Techniques for increasing reliability in IEEE 802.11

Abstract

To provide methods and apparatuses for increasing the reliability of frame transmission in IEEE 802.11 networks.SOLUTION: In a procedure for transmitting a plurality of copies of a frame, a first station (STA) being a wireless transmit / receive unit (WTRU) is configured to: generate at least one set of configurations that meets reliability requirements of a traffic flow associated with the frame, each set of configurations including the number of replications of the frame, a channel bandwidth, and a modulation and coding scheme (MCS); transmit, to a second STA, a plurality of request-to-send (RTS) frames over a plurality of channels; receive, from the second STA, a plurality of clear-to-send (CTS) frames indicating whether the channels are available; select a first configuration from the set of configurations on the basis of the number of available channels determined from the received CTS frames; and transmit, on the basis of the selected first configuration, a plurality of copies of the frame simultaneously over the available channels.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 849,547, filed May 17, 2019, the contents of which are incorporated herein by reference. [Background technology]

[0002] background Ultra-reliable low-latency communication (URLLC) is a set of features that provides low, deterministic delay communications (e.g., end-to-end latency of less than 10 ms) and ultra-high reliability for mission-critical applications that cannot tolerate data loss. While URLLC was introduced in 5G, URLLC can also be considered for other access technologies, such as wireless local area networks (WLANs). Currently, several mechanisms exist to increase reliability in 802.11 networks. For example, transmission rates can be reduced to increase transmission distance, thereby effectively reducing the signal-to-interference-and-noise ratio (SINR) required for successful reception. Furthermore, frame protection can be improved by adding more complex forward error correction (FEC) or error correction techniques. However, these mechanisms are insufficient to enable URLLC-level communications due to packet loss, complexity, and increased latency in the absence of a reserved medium for multicast / groupcast transmission. Therefore, there is a need for methods and devices to increase reliability in IEEE 802.11 networks. Summary of the Invention

[0003] overview

[0003] Methods and apparatuses for improving reliability in IEEE 802.11 networks are described herein. For example, a first station (STA) can generate at least one set of configurations that satisfy one or more reliability requirements of a traffic flow associated with a frame. Each of the at least one set of configurations can include a number of replications of the frame, a channel bandwidth, and a modulation and coding scheme (MCS) associated with the channel bandwidth. The first STA can transmit multiple request-to-send (RTS) frames to the second STA on multiple channels, for example, using a multicast media access control (MAC) address associated with the second STA. The first STA can receive multiple clear-to-send (CTS) frames from the second STA indicating whether multiple channels are available. The first STA can determine a number of available channels based on the availability of the multiple channels. The first STA can then select a first configuration from the at least one set of configurations based on the number of available channels. The first configuration satisfies one or more reliability requirements of the traffic flow and can include a first number of replications of the frame, a first channel bandwidth, and a first MCS associated with the first channel bandwidth. The first STA may simultaneously transmit multiple copies of a frame on available channels based on the first configuration.

[0004] BRIEF DESCRIPTION OF THE DRAWINGS A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate similar elements and in which: [Brief explanation of the drawings]

[0005] [Figure 1A] FIG. 5 is a system diagram illustrating an example of a communication system in which one or more disclosed embodiments may be implemented. [Figure 1B]

[0006] 1B is a system diagram illustrating an example of a wireless transmit / receive unit (WTRU) that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 1C]

[0007] 1B is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1D]

[0008] 1B is a system diagram illustrating a further example of a RAN and a further example of a CN that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 2]

[0009] FIG. 1 is a diagram illustrating an example of dynamic bandwidth operation (DBO). [Figure 3]

[0010] FIG. 1 is a diagram illustrating an example of frame replications and elimination for reliability (FRER). [Figure 4]

[0011] FIG. 10 illustrates an example of a groupcast with retries-request to send (GCR-RTS) frame format. [Figure 5]

[0012] FIG. 1 illustrates an example of a synthetic receiver address (SYNRA) format. [Figure 6]

[0013] FIG. 10 illustrates an example of an association identifier (AID) ordering SYNRA type format. [Figure 7]

[0014] FIG. 10 illustrates an example of an operation involving groupcast with retries-request to send / clear to send (GCR-RTS / CTS). [Figure 8]

[0015] FIG. 1 illustrates an example of frequency replication-DBO (FR-DBO) with simultaneous transmission of multiple copies of a frame. [Figure 9]

[0016] FIG. 1 illustrates an example of a procedure for intelligently controlling redundancy levels. [Figure 10]

[0017] FIG. 1 illustrates an example of a procedure for transmitting multiple copies of a frame based on FR-DBO and configuration of MAC properties according to a reliability factor. [Figure 11]

[0018] FIG. 10 illustrates another example of a procedure for transmitting multiple copies of a frame based on FR-DBO and configuration of MAC properties according to a reliability factor. [Figure 12]

[0019] FIG. 1 illustrates an example of DBO for generic link-groupcast operation with retries (GLK-GCR) transmission. DETAILED DESCRIPTION OF THE INVENTION

[0006] Detailed Description

[0020] 1A illustrates an example of a communication system 100 in which one or more disclosed embodiments can be implemented. The communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may use 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), zero-tailed unique word discrete Fourier transform spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0007]

[0021] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, and 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, and 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, any of which may be referred to as a station (STA), may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspot or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearable items, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated process chains), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0008]

[0022] The communications system 100 may also include a base station 114a and / or a base station 114b. 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 communications networks, such as the CN 106, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a NodeB, an eNodeB (eNB), a Home NodeB, a Home eNodeB, a next generation NodeB such as a gNode B (gNB), a new radio (NR) NodeB, a site controller, an access point (AP), a wireless router, etc. While the base stations 114a, 114b are each shown as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0009]

[0023] 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. The base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, one for each sector of the cell. In one embodiment, the base station 114a may use multiple input / output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming can be used to transmit and / or receive signals in desired spatial directions.

[0010]

[0024] 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, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0011]

[0025] More specifically, as noted above, the communications system 100 may be a multiple-access system and may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a and the WTRUs 102a, 102b, 102c in the RAN 104 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 (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0012]

[0026] In one embodiment, the base station 114a 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 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0013]

[0027] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using NR.

[0014]

[0028] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE radio access and NR radio access, e.g., using the principle of dual connectivity (DC). Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by transmissions sent to and from multiple types of radio access technologies and / or multiple types of base stations (e.g., eNBs and gNBs).

[0015]

[0029] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (e.g., Wireless Fidelity (WiFi)), IEEE 802.16 (e.g., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, 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), or the like.

[0016]

[0030] 1A may be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity within a local area, such as a business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, 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). In one embodiment, 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). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not need to access the Internet 110 through the CN 106.

