Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W16/00—Network planning, e.g. coverage or traffic planning tools; Network deployment, e.g. resource partitioning or cells structures
  • H04W16/24—Cell structures
  • H04W16/28—Cell structures using beam steering
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B7/00—Radio transmission systems, i.e. using radiation field
  • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
  • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
  • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
  • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
  • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
  • H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/04—Wireless resource allocation
  • H04W72/044—Wireless resource allocation based on the type of the allocated resource
  • H04W72/046—Wireless resource allocation based on the type of the allocated resource the resource being in the space domain, e.g. beams
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W74/00—Wireless channel access
  • H04W74/08—Non-scheduled access, e.g. ALOHA
  • H04W74/0808—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA]
  • H04W74/0816—Non-scheduled access, e.g. ALOHA using carrier sensing, e.g. carrier sense multiple access [CSMA] with collision avoidance
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W84/00—Network topologies
  • H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
  • H04W84/10—Small scale networks; Flat hierarchical networks
  • H04W84/12—WLAN [Wireless Local Area Networks]

Definitions

• a WLAN in Infrastructure basic service set (IBSS) mode has an
• the AP typically has access or an interface to a distribution system (DS), or another type of wired/wireless network that carries traffic in/out of the BSS, such as from/to the Internet.
• Traffic to STAs that originates from outside the BSS arrives through the AP and is delivered to the STAs.
• Traffic originating from STAs to destinations outside the BSS is sent to the AP to be delivered to the respective destinations.
• Traffic between STAs within the BSS may also be sent to through the AP, wherein the source STA sends traffic to the AP and the AP delivers the traffic to the destination STA.
• Such traffic between STAs within a BSS is considered peer-to-peer traffic.
• Such peer-to- peer traffic may also be sent directly between the source STA and destination STAs with a direct link setup (DLS) using an IEEE 802. lie DLS or an IEEE 802. llz tunneled DLS (TDLS).
• DLS direct link setup
• TDLS IEEE 802. llz tunneled DLS
• a WLAN in Independent BSS mode has no AP, and therefore STAs communicate directly with each other.
• a method and apparatus may be used for WiFi sectorization medium access control enhancement (WiSE MAC).
• An IEEE 802.11 STA may receive an omni- directional indication of a first sectorized transmission opportunity (TXOP) associated with a second STA.
• the omni- directional indication may include an identifier (ID) of a first sector associated with the first sectorized TXOP.
• the STA may transmit a directional indication of a second sectorized TXOP a condition that a second sector associated with the second sectorized TXOP does not interfere with the first sector associated with the first sectorized TXOP.
• FIG. IB is a system diagram of an example wireless transmit/receive unit (WTRU) that may be used within the communications system illustrated in Figure 1A;
• WTRU wireless transmit/receive unit
• Figure 2 shows a QLoad Report element as specified in the IEEE
• Figure 6 is an illustration of SO frame exchange sequence 2
• FIG. 7 is an illustration of SO frame exchange sequence 3
• Figure 9 shows how a CTS-to-self may facilitate the detection of the SO conditions
• FIG. 11 shows an example scenario in which sectorized transmissions of Request to Send (RTS)/Clear to Send (CTS) messages block an AP's transmission;
• Figure 12 illustrates how a Sectorized Transmission indication
• OBSS Capability information element (IE);
• Figure 14 shows an example scenario of two overlapping BSSs in which two APs are both capable of performing sectorized transmissions
• Figure 16 shows an example procedure for explicit inter-AP sectorized transmission training and feedback
• Figure 17 is an illustration of an additional SO frame exchange sequence
• Figure 18 describes a procedure for performing a sectorized transmission on a condition that the sectorized transmission is known not to conflict with an ongoing sectorized transmission
• Figure 19 is an example design of the Fast Sector Feedback IE.
• 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.
• 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 (OFDMA), single-carrier FDMA (SC-FDMA), and the like.
• CDMA code division multiple access
• TDMA time division multiple access
• FDMA frequency division multiple access
• OFDMA orthogonal FDMA
• SC-FDMA single-carrier FDMA
• the communications system 100 may include wireless transmit/receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and/or network elements.
• WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and/or communicate in a wireless environment.
• 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.
• UE user equipment
• PDA personal digital assistant
• smartphone a laptop
• netbook a personal computer
• a wireless sensor consumer electronics, and the like.
• the communications systems 100 may also include a base station
• Each of the base stations 114a, 114b 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 110, and/or the other networks 112.
• the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and/or network elements.
• the base station 114a 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.
• BSC base station controller
• RNC radio network controller
• the base station 114a and/or the base station 114b 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.
• the cell associated with the base station 114a may be divided into three sectors.
• the base station 114a may include three transceivers, i.e., one for each sector of the cell.
• the base station 114a may employ multiple -input multiple -output (MIMO) technology and, therefore, may utilize multiple transceivers for each sector of the cell.
• MIMO multiple -input multiple -output
• the base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, infrared (IR), ultraviolet (UV), visible light, etc.).
• the air interface 116 may be established using any suitable radio access technology (RAT).
• RAT radio access technology
• the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA).
• WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and/or Evolved HSPA (HSPA+).
• HSPA may include High-Speed Downlink Packet Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).
