay may be disclosed. The traffsc at the relay node may be divided into two categories - traffic from the relay to the AP and S^'TAs (e.g., outbound) and traffic to the relay from the AP and STAs (e.g., inbound). Outbound transmission may be sequential or parallel. Inbound transmission may be sequential or parallel.

[0186] R-AP and R-STA may be two logical entities inside a relay node, which may share RF chains or have separate RF chains. If there are separate RF -chains for the entities, simultaneous reception from AP and transmission to STA and vice versa may be achieved, e.g., using FDD. R-STA and R-AP may share common RF-chains. MU-MIMO (e.g., DL-MU-MIMO for outbound and UL-MU-MIMO for inbound traffic), or other orthogonal transmission (e.g., as described herein) may be used at PHY layer, e.g., for simultaneous transfer. FIG, 21 illustrates an exemplary R-STA and R-AP with separate RF chain. FIG. 22 illustrates an exemplary R- STA and R-AP sharing an RF chain.

[01 87] The traffsc between the AP and R-STA may be heavier than traffic between the R-AP and STAs, A channel condition between the AP and R-STA may be better, A channel between the AP and R-STA may be less correlated than the channel between the R-AP and different STAs. One or more of the follo wing may apply .

[0188] In MU-MIMO outbound traffic, linear or non-linear DL-MU-MIMO may be used. Eigen beamforming may be used in DL-MU-MIMO. Unequal modulation may be used for AP and different STAs. More spatial streams (e.g., layers) may be assigned for transmission to AP and may be reassigned, e.g., dynamically. If the transmissions are orthogonal in frequency domains, asymmetric and dynamically varying bandwidths may be used. The channel may be accessed in one or more of the following ways: R-PCF (Relay specific Point coordination function); or R- DCF (Relay specific Distributed Coordination Function). The relay node may switch between these modes, e.g., depending on the buffer conditions.

[01 89] A relay specific point coordinated function (R-PCF) may be used. This may include one or more of the following: a simultaneous R-PCF mode; polling based scheduling in simultaneous R-PCF; predetermined schedule simultaneous R-PCF; sequential R-PCF mode; polling based scheduling sequential R-PCF mode; or predetermined schedule in sequential R-PCF mode.

[0190] In R-PCF mode, latency between the AP and STA may be reduced, e.g., by using a relay as a central coordinator. This mode of operation may be activated in high-traffic scenarios. In the R-PCF mode, the AP may acquire TXOP establishing a contention free period (CFP) using a beacon, e.g., a special CFP. It may use the same beacon or the frame following the beacon to delegate the relay-node, e.g., to co-ordinate the traffic. The relay node may have, or may acquire, knowledge of the buffers of the AP and each of the STAs connected to it. The relay node may use this information to schedule the traffic. As discussed herein, PHY data may be transferred simultaneously or sequentially.

[0191] In a simultaneous mode of R-PCF, multiple STAs may send inbound data to the R-AP simultaneously. Depending on the situation, one or more STAs and AP may send the inbound data simultaneously to R-AP and R-STA respectively. At the PHY layer, the R-AP and R-STA may use MU downlink or MU uplink techniques separately or together. For outbound data, R- AP may send data simultaneously to multiple STAs. R-AP and R-STA may send to multiple STAs and AP simultaneously. For the simultaneous mode, types of scheduling may include one or more of the following: polling based scheduling; or predetermined schedule.

[0192] In polling based scheduling in simultaneous R-PCF, a poll may be sent by the relay-node to each group sequentially throughout CFP. Each of the members in the group may send data in MU uplink in response to the polling.

[0193] FIG. 23 illustrates exemplar '- oll based simultaneous transmission. In FIG, 23, the boxes labeled Data (STA 1 + STA 2) and Data (AP) may represent inbound simultaneous traffic and boxes labeled Data +CF-P0II (STA 1 + STA 2), CF-ACK+Data+CF-Poll (STA 1 + STA 2), CF-ACK+Data+CF-Poll (AP), and CF-End may represent outbound simultaneous traffic.

