Adjustable Multi-Link Idle Channel Assessment for Wireless Communication Networks

Abstract

This document discloses methods, systems, and devices related to digital wireless communications, and more specifically, to techniques for adjustable clear channel assessment for multi-link devices with limited simultaneous transmission and reception. The adjustable clear channel assessment method includes adjusting a signal strength measurement algorithm or adjusting an energy detection threshold used for assessment when setting a multi-link network allocation vector for transmission. A method for wireless communications includes identifying, by a wireless device, that a first wireless link and a second wireless link of the wireless device are in a detection state at a first time. The method further includes modifying, by the wireless device, a multi-link channel availability assessment process for the second wireless link based on detecting the transmission state of the first wireless link at the first time.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent document claims the benefit of priority under 35 U.S.C. §119(a) and the Paris Convention to International Patent Application No. PCT / CN2019 / 095428, filed on July 10, 2019, and International Patent Application No. PCT / CN2020 / 078991, filed on March 12, 2020. Portions of the contents of the aforementioned patent applications are incorporated herein by reference. Technical Field

[0003] This patent document relates generally to wireless communications. Background Art

[0004] Mobile communication technology is driving the world towards an increasingly networked society. Many use cases and deployment scenarios, such as factory automation, gaming, artificial intelligence (AI), virtual reality (VR), and augmented reality (AR), require rapid advancements in wireless communications to provide low-latency connections for these applications.

[0005] A wireless communication system may include a network of one or more access points (APs) communicating with one or more wireless stations (STAs). The AP may transmit radio signals carrying management information, control information, or user data to one or more STAs. The STA may transmit radio signals to the AP using techniques such as time division duplexing (TDD) in the same frequency channel or using techniques such as frequency division duplexing (FDD) in different frequencies.

[0006] The Institute of Electrical and Electronics Engineers (IEEE) 802.11 specifies specifications for wireless local area networks (WLANs) over radio channels in unlicensed frequency bands. The basic unit of a WLAN is the basic service set (BSS). An infrastructure BSS may include a BSS with stations that are connected to a wired network or the Internet by associating with an access point (AP). In an infrastructure BSS, both access points and stations can share the same frequency channel for multiple access and data transmission using carrier sense multiple access with collision avoidance (CSMA / CA) technology (a TDD mechanism). In addition, access points and stations can utilize developing multi-link technologies to perform simultaneous transmission and reception or simultaneous transmission and reception of limited communications. Summary of the Invention

[0007] This document discloses methods, systems, and devices related to digital wireless communications, and more particularly, to techniques for establishing a multi-link network allocation vector for transmission and / or reception, and an adjustable idle channel assessment mechanism to enhance idle channel assessment under constraints of multi-link communication to facilitate multi-link channel access in order to reduce access delay, improve transmission stability, and increase transmission throughput.

[0008] In one exemplary aspect, a method for wireless communication is disclosed. The method includes identifying, by a wireless device, that a first wireless link and a second wireless link of the wireless device are in a detection state at a first time. The method further includes modifying, by the wireless device, a multilink channel availability assessment process for the second wireless link based on detecting the transmission state of the first wireless link at the first time.

[0009] In another exemplary aspect, a method for wireless communication is disclosed. The method includes identifying, by a wireless device, that a first wireless link and a second wireless link of the wireless device are in a detecting state at a first time. The method further includes, in response to detecting that the first wireless link is in a transmitting state at the first time, adjusting, by the wireless device, a multilink channel availability assessment process for the second wireless link based on the transmitting state of the first wireless link, and initiating the multilink channel availability assessment process for the second wireless link.

[0010] In another exemplary aspect, a method for wireless communication is disclosed. The method includes: identifying, by a wireless device, that a first wireless link of the wireless device is receiving data at a first time and a second wireless link of the wireless device is in a detecting state. The method further includes: modifying, by the wireless device, initiation of a multilink channel availability assessment procedure for the second wireless link in response to detecting that the second wireless link is in the detecting state at a second time.

[0011] In another exemplary aspect, a method for wireless communication is disclosed. The method includes initiating, by a wireless device, a multi-link network reception period at a first time, wherein a first wireless link receives data during the multi-link network allocation vector reception period, and a second wireless link is in a detection state at the first time. The method further includes initiating, by the wireless device, a multi-link network allocation vector transmission period at a second time, wherein the first wireless link transmits data during the multi-link network transmission period, and the second wireless link is in a detection state at the second time. The method further includes modifying, by the wireless device, a multi-link channel availability assessment process for the second wireless link in response to detecting that the second wireless channel is in an idle state at the second time.

[0012] In another exemplary aspect, a method for wireless communication is disclosed. The method includes: initiating, by a wireless device, a first multi-link reception period at a first time, wherein the first wireless link receives a first data set during the first multi-link network reception period, and the second wireless link is in a detection state at the first time. The method further includes: initiating, by the wireless device, a multi-link network transmission period at a second time, wherein the first wireless link transmits data during the multi-link network transmission period, and the second wireless link is in an active state at the second time. The method further includes: initiating, by the wireless device, a second multi-link network reception period at a third time, wherein the first wireless link receives a second data set during the second multi-link network reception period, and the second wireless link is in a detection state at the first time. The method further includes: in response to detecting that the second wireless link is in the detection state at the third time, adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link.

[0013] In another exemplary aspect, a method for wireless communication is disclosed. The method includes: initiating, by a wireless device, a first multi-link network transmission period at a first time, wherein a first wireless link transmits a first data set during the first multi-link network transmission period, and a second wireless link is in a detection state during the first multi-link network transmission period. The method further includes: initiating, by the wireless device, a multi-link network reception period at a second time, wherein the first wireless link receives data during the multi-link network reception period, and the second wireless link is in a detection state during the multi-link network reception period. The method further includes: adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link to detect that the second wireless channel transitions to an idle state during the multi-link network reception period.

[0014] In another exemplary aspect, a method for wireless communication is disclosed. The method includes: initiating, by a wireless device, a first multi-link network transmission period at a first time, wherein a first wireless link transmits a first data set during the first multi-link network transmission period, and a second wireless link is in a detection state during the first multi-link network transmission period. The method further includes: initiating, by the wireless device, a multi-link network reception period at a second time, wherein the first wireless link receives data during the multi-link network reception period, and the second wireless link is in an active state during the multi-link network reception period. The method further includes: initiating, by the wireless device, a second multi-link network transmission period at a third time, wherein the first wireless link transmits a second data set during the second multi-link network transmission period, and the second wireless link is in a detection state before the third time. The method further includes: adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link to detect that the second wireless channel transitions to an idle state before the third time.

[0015] In another exemplary aspect, a method for wireless communication is disclosed. The method includes: initiating, by a wireless device, a first multi-link network transmission period at a first time, wherein a first wireless link transmits a first data set during the first multi-link network transmission period, and a second wireless link is in a detection state during the first multi-link network transmission period. The method further includes: detecting, by the wireless device, at a second time, that the first wireless link does not receive data during a multi-link network reception period, wherein the second wireless link is in a detection state during the multi-link network reception period. The method further includes: in response to detecting, at the second time, that the first wireless link does not receive data during the multi-link network reception period, adjusting, by the wireless device, a multi-link channel availability assessment process for the first wireless link and the second wireless link.

[0016] In another exemplary aspect, a wireless communication apparatus is disclosed that includes a processor configured to implement the methods described herein.

[0017] In yet another exemplary aspect, the various techniques described herein may be embodied as processor-executable code and stored on a computer-readable program medium.

[0018] Some embodiments may preferably implement the following solutions written in a clause format.

[0019] A solution for wireless communication is provided, comprising: identifying, by a wireless device, that a first wireless link and a second wireless link of the wireless device are in a detection state at a first time; and modifying, by the wireless device, a multi-link channel availability assessment process of the second wireless link based on detecting the transmission state of the first wireless link at the first time.

[0020] 2. The solution of clause 1, wherein the wireless device is an access point (AP) multi-link device (MLD) or a non-AP MLD capable of performing simultaneous transmission and reception constraint (STR-constraint) operation.

[0021] 3. The solution according to clause 1 further includes: determining by the wireless device that the first wireless link is in a transmission state at a second time, wherein modifying the multi-link channel availability assessment process includes postponing the initiation of the multi-link channel availability assessment process for the second wireless link to a third time.

[0022] 4. The solution of clause 1, wherein detecting that the first radio link is in a transmitting state comprises determining that a network allocation vector (NAV) value for the first radio link of the wireless device is not equal to zero.

[0023] 5. The solution according to clause 1 further includes: determining, by the wireless device, that a first multi-link NAV transmission period has expired; initiating, by the wireless device, a multi-link channel availability assessment process and a backoff process for the second wireless link at a time corresponding to the expiration of the first multi-link NAV transmission period; and transmitting, by the wireless device via the second wireless link, a first message in response to detecting the expiration of the backoff counter.

[0024] 6. A method for wireless communication, comprising: identifying, by a wireless device, that a first wireless link and a second wireless link of the wireless device are in a busy state at a first time; and in response to detecting that the first wireless link is in a transmission state at the first time, adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link based on the transmission state of the first wireless link, and initiating the multi-link channel availability assessment process for the second wireless link.

[0025] 7. The solution of clause 6, further comprising: in response to detecting that the first wireless link and the second wireless link are in a transmission state at a second time, adjusting, by the wireless device, a multi-link channel availability assessment process for a third wireless link based on the transmission state of the first wireless link and the second wireless link.

[0026] 8. The solution of clause 7, further comprising detecting, by the wireless device, channel availability of the third radio link at the third time via a multi-link channel availability assessment procedure for the third radio link.

[0027] 9. The solution according to clause 6, further comprising: establishing, by the wireless device at the first time, a first multi-link NAV transmission period, wherein the initiation of the multi-link channel availability assessment process for the second radio link and the third radio link is based on the first multi-link NAV transmission period.