• the base station 114a and the WTRUs are identical to the base station 114a and the WTRUs.
• E-UTRA Evolved UMTS Terrestrial Radio Access
• LTE Long Term Evolution
• LTE-A LTE- Advanced
• the base station 114a and the WTRUs are identical to the base station 114a and the WTRUs.
• the 102a, 102b, 102c may implement radio technologies such as IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 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.
• WiMAX Worldwide Interoperability for Microwave Access
• CDMA2000 Code Division Multiple Access 2000
• CDMA2000 IX Code Division Multiple Access 2000
• CDMA2000 EV-DO Code Division Multiple Access 2000 EV-DO
• IS-2000 Interim Standard 95
• IS-856 Interim Standard 856
• GSM Global System for Mobile communications
• EDGE Enhanced Data rates for GSM Evolution
• GERAN GSM EDGE
• the base station 114b in Figure 1A may be a wireless router
• the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN).
• the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN).
• WLAN wireless local area network
• WPAN wireless personal area network
• the base station 114b 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.
• a cellular-based RAT e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.
• the base station 114b may have a direct connection to the Internet 110.
• the base station 114b may not be required to access the Internet 110 via the core network 106.
• the core network 106 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.
• the core network 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and/or perform high- level security functions, such as user authentication.
• 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.
• the core network 106 may also be in communication with another RAN (not shown) employing a GSM radio technology.
• the processor 118 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 (IC), a state machine, and the like.
• the processor 118 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the WTRU 102 to operate in a wireless environment.
• the processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit/receive element 122. While Figure IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.
• the transmit/receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116.
• a base station e.g., the base station 114a
• the transmit/receive element 122 may be an antenna configured to transmit and/or receive RF signals.
• the transmit/receive element 122 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example.
• the transmit/receive element 122 may be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit/receive element 122 may be configured to transmit and/or receive any combination of wireless signals.
• 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 116.
• 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.
• the WTRU 102 may have multi-mode capabilities.
• the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, for example.
• the processor 118 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 118 may also output user data to the speaker/microphone 124, the keypad 126, and/or the display/touchpad 128.
• the processor 118 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 nonremovable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type 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.
• SIM subscriber identity module
• SD secure digital
• the processor 118 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).
• the processor 118 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.
• the power source 134 may include one or more dry cell 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.
• the processor 118 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 102.
• location information e.g., longitude and latitude
• the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location- determination method while remaining consistent with an embodiment.
• the processor 118 may further be coupled to other peripherals
• Figure 1C shows an example RAN 104 and an example core network 106 that may be used within the communications system 100 shown in Figure 1A.
• the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116.
• the serving gateway 144 may generally route and forward user data packets to/from the WTRUs 102a, 102b, 102c.
• the serving gateway 144 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.
• OBSS coordination in the IEEE 802.11aa standard, namely, QLoad reports and hybrid coordination function (HCF) controlled channel access (HCCA) transmission opportunity (TXOP) negotiation.
• HCF hybrid coordination function
• HCCA hybrid coordination function controlled channel access
• TXOP transmission opportunity negotiation.
• APs may use QLoad reports from all BSSs in the OBSS for channel selection as well as for conducting admission control and scheduling.
• An AP may include a QLoad Report element in a QLoad Report frame or Protected QLoad Report frame or optionally in a beacon to announce the traffic load of its own BSS as well as that of other BSSs in the OBSS whose traffic load the AP has obtained.
• the QLoad Report element is shown in Figure 2.
• the AP may also request associated STAs that are capable of a sending a Beacon Request message to report QLoad reports from other APs on the same primary channel, or on other channels.
• An HCCA AP that is capable of TXOP negotiation is able to maintain one or more dotllAPCEntry(s) for each collaboration candidate in the dotllAPCTable that indicate the schedules that the AP should try to avoid using when creating schedules for new traffic stream requests.
• TSPEC Traffic Specification
• HEMM Access Policy
• the AP's Hybrid Coordinated Function may first examine all dotllAPCEntry(s) that are present in the dotllAPCTable. The AP may then send a (Protected) HCCA TXOP advertisement to each collaboration candidate with a proposed TXOP reservation schedule.
• Each collaboration candidate may examine its own scheduled
• An HCCA AP may not send an ADDTS Response frame to the requesting STA until it is reasonably certain that the proposed TXOP schedule for the TS is not in conflict with other TXOPs scheduled at collaboration candidates.
• the HCCA AP may send the ADDTS Response frame when it has received an HCCA TXOP Response frame with the status "SUCCESS" from all of the APs to which the HCCA TXOP advertisements were sent.
• a beamformed TXOP may be reserved by transmitting beamformed Request to Send (RTS) and/or directional multi- gigabit (DMG) Clear to Send (CTS) frames.
• RTS Request to Send
• DMG directional multi- gigabit
• CTS Clear to Send
• STAs that receive the RTS/DMG CTS frames may obey their network allocation vectors (NAVs).
• a recipient DMG STA which receives a valid RTS from a source STA during a Service Period (SP) may also transmit a DMG Denial to Send (DTS) to direct the source STA to postpone transmissions if one of the NAV timers at the recipient STA is non-zero.