[0194] In the example of poll based simultaneous transmissions, one or more of ihe following may be performed. An AP may periodically establish CFP using the beacon. The AP may send a delegation poll to a specific R-STA, which it may want to delegate the coordination of the medium in that CFP. It may piggyback downlink data for STAl and STA2. It may indicate it has more data in buffer. The R-STA may send an ACK, e.g., accepting the delegation. The R- AP may transmit data to STAl and STA2 simultaneously using MU-Downlink, It may send CF- Poll. STA 1 may send CF-ACK and may indicate it has more data to send to the AP. STA2 may send CF-ACK. The R-AP may give grant to STA l and R-STA may give grant to the AP to send data simultaneously. The R-AP and R-STA may receive data using MU-Uplink on same PHY layer. The R-STA may fill the buffer with data to be transmitted to STAl and STA2 via R-AP. The R-AP may fill the buffer with data to be transmitted to AP via R-STA. Using a same PHY layer and MU-downlink, R-STA / R-AP may transmit data simultaneously. The R-STA may receive CF-ACK from the AP and R-AP may receive CF-ACK from STAl and STA2. R-AP and R-STA may send simultaneous CF-End to STA and AP respectively, which may end CF period. In the next CFP, a similar implementation may be repeated.

[0195] If the STA or AP fails to respond CF-Poii within PIFS, retransmission of the data and CF-Poli may be sent again. This may be as discussed in relation to the sequential R-PCF case. Each interval may be SIFS. A smaller interval such as RTFS may be used.

[0196] A predetermined schedule of simultaneous transmissions may be used for R-PCF. The predetermined schedule may be sent by the relay in first frame of the CFP and each of the groups may transmit data in that order. Each STA in a group may use MU techniques to perform simultaneous transmissions (e.g., all STAs in the group may transmit simultaneously via MIT techniques). Each of the STAs associated with a group for transceiver operation with a relay may^¬ be configured to use Multi-User MIMO procedures and protocols by the relay.

[0197] FIG. 24 illustrates an exemplary predetermined schedule based simultaneous transmission. In FIG, 24, the upper and lower boxes on the right of the figure may represent inbound simultaneous traffic. In FIG. 24, the boxes fully between AP and R-AP on the figure may represent outbound simultaneous traffic.

[0198] In the example of predetermined schedule based transmission, one or more of the following may be performed. The AP may periodically establish CFP using the beacon. The AP may send a delegation poll to a specific R-STA, to which it wants to delegate the coordination of the medium in that CFP. It may piggyback downlink data for STAI and STA2. It may indicate it has more data in buffer. The R-STA may send an ACK, e.g., accepting the delegation. The relay node may decide the schedule of transmission. The R-AP may send this schedule to STAI and R-STA. may send this schedule to the AP. The simultaneous outbound transmission may be performed using MU-downlink. This may update the NAV duration. According to schedule R- STA may send MU-downlink to STAI and STA2, e.g., received as described herein. STAI , STA2, and AP may send simultaneous inbound traffic (e.g., MU- Uplink at PHY layer) to R-AP and R-STA. The R-AP and R-STA may combine outbound transmission (e.g., MU-Downlink at PHY layer). The R-AP may relay the data received at R-STA (e.g., as described herein) from AP to STA I and STA 2. The R-STA may relay the data received at R-AP (e.g., as described herein) from STAI and STA2 to AP. STAI and AP may send simultaneous inbound traffic (e.g., MU-Uplink) to R-AP and R-STA. The R-AP and R-STA may combine outbound transmission (e.g., MU-Downlink). The R-AP may relay the data (e.g., as described herein) to STAI and STA2. The R-STA may relay data received (e.g., as described herein) to the AP. STAI and AP may send simultaneous inbound traffic to R-AP and R-STA. The R-AP and R-STA may combine outbound transmission. The R-AP may relay the data (e.g., as described herein) to STAl . The R-STA may relay data received (e.g., as described herein) to the AP. In the next CFP, a similar implementation may be repeated.

[0199] In the above, for inbound traffic (e.g., MU-Uplink) synchronization between different AP/STAs may be needed. Signaling of timing advance for each STA as well as AP while sending first-frame or pre-adjustment during polling may be used for coarse synchronization. Each of the intervals may be SIFS. A smaller interval such as RIFS may be used.

[0200] Sequential mode of R-PCF relay may be a specific case of simultaneous mode. In sequential mode of R-PCF, one node may transmit at a time. Types of scheduling may include one or more of the following: polling based scheduling; or predetermined schedule.

[0201] Polling based scheduling sequential R-PCF mode may be disclosed. In polling based scheduling where a poll may be sent by the relay-node to each node sequentially throughout CFP. FTG. 25 illustrates exemplary poll based sequential transmission.