[0028] 10. The solution according to clause 6, further comprising: establishing, by the wireless device, a second multi-link NAV transmission period at the second time, wherein the initiation of the multi-link channel availability assessment process for the third wireless link is based on the first multi-link NAV transmission period and the second multi-link NAV transmission period.

[0029] 11. A solution according to clause 6, wherein the multi-link channel availability assessment procedure for any wireless link of the wireless device comprises: a modified received signal strength measurement based on a measured received signal strength resulting from the transmission of other messages on the first channel.

[0030] 12. A solution as claimed in clause 6, wherein the multi-link channel availability assessment procedure comprises transmitting a first message on the second radio link in response to a backoff counter reaching zero.

[0031] 13. The solution of clause 11, wherein the modified received signal strength is indicated by the wireless device.

[0032] 14. The solution of clause 11, further comprising generating, by the wireless device, an interference measurement matrix comprising measured signal strengths for each transmitting wireless link of the wireless device as measured by non-transmitting links.

[0033] 15. The solution of clause 14, further comprising deriving, by the wireless device, a modified received signal strength in a multi-link channel availability assessment for any wireless link based on the interference measurement matrix.

[0034] 16. The solution of clause 14, further comprising modifying, by the wireless device, an energy detection threshold (EDT) of a wireless link based on the interference measurement matrix.

[0035] 17. The solution of clause 6, further comprising: in response to completion of the multi-link channel availability assessment process, transmitting, by the wireless device, a first downlink message on the first wireless link and a second downlink message on the second wireless link simultaneously.

[0036] 18. The solution of clause 6, further comprising: in response to completion of the multi-link channel availability assessment process, transmitting, by the wireless device, a first uplink message on the first wireless link and a second uplink message on the second wireless link simultaneously.

[0037] 19. The solution of clause 6, further comprising: in response to completion of the multi-link channel availability assessment process, transmitting, by the wireless device, a first uplink message on the first wireless link and a second uplink message on the second wireless link separately.

[0038] 20. The solution of clause 6, further comprising: in response to completion of a multi-link channel availability assessment procedure including a joint backoff procedure for both the first radio link and the second radio link, transmitting, by the wireless device, a first uplink message on the first radio link and a second uplink message on the second radio link simultaneously.

[0039] 21. A solution for wireless communication, comprising: identifying, by a wireless device, that a first wireless link of the wireless device is receiving data and a second wireless link of the wireless device is in a busy state at a first time; and in response to detecting that the second wireless link is in a busy state at a second time, modifying, by the wireless device, initiation of a multi-link channel availability assessment procedure for the second wireless link.

[0040] 22. A solution according to clause 21, wherein modifying the initiation of the multilink channel availability assessment procedure for the second radio link comprises initiating a backoff procedure for the second radio link at the second time.

[0041] 23. The solution according to any of clauses 21 and 22, further comprising deferring, by the wireless device, initiation of channel access and transmission of a first message on the second wireless link until reception of data at the first wireless link is complete.

[0042] 24. The solution of clause 23, further comprising: based on detecting that the NAV value of the first radio link is equal to zero, the wireless device determining that the first radio link has completed receiving data.

[0043] 25. The solution of clause 21, further comprising: initiating, by the wireless device, a second backoff procedure for the third wireless link at a second time; and in response to detecting completion of the first NAV transmission period, transmitting, by the wireless device, a first message at the second wireless link and a second message at the third wireless link simultaneously.

[0044] 26. A solution for wireless communication, comprising: initiating, by a wireless device, a multi-link network reception period at a first time, wherein a first wireless link receives data during the multi-link network allocation vector reception period, and a second wireless link is in a busy state at the first time; initiating, by the wireless device, a multi-link NAV transmission period at a second time, wherein the first wireless link transmits data during the multi-link network transmission period, and the second wireless link is in a busy state at the second time; and in response to detecting that the second wireless link is in an idle state at the second time, adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link.

[0045] 27. A solution as claimed in clause 26, wherein adjusting the channel availability assessment procedure for the second radio link comprises initiating a backoff counter for the second radio link at the second time.

[0046] 28. The solution of clause 26, further comprising: receiving, by the wireless device, a downlink message simultaneously on each of the first and second radio links at a third time in response to completion of the multi-link channel availability assessment procedure for the second radio link.

[0047] 29. A solution for wireless communication, comprising: initiating a first multi-link network reception period by a wireless device at a first time, wherein a first wireless link receives a first data set during the first multi-link network reception period, and a second wireless link is in a busy state at the first time; initiating a multi-link network transmission period by the wireless device at a second time, wherein the first wireless link sends data during the multi-link network transmission period, and the second wireless link is in an active state at the second time; initiating a second multi-link network reception period by the wireless device at a third time, wherein the first wireless link receives a second data set during the second multi-link network reception period, and the second wireless link is in a busy state at the third time; and in response to detecting that the second wireless link is in an idle state at the third time, adjusting a multi-link channel availability assessment process for the second wireless link by the wireless device.

[0048] 30. A solution as claimed in clause 29, wherein adjusting the channel availability assessment procedure for the second radio link comprises initiating the channel availability assessment procedure for the second radio link at a third time.

[0049] 31. A solution for wireless communication, comprising: a multi-link station initiating a first multi-link network transmission period at a first time, wherein a first wireless link transmits a first data set during the first multi-link network transmission period, and a second wireless link is in a busy state during the first multi-link network transmission period; the multi-link station initiating a multi-link network reception period at a second time, wherein the first wireless link receives data during the multi-link network reception period, and the second wireless link is in a busy state during the multi-link network reception period; and the multi-link station adjusting a multi-link channel availability assessment process for the second wireless link to detect that the second wireless channel transitions to an idle state during the multi-link network reception period.

[0050] 32. The solution of clause 31, wherein the multi-link station is a device capable of performing limited simultaneous transmission and reception operations.

[0051] 33. A solution as claimed in clause 31, wherein regulating the channel availability assessment procedure for the second radio link comprises initiating a backoff counter for the second radio link during the multi-link network reception period.

[0052] 34. The solution of clause 31, further comprising: at a third time during the second multi-link network transmission period, simultaneously transmitting by the multi-link station an uplink message on each of the first radio link and the second radio link, wherein the transmission of the uplink message is performed in response to completion of a multi-link channel availability assessment procedure for the second radio link.

[0053] 35. A solution for wireless communication, comprising: a multi-link station initiating a first multi-link network transmission period at a first time, wherein a first wireless link transmits a first data set during the first multi-link network transmission period, and a second wireless link is in a detection state during the first multi-link network transmission period; the multi-link station initiating a multi-link network reception period at a second time, wherein the first wireless link receives data during the multi-link network reception period, and the second wireless link is in an active state during the multi-link network reception period; the multi-link station initiating a second multi-link network transmission period at a third time, wherein the first wireless link transmits a second data set during the second multi-link network transmission period, and the second wireless link is in a detection state before the third time; and the multi-link station adjusting a multi-link channel availability assessment process for the second wireless link to detect that the second wireless channel transitions to an idle state before the third time.

[0054] 36. A solution according to clause 35, wherein adjusting the channel availability assessment process for the second wireless link includes: initiating a backoff counter for the second wireless link by the multi-link station at a third time; and in response to expiration of the backoff counter, transmitting a third data set by the multi-link station during the second multi-link network transmission period.

[0055] 37. A solution for wireless communication, comprising: a multi-link station initiating a first multi-link network transmission period at a first time, wherein a first wireless link transmits a first data set during the first multi-link network transmission period, and a second wireless link is in a detection state during the first multi-link network transmission period; the multi-link station detecting, at a second time, that the first wireless link does not receive data during a multi-link network reception period, wherein the second wireless link is in a detection state during the multi-link network reception period; and in response to detecting, at the second time, that the first wireless link does not receive data during the multi-link network reception period, adjusting, by the multi-link station, a multi-link channel availability assessment process for the first wireless link and the second wireless link.

[0056] 38. A solution according to clause 37, wherein regulating the multilink channel availability assessment process for the first radio link and the second radio link comprises initiating a joint backoff counter for the first radio link and the second radio link at a third time.

[0057] 39. A solution according to clause 37, wherein regulating the multi-link channel availability assessment process for the first radio link and the second radio link comprises: transmitting a second data set by the first radio link during the second multi-link network transmission period, and transmitting a third data set by the second radio link during the second multi-link network transmission period.

[0058] 40. An apparatus for wireless communication, comprising a processor configured to perform the solution according to any of clauses 1 to 39.

[0059] 41. A non-transitory computer-readable medium having stored thereon code which, when executed by a processor, causes the processor to implement the solution according to any one of clauses 1 to 39.

[0060] The details of one or more implementations are set forth in the appended drawings, and the description below. Other features will be apparent from the description and drawings, and from the clauses. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1An example multi-link access network including multi-link stations is shown.

[0062] Figure 2A An example reference architecture of a multi-link station and a multi-link access point according to the first embodiment is shown.

[0063] Figure 2B An example reference architecture of a multi-link station and a multi-link access point according to the second embodiment is shown.

[0064] Figure 3A An example multi-link network allocation vector setting process for transmission in simultaneous transmit and receive limited operation without clear channel assessment adjustment is shown.

[0065] Figure 3B An example multi-link network allocation vector setting process for transmission in simultaneous transmit and receive limited operation with adjustable clear channel assessment is shown.

[0066] Figure 3C An example multi-link network allocation vector setup procedure for reception in simultaneous transmit and receive limited operation with deferred channel access is shown.

[0067] Figure 4A An example signaling procedure for a simultaneous transmitting and receiving multi-link access point initiated adjustable clear channel assessment during ML-NAV for transmission in simultaneous transmit and receive limited operation is shown.

[0068] Figure 4B An example signaling procedure for a simultaneous transmitting and receiving multi-link access point initiated adjustable clear channel assessment during ML-NAV for reception in simultaneous transmitting and receiving limited operation is shown.

[0069] Figure 5A An example signaling procedure for simultaneously transmitting and receiving a restricted multi-link station-initiated adjustable multi-link clear channel assessment during ML-NAV for reception is shown.

