This disclosure relates generally to a primary link change procedure for a mobile AP MLD.
An AP MLD is typically able to simultaneously transmit and receive over all of its links. However, 802.11be standards define a special AP MLD, namely, NSTR Mobile AP MLD, which can have NSTR link pairs. An NSTR mobile AP MLD has a number of use cases (e.g., Wi-Fi hotspot support, peer to peer operation, etc.). As per the 802.11be standard, an NSTR mobile AP MLD shall designate one link of an NSTR link pair as the primary link. The other link of the NSTR link pair becomes the non-primary link.
IEEE 802.11be standards define primary link and non-primary link for NSTR Mobile AP MLD. The NSTR Mobile AP MLD designates one link of an NSTR link pair as the primary link and other link of the NSTR link pair as the non-primary link. Further, the non-primary link transmissions of a STA affiliated with the non-AP MLD (or the AP affiliated with the NSTR mobile AP MLD) are constrained so that they may happen only if the corresponding STA affiliated with the non-AP MLD (or the corresponding AP affiliated with the NSTR mobile AP MLD) is also initiating a transmission as a TXOP holder with the same start time. This can create some performance issues for the NSTR Mobile AP MLD especially when the primary link performance degrades or the primary link becomes inoperable due to a number of reasons, some of which are explained below, and the Mobile AP MLD may want to change the primary link designation:
Network congestion: It is possible that the network is highly contested in the primary link resulting in large delays in channel capture for the AP1 affiliated with the NSTR Mobile AP MLD or the STA1 affiliated with the non-AP MLD. Due to the transmission constraints on the non-primary link, AP2 and the STA2 will also face a performance degradation despite having a non-congested channel on the non-primary link.
RF environment degradation: It is possible that due to RF degradation, the primary link's condition can become inoperable. As a result, the performance of the non-primary link will also suffer.
Radar operation: As per the DFS operation described in Clause 11.8, an AP is required to move the BSS to a different channel if radar operation is detected on its current channel of operation. The standard mandates that before moving to a new channel, the AP has to perform a check to ensure that the new channel does not have radar operation on it. If radar operation is detected on the new channel, the AP may need to select another channel and continue the check until a channel without radar operation is detected. Depending on the region and the selected channel, such checks can take up to several minutes until a suitable channel is found. During such checks, the primary link may not be available and consequently, the performance on the non-primary link can also get disrupted. Further, the AP affiliated with the NSTR Mobile AP MLD and forming the primary link might have established a restricted TWT schedule with another non-AP MLD. Now if the primary link becomes unavailable, the latency sensitive traffic flow of the non-AP MLD will be interrupted as the non-primary link also becomes inoperable.
Consequently, the Mobile AP MLD may want to change the primary link designation. As a result, a solution to enable the Mobile AP MLD to change the primary link designation is needed.
Embodiments of the present disclosure provide methods and apparatuses for a primary link change procedure for a mobile AP MLD.
In one embodiment, a multi-link device (MLD) comprises: access points (APs) forming a mobile AP MLD, each AP comprising a transceiver configured to form a link with a corresponding station (STA) associated with a non-AP MLD; and a processor operably coupled to the APs, the processor configured to: instruct the (APs) to form a first link and a second link with the corresponding STAs; designate the first link as a primary link and the second link as a non-primary link; determine that the primary link is experiencing degradation; and in response to determining that the primary link is experiencing degradation, effect a change in the primary link designation, or implement a channel change procedure to change a channel within the primary link.
In another embodiment, a non-AP MLD comprises: STAs, each comprising a transceiver configured to form a primary link and a non-primary link with a corresponding AP of an MLD comprising APs forming a mobile AP MLD; and a processor operably coupled to the STAs, the processor, based on the primary link experiencing degradation, configured to receive via the transceiver an indication from the mobile AP MLD about a change in primary link designation.
In yet another embodiment, a method for wireless communication performed by an AP MLD, the AP MLD comprising APs forming a mobile AP MLD, the method comprising: forming links with corresponding STAs associated with a non-AP MLD; instructing the APs to form a first link and a second link with the corresponding STAs; designating the first link as a primary link and the second link as a non-primary link; determining that the primary link is experiencing degradation; and in response to determining that the primary link is experiencing degradation, effecting a change in the primary link designation, or implementing a channel change procedure to change a channel within the primary link.
Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.
Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C. As used herein, such terms as “1st” and “2nd,” or “first” and “second” may be used to simply distinguish a corresponding component from another and does not limit the components in other aspect (e.g., importance or order). It is to be understood that if an element (e.g., a first element) is referred to, with or without the term “operatively” or “communicatively”, as “coupled with,” “coupled to,” “connected with,” or “connected to” another element (e.g., a second element), it means that the element may be coupled with the other element directly (e.g., wiredly), wirelessly, or via a third element.
As used herein, the term “module” may include a unit implemented in hardware, software, or firmware, and may interchangeably be used with other terms, for example, “logic,” “logic block,” “part,” or “circuitry”. A module may be a single integral component, or a minimum unit or part thereof, adapted to perform one or more functions. For example, according to an embodiment, the module may be implemented in a form of an application-specific integrated circuit (ASIC).
Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.
Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.
For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts:
The following documents and standards descriptions are hereby incorporated into the present disclosure as if fully set forth herein:
[1] IEEE P802.11be/D1.0—Draft Standard for Information technology—Telecommunications and information exchange between systems Local and metropolitan area networks—Specific requirements—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications—Amendment 8: Enhancements for extremely high throughput (EHT).
[2] IEEE 802.11-2020—IEEE Standard for Information Technology—Telecommunications and Information Exchange between Systems—Local and Metropolitan Area Networks—Specific Requirements—Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.
Aspects, features, and advantages of the disclosure are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the disclosure. The disclosure is also capable of other and different embodiments, and its several details can be modified in various obvious respects, all without departing from the spirit and scope of the disclosure. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. The disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings.
As shown in
Depending on the network type, other well-known terms may be used instead of “access point” or “AP,” such as “router” or “gateway.” For the sake of convenience, the term “AP” is used in this disclosure to refer to network infrastructure components that provide wireless access to remote terminals. In WLAN, given that the AP also contends for the wireless channel, the AP may also be referred to as a STA. Also, depending on the network type, other well-known terms may be used instead of “station” or “STA,” such as “mobile station,” “subscriber station,” “remote terminal,” “user equipment,” “wireless terminal,” or “user device.” For the sake of convenience, the terms “station” and “STA” are used in this disclosure to refer to remote wireless equipment that wirelessly accesses an AP or contends for a wireless channel in a WLAN, whether the STA is a mobile device (such as a mobile telephone or smartphone) or is normally considered a stationary device (such as a desktop computer, AP, media player, stationary sensor, television, etc.).
Dotted lines show the approximate extents of the coverage areas 120 and 125, which are shown as approximately circular for the purposes of illustration and explanation only. It should be clearly understood that the coverage areas associated with APs, such as the coverage areas 120 and 125, may have other shapes, including irregular shapes, depending upon the configuration of the APs and variations in the radio environment associated with natural and man-made obstructions.
As described in more detail below, one or more of the APs may include circuitry and/or programming for facilitating a primary link change procedure for mobile AP MLD. Although
The AP 101 includes multiple antennas 204a-204n, multiple RF transceivers 209a-209n, transmit (TX) processing circuitry 214, and receive (RX) processing circuitry 219. The AP 101 also includes a controller/processor 224, a memory 229, and a backhaul or network interface 234. The RF transceivers 209a-209n receive, from the antennas 204a-204n, incoming RF signals, such as signals transmitted by STAs in the network 100. The RF transceivers 209a-209n down-convert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are sent to the RX processing circuitry 219, which generates processed baseband signals by filtering, decoding, and/or digitizing the baseband or IF signals. The RX processing circuitry 219 transmits the processed baseband signals to the controller/processor 224 for further processing.
The TX processing circuitry 214 receives analog or digital data (such as voice data, web data, e-mail, or interactive video game data) from the controller/processor 224. The TX processing circuitry 214 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate processed baseband or IF signals. The RF transceivers 209a-209n receive the outgoing processed baseband or IF signals from the TX processing circuitry 214 and up-converts the baseband or IF signals to RF signals that are transmitted via the antennas 204a-204n.