[0017]

[0031] The RAN 104 may communicate with the CN 106, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be understood that the RAN 104 and / or CN 106 may communicate directly or indirectly with other RANs that use the same RAT as the RAN 104 or a different RAT. In addition to being connected to the RAN 104, which may utilize, for example, NR radio technology, the CN 106 may also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0018]

[0032] The CN 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing Plain Old Telephone Service (POTS). The Internet 110 may include a worldwide system of interconnected computer networks and devices that use common communication protocols, such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) within the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may use the same RAT as the RAN 104 or a different RAT.

[0019]

[0033] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may use a cellular-based wireless technology, and with a base station 114b, which may use an IEEE 802 wireless technology.

[0020]

[0034] 1B is a system diagram illustrating an example of a WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, a processor 118, 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 / or other peripherals 138. It will be understood that the WTRU 102 may include any subcombination of the above elements while remaining consistent with an embodiment.

[0021]

[0035] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other function 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 FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated within an electronic package or chip.

[0022]

[0036] The transmit / receive element 122 may be configured to transmit or receive signals to or from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0023]

[0037] 1B depicts the transmit / receive element 122 as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may use 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.

[0024]

[0038] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate over multiple RATs, such as NR and IEEE 802.11.

[0025]

[0039] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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. Additionally, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable 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, etc. In other embodiments, the processor 118 may access information and store data in memory that is not physically located on the WTRU 102, such as on a server or on a home computer (not shown).

[0026]

[0040] The processor 118 may obtain power from the power source 134 and may be configured to distribute and / or control power to other components within 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 batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0027]

[0041] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or may determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by any suitable location determination method while remaining consistent with an embodiment.

[0028]

[0042] The processor 118 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 photos and / or videos), a universal serial bus (USB) port, a vibration device, a television receiver, a hands-free headset, a Bluetooth module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripherals 138 may include one or more sensors. The sensors may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, a direction sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor, etc.

[0029]

[0043] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals (e.g., associated with a particular subframe on both the UL (e.g., for transmission) and DL (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and / or substantially eliminate self-interference by hardware (e.g., choke) or processor-based signal processing (e.g., by a separate processor (not shown) or processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio where transmission and reception of some or all of the signals (e.g., associated with a particular subframe on the UL (e.g., for transmission) or DL ​​(e.g., for reception)) may be parallel and / or simultaneous.

[0030]

[0044] 1C is a system diagram illustrating the RAN 104 and the CN 106 according to one embodiment. As mentioned above, the RAN 104 may use E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0031]

[0045] The RAN 104 may include eNode-Bs 160a, 160b, and 160c, although it will be understood that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Thus, for example, the eNode-B 160a may use multiple antennas to transmit and / or receive wireless signals to and from the WTRU 102a.

[0032]

[0046] Each of the eNode-Bs 160a, 160b, 160c 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 UL and / or DL, etc. As shown in Figure 1C, the eNode-Bs 160a, 160b, 160c may communicate with each other over an X2 interface.

[0033]

[0047] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although the above elements are shown as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0034]

[0048] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 by an S1 interface and may act as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0035]

[0049] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 by an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions such as anchoring the user plane during handovers between eNode Bs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0036]

[0050] The SGW 164 may be connected to a PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0037]

[0051] The CN 106 may facilitate communications with other networks. For example, the CN 106 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 CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0038]

[0052] Although FIGS. 1A-1D depict the WTRU as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may use a wired communication interface (eg, temporarily or permanently) with a communication network.

[0039]

[0053] In a representative embodiment, the other network 112 may be a WLAN.

[0040]

[0054] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interface with a distribution system (DS) or another type of wired / wireless network that carries traffic into and out of the BSS. Traffic to a STA originating from outside the BSS may arrive and be delivered to the STA through the AP. Traffic originating from a STA to a destination outside the BSS may be sent to the AP to be delivered to its respective destination. Traffic between STAs within the BSS may be sent through the AP; for example, a source STA may send traffic to the AP, which can deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent (e.g., directly) between a source STA and a destination STA using direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs within or using an IBSS (e.g., all of the STAs) can communicate directly with each other. IBSS mode communication may also be referred to herein as an "ad hoc" mode of communication.

[0041]

[0055] When using 802.11ac infrastructure mode of operation or a similar mode of operation, an AP can transmit beacons on a fixed channel, such as a primary channel. The primary channel can be a fixed width (e.g., a 20 MHz wide band) or a dynamically configured width. The primary channel can be the operating channel of the BSS and can be used by STAs to establish a connection with the AP. In certain representative embodiments, for example, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) can be implemented within an 802.11 system. In CSMA / CA, STAs (e.g., all STAs), including the AP, can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is in use, the particular STA can back off. Within a given BSS, one STA (e.g., only one station) can transmit at any given time.

[0042]

[0056] For example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel, a high throughput (HT) STA can use the 40 MHz wide channel for communication.

[0043]

[0057] A Very High Throughput (VHT) STA may support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. A 40 MHz and / or 80 MHz channel can be formed by combining contiguous 20 MHz channels. A 160 MHz channel can be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, which may be called an 80+80 configuration. In the 80+80 configuration, the channel-encoded data can be passed through a segment parser, which can split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed separately for each stream. The streams can be mapped onto two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the above 80+80 configuration operation can be reversed, and the combined data can be sent to the Medium Access Control (MAC).

[0044]

[0058] Sub-1 GHz modes of operation are supported by 802.11af and 802.11ah. Compared to those used in 802.11n and 802.11ac, 802.11af and 802.11ah reduce channel operating bandwidths and carriers. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to exemplary embodiments, 802.11ah can support meter-type control / machine-type communication (MTC), such as MTC devices, within macro coverage areas. MTC devices may have limited functionality, including support for (e.g., only) specific and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0045]

[0059] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as a primary channel. The primary channel can have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be configured and / or limited by a STA among all STAs operating in the BSS that supports the minimum bandwidth operating mode. In the 802.11ah example, the primary channel can be 1 MHz wide for a STA (e.g., an MTC-type device) that supports (e.g., only supports) the 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) setting can depend on the state of the primary channel. For example, if the primary channel is in use by a STA (that only supports the 1 MHz operating mode) transmitting to the AP, all available frequency bands can be considered in use, even if a large portion of the available frequency band remains unused.

[0046]

[0060] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. Depending on the country code, the total available bandwidth for 802.11ah is 6MHz to 26MHz.

[0047]

[0061] 1D is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As mentioned above, the RAN 104 can communicate with the WTRUs 102a, 102b, 102c over the air interface 116 using NR radio technology. The RAN 104 can also communicate with the CN 106.