• DTS DMG Denial to Send
• a personal basic service set (PBSS) control point (PCP) may request a pair of STAs that intend to conduct directional transmissions to each other to conduct measurements while another pair of STAs is actively transmitting directionally. Subsequently, the PCP may request the second pair of STAs to conduct directional measurements while the first pair of STAs transmits directionally to each other. If both pairs of STAs report no or little interference from each other's transmissions, the two pairs of STAs may be scheduled in the same SP to conduct concurrent directional transmissions.
• New spectrum is being allocated in various countries around the world for wireless communication systems such as WLANs. Channels allocated in this spectrum are often quite limited in size and bandwidth.
• the spectrum may be fragmented in that available channels may not be adjacent, and it may not be possible to combine them to support larger transmission bandwidths.
• available channels may not be adjacent, and it may not be possible to combine them to support larger transmission bandwidths.
• WLAN systems built on the IEEE 802.11 standard may be designed to operate in such a spectrum. Given the limitations of such a spectrum, the WLANs systems may only be able to support smaller bandwidths and lower data rates compared to HT/VHT WLAN systems based, for example, on the IEEE 802.11n/802.11ac standards.
• the IEEE 802.11ah PHY operates below 1 GHz and is based on the IEEE 802.1 lac PHY. To accommodate the narrow bandwidths required by IEEE 802.11ah, the IEEE 802.1 lac PHY is down-clocked by a factor of 10. While support for 2, 4, 8, and 16 MHz can be achieved by the 1/10 down- clocking described above, support for the 1 MHz bandwidth requires a new PHY definition with an FFT size of 32.
• PLCP Convergence Protocol
• ACK Early Acknowledgement
• the two bit acknowledgement ACK indication (00: ACK; 01: Block ACK (BA); 10: No ACK; 11: a frame that is not ACK, BA, or CTS) is signaled in the SIG field.
• An IEEE 802. Hah AP may conduct sectorized transmissions, while an IEEE 802.11 non-AP may conduct omnidirectional transmissions.
• Sectorization for hidden node mitigation, or Type 0 sectorization is shown in Figure 4.
• An AP may divide the space into which is transmits into multiple sectors.
• the AP may use a time- division multiplexing (TDM) approach to allow STA transmissions in one sector at the time.
• STAs may transmit and receive data only in the time interval corresponding with their sector. For example, referring to Figure 4, the AP may transmit a beacon 400 in sector 1, and then STAs in sector 1 may transmit and receive data during the Sector 1 Interval 402.
• TDM time- division multiplexing
• the AP may transmit beacons 404, 408 in sectors 2 and 3, respectively. Each of the beacons may be followed by a respective Sector Interval 406, 410.
• the AP may also transmit an omni- directional beacon 412. Some intervals, such as the BSS Interval 414 in Figure 4, may be used for channel access by STAs in all sectors.
• an AP may both transmit and receive using omni and sectorized beams.
• the AP may switch back and forth between sectorized beams and omni beam.
• a sectorized beam may only be used when the AP is aware of a STA's best sector, or in a scheduled transmission such as a restricted access window (RAW) or during a TXOP of a STA.
• the AP may switch back to an omni beam otherwise.
• a sectorized transmit beam may be used in conjunction with a sectorized receive beam.
• An AP may associate a STA with a specific group (all STAs in the group having a same sector or group ID) based on the STA's best sector.
• SO Spatially Orthogonal
• the AP 500 may transmit an omni- directional packet 504 to establish a link with a STA 502 and set up TXOP protection 512 for the duration of the sectorized beam transmission.
• the AP may then transmit an omni-preamble 508 of a PPDU with long format, and a beamformed preamble 510 of the PPDU with long format.
• the AP may continue to transmit using sectorized transmissions (with Greenfield beamforming (BF)) for the remainder of the TXOP, as indicated by the shaded region 514.
• BF Greenfield beamforming
• the receiving STA 502 may send an ACK or other response frame 506 in response to the omnidirectional packet 504.
• the STA 502 may send an ACK 516 to acknowledge the long format packet 508, 510.
• the SO condition is met when an OBSS STA or AP does not receive the ACK or Response transmission 506 from the STA 502, and also does not receive the sectorized transmission portion 510 of the long format packet from the AP 500.
• the duration of the sectorized TXOP 512 may be spatially reused by spatially orthogonal OBSS STAs and APs.
• An OBSS STA or AP may infer its spatial orthogonality with the AP 500 by receiving the omni- directional packet 504 and the omni-preamble 508 of the long format packet, but not the beamformed preamble 510 of the long format packet.
• An OBSS STA or AP may infer its spatial orthogonality with the STA 502 by receiving no transmission between the omni- directional packet 504 and the omni-preamble 508 of the long format packet.
• the 600 may transmit an omni- directional packet 604 to establish a link with a STA 602 and to set up the protection 612 for the duration of the sectorized beam transmission.
• the STA 602 may send an ACK or other response frame 606 in response to the omni- directional packet 604.
• the AP 600 may then transmit an omni- directional short format packet, and subsequently a sectorized transmission (with Greenfield BF) may be used to transmit a sectorized short format packet 610.
• a sectorized beam may be used for the remainder of the TXOP 612, as indicated by the shaded region 614.