[0202] Each node may send data in response to the polling. In the example of polling based transmission, one or more of the following may be performed. The AP may periodically establish CFP using the beacon. The AP may establish NAV. The AP may send a delegation poll to a specific R-STA, to which it wants to delegate the coordination of the medium in that CFP. It may piggyback downlink data for STAl . The R-STA may send an ACK, e.g., accepting the delegation. The R-AP may transmit data to STAl . It may send CF-PoJl STA l may send CF-ACK and data to R-AP. R-STA may relay data from STAl (e.g., as described herein) received by R-AP to AP. The AP may send CF-ACK and data for STA2. The R-STA may send CF-ACK. The R-AP may relay data from AP (e.g., as described herein) to STA2 and wait for CF-ACK. After PIFS if R-AP did not receive CF-ACK, it may try to send data (e.g., again) to STA2, STA2 may send CF-ACK, e.g., along with more data for AP. The R-STA may relay this data (e.g., as described herein) to the AP. The AP may send CF-ACK. The relay may send CF- End. In the next CFP, a similar implementation may be repeated.

[0203] A predetermined schedule in sequential R-PCF mode may be disclosed. FIG. 26 illustrates an exemplary predetermined schedule based sequential transmission. In the predetermined schedule in sequential R-PCF mode, a predetermined schedule may be used where a sequence may be sent by the relay in a first frame of the CFP and each of the nodes may send data in that order.

[0204] In the example of predetermined schedule based transmission, one or more of the following may be performed. The AP may periodically establish CFP using the beacon. It may establish NA.V. The AP may send a delegation poll to a specific R-STA, to which it wants to delegate the coordination of the medium in that CFP. It may piggyback downlink data for ST I and STA 2. The R-STA may send an ACK, e.g., accepting the delegation. The R-AP and R- STA may send schedule to AP / STA. The R-AP may send data to STA 1 and then STA 2. The R-AP may receive data from STA I. The R-STA may relay it to the AP. The R-AP may receive data from STAI . The R-STA may relay it to the AP, The relay may send CF-End. In the next CFP, a similar implementation may be repeated. Each interval between each of the frames may be SIFS or smaller (RTFS).

[0205] A relay specific distributed coordination function (R-DCF) mode may be disclosed. The AP, STAs, R-AP, and/or R-STA may compete for medium simultaneously. In SU mode if may be similar to DCF in WLAN systems. For the MU case, the two traffic direction, inbound and outbound may function differently. For inbound traffic, timing synchronization of STAs and AP may be addressed, e.g., using Multiple-RTS / Group-CTS. One or more of the following may be performed. The AP may delegate authority to coordinate the group. The AP and each of the STAs may send RTS to the relay (e.g., R-AP and R-STA respectively). The relay may send a Group-CTS to those AP and STAs. This may clear the medium for the transmission. The AP and each of the STAs may send inbound traffic simultaneously in MU -Uplink. The relay may store data in a buffer and initialize outbound transmission.

[0206] Outbound traffic synchronization may not need to be addressed. The relay may access the medium with or without RTS/CTS. The R-AP and R-STA may perform a combined MU- Downlink PHY transmission to attached STAs and AP, e.g., depending on the data in relay buffer.

[0207] Load balancing among relay stations may be disclosed. This may include one or more of the following: adding relay statistics in the beacon; or providing distributed information fusion in a relay network.

[0208] Relay statistics (e.g., added statistics) may be included in the beacon. A. certain STA may listen to the beacon signal from multiple relay stations (RS) and may initiate an association request to join one relay station. Different criteria may be used to help the STA make the decision regarding which RS to associate with. For example, the STA may choose to associate with a RS with the highest channel strength, received signal quality, etc.

[0209] A certain RS may become a bottleneck of the STA-RS-AP link if many STAs try to relay through the RS, while other RSs may not be fully taken advantage of. For example, if many STAs see a strong signal from a single RS, this RS may be overwhelmed while neighboring RSs may stay relatively idle. Load balancing (e.g., at at multiple RSs) may be disclosed. One or more of the following may be performed.

[0210] Each active STA may record its average waiting/backoff time in a historical window and report it to the RS. The average waiting/backoff time may reflect the wireless medium busyness, e.g., from this STA's point of view. For example, the average waiting/backoff time may be placed in a control field. The RS may collect each waiting/backoff time from different STAs that are associated with it. The RS may summarize the statistics. For example, mean backoff time or median backoff time may be obtained at the RS. This may be updated (e.g.,

continuously) when control frames come in. The RS may broadcast the updated mean/median backoff time or other statistics of the backoff time within its domain in its beacon, e.g., regularly.