[0048]

[0062] While the RAN 104 may include gNBs 180a, 180b, and 180c, it will be understood that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit and / or receive signals to and from the gNBs 180a, 180b, and 180c. Thus, for example, the gNB 180a may use multiple antennas to transmit and / or receive wireless signals to and from the WTRU 102a. In one embodiment, the gNBs 180a, 180b, and 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers (not shown) to the WTRU 102a. A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In one embodiment, the gNBs 180a, 180b, and 180c may implement coordinated multipoint (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0049]

[0063] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using scalable numerology-related transmissions. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting for varying absolute times).

[0050]

[0064] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c without accessing any other RANs (e.g., eNode-Bs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c can utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with / connect to a gNB 180a, 180b, 180c while also communicating with / connecting to another RAN, such as an eNode-B 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0051]

[0065] Each of the gNBs 180a, 180b, 180c can be associated with a particular cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, DC, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D , the gNBs 180a, 180b, 180c can communicate with each other over the Xn interface.

[0052]

[0066] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While the above elements are shown as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0053]

[0067] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 by an N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling various protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating non-access stratum (NAS) signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service being utilized. Different network slices may be established for different use cases, for example, services relying on Ultra-Reliable Low Latency (URLLC) access, services relying on Enhanced Massive Mobile Broadband (eMBB) access, services for MTC access, etc. The AMFs 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that use other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0054]

[0068] The SMFs 183a and 183b may be connected to the AMFs 182a and 182b in the CN 106 via an N11 interface. The SMFs 183a and 183b may also be connected to the UPFs 184a and 184b in the CN 106 via an N4 interface. The SMFs 183a and 183b may select and control the UPFs 184a and 184b and configure the routing of traffic through the UPFs 184a and 184b. The SMFs 183a and 183b may perform other functions such as managing and assigning IP addresses for UEs, managing PDU sessions, enforcing policy and controlling QoS, providing DL data notification, etc. The type of PDU session may be IP-based, non-IP-based, Ethernet-based, etc.

[0055]

[0069] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 by an N3 interface, and the gNBs may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks such as the Internet 110 to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, and providing mobility anchoring.

[0056]

[0070] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to the local DNs 185a, 185b via the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0057]

[0071] 1A-1D and the corresponding descriptions thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation device may be used to test other devices and / or to simulate the functionality of a network and / or a WTRU.

[0058]

[0072] The emulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or to perform testing using wireless communications.

[0059]

[0073] The one or more emulation devices may perform one or more functions, inclusive, without being implemented / introduced as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a test laboratory and / or in a test scenario within an unintroduced (e.g., test) wired and / or wireless communication network to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0060]

[0074] Ultra-Reliable Low-Latency Communications (URLLC) is applicable to the Third Generation Partnership Project (3GPP) in 5G and can also be considered for other access technologies such as WLAN, with use cases such as home networking and consumer electronics (CE) devices where WLAN is a widely used access technology. URLLC can have several components, such as a focus on low, deterministic delay communications with end-to-end latency of less than 10 ms and a focus on reliability for mission-critical applications that cannot tolerate data loss. In IEEE 802.11, real-time communications may require very low, deterministic latency and high reliability in some use cases.

[0061]

[0075] Groupcast transmissions may be transmissions addressed to a group of stations that follow the rules of transmission (e.g., IEEE 802.11aa). These transmissions may be addressed to a hidden MAC address (e.g., a multicast MAC address) that is used to prevent stations that are not in the group from processing such packets.

[0062]

[0076] To increase the reliability of transmissions to a group of stations, several mechanisms are possible, called Groupcast with Retries (GCR), such as GCR Unsolicited Retries, GCR Direct Multicast, and / or GCR Block ACK.

[0063]

[0077] GCR Unsolicited Retries may be used where each frame is repeated a predetermined number of times.

[0064]

[0078] GCR Direct Multicast can be used to transform a multicast stream into several unicast streams addressed to different group-based stations, i.e. a multicast transmission can effectively become a set of unicast transmissions.

[0065]

[0079] GCR Block ACK can be used when transmitting a block of frames to a group. Once the block is transmitted, the AP requests each station in the group to confirm which frames of the block have not been received.

[0066]

[0080] These GCR mechanisms may differ from the normal multicast operation of the network and may use higher modulation schemes to achieve higher speeds, as opposed to normal multicast (known as Non-ACK), which uses a lower MCS to increase the probability of reception by all stations. These GCR mechanisms may require techniques to secure the medium and reduce the probability of collisions before using any of these mechanisms.

[0067]

[0081] In a related context, there is a possible model for IEEE 802.11 to interact with IEEE 802.1Q networks. This model, known as Generic Links (GLK), allows an IEEE 802.11 network to connect to an IEEE 802.1Q-compatible port and behave as an IEEE 802.1Q-compatible port. This can be done by creating point-to-point or point-to-multipoint logical links connecting various stations, each of which appears as a bridge port. A characteristic of GLK ports is that a port can connect to various stations and therefore must have groupcast communication with various nodes. An example of this is the connection of a set of wireless bridges and the need to communicate with only a subset of them to avoid loops (e.g., spanning tree determination). Like standard GCR, GLK-GCR may not use hidden groupcast addresses. However, a synthetic address known as a synthetic receiver address (SYNRA) may be used to group association IDs and identify the station that should process the frame. GLK therefore requires the use of GCR transmission, and thus techniques for preserving airtime are required.

[0068]

[0082] IEEE 802.11 can use channel bonding as a mechanism to increase the available throughput of a wireless network. IEEE 802.11-based standards operate using a base channel bandwidth of 20 MHz. To increase the available bandwidth for transmission, IEEE 802.11n can use a mechanism to bond several 20 MHz channels into a larger channel. In this way, bonded channels in IEEE 802.11n can reach 80 MHz, and this technique can be extended in IEEE 802.11ac to achieve up to 160 MHz (8 x 20 MHz) or 80 + 80 MHz channels (4 x 20 MHz + 4 x 20 MHz).

[0069]

[0083] However, due to the general saturation of the Industrial, Scientific, and Medical (ISM) channels used within the IEEE 802.11 band, channel bonding may not always work as expected. Channel bonding in IEEE 802.11n may work by STAs performing clear channel assessment (CCA) on a predefined and unique channel of width equal to the sum of the channels. Due to saturation of the wireless medium, this CCA procedure may typically not be successful, as the required bandwidth may not be simultaneously available, making channel bonding less than ideal in certain situations.

[0070]

[0084] IEEE 802.11ac addresses the channel bonding issue by utilizing the concept of Dynamic Bandwidth Operation (DBO), in which STAs wishing to transmit negotiate channels for bonding before transmitting a frame. DBO can function with very high-throughput (VHT) stations (STAs), where a request-to-send / clear-to-send (RTS / CTS) exchange using non-high-throughput (non-HT) duplicated physical layer (PHY) protocol data units (PPDUs) negotiates a possibly reduced channel width (compared to the channel width indicated by RTS) for subsequent transmissions within the current transmission opportunity (TXOP).