[0070] Figure 5B An example signaling procedure for simultaneously transmitting and receiving a restricted multi-link station-initiated adjustable multi-link clear channel assessment during ML-NAV for transmission is shown.

[0071] Figure 5C An example signaling procedure for multi-link clear channel assessment initiated by a simultaneously transmitting and receiving constrained multi-link station using a joint backoff mechanism for synchronous communication is shown.

[0072] Figure 6 A block diagram of a method for establishing a multi-link network allocation vector for transmission and / or reception and an adjustable clear channel assessment mechanism.

[0073] Figure 7 A block diagram representation of a portion of a hardware platform. DETAILED DESCRIPTION

[0074] The section headings used in this document are for ease of understanding only and do not limit the scope of the embodiments to the sections in which they are described. In addition, although the embodiments are described with reference to examples of wireless local access networks (WLANs), the disclosed technology can be applied to wireless systems that use protocols other than WLAN or IEEE 802.11 protocols.

[0075] Wireless local area network (WLAN) communications are rapidly becoming a popular mechanism for communicating with each other, either directly or via networks such as the Internet. Multiple wireless devices (e.g., smartphones, tablets, etc.) can attempt to transmit and receive data over a shared communication spectrum within an environment (e.g., an airport, a home, a building, a sports stadium, etc.). Furthermore, wireless devices (e.g., sensors, cameras, control units, etc.) are increasingly being used in networks for various applications (e.g., factory automation, vehicular communications, etc.).

[0076] In some cases, data transmission is based on an air interface as specified by the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards. Under this specification, devices can share the wireless medium including a specific set of rules. In IEEE 802.11, the Basic Service Set (BSS) is the building block of a wireless local area network (WLAN). Associated wireless stations (also called stations) in a radio coverage area can establish a BSS and provide basic services of the WLAN.

[0077] IEEE 802.11 specifies a wireless access protocol for operation in unlicensed and / or shared spectrum. Wireless stations can operate on channels in unlicensed bands (e.g., 2.4 GHz or 5 GHz) or in bands shared with other services (e.g., 6 GHz).

[0078] When operating on unlicensed or shared spectrum, transmission and reception of wireless messages may be unreliable due to interference from other stations located in the same coverage area, such as hidden node transmissions or "visible" nodes attempting to transmit using the same shared communication medium.

[0079] Devices operating on unlicensed bands can utilize the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) mechanism to control multiple medium access based on the IEEE 802.11 specification. Each station can implement CSMA / CA functionality. Before accessing the wireless medium, a station can use CSMA / CA to sense the medium occupancy status. If the station determines that the medium is busy, it may need to wait and retry to sense the medium later. If the station senses that the medium is idle, the station may wait for some inter-frame space (IFS) and then enter the contention window. In order to support multiple stations to access the medium, each station can back off for a random time before transmitting via the medium to reduce collisions and evenly distribute medium access. The backoff time can be defined as follows:

[0080] Back off Time = Random() x aSlotTime Equation (1)

[0081] Where Random() = a pseudorandom integer uniformly distributed in the interval [0, CW], and CW is an integer:

[0082] aCWmin≤CW≤aCWmax Equation (2)

[0083] The current CSMA / CA mechanism specified in the IEEE 802.11 standard can incur significant channel access delays in each transmission and lead to issues with medium utilization efficiency. When a large number of stations share the same medium and transmit simultaneously, the CSMA / CA mechanism suffers from unreliable transmission (e.g., increased packet loss, longer access delays, and greater jitter in unstable radio environments). This unreliable transmission can degrade the user experience and limit the performance of applications that require low latency and high reliability over IEEE 802.11 wireless access networks.

[0084] In some cases, the IEEE 802.11 standard allows a station to associate with an access point via a wireless link. If the associated wireless link is congested or interfered with on either the station or the access point side, this may make it difficult for the station to receive reliable transmissions. In other cases, if the associated wireless link is busy, this limitation in the IEEE 802.11 standard will restrict wireless communication between the station and the access point.

[0085] This embodiment may involve an adjustable multi-link clear channel assessment (ML-CCA) mechanism to reduce channel access delay, improve transmission reliability, and increase transmission throughput in a WLAN.

[0086] Figure 1An example WLAN with an infrastructure BSS configuration is shown. The infrastructure BSS WLAN may include multiple ML stations (i.e., ML-STAs or non-AP ML devices), such as, for example, ML-STA1 110 and ML-STA2 112. ML stations may be within the coverage of a first ML access point (i.e., ML-AP or referred to as an AP ML device), such as ML-AP1 120 and / or a second ML access point ML-AP2 122. ML-AP1 120 may form infrastructure ML-BSS1, and ML-AP2 122 may form infrastructure ML-BSS2. ML-AP1 120 and ML-AP2 122 may be interconnected via a switch through a distribution system (DS) to form ML-BSS 100. ML-AP1 120 and ML-AP2 122 may be coordinated via an ML-BSS controller 150 for ML operations across multiple ML-APs.

[0087] In some embodiments, an ML-STA with multiple radios (e.g., ML-STA1 110) can be configured to operate on multiple channels (or OFDMA subchannels) in the same frequency band or different frequency bands to communicate with an ML-AP (e.g., ML-AP1 122). The ML-STA can associate with one or more ML-APs within the coverage area of the ML-BSS for ML communications.

[0088] An active link of an ML can operate in one of the following states: transmit state (TX), receive state (RX), and listen state (i.e., a state in which it detects (DT) transmissions from other links). Depending on the mode of operation, the operation of an active link can be independent of or constrained by the operation of other active links.

[0089] A simultaneous transmit and receive (STR) mode of operation may refer to a mode of operation that allows transmission on an enabled active link to be independent of (uninterruptible from) operation on another enabled active link.

[0090] The simultaneous transmit and receive constrained (STR-constraint) mode of operation may mean that operation on an STR-constraint link may depend on the operational state of one or more other STR-constraint links. That is, if transmission on an active link causes reception on another active link to be interrupted, then the transmission may be constrained. Therefore, it may be assumed that the link with which the ML-CCA is associated is the active link.

[0091] The ML device may be configured to have all links operating on STR operation, a portion of links operating on STR operation and another portion of links operating on STR-constraint, and / or all links operating on STR-constraint operation.

[0092] In some embodiments, ML-AP 122 and ML-STA 110 may perform leveraged ML operations for simultaneous transmission and reception (STR) via one or more radio frequency channels to reduce access latency, improve transmission reliability, and / or increase transmission throughput, coordinated by ML-MBSS controller 150. ML communications may include bidirectional transmissions between the ML-STA and the ML-AP over some or all ML links.

[0093] In some embodiments, the ML-AP 122 and the ML-STA 110 may leverage ML operations for non-simultaneous transmission and reception-constrained (STR-constraint) operations via some or all ML links.

[0094] Figures 2A-2B An example ML system architecture for ML-STA and ML-AP is shown. Figure 2A In the first embodiment shown, the ML system 200 a may include an ML-STA 210 and an ML-AP 220 .

[0095] like Figure 2A As shown, ML-STA 210 may include ML radios 211, 212, and 213. Each radio of ML-STA 210 may include an 802.11 PHY and a portion of a MAC (i.e., a lower layer MAC (MAC-L)). ML radio 211 may operate on a wireless channel (CH1) to establish a radio link 251 to ML-AP 220. Similarly, ML radios 212 and 213 may operate on wireless channels (CH2 and CH3) to establish radio links 2 252 and 3 253 to ML-AP 220, respectively. ML-STA 210 may include an ML radio controller 241, which may include a common 802.11 MAC (i.e., an upper layer MAC (MAC-U)) and a management entity that manages ML operations of ML-STA 210.

[0096] ML-AP 220 may include ML radios 221, 222, and 223. Each radio of ML-AP 220 may include an 802.11 PHY and a partial MAC (i.e., MAC-L). Radio 221 of ML-AP 220 may operate on a wireless channel (CH1) to establish a radio link 251 to ML-STA 210. Similarly, ML radios 222 and 223 of ML-AP 220 may operate on wireless channels (CH2 and CH3) to establish radio link 2 252 and link 3 253 to ML-STA 210, respectively. ML-AP 220 may have an ML radio controller 242, which may include a common 802.11 MAC (i.e., MAC-U) and a management entity that manages ML operations of ML-AP 220.

[0097] In such Figure 2B In the second embodiment shown, the ML system 200b may include an ML-STA 210, an ML-AP 220, and an ML-BSS controller 230. Figure 2B As shown, ML-STA 210 may include ML radios 211, 212, and 213. Each radio of ML-STA 210 may include an 802.11 PHY and a partial MAC (i.e., MAC-L). Radio 211 may operate on a wireless channel (CH1) to establish radio link 1 231 to ML-AP 220. Similarly, ML radios 212 and 213 may operate on wireless channels (CH2 and CH3) to establish radio link 2 252 and link 3 253 to ML-AP 220, respectively. ML-STA 210 may have an ML radio controller 241, which may include a common 802.11 MAC (MAC-U) and a management entity that manages ML operations of ML-STA 210.

[0098] ML-AP 220 may include ML radios 221, 222, and 223. Each radio of ML-AP 220 may include an 802.11 PHY and a partial MAC (i.e., MAC-L). ML radio 221 may operate on a wireless channel (CH1) to establish a radio link 251 to ML-STA 210. Similarly, ML radios 222 and 223 may operate on wireless channels (CH2 and CH3) to establish radio link 2 252 and link 3 253 to ML-STA 210, respectively. ML-AP 220 may have an ML radio controller 242, which may include a common 802.11 MAC (i.e., MAC-U) and a management entity that manages ML operations of ML-AP 220.

[0099] The ML-BSS controller 230, which may be integrated with the ML-AP 220 or located separately as a single network entity, may coordinate one or more ML radio controllers 242 for ML operations across multiple ML-APs.