• the SO condition is met when an OBSS STA/AP does not receive the STA's transmission 606, and also does not receive the AP's sectorized transmissions during the remainder of the TXOP 612 following the omnidirectional packet of the short format 608. Accordingly, the duration of the sectorized TXOP 612 may be spatially reused by spatially orthogonal OBSS STAs and APs.
• An OBSS STA or AP may infer its orthogonality with the AP 600 by receiving the omni- directional packet 604 and omni- directional packet of the short format 608, but not the beamformed short format packet 610.
• An OBSS STA or AP may infer its orthogonality with the STA 602 by receiving no transmission between the omni- directional packet 604 and the omnidirectional packet of the short format 608.
• the 700 may start a frame exchange with an omni-transmission RTS 704 to solicit a CTS response 706 from a STA 702. As shown in Figure 7, the AP 700 may then transmit an omni- directional preamble 708 of a long format packet. The AP 700 may then switch to sectorized beam transmission for the remainder 710 of the long format packet, and for the remainder of the protected duration 712. The shading 714 indicates the use of a sectorized beam. The STA 702 may send an ACK 716 acknowledging the long format packet 708, 710.
• the SO condition is met when an OBSS STA or AP observes the omni-transmission 708 of the AP 700 but not the beamformed transmission 710 of the AP 700, or the STA's transmissions 706, 716.
• An OBSS STA or AP may infer its spatial orthogonality with the AP 700 by observing the omni- transmission RTS packet 704 and the omni-preamble 708 of the long format, but not the sectorized remainder 710 of the long format packet.
• An OBSS STA or AP may infer its spatial orthogonality with the STA 702 by observing a gap of no transmission between the omni-transmission RTS packet 704 and the omni-preamble 708 of the long format packet.
• an AP 718 may start a frame exchange with an omni-transmission RTS 722 to solicit a CTS response 724 from a STA 720.
• the AP 718 may then transmit an omni- directional short format packet 726.
• the AP 718 may then switch to sectorized beam transmission to transmit a second short format packet 728, and may continue with sectorized transmission for the remainder of the protected duration 730.
• the shading 732 indicates the use of a sectorized beam.
• the STA 720 may send an ACK 734.
• the 802 transmits a PS-Poll, trigger, or other frame 804 to establish a link with an AP 800.
• the AP 800 responds with an omni-transmission short format packet 806 that establishes protection 808 for the remaining duration of the TXOP 810.
• the STA 802 may transmit an ACK or response 812 to acknowledge the short format packet 806.
• the AP 800 may transmit an omni-preamble 814 of a long format packet and then switch to sectorized beam transmission for the remainder 816 of the long format packet, and the remainder of the protected duration 808.
• the SO condition is met when an OBSS STA or AP receives the omni-transmission 824 from the AP 818, but does not receive the sectorized transmission 832 from the AP 818, or the STA's transmissions 822, 830.
• An OBSS STA or AP may infer its spatial orthogonality with the AP 818 by observing the omni-transmission short format packet 824, but not the sectorized transmission of the second short format packet 832.
• An OBSS STA or AP may infer its spatial orthogonality with the STA 820 by observing a gap of no transmission between the omni-transmission short format packet 824 and the sectorized transmission short format packet 830.
• API 1100 and STAl 1102 may use omni- directional packets to reserve a sectorized TXOP for transmissions from API 1100 to STAl 1102.
• AP2 1104 may not be allowed to conduct any transmissions if it receives an omni- directional CTS from STAl 1102 although a sectorized transmission from AP2 1104 to STA2 1106 would not impact the ongoing sectorized transmissions from API 1100 to STAl 1102.
• An improvement of the NAV setting in relation to the defined SO conditions is needed to optimize network throughput and performance.
• Some STAs may be mobile and may change their location during the time of association of an AP.
• channel conditions may change between a STA and its AP. Consequently, a STA's sector in a BSS may change from time to time.
• a procedure is needed for providing fast sector feedback in an effective and efficient manner without much overhead.
• STAs and APs may provide indications that they are capable of conducting inter-AP/inter-BSS sectorized transmission training, feedback, and coordination. This may be done using the OBSS Capability information element (IE) 1300 shown in Figure 13.
• IE OBSS Capability information element
• the OBSS Capability IE may further include an OBSS
• This field may indicate the options for OBSS Sectorization Feedback, which may include the following: Feedback Directly to OBSS AP may indicate that the transmitting STA or AP may provide feedback directly to the OBSS AP after OBSS sectorized transmission training; Feedback to Own AP may indicate that the transmitting STA, for example, a STA that is already associated with an AP, may provide feedback directly to its own AP after OBSS sectorized transmission training; and Feedback to a Coordinating AP may indicate that the transmitting STA, for example, an AP or a STA that is associated with its own AP, may provide feedback to a coordinating node, such as an AP in charge of coordinating an OBSS, after OBSS sectorized transmission training.
• a coordinating node such as an AP in charge of coordinating an OBSS
• Option field 1310 may specify the various options that the transmitting STA is capable of performing for providing OBSS sectorized training feedback.
• the options may include Scheduled, Contention Based, Wireless, Wired, and Multiband subfields.