[0071]

[0085] 2 illustrates an example of dynamic bandwidth operation (DBO) 200 in which an 80 MHz channel is requested but a 40 MHz channel is granted, which may be used in combination with any of the other embodiments described herein. As shown in FIG. 2, STA1 201a may transmit multiple RTS frames 202, 204, 206, 208 to STA2 201b (e.g., requesting 80 MHz) in all channels identified by STA1 201a to learn which channels are available. In response to the multiple RTS frames 202, 204, 206, 208, STA1 201a may receive multiple CTS frames 212, 214, 218 from STA2 201b indicating whether the channels on which the RTS frames 202, 204, 206, 208 were received are available. 2, STA1 201a receives three CTS frames 212, 214, and 218 indicating that the channels on which it received RTS frames 202, 204, and 208 are available. Because the primary and secondary 20 MHz channels are contiguous and available, STA1 201a can aggregate these channels into 40 MHz channel 222 and transmit data on 40 MHz channel 222.

[0072]

[0086] More specifically, to transmit within several 20 MHz channels, IEEE 802.11ac may require that STA1 201a receive a CTS frame 212 for its primary 20 MHz channel 230 and secondary 20 MHz channel 235 (e.g., for 40 MHz channel 240). For example, if 80 MHz channel bonding 250 is desired, the primary 40 MHz channel 240 must be free, and the secondary 40 MHz channel 245 must also be free. This scheme may focus on bonding channels, and thus the objective may be to find a pair of primary and secondary channels that results in a bonded channel with the maximum available bandwidth. This scheme may have strict rules for the behavior of secondary channels enforced within the standard. Except in the case of an 80+80 MHz allocation, the use of disjoint (i.e., non-contiguous) channels may not be permitted. The DBO mechanism shown in FIG. 2 results in unique transmissions over channels with bandwidth equal to the sum of the bandwidths of the various available channels and can be used for unicast transmissions.

[0073]

[0087] FIG. 3 illustrates an example of Frame Replication and Elimination for Reliability (FRER) 300 in a WLAN, which can be used in combination with any of the other embodiments described herein. The FRER mechanism (e.g., IEEE 802.1CB) may enable IEEE 802.1Q switches at the endpoints or intermediate points of a communication to replicate frames, sequence them, and eliminate duplicate frames. As shown in FIG. 3, the Generic Links (GLK) IEEE 802.11ak specification may enable the FRER mechanism to be applied to IEEE 802.11 networks. As shown in FIG. 3, an AP 310 as a stream source is connected to a STA 370 as a stream destination via multiple bridges 320, 330, 340, 350, and 360. The AP 310 and bridges 320, 330, and 340 may form an IEEE 802.1 GLK network by connecting to each other via IEEE 802.11 connections 312, 314, and 316. The AP 310 may be a stream source requiring high reliability. The AP 310 can add a tag to the frame containing a sequence number for replication and can transmit the frame to the STAs 370 in the wireless network via two separate paths 325, 335. For example, using separate paths can be achieved by using a GLK-GCR transmission using a SYNRA address as the RA in the frame and transmitting the frame to two of the three stations (i.e., bridges 320, 330, 340) in the link. In this way, the frame is replicated via a single transmission.

[0074]

[0088] As noted above, IEEE 802.11 includes a mechanism by which stations may be able to negotiate the available bandwidth (20, 40, 80, 80+80 MHz) through Dynamic Bandwidth Operation (DBO). The DBO mechanism may not be available for groupcast or multicast transmissions, and therefore implementations of FRER as described above may use static channel allocation.

[0075]

[0089] There are several possible approaches to increasing reliability in 802.11. For example, the rate at which frames are transmitted can be slowed, which effectively reduces the SINR required for successful reception and thereby increases transmission distance. For example, frames can be better protected by adding more complex FEC or including error correction techniques. For example, several copies of transmitted frames can be sent, as is done in IEEE 802.11aa. For example, IEEE 802.11CB (Frame Replication and Elimination for Reliability, FRER) can be used in IEEE 802.1 networks, and FRER in IEEE 802.11 networks may require requests for groupcast transmissions (using IEEE 802.11ak GLK SYNRA addresses), techniques for reserving channels for groupcast or multicast transmissions, etc.

[0076]

[0090] These techniques may not enable URLLC-level communication in some scenarios. For example, in some scenarios, there may be a mechanism for using sequential transmission of redundant frames, resulting in increased latency if a packet is lost. For example, in some scenarios, there may be no mechanism for reserving the medium before transmitting groupcast / multicast frames, resulting in collisions and significantly degrading channel performance. For example, in some scenarios, optimized channel bonding (e.g., using Static Bandwidth Operation (SBO)) may not be used for multicast / groupcast, resulting in those transmissions being unable to use the high MCS developed in 802.11ac / 802.11ax.

[0077]

[0091] Therefore, there is a need to address how reliability in IEEE 802.11 can be increased by simultaneously transmitting multiple copies of the same frame while using opportunistic channel bonding and high MCS to keep latency as low as possible. This need can be addressed by the embodiments disclosed herein.

[0078]

[0092] One or more embodiments may focus on enhancing the reliability of IEEE 802.11 to meet the reliability required by URLLC level applications by extending the mechanisms for reserving the medium (RTS / CTS) with the following features: (1) extending the GCR-RTS / CTS to reserve a channel for a group of stations and the IEEE 802.11ac Dynamic Bandwidth Operation mechanism to find the best channel allocation for groupcast transmissions; (2) defining the use of FRER in IEEE 802.11ak GLK networks and using the GLK GCR-RTS / CTS mechanism to reserve the medium and find the best channel allocation to optimize the throughput of GCR-GLK transmissions; (3) enhancing the IEEE 802.11ac Dynamic Bandwidth Operation mechanism to send frame replications to stations using several channels; and / or (4) a mechanism for a STA to define the reliability level and its mapping to several copies to be transmitted, and the required bandwidth allocation, as well as the configuration of the STA's MAC layer mechanisms.

[0079]

[0093] In one embodiment using Groupcast with Retries (GCR) RTS / CTS, RTS / CTS may be extended for groupcast transmissions, allowing all stations in the group to reserve airtime. The GCR RTS / CTS may need to address all stations in the group because there may be hidden nodes in the network, and only using both RTS and CTS safely blocks the Network Allocation Vector (NAV) of the remaining stations in the network.

[0080]

[0094] 4 illustrates an example of a groupcast with retries-request to send (GCR-RTS) frame format 400, which can be used in combination with any of the other embodiments described herein. The RTS / CTS format can be enhanced to include new rules for airtime reservation defined in the duration field. This GCR-RTS frame can be defined as a new control frame for IEEE 802.11. As shown in FIG. 4, the GCR-RTS frame 400 can include a frame control field 405, a duration field 410, a receiver address (RA) field 415, a transmit address (TA) field 420, an association ID (AID) order field 425, and an FCS field 430.