[0100] MLs 251, 252, and 253 may be wireless links that may operate on radio channels in the same frequency band or in different frequency bands, such as at 2.4 GHz, 5 GHz, 6 GHz bands, etc. The links may have the same channel bandwidth, such as 20 MHz, 40 MHz, 80 MHz, 160 MHz, etc. Alternatively, the links may allow a combination of different channel bandwidths, such as 160 MHz + 160 MHz + 20 MHz or 160 MHz + 80 MHz + 20 MHz, etc.

[0101] An ML-STA may associate with an ML-AP via any link to establish ML communication between them. During ML association, the ML-STA and ML-AP may exchange ML capability information and determine supported ML operations.

[0102] An ML-STA can turn on its radio to listen for transmissions in the unlicensed band and search for beacon frames. An ML-STA can turn on multiple ML radios to quickly search across multiple channels simultaneously to reduce search time. If an ML-STA receives an ML beacon frame, it can determine whether it can associate with the ML-AP based on the ML capability information broadcast in the beacon frame.

[0103] A wireless device may use a clear channel assessment (CCA) mechanism to determine whether a channel is occupied by other transmissions. In IEEE 802.11, two types of CCA detection mechanisms are defined.

[0104] The first type of CCA detection can include preamble detection (PD). In PD, this CCA mechanism can detect the preamble signal of the IEEE 802.11 frame. Once the detected preamble signal strength is equal to or greater than the PD threshold (PDT, i.e., -82dBm), CCA can declare that the channel is busy, i.e., occupied by another transmission. If the detected preamble signal strength is less than the PDT, the channel can be declared idle and the wireless device can transmit frames on this idle channel.

[0105] The second type of CCA detection can include energy detection (ED). In ED, this CCA mechanism can detect the energy of any type of wireless signal, even if the preamble is not within the detection period or cannot be detected due to strong interference. If CCA detects a signal strength measurement on the operating channel that is equal to or greater than the ED threshold (EDT, i.e., -62dBm), CCA can determine that the channel is busy, i.e., occupied by other transmissions. If the detected signal strength is less than the EDT, the channel can be declared idle, and the wireless device can transmit frames on this idle channel.

[0106] When using the existing CCA mechanism on the link of the ML device to detect the operating channel status, there may be special constraints on the STR-constraint ML operation.

[0107] Because STR-constraint ML operation does not allow simultaneous transmission and reception, the CCA mechanism of an STR-constraint link may be hindered by self-interference or result in incorrect measurements when the ML device is transmitting on another STR-constraint link. The impact of transmissions on the CCA mechanism of an STR-constraint link may depend on any of the following: the channel on which the STR-constraint link of the ML device (or "wireless device" or "wireless ML device") performs CCA and the channel on which the STR-constraint link of the ML device is transmitting frames; the physical separation between the two radio modules of the STR-constraint link of the ML device; and the total transmit power of one or more STR-constraint links from the ML device.

[0108] To address this issue of CCA in links on STR-constraint ML operation, adjustable CCA can be utilized along with the ML-NAV mechanism.

[0109] ML devices can apply an adjustable ML-CCA mechanism on STR-constrained links. ML-CCA on each link can be performed independently without any channel estimation adjustments, but some restrictions on the channel estimation period may be required.

[0110] ML-CCA on a link can determine a self-interference strength measurement (e.g., RSSI) based on the total signal strength measurement on that channel, where self-interference may come from one or more other channels on which one or more STR-constraint links of the ML device are transmitting. ML-CCA of the STR-constraint links of the ML device can accurately measure the channel's clearness based solely on other devices.

[0111] ML-CCA measurements on STR-constrained links can use an adjusted energy detection threshold (EDT) for clear channel assessment.

[0112] Adjusted EDT (AEDT) = EDT + self-interference signal strength measurement of one or more other transmission links on the STR-constraint operation from the ML device. Equation (3)

[0113] In the STR-constraint mode of operation, the ML network allocation vector (ML-NAV) may be used to reflect the restriction of the operating state of those links in the STR-constraint mode of operation.

[0114] ML-NAV(TX) may include a Tx-restricted period within the MLD. The duration of ML-NAV(TX) may be equal to the duration of the PPDU to be transmitted on the link in STR-constraint mode plus the SIFS time. When a link in STR-constraint mode is set to ML-NAV(TX), other links in STR-constraint mode may be in DT or TX state.

[0115] ML-NAV(RX) may include an intra-MLD Rx restricted period. The duration of ML-NAV(RX) may be equal to the duration of a PPDU received on a link in STR-constraint mode plus the SIFS time. When a link in STR-constraint mode is set to ML-NAV(RX), other links in STR-constraint mode may be in DT or RX state.

[0116] When a link in STR-constraint operation mode is set to ML-NAV(TX), adjustable ML-CCA on other links in STR-constraint operation mode can be used to adjust the self-interference impact on the CCA process on other links.

[0117] When a link in the STR-constraint operation mode is set to ML-NAV (RX), the state of other links in the STR-constraint operation mode may not be changed to TX in order to prevent self-interference from affecting the reception process on the link.

[0118] An ML device transmitting a frame on a STR-constrained link can set the ML-NAV(TX) (i.e., the intra-MLD Tx restricted period) to the duration of the PPDU being transmitted plus the SIFS period. The ML-NAV(TX) can be the duration of the frame being transmitted by the ML device on the STR-constrained link plus the SIFS period. During this period, the ML device can perform adjustable ML-CCA procedures and channel access on other STR-constrained links. This helps align new transmissions within the period of existing transmissions on other STR-constrained links.

[0119] Once ML-NAV(TX) is set, the adjustable ML-CCA on the link can measure the self-interference from the other channel and adjust its CCA algorithm.

[0120] If adjustable ML-CCA is disabled (i.e., not supported), no adjustments can be performed on that link. Adjustable ML-CCA may not perform CCA on a link during ML-NAV(TX) because the measurements may be incorrect.

[0121] If adjustable ML-CCA is enabled, the adjustment may be an adjustment of the ML-CCA measurement value, indicating that the adjustable ML-CCA on the link may subtract the self-interference from other channels from the total ML-CCA measurement result before evaluating the channel clearness, or an adjustment of the ML-CCA EDT including the adjustable ML-CCA on the link may compensate the EDT by the self-interference measurement value from another channel and use the AEDT as the clear channel assessment threshold.

[0122] When the measured value of the adjustable ML-CCA is greater than the EDT (or the measured value of the ML-CCA is greater than the AEDT), the measured value of the adjustable ML-CCA may identify the channel as busy; otherwise, the channel may be determined to be idle.

[0123] An ML device receiving a frame on a STR-constrained link can set ML-NAV(RX), the limited RX period within the MLD, to the duration of the received PPDU plus the SIFS. ML-NAV(RX) can be the duration of the frame the ML device is receiving on the STR-constrained link plus the SIFS. When a PPDU is being received on another STR-constrained link of the ML device, ML-NAV(RX) can be used on the link performing adjustable ML-CCA and channel access. ML-NAV(RX) helps hold a new transmission until the current transmission on the other link is complete. This prevents new transmissions from interfering with existing communications.

[0124] The ML-NAV value for TX or RX decreases over time. Once the ML-NAV reaches "0", the channel estimation can return to normal.

[0125] ML devices can use the physical CCA mechanism on STR-constraint links in combination with virtual carrier sensing to determine channel availability.

[0126] ML virtual carrier sensing can rely on the ML network allocation vector (ML-NAV) to assess channel availability. An ML device can include multiple STR-constraint links, each with a CCA for physically clear channel assessment. When a link's CCA detects a preamble on its operating channel, it can set the ML-NAV associated with that channel to have an occupancy period indicated by the duration field of the received packet plus the SIFS time. The type of ML-NAV can depend on whether the ML device's STR-constraint link is transmitting or receiving frames.

[0127] If CCA on an STR-constrained link detects that a transmitted preamble has leaked from another channel of the ML device, the ML device may set the ML-NAV(TX) associated with that channel to be occupied for the period indicated by the duration field of the leaked transmission plus the SIFS time. Another possible way to set the ML-NAV(TX) is for the ML device's STR-constrained link to directly mark the ML-NAV(TX) on the channel as occupied for the transmission period that the ML device's STR-constrained link is about to transmit. Therefore, once the ML device is transmitting a frame on the STR-constrained link, the ML device's other enabled STR-constrained links can be constrained by the ML-NAV(TX) for adjustable ML-CCA.

[0128] If the ML device is receiving frames on a STR-constraint link, it may set ML-NAV(RX) for the period indicated by the Duration field of the received frame plus the SIFS time.

[0129] Adjustable ML-CCA can support various backoff procedures. For example, independent backoff procedures can be used for adjustable ML-CCA. For independent backoff of adjustable ML-CCA, each link can have its own CCA for channel availability assessment and its own set of backoff counters. Each backoff counter can correspond to an access category, such as background (AC_BK), best effort (AC_BE), video (AC_VI), or voice (AC_VO). When the channel is sensed as idle by its CCA, the backoff counter of the link can be decremented by "1".

[0130] As another example, a joint backoff process can be used for scalable ML-CCA. In the joint backoff process for ML-CCA, each link can have its own CCA for clear channel assessment, but share a set of backoff counters, i.e., joint backoff. Each backoff counter corresponds to an access category, such as background (AC_BK), best effort (AC_BE), video (AC_VI), or voice (AC_VO), but when scalable ML-CCA detects that multiple channels are clear, the backoff counters can be decremented jointly. This allows ML devices to access the medium faster than with independent backoff processes.

[0131] The STR-constraint link of an ML device can choose adjustable ML-CCA with an independent backoff process or an adjustable ML-CCA with a joint backoff process for channel assessment and access.

[0132] Figures 3A-3C An example process for adjustable ML-CCA for STR-constraint ML operation using independent backoff procedures on each link or a joint backoff procedure with or without CCA adjustment is shown. Figures 3A-3C In an embodiment, the STR-constraint ML device can be composed of three radios, which operate on radio channel 1 (CH1), radio channel 2 (CH2) and radio channel 3 (CH3) respectively to establish STR-constraint operations on corresponding communication link 1 351, link 2 352 and link 3 353.