[021 1 ] With the network backoff time statistics (NBTS, e.g., mean/median) broadcasted in the beacon in each RS, a STA may make a better choice in detennining which RS to associate with. For example, both the NBTS and received signal quality may be taken into account in reaching a final decision.

[0212] On top of the NBTS, the RS may include other network siatistics in the beacon. For example, the number of associated STAs (NASS) may be broadcast in the beacon. For example, the higher NASS is, the higher the potential wait time may be,

[0213] The NASS may not be accurate enough since some STAs may not be active while associated. The number of active STAs expected ( ACS) may be broadcasted in the beacon. For example, the RS may divide the STAs in several groups and each group may be allowed to access the channel in a certain restricted access window (RAW). The RS might have a good estimate on the number of active STAs expected.

[0214] Distributed information fusion in a relay network may be disclosed. The network statistics may be fused at the RS with each STA reporting its own sample. One or more of the following may be performed.

[0215] The RS may include in the beacon a raw estimate of the NBTS (e.g.,

mean/median/others) and broadcast to each ST A. Each STA may participate in the channel access activity, e.g., following the random access/CSMA principle. Suppose STA 1 grabs the medium and starts transmitting its own data packet. STA 1 may update the existing NBTS state (e.g. the NBTS broadcast in the beacon) with its own average backoff time. This may be done via a low pass filtering. For example,

Updated NBTS at STA 1 = existing NBTS * 0.95 + backoff time at STA 1 * (1-0.95) STA1 may piggyback the updated NBTS within its own data packet. While STA 1 is transmitting, other STAs may monitor the medium and may be able to hear the transmission and the updated NBTS at STA 1. Suppose STA 2 and STA 3 hear the updated NBTS and then STA 2 grabs the medium. STA 2 may update the existing NBTS state further with its own average backoff time. This may be done via a similar low pass filtering. For example,

Updated NBTS at STA 2 = updated NBTS at STA 1 * 0.95 + backoff time at STA 2 * (1-0.95)

STA 2 may piggyback the further updated NBTS within its own data packet.

[0216] Other STAs may follow a similar implementation, and, the NBTS may be updated in a distributed manner. With the NBTS updated in a distributed manner, a STA that may need to determine an RS (e.g., a new STA) may make a better choice in determining an RS with which to associate.

[0217] interference mitigation may be disclosed. This may include one or more of the following: sectorized relay coordination (e.g., downlink sectorized relay coordination, random access based sectorized relay coordination, etc.); or use of transmit power control with relays in overlapping BSS (e.g., mandate STAs in overlapped area of overlapping BSS to be limited to relay use and combine with TPC).

[0218] Sectorized relay coordination may be disclosed. Sectorized relaying may be used for downlink traffic, e.g., from access point (AP) to relay stations (RS) and then to end stations (S). FIG. 27 illustrates an example of an AP broadcasting information to multiple relays. One or more of the following may be performed.

[0219] The originator (e.g., AP) may send data streams (e.g., to be relayed to their destinations via the RSs) to multiple relay stations (RS). As illustrated in FIG. 27, the multiple RSs may be at different directions from the AP within a certain distance. The data symbols to different RSs may be different. This may be achieved by the AP broadcasting, e.g., as in IEEE 802.1 In/ac technologies, in which case an omm-directional transmission may originate from the AP; the omni-directional transmission packet may need to include each data symbol to the different RSs. This may be achieved by downlink MU-MIMQ, with the AP serving as the transmitter, and multiple RSs serving as the individual receiver. For example, linear zero-forcing or regularized zero forcing precoding may be used at the AP side.

[0220] Each of the multiple distributed RSs may select a station (S) to serve. FIG. 28 illustrates an example of simultaneous spatial orthogonal transmissions from multiple sectorized relays. In the example of FIG . 28, RS 1 may select S3 to serve, RS 2 may select 86 to serve, RS 3 may select S9 to serve, and RS 4 may select S 12 to serve. ^'TO coordinate station selection from the RSs, control/scheduling information may be sent from the AP to the multiple RSs. The control/scheduling information may be piggybacked with the data stream transmission, e.g., as described herein. The control/scheduling information may be used to coordinate multiple sectorized transmissions such that they do not interfere with each other (e.g., or are spatially orthogonal to each other).