[0081]

[0095] The duration value in the frame duration field 410 may need to be set to the estimated time in microseconds it will take to transmit the pending frame, as many GCR-CTS frames as there are stations in the group separated by an IFS, one ACK or Block ACK frame if needed, any required Null Data Packets (NDPs), explicit feedback if needed, and the applicable IFS.

[0082]

[0096] The RA field 415 value of the GCR-RTS frame 400 can be a hidden groupcast address of a group of stations to respond to GCR RTS / CTS exchanges. The TA field 420 can follow the same rules as certain legacy IEEE 802.11 protocols. The Association ID (AID) Order field 425 can be used to present a list of association identifiers in order, and can be used to respond to GCR-RTS in the order presented in the list. This field can follow the same format as a SYNRA address.

[0083]

[0097] SYNRA may be defined as a 48-bit composite address that provides a list of AIDs in a compact manner (e.g., the format in IEEE 802.11ak). Figure 5 shows an example of a composite receiver address (SYNRA) format 500 that may be used in combination with any of the other embodiments described herein. As shown in Figure 5, SYNRA format 500 may include an 11 field 505, a SYNRA type field 510, and a SYNRA control field 515.

[0084]

[0098] There may be other types of SYNRAs based on Table 1, and the AIR-ordered SYNRA control is based on FIG. 6, which shows an example of an AID-ordered SYNRA type format 600 that can be used in combination with any of the other embodiments described herein.

[0085] [Table 1]

[0086]

[0099] 6, AID Order SYNRA Type Former 600 may include an AID Bitmap Offset subfield 605 and an AID Bitmap subfield 610. The AID Bitmap Offset subfield 605 in the AID Order SYNRA Control may be used to indicate a starting AID value to be associated with bit 0 of the AID Bitmap subfield 610. For example, the value may be generated by multiplying by 4 to find the starting AID value, which may have a value from 0 to 494 for non-S1G STAs and from 0 to 2040 for S1G STAs. Other values ​​may be reserved.

[0087]

[0100] The AID Bitmap subfield 610 within the AID Order SYNRA control can provide an indication of the need to respond with a GCR-CTS frame over a range of, for example, 33 consecutive AIDs. For example, bits B11 through B43 represent AID values ​​within the range of AID Bitmap Offset x4+1 through AID Bitmap Offset x4+33, respectively. For each bit within the AID Bitmap subfield, a value of 1 indicates that a GCR-CTS is expected, and a value of 0 indicates that a GCR-CTS frame is not expected. The order in which the bits appear can indicate the order in which GCR-CTS frames are transmitted by the station.

[0088]

[0101] FIG. 7 illustrates an example of operations 700 involving a groupcast with retries-request to send / clear to send (GCR-RTS / CTS) frame, which may be used in combination with any of the other embodiments described herein. As shown in FIG. 7, an AP 714 (or STA) may groupcast a GCR-RTS frame 705 to a group of STAs including STA1 702a and STA2 702b. The GCR-RTS frame 705 may include an AID order field containing a list of AIDs, in order. The AID list indicates which STAs should respond with GCR-CTS frames 710, 715 in response to the GCR-RTS frame 705, and in what order. For example, STA1 702a has an association identifier (AID) located in the AID bitmap before STA2's, and may respond with a GCR-CTS frame 710 to the AP 714 before the GCR-CTS frame 715 from STA2 702b. After the AP 714 receives the GCR-CTS frames 710, 715, the AP 714 knows which channels are available between the AP 714 and the STAs 702a, 702b. Based on this availability information, the AP 714 can transmit data 720, 725 on the available channels.

[0089]

[0102] The example of GCR-RTS / CTS operation shown in Figure 7 may exhibit overhead when many STAs are addressed. At the same time, if multiple frames are exchanged, e.g., using the GCR blocking mechanism, this overhead must be considered along with the benefit of avoiding retransmissions due to collisions.

[0090]

[0103] The GCR-CTS frames 710, 715 may be identical to standard CTS frames except for the duration field, which may need to contain the time taken by the remaining STAs indicated in the AID bitmap after that position plus all IFSs between them.

[0091]

[0104] In one example of GCR-RTS / CTS, an originating AP 714 or STA can transmit a GCR-RTS message 705 with a SYNRA in the AID order field. This GCR-RTS message 705 can be sent to a hidden MAC address (or multicast MAC address) of a group that includes STAs such as STA1 702a and STA2 702b. The AID order can indicate (e.g., by providing the AIDs) which STAs require responses and in what order. The addressed STAs 702a, 702b respond with GCR-CTS messages 710, 715 in the order indicated in the SYNRA. As a result, no CTS collisions occur between the addressed STAs 702a, 702b.

[0092]

[0105] In one embodiment, a generic link (GLK)-GCR RTS / CTS frame may be used. This format may be similar to GCR-RTS / CTS, but considers the case of a Generic Link (GLK) (IEEE 802.11ak) compatible network. GLK has considerations that make the case different from GCR-RTS / CTS, such as the possibility that there may not be groupcast messages sent directly to hidden and SYNRA addresses.

[0093]

[0106] There may be one or more differences between the GCR and the GLK GCR, such as in the case of GLK stations, where a group of stations in IEEE 802.11ak can be addressed by a basic SYNRA specified in the Clause, and in IEEE 802.11ak SYNRA can be set up based on association and may need to be used to address the station since the GCR hidden address is not available.

[0094]

[0107] For this reason, GLK-GCR RTS / CTS may enforce the use of an AID-ordered SYNRA to carry within the RA field of the RTS frame. Thus, the format of a GLK-GCR RTS frame may be the same as a standard RTS frame except for the use of an AID-ordered SYNRA as the RA. Note that stations receiving an AID-ordered SYNRA may respond to the GLK-GCR RTS frame with a GLK-GCR CTS frame in the order established in the AID-ordered bitmap. The Duration field of the GLK-GCR RTS frame may need to be set to the estimated time in microseconds it will take to transmit the pending frame, as many GLK-GCR CTS frames as there are stations in the group separated by an IFS, one ACK or Block-ACK frame if necessary, any required Null Data Packets (NDPs), explicit feedback if necessary, and the applicable IFS.

[0095]

[0108] As discussed earlier in this specification, the behavior of the AP and STA may be the same, but differs in the format of the GLK-GCR RTS / CTS SYNRA address that may be used in the AID-ordered SYNRA.

[0096]

[0109] These approaches for GLK-GCR RTS / CTS and GCR RTS / CTS may be described herein to explain techniques for FRER in IEEE 802.11 networks.