[0133] The ML device can include multiple independent adjustable ML-CCA sensors for the STR-constraint link. Each sensor can be associated with a STR-constraint link and can have an independent backoff counter or share a joint backoff counter. The adjustable ML-CCA can use the same set of EDCA parameters (such as CW, CWmin, CWmax, etc.) corresponding to the AC.

[0134] In the first embodiment, as Figure 3A FIG. 5 shows an adjustable ML-CCA process for STR-constraint ML operation without channel estimation adjustment.

[0135] At time T0, the ML device can receive queued MSDUs from the application and initiate adjustable ML-CCA for the enabled STR-constraint links (i.e., Link 1 351, Link 2 352, and Link 3 353). In this example, since channels CH2 and CH3 are occupied by the OBSS at time T0 based on their NAV values, the ML device's STR-constraint Link 1 351 can initiate adjustable ML-CCA for CH1, which has a NAV value of "0," and postpone adjustable ML-CCA for the other links until their NAVs reach "0." If the adjustable ML-CCA for Link 1 351 detects that its channel (e.g., CH1) is idle, it can decrement the adjustable ML-CCA backoff counter for the corresponding AC by "1." If none of the backoff counters reaches "0," the adjustable ML-CCA process can continue for the corresponding link (e.g., Link 1) until at least one of the adjustable ML-CCA backoff counters reaches "0." Once one of the adjustable ML-CCA backoff counters reaches “0” and the channel (e.g., CH1) link is still sensed as idle, the STR-constraint link 1351 of the ML device may begin acquiring a TXOP on the channel (e.g., CH1) by transmitting frames such as control frames, management frames, or data frames.

[0136] Meanwhile, when the ML device is about to transmit a frame on STR-constraint link 1 351, it can set the ML-NAV(TX1) for one or more other enabled links (e.g., link 2 352 and link 3 353) to the duration of the PPDU to be transmitted plus the SIFS time. If the ML device does not support adjustable ML-CCA for STR-constraint links, it can disable the adjustment of STR-constraint links 2 352 and 3 353, as shown in this example. However, CCAs on those links may obtain incorrect measurements or may be interrupted.

[0137] After the ML device is transmitting a frame on CH1, the adjustable ML-CCA on STR-constraint link 2 and link 3 can detect the preamble of the transmission leaked from CH1 and set ML-NAV(TX1) accordingly, if ML-NAV(TX1) has not been set by the STR-constraint MLD.

[0138] When the NAV on CH2 becomes "0" at T1, the adjustable ML-CCA for link 2 352 can begin physical channel assessment for CH2 without any adjustments. Due to self-interference leakage from transmissions on CH1, the disabled adjustable ML-CCA for link 2 352 may not obtain a clear channel assessment result for CH2. Therefore, the disabled adjustable ML-CCA for link 2 352 may not perform the backoff process, even if there are no other transmissions on CH2 at T1. After the ML device completes its transmission on STR-constrained link 1 351 at the end of ML-NAV (TX1), the adjustable ML-CCA for link 2 352 can return to normal and begin its backoff process.

[0139] If the adjustable ML-CCA for link 2 352 detects that its channel (e.g., CH2) is idle after ML-NAV (TX1) ends, the adjustable ML-CCA backoff counter corresponding to the AC can be decremented. If none of the backoff counters reaches "0," the adjustable ML-CCA process can continue on the corresponding links (e.g., CH2 and CH3) until at least one of the adjustable ML-CCA backoff counters reaches "0." If one of the adjustable ML-CCA backoff counters reaches "0" and the channels (e.g., CH2 and CH3) are still sensed as idle, the device can begin acquiring those channels (e.g., CH2 and CH3) by transmitting frames such as control frames, management frames, or data frames on the corresponding STR-constraint links.

[0140] In the second embodiment, as Figure 3B , which illustrates an adjustable ML-CCA process for STR-constraint ML operation. The ML device may receive an indication of pending MSDUs in the queue from the application at time T0 and initiate adjustable ML-CCA for enabled STR-constraint links (i.e., link 1 351, link 2 352, and link 3 353). In this example, since channels CH2 and CH3 are occupied by the OBSS at time T0 based on their NAV values, the STR-constraint ML device may initiate an adjustable ML-CCA process for CH1, which has a NAV value of "0," and postpone adjustable ML-CCA for other links until their NAV values become "0." If the adjustable ML-CCA for link 1 351 detects that its channel (e.g., CH1) is idle, the adjustable ML-CCA backoff counter corresponding to the AC may be decremented. If none of the backoff counters reaches "0", the adjustable ML-CCA process may continue on the corresponding link (e.g., Link 1) until at least one of the adjustable ML-CCA backoff counters reaches "0". Once one of the adjustable ML-CCA backoff counters reaches "0" and the channel (e.g., CH1) is still sensed as idle, the ML device may begin acquiring the channel (e.g., CH1) by transmitting frames such as control frames, management frames, or data frames on the corresponding STR-constraint link.

[0141] Meanwhile, when the ML device is about to transmit a frame on the STR-constraint link, it may set the ML-NAV(TX1) for other enabled non-transmitting links (eg, Link 2 352 and Link 3 353) to the duration of the PPDU to be transmitted plus the SIFS time.

[0142] After the ML device is transmitting a frame on CH1, the adjustable ML-CCA on STR-constraint link 2 and link 3 can detect the preamble of the transmission leaked from CH1 and set ML-NAV(TX1) accordingly, if ML-NAV(TX1) has not been set by the STR-constraint ML device.

[0143] Adjustment of the adjustable ML-CCA can be performed according to any of the following methods. A first method may include the ML device directly notifying the adjustable ML-CCAs of other STR-constraint links of the adjustment amount according to the settings and calibration via an internal communication connection (such as a shared memory or bus). The self-interference strength can be calibrated in an external noise-free environment by measuring the received signal strength on each other STR-constraint link while transmitting on one STR-constraint link at multiple transmit power levels, and generating a self-interference measurement matrix for each STR-constraint link at the multiple transmit power levels.

[0144] A second method may include an adjustable ML-CCA for a link (eg, link 2 352 or link 3 353 ) measuring real-time self-interference from another channel (eg, CH1 ) starting at ML-NAV(TX1 ) and adjusting the overall measurement or EDT.

[0145] As shown in this example, the adjustable ML-CCA on Link 2 352 and / or Link 3 353 can measure the self-interference from CH1 when ML-NAV(TX1) is set, and adjust the measurement results or the adjustable ML-CCA in the EDT.

[0146] For the option of an adjustable ML-CCA measurement mechanism, the self-interference measurement result of CH1 can be subtracted from its total adjustable ML-CCA measurement result. For the option of an adjusted ML-CCA ED threshold, the self-interference signal strength of CH1 on the EDT can be compensated, where the self-interference signal strength is notified by the ML device when setting ML-NAV(TX1) or measured in real time by the adjustable ML-CCA of STR-constraint link 2 352 or link 3 353.

[0147] When the NAV on CH2 reaches "0" at T1, the adjustable ML-CCA for Link 2 352 may begin physical channel assessment for CH2 with regulation. If the adjustable ML-CCA for Link 2 352 detects that its channel (e.g., CH2) is idle, the adjustable ML-CCA may trigger a backoff process to decrement the backoff counters. If none of the backoff counters on Link 2 reaches "0," the adjustable ML-CCA process may continue on CH2 until at least one of the adjustable ML-CCA backoff counters reaches "0." If the adjustable ML-CCA backoff counter for Link 2 reaches "0" and the channel (e.g., CH2) is still sensed as idle, the ML device may begin transmitting frames on STR-constrained Link 2 352 during ML-NAV (TX1). Transmissions on Link 2 352 may be aligned with the end of transmissions on Link 1 351.

[0148] Meanwhile, when the ML device is about to transmit a frame on a STR-constraint link (e.g., link 2 352), the ML-NAV(TX2) for one or more other enabled non-transmitting STR-constraint links (e.g., link 3 353) may be set to the duration of the PPDU to be transmitted plus the SIFS time.

[0149] Similarly, after the ML device transmits a frame on CH2, the adjustable ML-CCA on STR-constraint link 3 can detect the preamble of the transmission leaked from CH2 and set ML-NAV(TX2) accordingly, if ML-NAV(TX2) has not been set by the STR-constraint MLD.

[0150] As shown in this example, once ML-NAV(TX2) is set, the adjustable ML-CCA for link 3 353 measures the self-interference from CH2, in addition to measuring the self-interference from CH1 after ML-NAV(TX1) is set. When ML-NAV(TX2) is set for transmission, the adjustable ML-CCA for STR-constraint link 3 can adjust its CCA using the self-interference signal strength notified by the ML device or the self-interference measured by itself.

[0151] For the adjusted channel measurement option of the adjustable ML-CCA mechanism, when ML-NAV(TX1) is set, the self-interference signal strength of CH1 can be subtracted from its total adjustable ML-CCA measurement result, and when ML-NAV(TX2) is set, the self-interference signal strength from CH2 can be subtracted from its total adjustable ML-CCA measurement result.

[0152] For the adjustment option of the ED threshold of the adjustable ML-CCA mechanism, when setting ML-NAV(TX1), the signal strength of the self-interference of CH1 can be used to compensate for EDT, and when setting ML-NAV(TX2), the signal strength of the self-interference of CH2 can be used to compensate for EDT.

[0153] When the NAV on CH3 reaches "0" at time T1', the adjustable ML-CCA for link 3 353 may initiate an adjustable ML-CCA for CH3. If the adjustable ML-CCA for link 3 353 detects that CH3 is idle, the adjustable ML-CCA may trigger a backoff process to decrement the backoff counters on link 3 353. If none of the backoff counters reaches "0," the adjustable ML-CCA process may continue on CH3 until at least one of the adjustable ML-CCA backoff counters reaches "0." If one of the adjustable ML-CCA backoff counters on link 3 353 reaches "0" and the channel (e.g., CH3) is still sensed as idle, the ML device may begin transmitting frames on the STR-constrained link 3 353. The end time of transmission on link 3 353 may be aligned with both ML-NAV (TX1) and ML-NAV (TX2).