• the Scheduled subfield may indicate whether the transmitting STA may provide feedback according to a schedule, such as a RAW, a Periodic RAW (PRAW), an automatic power save delivery (ASPD), or a power save multi-poll (PSMP) slot.
• the Contention Based subfield may indicate whether the transmitting STA may provide feedback using a contention based method, which may take place in a given beacon interval or subinterval.
• the Wireless subfield may indicate whether the transmitting STA may provide feedback over a wireless interface, such as the same or a separate IEEE 802.11 interface.
• the Wired subfield may indicate whether the transmitting STA may provide feedback over a wired interface, such as a wired Ethernet connection.
• the Multiband subfield may indicate whether the transmitting STA may provide feedback using an interface on a separate frequency band, such as an IEEE 802. Had, 802.11aj, or 802.11ac interface.
• Capable of Receiving OBSS Feedback from Associated STAs may indicate that the transmitting STA, such as an AP, is capable of receiving OBSS sectorized transmission training feedback from the STAs that are associated with it.
• Capable of Coordinating AP may indicate that the transmitting STA may serve as a coordinating AP.
• the OBSS Sectorized Coordination field 1312 may further indicate a number of sectorization coordination options.
• Type 0 Sectorization may indicate that the transmitting STA is capable of coordinating Type 0 sectorization across an OBSS.
• Type 1 Sectorization may indicate that the transmitting STA is capable of coordinating Type 1 sectorization across an OBSS.
• the OBSS Sectorized Coordination field 1312 may further include an Options subfield that specifies options for OBSS Sectorized Transmission Coordination.
• the options may include Distributed, in which the transmitting STA is capable of distributed coordination, and Centralized, in which the transmitting STA performs OBSS sectorized transmission coordination through a coordinating node, such as a coordinating AP.
• a STA may include the OBSS Capability IE in frames such as
• Probe Requests may indicate that it is capable of providing OBSS sectorized training feedback directly to its AP, provided that the AP is capable of receiving OBSS feedback from its associated STAs.
• An AP may instruct the STA to report OBSS feedback periodically.
• the OBSS Capability IE 1300 or any subset of the fields thereof may be implemented as a subfield or subset of subfields of any existing or new IE, such as the SlG Capability, SlG Extended Capability, Sector Operation, Sector Capability, Type 0 Sectorization Scheme, and Type 1 Sectorization Scheme elements, or as part of any control, management, or extension frames or MAC/PLCP headers.
• SlG Capability SlG Extended Capability
• Sector Operation Sector Capability
• Sector Capability Type 0 Sectorization Scheme
• Type 1 Sectorization Scheme elements or as part of any control, management, or extension frames or MAC/PLCP headers.
• Signaling and procedures for inter-AP sectorization transmission training and feedback are described herein. Without loss of generality, a generic scenario is considered with two APs to illustrate the proposed procedures. Each AP may have numerous STAs associated with it.
• AP2 1400 may know the location/sectors of its associated STAs, such as STA1 1402, STA2 1404, ... STAM 1414.
• API 1416 may know the location/sectors of the STAs 1418-1428 associated with it.
• the implicit OBSS sector training and feedback procedure may be as follows. If API and AP2 are within range of each other, they may detect each other's beacons which may indicate that they are both capable of implicit OBSS sectorized transmission training and feedback. API may start a sector training sounding sequence as normal, as shown in Figure 10 for intra-BSS sector training. AP2 may also reserve the same period of time as quiet time so that no STAs may transmit during API's sector training time.
• API may provide a schedule to each of the OBSS APs that has previously indicated that it is capable of OBSS sectorized coordination and capable of providing sector training feedback directly to a peer AP.
• the schedule may indicate when the OBSS APs should provide their feedback for API's sector training.
• Such a schedule may be a RAW, a PRAW, a beacon interval or subinterval, or an access window.
• API may instruct AP2 to provide sector training feedback either using contention-free or contention-based access.
• Figure 15 illustrates an example sectorized training procedure
• AP2 may schedule a RAW, PRAW, or other interval for itself within its own BSS (step 1504).
• AP2 may also provide a schedule for STAs in its own BSS that have indicated that they are capable of providing OBSS sector training feedback to their own associated AP (step 1506).
• AP2 may use the feedback from the STAs to provide OBSS training feedback to API.
• AP2 may record the Sector IDs of those sounding packets that it receives, identifying each sector as an Interfering Sector (step 1510).
• STAs that are associated with AP2 may also listen to the sector training transmissions from API and may record the Sector IDs of those sounding packets that they receive, identifying each sector as an Interfering Sector.
• AP2 and STAs in BSS2 having received an ODP, ODSP, or omnidirectional portion of an HMP that contains a Sector TXOP indication and/or a Sector ID indication may also record the Sector ID and identify it as an Interfering Sector.
• the BSSID associated with the Interfering Sector may be obtained from the Receiver Address (RA) or Destination Address (DA) field of the ODP, ODSP, or omni- directional portion of the HMP.
• RA Receiver Address
• DA Destination Address
• STAs in BSS2 may provide OBSS Sector Reports to AP2 with any
• Interfering Sectors that they have observed and the BSSID associated with each sector may also provide to AP2 their own Sector ID in BSS2.