[0097]

[0110] In one embodiment, there may be discovery of available channels for unicast transmission using DBO. As discussed above, one way to increase reliability in WLAN networks is to transmit several copies of the same data. This is typically done at the MAC layer by transmitting successive copies of the data within the same channel. This method uses Dynamic Channel Operation to discover and reserve multiple channels, but instead of transmitting a single PLCP Protocol Unit (PPDU) across the entire discovered bandwidth, replicated copies of the PPDU are transmitted within multiple channels, effectively reducing the probability of frame loss. This may reduce transmission bandwidth but improves reliability, and this mechanism is sometimes referred to as Frame Replication-DBO (FR-DBO).

[0098]

[0111] FIG. 8 illustrates an example of Frame Replication-DBO (FR-DBO) involving simultaneous transmission of multiple copies of a frame, which can be used in combination with any of the other embodiments described herein. For example, STA1 801a may have at least one set of possible different configurations that meet the reliability requirements (e.g., 60% reliability) of a certain traffic flow, such as voice or video traffic. Each configuration in the set of configurations also meets the reliability requirements and may include the number of replications (i.e., redundancy) of the frame, the channel bandwidth, and the modulation and coding scheme (MCS) associated with the channel bandwidth (e.g., redundancy 3X, 20 MHz, MCS5, or redundancy 1X, 40 MHz, MCS2). As shown in FIG. 8, STA1 801a may groupcast or multicast RTS frames 802, 804, 806, and 808 to multiple STAs, including STA2 801b, in all channels identified by STA1 801a, e.g., primary 20 MHz channel 830, secondary 20 MHz channel 835, and 20 MHz channels 840 and 845. In response to the RTS frames 802, 804, 806, and 808, STA1 may receive one or more CTS frames 821, 814, and 818 from STA2 801b indicating whether the channels 830, 835, 840, and 845 on which the RTS frames 802, 804, 806, and 808 were received are available. As shown in FIG. 8 , STA1 801a receives three CTS frames 812, 814, and 818 indicating that the primary 20 MHz channel 830, the secondary 20 MHz channel 835, and the 20 MHz channel 808 are available. STA1 801a may determine that the number of available channels is three. Based on the number of available channels, STA1 801a may select a configuration from a set of possible configurations that meets the reliability requirements of the traffic flow. For example, assuming a reliability requirement for a traffic flow is 60% reliability, STA1 801a may select a configuration (for a 20 MHz channel) that includes redundancy 3X, 20 MHz, and MCS5 to transmit multiple copies 822, 824, 828 of a frame on three available channels 830, 835, 845, giving 33% reliability on the 20 MHz channel.Based on the selected configuration, STA1 801a can simultaneously transmit three copies of a frame (i.e., Frame X Copy 1 822, Frame X Copy 2 824, and Frame X Copy 3 828) within the three available channels (i.e., primary 20 MHz channel 830, secondary 20 MHz channel 835, and 20 MHz channel 845). Because the selected configuration (e.g., MCS5) can provide STA1 801a with 33% reliability for transmission on the 20 MHz channels, STA1 801a can achieve the reliability requirement of the traffic flow (e.g., 60%) by transmitting three copies of the frame based on the configuration (e.g., MCS5) that provides STA1 801a with 33% reliability on each of channels 830, 835, and 845. It should be noted that the STAs 801a and 801b shown in FIG. 8 can be APs, bridges, or WTRUs.

[0099]

[0112] In this embodiment, multiple channels and channel aggregations can be used based on the available channels detected by FR-DBO. Thus, the original frame (e.g., Copy 1 of Frame X 822) and two copies of the frame (e.g., Copy 2 of Frame X 824 and Copy 3 of Frame X 825) can be transmitted simultaneously. The transmission may have to include the original main channel of the BSSID so that the receiving station can receive information about which other channels are being used.

[0100]

[0113] With regard to the ACK 832 for this frame, one or more options may be utilized: (1) the frame is acknowledged only in the primary channel (regardless of channel bandwidth); (2) the frame is acknowledged in all channels on which it is received; and / or (3) a block ACK mechanism is used.

[0101]

[0114] The ability to discover multiple combinations of channels, channel widths, and MCSs may allow for generating optimal resource allocations that adhere to certain reliability requirements, as discussed further herein.

[0102]

[0115] In one embodiment, there may be intelligent control of redundancy levels. Following the techniques of the FR-DBO mechanism discussed herein, there may be several parameters that need to be considered to use this mechanism. This method may address a control mechanism within the AP or STA transmitting the duplicate frames to understand the required level of protection and configure the protection level accordingly.

[0103]

[0116] 9 illustrates an example of a procedure for intelligently controlling redundancy levels, which may be used in combination with any of the other embodiments described herein. As shown in FIG. 9, a station (AP, WTRU, or terminal) may have a set of queues 905, 910, 915, 920 (e.g., queues defined in IEEE 802.11e). Each queue 905, 910, 915, 920 may be associated with a traffic type, such as voice (VO), video (VI), best effort (BE), and background (BE), and a set of MAC parameters that may set the priority level of frames while accessing the wireless medium.

[0104]

[0117] On each of queues 905, 910, 915, and 920, there may be packets 907, 912, and 917 that are specifically marked as requiring high reliability. These packets 907, 912, and 917 are shown as PK HR in Figure 9. Each of packets 907, 912, and 917 may belong to a different traffic type (i.e., queue) and may have a different marking. The marking of these packets 907, 912, and 917 may conform to, for example, FRER in IEEE 802.1CB.

[0105]

[0118] An external entity or protocol may oversee the configuration of the mapping between marking and traffic characteristics. One example of a possible protocol that can be used for this marking may be the Multiple Streams Reservation Protocol (MSRP). These traffic characteristics may include, among other things, the bandwidth requirements of the flow (e.g., this flow requires at least 10 Mbps) and / or the level of reliability (e.g., a frame loss probability of less than X) or replicability (or how many copies are sent).

[0106]

[0119] Based on the STA's configuration, the STA (e.g., a MAC configuration module) can derive a set of applicable configurations for MAC depending on the FR-DBO results. For example, the MAC configuration module can read indicia in a frame received from one of the queues 905, 910, 915, 920 (i.e., traffic flows). The indicia may include an indication 925 that indicates the reliability level, bandwidth, and / or latency requirements of the traffic flow associated with the frame. Based on the reliability requirements indicated by the indicia, the MAC configuration module can perform a procedure 930 to configure MAC / PHY parameters, such as MCS, that meet the minimum bandwidth. The MAC configuration module can generate a set of all possible configurations 935 for the MAC / PHY layer mechanisms. A configuration can be selected from the set and applied based on the FR-DBO results (i.e., the number of available channels).