[0154] In the third embodiment, Figure 3C FIG. 4 shows an adjustable ML-CCA process for a STR-constraint link of an ML device with deferred channel access.

[0155] At time T0, the ML device may receive a frame on STR-constraint link 1 351 from the associated AP ML device. Simultaneously, the ML device may detect that CH2 and CH3 are occupied by the OBSS based on their NAV values. The ML device may set the ML-NAV (RX1) for the enabled STR-constraint link 2 352 and link 3 353 to the duration of the PPDU received on link 1 351 plus the SIFS time.

[0156] After time T0, the ML device may receive a queued MSDU from the application and intend to begin adjustable ML-CCA on the enabled STR-constraint link. Because frames are being received on link 1 351, it may begin adjustable ML-CCA on the other links, namely link 2 352 and link 3 353. However, since the NAVs for both link 2 352 and link 3 352 are set from OBSS transmissions and have not yet decreased to "0," adjustable ML-CCA may be postponed until at least one of the NAV values decreases to "0." At time T1, the NAV on link 2 352 may become "0," and therefore adjustable ML-CCA on link 2 352 may begin without channel assessment adjustments.

[0157] If the adjustable ML-CCA of link 2 352 detects that its channel (e.g., CH2) is idle, the adjustable ML-CCA may trigger a backoff process to decrement the backoff counters. If none of the backoff counters reaches "0," the adjustable ML-CCA process may continue on the corresponding link (e.g., link 2 352) until at least one of the backoff counters reaches "0." Once one of the adjustable ML-CCA backoff counters reaches "0" and the channel (e.g., CH2) is still sensed as idle, the ML device may check the ML-NAV setting for the STR-constraint link. If ML-NAV (RX1) is set and its value has not decreased to "0," the ML device may defer channel access to STR-constraint link 2 352 until the ML-NAV (RX1) value decreases to "0." The ML device may then acquire the channel (e.g., CH2) by transmitting frames such as control frames, management frames, or data frames.

[0158] Similarly, at time T1 ′, the NAV on the STR-constraint link 3 353 may become “0” and then the adjustable ML-CCA may begin the CCA process on link 3 353 without evaluating adjustments.

[0159] If the adjustable ML-CCA of link 3 353 detects that its channel (e.g., CH3) is idle, the adjustable ML-CCA may trigger a backoff procedure to decrement the backoff counters. If none of the backoff counters reaches "0," the adjustable ML-CCA process may continue on the corresponding channel (e.g., CH3) until at least one of the adjustable ML-CCA backoff counters reaches "0." Once one of the adjustable ML-CCA backoff counters reaches "0" and the channel (e.g., CH3) is still sensed as idle, the ML device may check the ML-NAV setting for the STR-constraint link. If ML-NAV (RX1) is set and its value has not decreased to "0," the ML device may defer channel access to STR-constraint link 3 353 until the ML-NAV (RX1) value decreases to "0." The STR-constraint ML device may then acquire the channel (e.g., CH3) by sending a frame, such as a control frame, a management frame, or a data frame. Therefore, after the ML-NAV(RX1) ends, the ML device may transmit PPDUs on both STR-constraint link 2 352 and link 3 353 synchronously with the transmission on link 1 351 .

[0160] Figures 4A-4B This section illustrates an example procedure for adjustable ML-CCA initiated by an AP ML device for STR-constraint ML operation. Before an AP ML device establishes ML communication with a non-AP ML device, they can exchange ML capability information and set an agreed-upon ML operation mode. In this example, the AP ML device can be an ML device with STR capabilities, and the non-AP ML device can be an ML device with STR-constraint capabilities. Therefore, when the AP ML device communicates with the non-AP ML device, both can use the STR-constraint operation mode on Link 1 and Link 2. These procedures are applicable to situations where both the AP ML and the non-AP ML have STR-constraint links.

[0161] In such Figure 4AIn the illustrated embodiment, a CCA procedure initiated by an example STR AP ML device may be shown during transmission of ML-NAV set for STR-constraint ML operation. When CH2 is occupied by the OBSS from the NAV indication, the STR AP ML device may begin transmitting an ML-RTS to obtain an ML TXOP for DL transmission after performing a CCA on link 1. The STR AP ML device may set ML-NAV for STR-constraint operation with the non-AP ML device. Upon receiving the ML-RTS on link 1, the STR-constraint non-AP ML device may set ML-NAV (RX1) 461 for STR-constraint ML operation. It may then respond to an ML-CTS on the same link and set ML-NAV (TX1) for STR-constraint operation. The STR AP ML device may also similarly set ML-NAV (TX1) for STR-constraint operation with the non-AP ML device.

[0162] Once CH2 is released by the OBSS, the STR AP ML device can initiate a CCA procedure to acquire CH2, thereby establishing additional transmission on Link 2. Since ML-NAV is set for transmissions with STR-constraint operation, the STR AP ML device can complete the CCA procedure within the ML-NAV (TX1) period. If the CCA reports that CH2 is idle, the STR AP ML device may or may not synchronize DL transmissions via Link 1 and Link 2 in the next ML-NAV (RX1) period. Figure 4A It can be shown that the STR APML device synchronizes and transmits DL packets via Link 1 and Link 2 in the next ML-NAV period.

[0163] In such Figure 4BIn the illustrated embodiment, a CCA procedure is shown that is initiated by an example STR AP ML device during reception of an ML-NAV set for STR-constraint ML operation. When CH2 is occupied by an OBSS from a NAV indication, the STR AP ML device, after performing a CCA on Link 1, can begin transmitting an ML-RTS to acquire an ML TXOP for DL transmission. The STR AP ML device can then set an ML-NAV (RX1) for STR-constraint operation with the non-AP ML device. Upon receiving an ML-RTS on Link 1, the STR-constraint non-AP ML device can set an ML-NAV (RX1). It can then respond to an ML-CTS on the same link and set an ML-NAV (TX1) 472 for STR-constraint operation. Similarly, upon receiving an ML-CTS, the AP ML device can also set an ML-NAV (TX1) for STR-constraint operation with the STR-constraint non-AP ML device.

[0164] Since CH2 is still occupied by the OBSS when the ML-CTS is received, the STR AP ML device can only start DL transmission on link 1 and set ML-NAV (RX1) for STR-constraint operation with the non-AP ML device. The STR-constraint non-AP ML device that receives the DL transmission can set ML-NAV (RX1) 471. After the DL transmission starts, the AP ML can detect that CH2 is in the idle state via the NAV indication. It can then start CCA for link 2 within the period of ML-NAV (RX1) for STR-constraint operation. If the CCA for link 2 declares CH2 idle, the STR AP ML device can start transmitting another DL frame on link 2. DL transmission on link 2 should end at the time when ML-NAV (RX1) is completed.

[0165] In this way, the STR AP ML device can asynchronously transmit different DL PPDUs to non-AP ML devices via different STR-constraint links.

[0166] Figures 5A-5CThis section illustrates example procedures for scalable ML-CCA initiated by a non-AP ML device for STR-constraint ML operation. Before an AP ML device establishes ML communication with a non-AP ML device, they can exchange ML capability information and set an agreed-upon ML operation mode. In these examples, the AP ML device is an ML device with STR capabilities, and the non-AP ML device is an ML device with STR-constraint capabilities. Therefore, when the AP ML device communicates with the non-AP ML device, both can use the STR-constraint operation mode. These procedures are applicable to situations where both the AP ML and the non-AP ML have STR-constraint links.

[0167] In such Figure 5A In the illustrated embodiment, an example STR-constraint non-AP ML device initiates an adjustable ML-CCA procedure during reception of an ML-NAV set for STR-constraint ML operation. When CH2 is occupied by the OBSS indicated in the NAV, the non-AP ML device, after performing an adjustable ML-CCA on STR-constraint link 1, can begin transmitting an ML-RTS to acquire an ML TXOP for UL transmission. The non-AP ML device can set the ML-NAV for STR-constraint operation (TX1). Upon receiving an ML on link 1, the STR AP ML device can set the ML-NAV for STR-constraint operation with the non-AP ML device (RX1). It can then respond to an ML-CTS on the same link and set the ML-NAV for STR-constraint operation with the non-AP ML device (RX1). After receiving the ML-CTS, the non-AP ML device can set the ML-NAV for STR-constraint operation (RX1).

[0168] At this point, CH2 can be released by the OBSS. The non-AP ML can initiate an adjustable ML-CCA procedure on STR-constraint link 2 to acquire CH2 for additional UL transmission. Since ML-NAV can be set for reception of STR-constraint operations, the non-AP ML device can complete the adjustable ML-CCA procedure within the ML-NAV (RX1) 572 period. If the adjustable ML-CCA reports that CH2 is idle, the non-AP ML device may or may not synchronize UL transmissions over STR-constraint link 1 and link 2 in the next ML-NAV (TX1) 571 period. Figure 5AThe non-AP ML device that may show STR-constraint synchronizes and transmits UL packets via Link 1 and Link 2 in the next ML-NAV period.

[0169] In such Figure 5B The illustrated embodiment shows an example non-AP ML device initiating an adjustable ML-CCA procedure during transmission to set the ML-NAV for STR-constraint ML operation. When CH2 is occupied by the OBSS indicated by the NAV, the non-AP ML device, after performing an adjustable ML-CCA on link 1, begins transmitting an ML-RTS on STR-constraint link 1 to acquire an ML TXOP for UL transmission. The non-AP ML device sets the ML-NAV for STR-constraint operation (TX1). After receiving the ML-RTS on STR-constraint link 1, the STR AP ML device may set the ML-NAV for STR-constraint operation with the non-AP ML device (TX1). It may then respond to an ML-CTS on the same link and set the ML-NAV for STR-constraint operation with the non-AP ML device (RX1). Upon receiving the ML-CTS, the non-AP ML device may set the ML-NAV for STR-constraint operation (RX1).