The controller/processor 224 can include one or more processors or other processing devices that control the overall operation of the AP 101. For example, the controller/processor 224 could control the reception of forward channel signals and the transmission of reverse channel signals by the RF transceivers 209a-209n, the RX processing circuitry 219, and the TX processing circuitry 214 in accordance with well-known principles. The controller/processor 224 could support additional functions as well, such as more advanced wireless communication functions. For instance, the controller/processor 224 could support beam forming or directional routing operations in which outgoing signals from multiple antennas 204a-204n are weighted differently to effectively steer the outgoing signals in a desired direction. The controller/processor 224 could also support OFDMA operations in which outgoing signals are assigned to different subsets of subcarriers for different recipients (e.g., different STAs 111-114). Any of a wide variety of other functions could be supported in the AP 101 by the controller/processor 224 including facilitating a primary link change procedure for mobile AP MLD. In some embodiments, the controller/processor 224 includes at least one microprocessor or microcontroller. The controller/processor 224 is also capable of executing programs and other processes resident in the memory 229, such as an OS. The controller/processor 224 can move data into or out of the memory 229 as required by an executing process.
The controller/processor 224 is also coupled to the backhaul or network interface 234. The backhaul or network interface 234 allows the AP 101 to communicate with other devices or systems over a backhaul connection or over a network. The interface 234 could support communications over any suitable wired or wireless connection(s). For example, the interface 234 could allow the AP 101 to communicate over a wired or wireless local area network or over a wired or wireless connection to a larger network (such as the Internet). The interface 234 includes any suitable structure supporting communications over a wired or wireless connection, such as an Ethernet or RF transceiver. The memory 229 is coupled to the controller/processor 224. Part of the memory 229 could include a RAM, and another part of the memory 229 could include a Flash memory or other ROM.
As described in more detail below, the AP 101 may include circuitry and/or programming for facilitating a primary link change procedure for mobile AP MLD. Although
The STA 111 includes antenna(s) 205, a radio frequency (RF) transceiver 210, TX processing circuitry 215, a microphone 220, and receive (RX) processing circuitry 225. The STA 111 also includes a speaker 230, a controller/processor 240, an input/output (I/O) interface (IF) 245, a touchscreen 250, a display 255, and a memory 260. The memory 260 includes an operating system (OS) 261 and one or more applications 262.
The RF transceiver 210 receives, from the antenna(s) 205, an incoming RF signal transmitted by an AP of the network 100. The RF transceiver 210 down-converts the incoming RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is sent to the RX processing circuitry 225, which generates a processed baseband signal by filtering, decoding, and/or digitizing the baseband or IF signal. The RX processing circuitry 225 transmits the processed baseband signal to the speaker 230 (such as for voice data) or to the controller/processor 240 for further processing (such as for web browsing data).
The TX processing circuitry 215 receives analog or digital voice data from the microphone 220 or other outgoing baseband data (such as web data, e-mail, or interactive video game data) from the controller/processor 240. The TX processing circuitry 215 encodes, multiplexes, and/or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The RF transceiver 210 receives the outgoing processed baseband or IF signal from the TX processing circuitry 215 and up-converts the baseband or IF signal to an RF signal that is transmitted via the antenna(s) 205.
The controller/processor 240 can include one or more processors and execute the basic OS program 261 stored in the memory 260 in order to control the overall operation of the STA 111. In one such operation, the controller/processor 240 controls the reception of forward channel signals and the transmission of reverse channel signals by the RF transceiver 210, the RX processing circuitry 225, and the TX processing circuitry 215 in accordance with well-known principles. The controller/processor 240 can also include processing circuitry configured to facilitate a primary link change procedure for mobile AP MLD. In some embodiments, the controller/processor 240 includes at least one microprocessor or microcontroller.
The controller/processor 240 is also capable of executing other processes and programs resident in the memory 260, such as operations for facilitating a primary link change procedure for mobile AP MLD. The controller/processor 240 can move data into or out of the memory 260 as required by an executing process. In some embodiments, the controller/processor 240 is configured to execute a plurality of applications 262, such as applications for detect interference from a neighboring BSS and inform the associated AP of the interference. The controller/processor 240 can operate the plurality of applications 262 based on the OS program 261 or in response to a signal received from an AP. The controller/processor 240 is also coupled to the I/O interface 245, which provides STA 111 with the ability to connect to other devices such as laptop computers and handheld computers. The I/O interface 245 is the communication path between these accessories and the controller 240.