[0107]

[0120] Various mechanisms that may be considered are various configurations of possible channel aggregations, which may be a parameter that sets the maximum rate at which frames can be transmitted (e.g., after the end of FR-DBO, a mechanism may result in an available 80 MHz bonded channel that can be used to transmit a single frame at maximum rate on the 80 MHz channel, or to transmit two frames on two 40 MHz channels, or to transmit four frames on 20 MHz), modulation coding schemes available for various channel aggregations, where a lower MCS (fewer bits per symbol) may result in higher reliability since a lower SINR may be required to decode without error frames, and / or measured loss levels per STA and MCS.

[0108]

[0121] When considering these parameters and requirements configured per flow, the MAC / PHY configuration mechanism can select a configuration that meets the requirements depending on the outcome of the DBO for this particular frame.

[0109]

[0122] FIG. 10 illustrates an example procedure 1000 for transmitting multiple copies of a frame based on FR-DBO and configuration of MAC properties depending on a reliability factor, which can be used in combination with any of the other embodiments described herein. Depending on the station's processing capabilities, the process of selecting the configuration to apply (i.e., step 1060), along with the generation of other information (i.e., steps 1010-1040), can occur before or after FR-DBO (i.e., step 1050). Procedure 1000 may begin in step 1010 by reading a new frame associated with a traffic flow to transmit. This frame may include an indication that the traffic flow requires a certain reliability level. The STA performing procedure 1000 can query the configuration to obtain the requirements for this flow. The requirements may be specified as a minimum bandwidth and a reliability level. For example, reliability level 1 means that no losses are tolerated.

[0110]

[0123] In step 1020, the STA may select an MCS for each channel that can meet the required data rate for the traffic flow, for example, based on a minimum bandwidth requirement. For example, with a minimum bandwidth of 150 Mbps, MCSs 5, 6, and 7 may be selected for 20 MHz channels, MCSs 2, 3, and 4 may be selected for 20 MHz channels, and all MCSs may be selected for 80 MHz channels.

[0111]

[0124] In step 1030, the STA may read internal information regarding the loss for each selected MCS and the SINR of the target STA. The STA may then calculate the probability of error (or probability of failure) for each selected MCS, taking into account the last measurement of the target station's SINR. For example, the probability of error may be 0.1 for MCS5 associated with a 20 MHz channel, 0.2 for MCS6 associated with a 20 MHz channel, and / or 0.3 for MCS7 associated with a 20 MHz channel.

[0112]

[0125] In step 1040, the STA may consider various available data rates (MCSs), possible channel aggregation options, and the number of duplicated frames required for a channel given the MCS, and may generate at least one set of possible configurations based on the information (e.g., probability of failure) determined in step 1040. Each of the set of possible configurations may include a number of frame replications (redundancy), a channel bandwidth, and an MCS. For example, one set of possible configurations may include 2X redundancy for a 20 MHz channel given an MCS of 5, and 1X redundancy for a 40 MHz channel given an MCS of 2.

[0113]

[0126] Once the set of possible configurations is created, the STA may perform the FR-DBO procedure described above in step 1050. Based on the resulting information (e.g., the number of reserved channels fed back into the STA), the STA may select a configuration from the set of possible configurations in step 1060. In step 1070, the STA may apply the selected configuration to simultaneously transmit multiple copies of a frame on the available channels determined by FR-DBO.

[0114]

[0127] FIG. 11 illustrates another example procedure 1100 for transmitting multiple copies of a frame based on FR-DBO and configuration of MAC properties depending on a reliability factor, which can be used in combination with any of the other embodiments described herein. In step 1110, the STA may generate at least one set of possible configurations that satisfy the reliability requirements of the traffic flow, as described above. Each configuration in the set of configurations also satisfies the reliability requirements. Configurations in the set of configurations may include the number of replications of the frame, the channel bandwidth, and the modulation and coding scheme (MCS) associated with the channel bandwidth. For example, the set of possible configurations may be {{redundancy 3x, 20 MHz, MCS5}, {redundancy 2x, 40 MHz, MCS2}, {redundancy 1x, 80 MHz, MCS1}}. Examples of reliability requirements may include, but are not limited to, the amount of loss, latency, minimum bandwidth, and maximum bandwidth allowed for the traffic flow. Examples of traffic flows may include, but are not limited to, voice traffic, video traffic, best-effort traffic, and background traffic. It is noted that the generation of the set of possible configurations described in step 1110 can be performed before or after the FR-DBO procedure described in steps 1120 and 1130, for example.

[0115]

[0128] The STA may perform the FR-DBO procedure described above. For example, in step 1120, the STA may transmit multiple RTS frames to one or more neighboring STAs on multiple channels identified by the STA. In particular, the STA may transmit multiple RTS frames to one neighboring STA in multiple channels and simultaneously transmit multiple RTS frames to other neighboring STAs in multiple channels. These multiple RTS frames may be transmitted based on multicast or groupcast MAC addresses associated with the neighboring STAs. After transmitting the multiple RTS frames, the STA may receive multiple CTS frames in step 1130 indicating whether multiple channels are available. Based on the received CTS frames, the STA may determine the number of available channels. In one embodiment, the STA may receive only one CTS frame, in which case the number of available channels is one.

[0116]

[0129] In step 1140, the STA may select a first configuration from a set of configurations that meets the reliability requirements of the traffic flow based on the number of available channels. In the example shown in FIG. 8, the STA may determine that three channels are available based on the received CTS frame. Assuming that the reliability requirement is 60% and transmission at MCS5 provides 33% reliability on each channel, the STA may select {redundancy 3x, 20 MHz, MCS5} as the first configuration. In step 1050, the STA may apply the first configuration to the transmission and simultaneously transmit three copies of the frame on the three available channels. Because each transmission has 33% reliability, multiple copies of the 33% transmission can provide reliability greater than 60%, thereby meeting the reliability requirements of the traffic flow. It should be noted that depending on the reliability requirement and the number of available channels, the STA may apply a second or third configuration to the transmission of multiple copies of the frame.

[0117]

[0130] In one embodiment, there may be use of FR-DBO in groupcast communications. As described herein, FRER may be a mechanism that allows for replicating frames of a flow into multiple subflows along disjoint paths to improve network reliability.

[0118]

[0131] In the case of GLK networks, FRER can be used since IEEE802.11-GLK can be considered as an IEEE802.1Q compliant port. In addition, IEEE802.11ak can use the inherent multicast feature of WLAN to replicate frames on the wireless medium by sending them to a groupcast address, which in the case of GLK stations is the SYNRA address.

[0119]

[0132] An operational limitation of IEEE 802.11 is that the DBO mechanism is only specified for point-to-point links, so two stations can agree on the channel bandwidth to use, but it does not specify groupcast transmissions, which can only relay on static channel configurations and therefore effectively use lower speeds due to overloading of current WLAN channels.