• AP2 may then construct a Conflict Sector Table as shown in Table 1 (step 1514).
• Table 1 the column Transmitting BSSID indicates the transmitting OBSS, for example, BSSl; the column Transmitting Sector ID indicates the transmitting Sector in the OBSS, for example, Sector 2 in BSSl; and the column Conflicting Sector IDs in Own BSS indicates those sectors in the AP's own BSS in which interference is experienced due to the sectorized transmissions indicated in the first and second columns.
• the first row in Table 1 indicates that interference is experienced in sectors 2 and 3 and at AP2 of BSS2 due to the sectorized transmissions in sector 1 of BSSl.
• a value of "AP" in the Conflict Sector IDs in the Own BSS column may indicate that a sectorized transmission in BSSl, Sector 1 aims directly at AP2 in BSS2. It may suggest that AP2 and Sector 1 in BSSl should not share any concurrent or overlapping TXOP.
• Table 1 An example of a Conflict Sector Table
• the implication of the Conflict Sector Table is that there may be no concurrent sectorized transmissions in the Transmitting Sector and Conflicting Sectors in BSSl and BSS2.
• AP2 may provide the Conflict Sector Table to its peer APs, or it may only provide the relevant part of the Conflict Sector Table to its peer APs (step 1516).
• API may then enhance its own Conflict Sector Table using the newly received information from AP2.
• API may then broadcast the Conflict Sector Table to all STAs associated with it so that each STA in BSSl may know which sectors may be in conflict with which sectors in neighboring BSSs.
• AP2 may provide the Conflict Sector
• the coordinating AP/STA may have all copies of the Conflict Sector Table from all APs in the OBSS and may merge them together into an OBSS Conflict Sector Table.
• the OBSS Conflict Sector Table, or the relevant parts thereof, may then be distributed to each of the APs in the OBSS.
• Each AP may then subsequently broadcast the OBSS Conflict Sector Table, or the relevant parts thereof, to all STAs in its BSS.
• AP2 may conduct OBSS sector training for all STAs within its range, such as STAs and API in BSSl.
• AP2 may receive feedback directly from all STAs in BSSl and from API, either using a scheduled RAW or PRAW, or using a contention-based method.
• API may collect all OBSS sector feedback from all STAs associated with it and may construct a Conflict Sector Table and send it to AP2.
• API may send the Conflict Sector Table to a coordinating AP in a centralized coordination scheme.
• the coordinating AP may merge all copies of the Conflict Sector Table into an OBSS Conflict Sector Table and may send it, or the relevant parts thereof, to each of the AP in the OBSS.
• Each AP may then subsequently broadcast the OBSS Conflict Sector Table, or the relevant parts thereof, to all STAs in its BSS.
• Explicit OBSS sectorized training and feedback may be an alternative to implicit OBSS sectorized training and feedback.
• An example of the explicit OBSS sector training and feedback procedure is shown in Figure 16.
• API 1600 may have observed a number of STAs within its range with which it is not associated. These STAs may include OBSS APs, such as AP2 1602, and STAs, such as STAl 1604, STA2 1606, STAM 1608.
• API 1600 may send out a broadcast or multicast sector measurement request 1610 to all OBSS STAs and APs, followed by null data packets (NDPs) 1612-1616 for each of its sectors.
• NDPs null data packets
• API 1600 After API 1600 completes the transmission of the sectorized sounding packets 1612-1616, it may send out a Sector Feedback poll 1618. If the group of STAs being polled is known and an order has been predetermined, API may send out a multicast Sector Feedback poll. The OBSS STAs and APs may then transmit sector training feedback 1620-1624 according to the pre- determined order, one after another with an interframe space (IFS), for example, a short interframe space (SIFS), between them. In another implementation, instead of polling a group of STAs, the API may individually send a Sector Feedback Poll to each of the known OBSS STAs and APs, to which the polled OBSS STA or AP may respond with a Sector Feedback frame.
• IFS interframe space
• SIFS short interframe space
• AP2 may send out a Sector Feedback poll to collect
• AP2 may create a Conflict Sector Table and send it to API.
• AP2 may send the Conflict Sector Table to a coordinating AP in a centralized coordination scheme.
• the coordinating AP may merge all copies of the Conflict Sector Tables into an OBSS Conflict Sector Table and send the table, or the relevant parts thereof, to each of the APs in the OBSS.
• AP2 may conduct OBSS sector training for all STAs within its range, such as STAs and API in BSSl.
• AP2 may directly receive feedback from all STAs in BSSl and from API.
• API may collect all OBSS sector feedback from all STAs associated with it, construct a Conflict Sector Table, and send the table to AP2.
• API may send the Conflict Sector Table to a coordinating AP in a centralized coordination scheme.
• the coordinating AP may merge all copies of the Conflict Sector Tables from all APs in the OBSS into an OBSS Conflict Sector Table and send it, or the relevant parts thereof, to each of the APs in the OBSS.
• Each AP may then subsequently broadcast the OBSS Conflict Sector Table, or relevant parts thereof, to the STAs in its BSS.
• OBSS STA/AP receiving an omni transmission preceding a sectorized transmission, but not receiving the sectorized transmission from an AP (which is either the TXOP holder or responder) or an expected transmission from a STA (which is either the TXOP responder or holder), such as an ACK.