The controller/processor 240 is also coupled to the touchscreen 250 and the display 255. The operator of the STA 111 can use the touchscreen 250 to enter data into the STA 111. The display 255 may be a liquid crystal display, light emitting diode display, or other display capable of rendering text and/or at least limited graphics, such as from web sites. The memory 260 is coupled to the controller/processor 240. Part of the memory 260 could include a random-access memory (RAM), and another part of the memory 260 could include a Flash memory or other read-only memory (ROM).
Although
As depicted in
In the embodiments described herein, two entities can be considered—an initiator and a responder. The initiator (e.g., the Mobile AP MLD) intends to change the designation of the primary link and starts the process with the responder (e.g., the non-AP MLD associated with the Mobile AP MLD).
According to one embodiment, when the initiator (e.g., the Mobile AP MLD) decides to change the designation of the primary link, the initiator can transmit the primary link designation change information on the current primary link as shown in
An example format of the MLD Capabilities subfield combining embodiments described herein is as shown in
According to one embodiment, the primary link designation change information can be included in the MLD capabilities subfield of the Basic Multi-Link element. According to this embodiment, the upon receiving the primary link designation change information in the MLD capabilities subfield of the Basic Multi-Link element, the responder can update the primary link information according to the information indicated in the MLD capabilities subfield.
According to one embodiment, the initiator can convey its intention to change the primary link designation by using one or more of the bits in the MLD capabilities subfield of the Basic Multi-Link element. According to one embodiment, the MLD capabilities subfield of the Basic Multi-Link element can contain a Mobile AP MLD Primary Link Designation Change Indication bit. The initiator that intends to change the designation of the primary link of the Mobile AP MLD, can set the Mobile AP MLD Primary Link Designation Change Indication bit to 1 to indicate the change. When set to 0, the same primary link can be retained.
According to one embodiment, when there are only two links for a Mobile AP MLD (one primary link and one non-primary link) and the initiator sets the Mobile AP MLD Primary Link Designation Change Indication bit to 1, the non-primary link becomes the new primary link and the primary link becomes the new non-primary link.
According to one embodiment, the initiator can indicate the link that it intends to use as the new primary link when making the primary link designation change. Further, according to this embodiment, the initiator can indicate the link ID of the new primary link in the MLD capabilities subfield of the Basic Multi-Link element. As an example, the link ID of the new primary link can be indicated by using the B8˜B11 bits.
According to one embodiment, the initiator can indicate the time it intends to change the primary link designation. According to one embodiment, the time it intends to change the primary link designation can be indicated in the MLD capabilities subfield of the Basic Multi-Link element. According to one embodiment, the primary link designation change time can be indicated in terms of a counter whose value would count down in each MLD capabilities subfield that is transmitted by the initiator. As an example, the counter value can be indicated by using the reserved bits (B14˜B15) in the MLD capabilities subfield of the Basic Multi-Link element.
According to another embodiment, the time the initiator intends to change the primary link designation can be indicated in the MLD capabilities subfield as a multiple of a fixed pre-negotiated or pre-known value (e.g., TBTT, TU). As an example, the time the initiator intends to change the primary link designation can be indicated by using one or more of the reserved bits (e.g., B14˜B15) in the MLD capabilities subfield of the Basic Multi-Link element.
When the responder is the non-AP MLD, then according to one embodiment, the non-AP MLD can switch the primary link operation without any explicit notification to the initiator. In another embodiment, as illustrated in
When the initiator is the non-AP MLD, the NSTR Mobile AP MLD may or may not accept the primary link designation change. In such a scenario, the NSTR Mobile AP MLD can explicitly indicate to the non-AP MLD that its request for primary link designation change has been denied by transmitting a basic multi-link element with the primary link change subfield set to 0.