[0120]

[0133] The techniques and mechanisms described herein can extend the DBO mechanism to groupcast using the GLK-GCR RTS / CTS exchange defined above. In this way, transmissions can use a wider range of dynamic channel allocations.

[0121]

[0134] In one example, there may be a procedure where the AP exchanges GLK-GCR RTSs indicating in the SYNRA (e.g., AID order type) the stations to respond with the bandwidth that the CTS has found. This may be advertised in the TA field of the RTS. After the GLK-GCR RTS procedure is complete, the AP may be able to calculate the best allocation of channel bandwidth that all stations find free, and thus be able to transmit frames to the group of stations at a faster rate.

[0122]

[0135] If the number of stations being addressed is large, multiple CTS frames can be generated, and the channel can remain busy with control frame traffic for some time. Using mechanisms such as GLK GCR Block ACK can minimize this effect, allowing many frames to be sent quickly.

[0123]

[0136] 12 illustrates an example of a DBO 1200 for generic link-groupcast operation with retries (GLK-GCR) transmission, which may be used in combination with any of the other embodiments described herein. In the figure, STA1 1202a, STA2 1202b, and STA3 1202c may respond with GLK-GCR CTS frames 1212, 1214, 1218, 1222, 1224, 1226, 1232, and 1234 in an order determined by the AID order SYNRA.

[0124]

[0137] As shown in Figure 12, the AP 1201 may perform FR-DBO for a group of stations STA1 1202a, STA2 1202b, and STA3 1202c to negotiate the best available channel allocation, bandwidth, and MCS for groupcasting frames to the set of stations 1202a, 1202b, and 1202c. Using the techniques described above, the AP 1201 may transmit GLK-GCR RTS / CTS frames 1202, 1204, 1206, and 1208 within multiple channels identified by the AP 1201. Each of the GLK-GCR RTS frames 1202, 1204, 1206, and 1208 may include an AID sequence SYNRA. Stations 1202a, 1202b, and 1202c receiving GLK-GCR RTS frames 1202, 1204, 1206, and 1208 can respond in the order indicated in the AID order SYNRA. For example, STA1 1201a can respond first with GLK-GCR CTS frames 1212, 1214, and 1218 on the primary 20 MHz channel 1230, the secondary 20 MHz channel 1235, and the 20 MHz channel 1245, respectively. STA2 1201b can then respond with GLK-GCR CTS frames 1222, 1224, and 1226 on the primary 20 MHz channel 1230, the secondary 20 MHz channel 1235, and the 20 MHz channel 1240, respectively. Finally, STA3 1201c can respond with GLK-GCR CTS frames 1232 and 1234 on the primary 20 MHz channel 1230 and secondary 20 MHz channel 1235, respectively. According to the FR-DBO mechanism, STAs 1202a, 1202b, and 1202c can reply on all channels (or all available channels or the channels indicated in GLK-GCR RTS frames 1202, 1204, 1206, and 1208). After receiving all replies, AP 1201 can perform the procedure described above to calculate the best resource allocation. AP 1201 can then transmit multiple copies of the frame to the group of stations 1202a, 1202b, and 1202c.

[0125]

[0138] In one embodiment, there may be a process for increasing the reliability of transmissions on 802.11 networks by simultaneously transmitting multiple replicated or redundant frames using opportunistic channel bonding and a high MCS to achieve the lowest possible latency. An AP or STA may need to reliably transmit frames to a group of stations. The AP or STA may send an Advanced Group Cast with Retries (GCR) RTS frame to block (or bond) some channels for group transmission. Addressed STAs may respond with GCR-CTS frames in the order indicated in the GCR-RTS frame. The AP or STA may configure MAC / PHY transmission parameters depending on the available channels and the required reliability factor. The AP or STA may transmit duplicate frames using the full available bandwidth (frame replication, FR-DBO). The STA may acknowledge frames in the primary channel, all channels, available channels, or with a Block ACK.

[0126]

[0139] In one embodiment, there may be a process for addressing the reliability of transmissions on 802.11 networks by simultaneously transmitting multiple replicated frames using opportunistic channel bonding and a high MCS to achieve the lowest possible latency. There may be an extension to the RTS / CTS mechanism (e.g., GCR RTS / CTS) to block some channels for group transmissions. This mechanism may also be extended to GLK networks (GLK-GCR RTS / CTS). There may then be an extension to the Dynamic Bandwidth Operation (DBO) mechanism (frame replication, FR-DBO) to transmit duplicate frames using the full available bandwidth, as well as a procedure for configuring transmissions depending on the available channels and the required reliability factor. Finally, there may be a combination of GCR RTS / CTS, GLK-GCR RTS / CTS, and FR-DBO, and a mechanism may be defined to perform FRER using all available bandwidth and a high MCS.

[0127]

[0140] While features and elements have been described above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with the other features and elements. Additionally, the methods described herein can be implemented by a computer program, software, or firmware embodied 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-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor in conjunction with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. 1. A method performed by a first station (STA), comprising: transmitting a request to send (RTS) frame to a plurality of STAs, the RTS frame including an association identifier (AID) order field; receiving one or more clear to send (CTS) frames from one or more of the plurality of STAs indicating a plurality of channels available for transmission by the first STA; selecting transmission configuration information based on the available channels and one or more reliability requirements of a traffic flow associated with the frame, the transmission configuration information satisfying the one or more reliability requirements; transmitting multiple copies of the frame over at least two of the available channels based on the transmission configuration information; A method comprising:

2. The method of claim 1 , wherein the AID order field indicates which STA of the plurality of STAs is to transmit a CTS frame.

3. The method of claim 1 , wherein the AID order field provides an order in which one or more of the plurality of STAs transmit CTS frames.

4. The method of claim 1 , wherein the AID order field includes an AID bitmap offset subfield and an AID bitmap subfield.

5. The method of claim 1 , wherein the first STA is an access point.

6. A transceiver; Processor and A first station (STA) comprising: The transceiver and processor transmitting a request to send (RTS) frame to a plurality of STAs, the RTS frame including an association identifier (AID) order field; receiving one or more clear to send (CTS) frames from one or more of the plurality of STAs indicating a plurality of channels available for transmission by the first STA; selecting transmission configuration information based on the available channels and one or more reliability requirements of a traffic flow associated with the frame, the transmission configuration information satisfying the one or more reliability requirements; transmitting multiple copies of the frame over at least two of the available channels based on the transmission configuration information; A first STA configured to:

7. The first STA of claim 6 , wherein the AID order field provides which STA of the plurality of STAs transmits a CTS frame.

8. The first STA of claim 6 , wherein the AID order field provides an order in which one or more of the plurality of STAs transmit CTS frames.

9. The first STA of claim 6 , wherein the AID order field includes an AID bitmap offset subfield and an AID bitmap subfield.

10. The first STA of claim 6 , wherein the first STA is an access point.

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