• An SO frame exchange sequence in addition to the sequences described above is now considered.
• An OBSS STA/AP which receives an omnidirectional transmission from a STA reserving a sectorized TXOP (TXOP1) may initiate its own sectorized TXOP (TXOP2) if the associated sectorized transmission frame exchange sequence in TXOP2 is known not to conflict with the sectorized transmission frame exchange sequence in TXOP1.
• TXOP1 STA reserving a sectorized TXOP
• TXOP2 sectorized TXOP
• STAl 1702 may respond with an omni- directional frame. If the omni- directional frame is meant to further extend the sectorized TXOP, it may also carry a Sectorized TXOP indication and a Sector ID indication. If the omni- directional frame is the last frame of the frame exchange sequence, it may not carry Sectorized TXOP or Sector ID indications.
• Any OBSS STA that is capable of sectorized transmissions may initiate its own sectorized transmission, for example, to STA2 1706, if the associated sectorized transmission is known not to conflict with the transmission from API 1700 to STAl 1702.
• AP2 may evaluate whether such an omni-transmission is meant to reserve a sectorized TXOP by examining the Sectorized TXOP indication (step 1802). If the packet carries a Sectorized TXOP indication and a Sector ID indication, the OBSS STA may evaluate whether the packet is transmitted by an OBSS non-AP STA.
• a non-AP STA in a sectorized TXOP may transmit an omni- directional ACK/Response frame, CTS frame, or PS- Poll/Trigger frame.
• the BSSID may be obtained from the DA or RA field of the omni- directional frame.
• an OBSS STA may determine the BSS and the sector for which a sectorized TXOP is being reserved by the omni- directional transmission (step 1804).
• the OBSS STA may refer to its own Conflict Sector table to see if there are any Interfering Sectors that are associated with the combination of BSSID and Sector ID identified above (step 1806). If any Interfering Sectors are discovered, the OBSS STA may set a NAV for the duration of the sectorized TXOP for these interfering sectors (step 1808).
• the STA may reserve a sectorized TXOP for a sector for which a NAV has not been set (step 1810).
• the STA may transmit a sectorized RTS (with the Sectorized Transmission indication, Sectorized TXOP indication, and Sector ID indication) in that sector (step 18).
• An intended STA receiving a sectorized RTS may reply using an omni- directional CTS frame carrying a Sectorized TXOP indication and Sector ID indication if a NAV has not been set for any of its sectors or for the omni- directional antenna pattern.
• the STA may then send a sectorized transmission, such as a data packet, to the intended STA (step 1816).
• the sectorized TXOP reserved by the sectorized RTS may be required to end no later than the shortest NAV in any of the OBSS STA's sectors.
• RTS carrying a Sectorized TXOP indication may recognize that the RTS is used to reserve a sectorized TXOP.
• the OBSS STA/AP may attempt to detect a CTS and/or Hybrid Mode Packet (HMP). If the OBSS STA/AP has detected a RTS for reserving a sectorized TXOP, as well as the omni-portion of the HMP, and it does not hear the omni- directional CTS from the STA and the sectorized portion of the HMP, it may attempt to reserve a sectorized TXOP for itself.
• HMP Hybrid Mode Packet
• a STA If a STA is capable of transmitting and/or receiving using an omni- directional or sectorized beam, it may behave as follows. If a NAV has not been set for any sectors or for the omni- directional antenna pattern of the STA, it may reserve a sectorized TXOP with an AP using an omni- directional RTS addressed to the AP that carries a Sectorized TXOP indication and/or a Sector ID indication, or a combination thereof.
• PS-Poll, short PS-Poll, or other trigger frame, or an omni- directional portion of an HMP packet carrying a Sectorized TXOP indication may recognize that the HMP is used to reserve a sectorized TXOP.
• the OBSS STA or AP may then attempt to detect an ODSP and/or Hybrid Mode Packet (HMP). If the OBSS STA or AP detects an ODSP or omni- directional portion of a HMP for reserving a sectorized TXOP, and it does not hear the PS-Poll, short PS-Poll, or trigger frames preceding it, it may attempt to reserve a sectorized TXOP for itself.
• HMP Hybrid Mode Packet
• Sector Feedback Operation field 1908 that indicates whether a fast sector feedback operation is used in the current BSS. It may be implemented as one or more bits. For example, if a fast sector feedback operation is used in the current BSS, the field may contain "1"; otherwise, the field may contain "0".
• An Accepted SO Conditions field 1910 may indicate which SO conditions are being supported by the transmitter or used in the current BSS. This field may be implemented as a bit map (for example, a bit map of length 4), wherein each bit indicates the support or use of a particular SO condition.
• the Fast Sector Feedback IE 1900 may further include a
• Sectorization Directions field 1912 that indicates in which direction sectorized transmission may be used in the BSS or supported by the transmitter.
• This field may be implemented as a bitmap.
• the field may be two bits long, with one bit indicating that the supported sectorization direction is downlink (DL), or AP to STA, and one bit indicating that the supported sectorization direction is uplink (UL), or STA to AP.