According to another embodiment, the NSTR Mobile AP MLD can use a Mobile AP MLD Primary Link Change element to indicate to its associated non-AP MLD about the intention of the NSTR Mobile AP MLD to change the designation of the primary link and the non-primary link via link swapping. The NSTR Mobile AP MLD Primary Link Change element can contain one or more of the following fields:
An example embodiment of the NSTR Mobile AP MLD Primary Link Change element is as shown in
Further, according to this embodiment, for changing the primary link designation, the NSTR mobile AP MLD may also indicate the time in terms of TB TT when the primary link designation will be changed. Moreover, it can also indicate periodicity of the change if the NSTR Mobile AP MLD intends to periodically switch the designation of the primary link and non-primary link.
In order to realize this, the NSTR Mobile AP MLD can send a Mobile AP MLD Primary Link Change element to its associated non-AP MLD in order to indicate the NSTR Mobile AP MLD's intention to change the designation of the primary link and non-primary link.
According to another embodiment, one or more of the above subfields can be absent from the Mobile AP MLD Primary Link Change element. According to another embodiment, one or more subfields in addition to the subfields described above can also be present in the Mobile AP MLD Primary Link Change element.
According to another embodiment, the NSTR Mobile AP MLD can send a NSTR Mobile AP MLD Primary Link Change Notification frame to its associated non-AP MLD in order to indicate the NSTR Mobile AP MLD's intention to change the designation of the primary link and non-primary link. The contents of the NSTR Mobile AP MLD Primary Link Change Notification frame would be similar to the subfields described in the previous embodiments—New Primary Link-Link ID, Primary Link Change Count, and Primary Link Change Period.
According to another embodiment, a non-AP MLD can request its associated NSTR Mobile AP MLD to change its Primary link designation. In order to indicate this request, the non-AP MLD can send a Mobile AP MLD Primary Link Change element or NSTR Mobile AP MLD Primary Link Change Notification frame to its associated NSTR Mobile AP MLD.
According to another embodiment, upon reception of a request of NSTR Mobile AP MLD Primary link change from an associated non-AP MLD, the NSTR Mobile AP MLD, as a response to the request, can send another Mobile AP MLD Primary Link Change element or NSTR Mobile AP MLD Primary Link Change Notification frame with the same content as that of request received from the non-AP MLD if the NSTR Mobile AP MLD accepts the request. The procedure for this is as depicted in
According to another embodiment, the NSTR indication bitmap subfield of the per-STA profile sub-element in the basic multi-link element can be used for primary link designation indication. Further according to this embodiment, the bit corresponding to the primary link can be set to 1 in this bitmap to indicate the primary link designation.
In one embodiment, this NSTR indication bitmap can be advertised on the non-primary link. Thus, by using the indication, STA(s) of non-AP MLDs operating on the non-primary link can identify the primary link.
In another embodiment, this same bit that is used for primary link designation can be used for primary link designation change. According to this embodiment, when a primary link designation change occurs, the AP can set the bit corresponding to the new primary link in the bitmap to 1. Therefore, STA(s) of non-AP MLDs that receive such a bitmap from the AP can identify the new primary link based which bit is set to 1.
In another embodiment, channel switching can be performed when a need to change the primary link occurs. According to this embodiment, the channel corresponding to the primary link can be changed by performing a channel switching procedure.
The above flowcharts illustrate example methods that can be implemented in accordance with the principles of the present disclosure and various changes could be made to the methods illustrated in the flowchart. For example, while shown as a series of steps, various steps could overlap, occur in parallel, occur in a different order, or occur multiple times. In another example, steps may be omitted or replaced by other steps.
Although the present disclosure has been described with an exemplary embodiment, various changes and modifications may be suggested to one skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. None of the description in this application should be read as implying that any particular element, step, or function is an essential element that must be included in the claims scope. The scope of patented subject matter is defined by the claims.
This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63/288,168 filed on Dec. 10, 2021, U.S. Provisional Patent Application No. 63/333,445 filed on Apr. 21, 2022, and U.S. Provisional Patent Application No. 63/398,447 filed on Aug. 16, 2022, which are hereby incorporated by reference in their entirety.
Number | Date | Country | |
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63288168 | Dec 2021 | US | |
63333445 | Apr 2022 | US | |
63398447 | Aug 2022 | US |