[0170] If CH2 is still occupied by the OBSS when the ML-CTS is transmitted, the non-AP ML device can only start UL transmission on STR-constraint link 1 and set the ML-NAV (TX1) for STR-constraint operation. The STR AP ML device receiving the UL transmission can set the ML-NAV (TX1) for STR-constraint operation with the non-AP ML device.

[0171] After the UL transmission begins, the non-AP ML device detects that CH2 is idle from the NAV indication and can then start an adjustable ML-CCA on STR-constraint link 2 within the ML-NAV(TX1) period of the STR-constraint operation. If the adjustable ML-CCA on link 2 declares CH2 idle, the non-AP ML device can start another UL transmission on STR-constraint link 2. UL transmission can end at the time ML-NAV(TX1) is completed.

[0172] In such Figure 5CIn the illustrated embodiment, an example non-AP ML device-initiated ML-CCA procedure with a joint backoff mechanism is shown. When CH2 is occupied by an OBSS indicated by a NAV, the non-AP ML device, after performing an adjustable ML-CCA on link 1, can begin transmitting an ML-RTS on STR-constraint link 1 to obtain an ML TXOP for UL transmission. The non-AP ML device can set an ML-NAV (TX1) for STR-constraint operation. After receiving the ML-RTS on STR-constraint link 1, the AP ML device can set an ML-NAV (TX1) for STR-constraint operation with the non-AP ML device. It then responds to an ML-CTS on the same link and sets an ML-NAV (RX1) for STR-constraint operation with the non-AP ML device. However, the non-AP ML device does not receive an ML-CTS message on STR-constraint link 1. Therefore, the non-AP ML may have to contend for the medium again.

[0173] The ML-CCA of the non-AP ML device can independently detect both STR-constraint links 1 and 2. Since both channels are sensed as idle, the joint backoff counter for both STR-constraint links can be decremented. ML-CCA can continue the same process until at least one of the joint backoff counters reaches "0." Once the joint backoff counter reaches "0," the non-AP ML can transmit an ML-RTS on the idle STR-constraint links, i.e., Link 1 and Link 2, and set ML-NAV (TX1) and ML-NAV (TX2) for STR-constraint operation.

[0174] After receiving the ML-RTS on both STR-constraint links, the AP ML device can also set the ML-NAV (TX1) and ML-NAV (TX2) for STR-constraint operation with the non-AP ML device. It can then respond to the ML-CTS on both links and set the ML-NAV (RX1) and ML-NAV (RX2) for STR-constraint operation with the non-AP ML device. When receiving the ML-CTS on the STR-constraint link, the non-AP ML can set the ML-NAV (RX1) and ML-NAV (RX2) for STR-constraint operation.

[0175] In this way, the non-AP ML device can transmit different UL PPDUs to the STR AP ML device via different STR-constraint links asynchronously or synchronously.

[0176] Figure 6 The invention is a block diagram of a method for establishing a multi-link network allocation vector for transmission and / or reception and an adjustable clear channel assessment mechanism. The method may include: a wireless device identifying that a first wireless link and a second wireless link of the wireless device are in a detection state at a first time (block 602).

[0177] The detection state may indicate that the radio link is actively performing tasks such as transmitting data, receiving data, or listening if the radio channel is busy with other data transmissions, etc. The radio link may include, for example, operating on either the AP MLD's channel or a non-AP MLD station.

[0178] The method may also include, based on detecting a transmission state of the first radio link at a first time, modifying, by the wireless device, a multi-link channel availability assessment process for the second radio link (block 604). Detecting the transmission state of the radio link may include identifying whether the radio link is in a transmission state. If the radio link is in a detection state, the multi-link channel availability assessment process may be modified based on the determination of the radio link.

[0179] In some embodiments, the wireless device is an access point (AP) multi-link device (MLD) capable of performing simultaneous transmit and receive limited (STR-constraint) operation.

[0180] In some embodiments, the method includes: determining by the wireless device that the first wireless link is in a transmission state at a second time, wherein modifying the multi-link channel availability assessment process includes: postponing the initiation of the multi-link channel availability assessment process for the second wireless link to a third time.

[0181] In some embodiments, detecting that the first radio link is in the transmit state includes determining that a network allocation vector (NAV) value for the first radio link of the wireless device is not equal to zero.

[0182] In some embodiments, the method includes: determining, by the wireless device, that a first multi-link NAV transmission period has expired; initiating, by the wireless device, a multi-link channel availability assessment process and a backoff process for a second wireless link at a time corresponding to the expiration of the first multi-link NAV transmission period; and transmitting, by the wireless device, a first message via the second wireless link in response to detecting the expiration of the backoff counter.

[0183] In another example embodiment, a method for wireless communication includes: identifying, by a wireless device, that a first wireless link and a second wireless link of the wireless device are in a detection state at a first time; and in response to detecting that the first wireless link is in a transmission state at the first time, adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link based on the transmission state of the first wireless link, and initiating the multi-link channel availability assessment process for the second wireless link.

[0184] In some embodiments, the method includes: in response to detecting that the first wireless link and the second wireless link are in a transmission state at a second time, the wireless device adjusts a multi-link channel availability assessment process for the third wireless link based on the transmission state of the first wireless link and the second wireless link.

[0185] In some embodiments, the method includes: detecting, by the wireless device, via a multi-link channel availability assessment procedure for the third wireless link, that the third wireless link is in a detecting state at a third time.

[0186] In some embodiments, the method includes: establishing, by the wireless device, a first multilink NAV transmission period at a first time, wherein initiation of a multilink channel availability assessment process for the second radio link and the third radio link is based on the first multilink NAV transmission period.

[0187] In some embodiments, the method includes: establishing, by the wireless device, a second multilink NAV transmission period at a second time, wherein initiation of a multilink channel availability assessment process for a third wireless link is based on the first multilink NAV transmission period and the second multilink NAV transmission period.

[0188] In some embodiments, the multi-link channel availability assessment process for any wireless link of the wireless device includes modifying received signal strength measurements based on measured received signal strengths resulting from transmissions of other messages on the first channel.

[0189] In some embodiments, the multi-link channel availability assessment process includes transmitting the first message on the second wireless link in response to a backoff counter reaching zero.

[0190] In some embodiments, the modified received signal strength is indicated by the wireless device.

[0191] In some embodiments, the method includes generating, by the wireless device, an interference measurement matrix comprising measured signal strengths for each transmit wireless link of the wireless device.

[0192] In some embodiments, the method includes: deriving, by the wireless device, a measured signal transmission strength for each wireless link of the wireless device;

[0193] In some embodiments, the method includes deriving, by the wireless device, a modified received signal strength in a multi-link channel availability assessment process for any wireless link based on the interference measurement matrix.

[0194] In some embodiments, the method includes modifying, by the wireless device, an energy detection threshold (EDT) of the wireless link based on the interference measurement matrix.

[0195] In some embodiments, the method includes, in response to completion of the multi-link channel availability assessment procedure, simultaneously transmitting, by the wireless device, a first downlink message on the first wireless link and a second downlink message on the second wireless link.

[0196] In some embodiments, the method includes transmitting, by the wireless device, a first uplink message on the first wireless link and a second uplink message on the second wireless link, respectively, in response to completion of the multi-link channel availability assessment procedure.

[0197] In some embodiments, the method includes, in response to completion of the multi-link channel availability assessment procedure, transmitting, by the wireless device, a first uplink message on the first wireless link and a second uplink message on the second wireless link simultaneously.

[0198] In some embodiments, the method includes: in response to completion of a multi-link channel availability assessment process including a joint backoff process for both the first radio link and the second radio link, transmitting, by the wireless device, a first uplink message on the first radio link and a second uplink message on the second radio link simultaneously.

[0199] In another example embodiment, a method for wireless communication includes: identifying, by a wireless device, that a first wireless link of the wireless device is receiving data and a second wireless link of the wireless device is in a detection state at a first time; and in response to detecting that the second wireless link is in the detection state at a second time, modifying, by the wireless device, initiation of a multi-link channel availability assessment procedure for the second wireless link.

[0200] In some embodiments, modifying the initiation of the multi-link channel availability assessment procedure for the second radio link includes initiating a backoff procedure for the second radio link at a second time.

[0201] In some embodiments, the method includes deferring, by the wireless device, initiation of channel access and transmission of the first message on the second wireless link until receipt of data at the first wireless link is complete.

[0202] In some embodiments, the method includes determining, by the wireless device, that the first wireless link has completed data reception based on detecting that the NAV value of the first wireless link is equal to zero.

[0203] In some embodiments, the method includes: initiating, by the wireless device, a second backoff procedure for a third wireless link at a second time; and in response to detecting completion of the first NAV transmission period, transmitting, by the wireless device, a first message at the second wireless link and a second message at the third wireless link simultaneously.

[0204] In another example embodiment, a method for wireless communication includes: initiating, by a wireless device, a multi-link network reception period at a first time, wherein the first wireless link receives data during the multi-link network allocation vector reception period and the second wireless link is in a detection state at the first time; initiating, by the wireless device, a multi-link NAV transmission period at a second time, wherein the first wireless link sends data during the multi-link network transmission period and the second wireless link is in a detection state at the second time; and in response to detecting that the second wireless link is in the detection state at the second time, adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link.

[0205] In some embodiments, adjusting the channel availability assessment process for the second radio link includes initiating a backoff process for the second radio link at a second time when the second radio channel is sensed as idle.

[0206] In some embodiments, the method includes receiving, by the wireless device, a downlink message simultaneously on each of the first and second wireless links at a third time in response to completion of the multilink channel availability assessment procedure for the second wireless link.