[0221] Each of the RSs may perform sectorized transmission to relay data to its selected STA. In the example illustrated in FIG. 28, the multiple sectorized transmissions may occur at the same time, e.g., transmissions 1, 2, 3, 4 may be spatially orthogonal to each other, where transmission 1 is the sectorized transmission from RS 1 to S3, transmission 2 is the sectorized transmission from RS 2 to S6, transmission 3 is the sectorized transmission from RS 3 to S9, transmission 4 is the sectorized transmission from RS 4 to S I 2.

[0222] This may be illustrated in FIG. 29 thai illustrates an example of multiple sect orized relaying in the downlink, where relaying from RS 1 and RS 2 are included for simplicity.

Relaying operation from RS 3 and RS 4 may be similar. The transmissions from different RSs may happen at the same time, e.g., due to spatial orthogonality.

[0223] Random access based sectorized relay coordination may be disclosed. Sectorized relaying may be used, e.g., for uplink traffic from end stations (S) to relay stations (RS) and to the access point (AP). This may include one or more of the following.

[0224] To coordinate station selection from the RSs, control/scheduling information may be sent from the AP to the multiple RSs. The control/scheduling information may be used to coordinate random access to multiple R Ss such that those multiple random accesses may not interfere with each other (e.g., or are spatially orthogonal to each other).

[0225] Each of the multiple distributed RSs may select a sector for random access, which may follow the control/scheduling decision from the AP, and, may announce its access rule to its own STAs. FIG, 30 illustrates example simultaneous spatial orthogonal transmissions from multiple sectorized relays. In the example of FIG. 30, RS 1 may select the S3 sector for CSMA (e.g., the STAs in the sector where S3 lies in may be able to access the medium following CSMA rules while the STAs in other sectors may be forbidden to access the medium), RS 2 may select the S6 sector for CSMA, RS 3 may select the 89 sector for CSMA, and RS 4 may select the S 12 sector for CSMA.

[0226] It may be the AP's responsibility to decide on proper rules for each RS. The

control/scheduling decision made by the AP may be made such that transmission to one sectorized RS would be spatially orthogonal to transmission to another sectorized RS. As a result, multiple transmissions may occur simultaneously.

[0227] STAs in the allowable sector of each RS may try to access the channel medium randomly, e.g., following CSMA. Each RS may be equipped with a sectorized/directional antenna such that it may be limited to hearing its own STAs in the allowable sector, but not STAs of other RSs in their corresponding sectors (e.g., on the condition that the AP makes a proper control/scheduling decision). At the end of the specified TXOP, RSs may be filled with information to be forwarded to the AP.

[0228] FIG. 31 illustrates an example of data forwarding from multiple relays to the AP. Each of the RSs may forward the data streams to the AP. This may be achieved by single user transmission from each RS to the AP; the RSs may take turns (e.g., round-robin or CSMA) to complete the data forwarding task. This may be achieved by uplink MU-MIMO, with the AP serving as the receiver, and multiple RSs serving as the individual transmitter.

[0229] This may be illustrated in the example of FIG. 32, which illustrates an example of data forwarding. S3-A, S3-B, 83-C, , .. may be stations in the allowable sector for RS 1 and may perform CSMA to send their own data packets to RSI; S6-A, S6-B, S6-C, ... may be stations in the allowable sector for RS2 and may perform CSMA to send their own data packets to RS2. Random access to the sectorized RS 1 and random access to the sectorized RS 2 may happen at the same time, e.g., due to spatial orthogonality,

[0230] Use of transmit power control with relays in overlapping BSSs may be disclosed. STAs in an overlapped area of overlapping BSSs may be mandated to be limited to relay use and combine with TPC. A range extension relay may be used with transmit power control (TPC), e.g., to limit the amount of interference in an OBSS. FIG. 33 illustrates an example OBSS with STA 1/BSS 1 transmitting.

[0231] In the example of FIG. 33, an OBSS with STA1 from BSS 1 that may transmit data to the AP. In this case, the transmission from STA1 in BSS I (e.g., the upper middle BSS in FTG. 33) may prevent transmission in BSS2 (e.g., the lower middle BSS in FIG. 33), e.g., as the effect of the ST12/BSSl 's transmission is seen by each of the devices (e.g., STAs and the AP) in BSS2.

[0232] Introduction of a range extension device (e.g., a relay) coupled with transmit power control may allow for transmission in both BSSs, e.g., as shown in the example of FIG. 34.

STA1/BSS1 may transmit to the relay in BSSI and the relay may transmit the data to API .