• the field may be three bit long, with one bit indicating that the supported sectorization direction is DL, one bit indicating that the supported sectorization direction is UL, and a third bit indicating that the supported sectorization direction is peer-to-peer (P2P).
• the Fast Sector Feedback IE 1900 may further include an HMP/ODSP Usage field 1914 that indicates whether HMP or ODSP should be used to reserve a sectorized TXOP.
• Sub-1 GHz (SlG), 802.11ax, or 802.11 APs and STAs may include the Fast Sector Feedback IE 1900 in frames such as beacons, short beacons, or any other type of management, control or extension frames.
• APs and STAs may include the Fast Sector Feedback IE 1900 in frames that they exchange at the time of association or at other times, such as Probe Request/Response frames, Association Request/Response frames, and short Probe Request/Response frames.
• the Fast Sector Feedback IE 1900 or any subset of the fields or subfields thereof may be implemented as a subfield or subset of subfields of any existing or new IE, such as the SlG/HEW Capability, SlG/HEW Extended Capability, Sector Operation, Sector Capability, Type 0 Sectorization Scheme, or Type 1 Sectorization Scheme elements, or as a part of any control, management, or extension frames, or MAC/PLCP headers.
• any existing or new IE such as the SlG/HEW Capability, SlG/HEW Extended Capability, Sector Operation, Sector Capability, Type 0 Sectorization Scheme, or Type 1 Sectorization Scheme elements, or as a part of any control, management, or extension frames, or MAC/PLCP headers.
• a STA may provide fast sector feedback to an AP if its sector has changed since the last sectorized transmissions between it and the AP, or since the last sector feedback that the STA sent to the AP.
• the fast sector feedback procedure may include the following.
• the AP after receiving the Sector Training Request, may respond by sending a packet to the requesting STA that points to a periodic sector training that will start within a pre-defined interval from the time of the Sector Training Request.
• the AP may include a schedule or starting time of the next periodic sector training, or may include the time until the start of the next sector training.
• the AP may also respond with an ACK, short ACK, or other type of response frame to acknowledge the reception of the Sector Training Request.
• the AP may initiate sector training within the pre-defined interval starting from the Sector Training Request. Alternatively or additionally, the AP may initiate sector training once it has received a certain number of Sector Training Request frames from the STAs.
• the AP may use a Resource Allocation frame to assign a RAW, TWT, or time slots for STAs to transmit sector training feedback.
• a Resource Allocation frame may also be included in beacons, short beacons, or other types of management, control, or extension frames.
• RAWs, access windows, time slots, and beacon intervals or subintervals may be reserved for STAs that have explicitly requested Sector training, or for STAs that overheard the sector training frames.
• a STA that is not yet associated with an AP may overhear the sector training packets, and may include its Sector ID or a Preferred Sector field (which may be implemented as a bitmap) in the frames that it sends to the AP during association, such as Probe Request frames, Association Request frames, or any other type of management, control or extension frames.
• a fast sector feedback capable STA may choose not to send explicit sector training feedback in a separate frame. Instead, the fast sector feedback capable STA may include its new sector in an uplink packet sent to the AP when the STA and the AP reserve a sectorized TXOP.
• the AP may send an omni- directional frame such as RTS or a Sector RTS frame, which may carry a Sectorized TXOP indication and/or Sector ID indication.
• the STA after receiving the omni- directional frame, may respond with a modified CTS or other type of response frame that carries a Sector ID indication with its new sector ID, if it knows that its sector ID has changed since the last sectorized TXOP with the AP, or since the STA last sent sector training feedback to the AP. If the STA's sector ID has not changed, the STA may follow the regular sectorized TXOP reservation protocol.
• the AP after receiving a modified response frame with a Sector ID indication, may subsequently send its sectorized transmission using the sector beam associated with the new sector ID. Otherwise, it may use the sector beam associated with the STA's old sector.
• the STA may send an omnidirectional frame, such as PS-Poll frame, short PS-Poll frame, Sector PS-Poll frame, trigger frame, etc.
• the frame may carry a Sectorized TXOP indication and/or a Sector ID indication with the STA's new Sector ID, if the STA knows that its Sector ID has changed since its last sectorized TXOP with the AP, or since the STA last sent sector training feedback to the AP. If the STA's Sector ID has not changed, the STA may follow the regular sectorized TXOP reservation protocol by sending a regular PS-Poll, short PS-Poll, or trigger frame.
• the AP after receiving the omni- directional frame, may respond with an HMP or a combination of an ODSP and a sectorized packet.
• the AP after receiving a modified trigger frame with a Sector ID indication, may subsequently send its sectorized transmissions using the sector beam associated with the new Sector ID. Otherwise, it may use the sector beam associated with the STA's old sector.
• the Sector RTS and PS-Poll frames may be implemented as SlG
• the Sector RTS and PS- Poll frames may also be implemented as HEW Control Frame Extensions. These frames may be implemented as any other type of NDP, control, action, or extension frames, and may contain a Sector ID indication in the frame body, preamble, or MAC headers.
• a first AP when transmitting a beacon, includes the OBSS capability IE to indicate its capability for OBSS sectorized transmission training, feedback, and coordination.
• a transmitter in communication with the transmitter and the receiver.

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