[0207] In another example embodiment, a method for wireless communication includes: initiating, by the wireless device, a first multi-link network reception period at a first time, wherein the first wireless link receives a first data set during the first multi-link network reception period, and the second wireless link is in a detection state at the first time; initiating, by the wireless device, a multi-link network transmission period at a second time, wherein the first wireless link sends data during the multi-link network transmission period, and the second wireless link is in an active state at the second time; initiating, by the wireless device, a second multi-link network reception period at a third time, wherein the first wireless link receives a second data set during the second multi-link network reception period, and the second wireless link is in a detection state at the third time; and in response to detecting that the second wireless link is in the detection state at the third time, adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link.

[0208] In some embodiments, adjusting the channel availability assessment process for the second radio link includes initiating a channel availability assessment process for the second radio link at a third time.

[0209] In another example embodiment, a method for wireless communication includes: initiating, by a multi-link station, a first multi-link network transmission period at a first time, wherein the first wireless link transmits a first data set during the first multi-link network transmission period, and the second wireless link is in a detection state during the first multi-link network transmission period; initiating, by the multi-link station, a multi-link network reception period at a second time, wherein the first wireless link receives data during the multi-link network reception period, and the second wireless link is in a detection state during the multi-link network reception period; and adjusting, by the multi-link station, a multi-link channel availability assessment process for the second wireless link to detect that the second wireless channel transitions to an idle state during the multi-link network reception period.

[0210] In some embodiments, the wireless device is a device capable of performing limited simultaneous transmission and reception operations.

[0211] In some embodiments, adjusting the channel availability assessment process for the second radio link includes initiating a backoff counter for the second radio link during the multi-link network reception period.

[0212] In some embodiments, the method includes: at a third time during the second multi-link network transmission period, simultaneously transmitting, by the wireless device, an uplink message on each of the first wireless link and the second wireless link, wherein the transmission of the uplink message is performed in response to completion of a multi-link channel availability assessment procedure for the second wireless link.

[0213] In another example embodiment, a method for wireless communication includes: initiating, by a wireless device, a first multi-link network transmission period at a first time, wherein the first wireless link transmits a first data set during the first multi-link network transmission period, and the second wireless link is in a detection state during the first multi-link network transmission period; initiating, by a multi-link station, a multi-link network reception period at a second time, wherein the first wireless link receives data during the multi-link network reception period, and the second wireless link is in an active state during the multi-link network reception period; initiating, by the multi-link station, a second multi-link network transmission period at a third time, wherein the first wireless link transmits a second data set during the second multi-link network transmission period, and the second wireless link is in a detection state before the third time; and adjusting, by the wireless device, a multi-link channel availability assessment process for the second wireless link to detect that the second wireless channel transitions to an idle state before the third time.

[0214] In some embodiments, adjusting the channel availability assessment process for the second wireless link includes: initiating, by the multi-link station, a backoff process for the second wireless link at a third time; and transmitting, by the wireless device, a third data set during the second multi-link network transmission period in response to expiration of the backoff counter.

[0215] In another example embodiment, a method for wireless communication includes: initiating, by a wireless device, a first multi-link network transmission period at a first time, wherein the first wireless link transmits a first data set during the first multi-link network transmission period, and the second wireless link is in a detection state during the first multi-link network transmission period; detecting, by the wireless device, at a second time, that the first wireless link does not receive data during a multi-link network reception period, wherein the second wireless link is in a detection state during the multi-link network reception period; and in response to detecting, at the second time, that the first wireless link does not receive data during the multi-link network reception period, adjusting, by the multi-link station, a multi-link channel availability assessment process for the first wireless link and the second wireless link.

[0216] In some embodiments, adjusting the multi-link channel availability assessment process for the first radio link and the second radio link includes initiating a joint backoff process for the first radio link and the second radio link at a third time.

[0217] In some embodiments, adjusting the multi-link channel availability assessment process for the first wireless link and the second wireless link includes: transmitting the second data set by the first wireless link during the second multi-link network transmission period and transmitting the third data set by the second wireless link during the second multi-link network transmission period.

[0218] Figure 7 7 is a block diagram representation of a portion of a hardware platform. A hardware platform 705, such as a network device or base station or wireless device (or UE), may include a processor electronic device 710, such as a microprocessor, that implements one or more of the wireless technologies described in this document. The hardware platform 705 may include a transceiver electronic device 715 to transmit and / or receive wired / wireless signals via one or more communication interfaces such as an antenna 720 or a wired interface. The hardware platform 705 may implement other communication interfaces with defined protocols for transmitting and receiving data. The hardware platform 705 may include one or more memories (not explicitly shown) configured to store information such as data and / or instructions. In some embodiments, the processor electronic device 710 may include at least a portion of the transceiver electronic device 715. In some embodiments, at least some of the disclosed techniques, modules, or functions are implemented using the hardware platform 705.

[0219] in conclusion

[0220] From the foregoing, it will be appreciated that specific embodiments of the presently disclosed technology have been described herein for illustrative purposes, but various modifications may be made without departing from the scope of the invention. Accordingly, the presently disclosed technology is not to be limited, except as by the appended claims.

[0221] The disclosed and other embodiments, modules, and functional operations described in this document may be implemented in digital electronic circuitry or computer software, firmware, or hardware (including the structures disclosed in this document and their equivalents), or a combination of one or more thereof. The disclosed and other embodiments may be implemented as one or more computer program products, i.e., one or more modules encoding computer program instructions for execution by or control operations of a data processing apparatus on a computer-readable medium. The computer-readable medium may be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter that effects a machine-readable propagated signal, or one or more combinations thereof. The term "data processing apparatus" encompasses all apparatuses, devices, and machines for processing data, including, by way of example, a programmable processor, a computer, or multiple processors or computers. In addition to hardware, an apparatus may also include code that creates an execution environment for the computer program in question, such as code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more thereof. A propagated signal is an artificially generated signal, such as a machine-generated electrical, optical, or electromagnetic signal, that is generated to encode information for transmission to a suitable receiver device.

[0222] A computer program (also referred to as a program, software, software application, script, or code) can be written in any form of programming language (including compiled or interpreted languages) and can be deployed in any form, including stand-alone programs, or modules, components, subroutines, or other units suitable for use in a computing environment. A computer program does not necessarily correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, subroutines, or portions of code). A computer program can be deployed to execute on one computer, or on multiple computers located at one site or distributed across multiple sites and interconnected by a communications network.

[0223] The processes and logic flows described in this document may be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows may also be performed by, and apparatus may be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit).

[0224] Processors suitable for executing computer programs include, for example, both general-purpose and special-purpose microprocessors, as well as any one or more processors of any kind of digital computer. Typically, a processor will receive instructions and data from read-only memory or random-access memory, or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Typically, a computer will also include one or more mass storage devices for storing data, such as magnetic, magneto-optical, or optical disks, or be operatively coupled to receive data from or transfer data to, or both, a mass storage device. However, a computer need not have such devices. Computer-readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media, and storage devices, including, for example, semiconductor memory devices such as EPROM, EEPROM, and flash memory devices; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented by, or incorporated in, special-purpose logic circuitry.

[0225] Although this patent document contains many details, these details should not be interpreted as limitations on any invention or the scope of what may be claimed, but rather as descriptions of features that may be specific to a particular embodiment of a particular invention. Certain features described in this patent document in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, the various features described in the context of a single embodiment may also be implemented separately in multiple embodiments or in any suitable subcombination. In addition, although features may be described as working in certain combinations or even in the originally claimed combination as described above, in some cases one or more features from the claimed combination may be separated from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0226] Similarly, while operations may be depicted in a particular order in the drawings, this should not be understood as requiring that such operations be performed in the particular order shown, or in sequential order, or that all illustrated operations be performed, to achieve desired results. Furthermore, the separation of various system components in the embodiments described in this patent document should not be understood as requiring such separation in all embodiments.

[0227] Only a few implementations and examples are described, and other implementations, enhancements, and variations can be made based on what is described and illustrated in this patent document.

Claims

1. A method for wireless communication, comprising: identifying, by the wireless device, that a first wireless link of the wireless device and a second wireless link of the wireless device are busy at a first time; In response to detecting that the first radio link is in a transmission state at the first time, adjusting, by the wireless device, a multilink channel availability assessment process for the second radio link based on the transmission state of the first radio link, and initiating a multilink channel availability assessment process for the second radio link; as well as A first multi-link network allocation vector NAV transmission period is established by the wireless device at the first time, wherein initiation of a multi-link channel availability assessment process for the second radio link and the third radio link is based on the first multi-link NAV transmission period.

2. The method according to claim 1, further comprising: A second multilink NAV transmission period is established by the wireless device at a second time, wherein initiation of a multilink channel availability assessment procedure for the third wireless link is based on the first multilink NAV transmission period and the second multilink NAV transmission period.

3. The method according to claim 1, wherein The multi-link channel availability assessment process for the second wireless link of the wireless device includes modifying received signal strength measurements based on measured received signal strengths resulting from transmission of other messages on the first channel.

4. The method according to claim 3, further comprising: An interference measurement matrix is generated by the wireless device, the interference measurement matrix including measured signal strengths for each transmitting wireless link of the wireless device as measured by non-transmitting links.

5. The method according to claim 4, further comprising: An energy detection threshold (EDT) of a wireless link is modified by the wireless device based on the interference measurement matrix.

6. The method according to claim 5, further comprising: In response to completion of the multi-link channel availability assessment procedure, a first downlink message is transmitted on the first wireless link and a second downlink message is transmitted on the second wireless link simultaneously by the wireless device.

7. The method according to claim 5, further comprising: In response to completion of the multi-link channel availability assessment procedure, a first uplink message is transmitted on the first wireless link and a second uplink message is transmitted on the second wireless link simultaneously by the wireless device.

8. An apparatus for wireless communication, comprising a processor configured to perform the method according to any one of claims 1 to 7.

9. A non-transitory computer-readable medium having stored thereon codes which, when executed by a processor, cause the processor to implement the method according to any one of claims 1 to 7.

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