Based on use of TPC, AP2 and STA2/BSS2 may be able to transmit simultaneously. This may imply that the interference resulting from the o verlap of the BSS is mitigated, [0233] One or more of the following may be performed. The AP in each BSS may identify the STAs in the overlapped area of the BSS, e.g., STAs that may offer interference to neighbouring BSSs when transmitting. The AP may identify candidate relay-APs for the STA to associate with, which may include one or more of: the AP directing candidate STAs to a specific subsei of R-APs to connect with, or, the AP directing R-AP to send unsolicited probe response to candidate STAs, e.g., with flag set as mandator '-. STA, relay, and AP may perform TPC calibration to establish the transmit pow er used. This may be by a pre- determined set of TPC request/response frame transmissions. Other TPC implementations may be used ( e.g., as described herein). Data transmission may occur with candidate stations restricted to transmission or reception using the relay device.

[0234] Longer range STAs (e.g., transmitting at regular power) may kill a shorter range STAs' (e.g., transmitting at reduced power) transmissions. The shorter range STA may obey NAV for the transmissions of the longer range STAs. The longer range STAs may not hear the

NAV/transmissions of the shorter range STAs, and, may transmit and interrupt ihe packets from the shorter range STAs.

[0235] One or more of the following may be performed, which may be associated with such interference (e.g., mitigation), A TXOP may be reserved by the AP for the AP-to- elay-to-STA transmission. The coverage of the TXOP reservation signal may be limited to being over the AP's BSS. The transmission between the relay node and the STA may use mandatory RTS/CTS with the power levels of ihe relay node that may maximize coverage over the BSS with which it is associated.

[0236] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element may be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer- readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer- readable storage media. Examples of computer- eadable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, WTRU, terminal, base station, RNC, or any host computer.

Claims

CLAIMS What s Claimed:

1. A method for a device to provide traffic prioritization, the method comprising:

determining an average priority associated with relay traffic;

transmitting a beacon including ihe average priority;

receiving a probe request from a station; and

transmitting traffic based on a priority allocated to the station, wherem the traffic comprises traffic from the station,

2. The method of claim 1, further comprising:

transmitting a probe response with the allocated priority for the station; and

receiving the traffic from the station.

3. The method of claim 1 , wherein the device is a relay or a station acting as a relay.

4. The method of claim 1 , wherein the transmitted beacon with the average priority is transmitted periodically.

5. The method of claim 1, further comprising:

determining that ihe device has device traffic to send;

determining to transmit the device traffic based on one or more of the allocated priority, existing traffic in a buffer, or the device traffic; and

transmitting the device traffic.

6. The method of claim 1 , wherein the traffic includes data associated with the station traffic aggregated with device data associated with device traffic.

7. The method of claim 1, further comprising:

determining a priority factor associated with the station; and

sending the priority factor to the station.

8. The method of claim 1, wherein the device is a non-dedicated relay.

9. The method of claim 8, further comprising:

determining that an uplink buffer associated with the device is full or that the device has an amount of data to send that is above a threshold; and

setting a priority factor associated with the device to a value that gives priority to the device to access a channel.

10. The method of claim 9, wherein the set priority factor reduces a total deferral period associated with the device.

1 1. A device comprising:

a processor configured to:

determine an average priority associated with relay traffic;

transmit a beacon including the average priority;

receive a probe request from a station; and

transmit traffic based on a priority allocated to the station, wherein the traffic comprises traffic from the station.

12. The de vice of claim 1 1 , wherein the processor is configured to:

transmit a probe response with the allocated priority for the station; and

receive the traffic from the station,

13. The device of claim 1 1, wherein the device is a relay or a station acting as a relay.

14. The device of claim 1 1, wherein the transmitted beacon with the average priority is transmitted periodically.

15. The device of claim 1 1 , wherein the processor is configured to:

determine that the device has device traffic to send;

determine to transmit the device traffic based on one or more of the allocated priority, existing traffic in a buffer, or the device traffic; and

transmit the device traffic.

16. The device of claim 1 1, wherein the traffic includes data associated with the station traffic aggregated with device data associated with device traffic.

17. The device of claim 1 1 , wherem the processor is configured to:

determme a priority factor associated with the station; and

send the priority factor to the station.

18. The device of claim 1 1, wherein the device is a non-dedicated relay.

1 . The device of claim 18, wherein the processor is configured to:

determme that an uplink buffer associated with the device is full or that the device has an amount of data to send that is above a threshold; and

set a priority factor associated with the device to a value that gives priority to the device to access a channel.

20. The device of claim 19, wherem the set priority factor reduces a total deferral period associated with the device.