PATENT DOCUMENT

Publication Number: US-12004050-B2
Application Number: US-202217721978-A
Country: US
Kind Code: B2

Title: Group cast with retries (GCR) in a multi-link WLAN system

Abstract:
Embodiments are disclosed for group cast with retries (GCR) in a multi-link wireless communications system. In some embodiments, an access point (AP) multi-link device (MLD) can exchange information with a non-AP MLD to establish a GCR-multi-link operation (MLO) agreement corresponding to a group address, wherein the information includes, but is not limited to: a GCR primary link or a GCR primary link set of the AP MLD, an association identifier (AID) that corresponds to the group address. In some embodiments, the AP MLD can transmit a GCR frame subject to the GCR-MLO agreement, where the GCR frame includes a sequence number assigned from sequence number space (SNS)_GCR_MLO defined at a MLD level, and generate a Group Temporal Key (GTK)_GCR_ML at the MLD level, where the GTK_GCR_ML enables encryption and decryption of the GCR frame.

Claims:
What is claimed is: 
     
       1. An access point (AP) multi-link device (MLD), comprising:
 a transceiver; and 
 a processor communicatively coupled to the transceiver, configured to:
 transmit, via the transceiver, an advertisement indicating an availability of a group cast with retries (GCR)-multi-link operation (MLO) service for a group address; 
 receive, via the transceiver, a GCR request comprising the group address associated with the GCR-MLO service, wherein the group address corresponds to a GCR-MLO group for which at least one member is not available on a common link during a GCR frame delivery time; and 
 transmit, via the transceiver, a GCR response comprising the group address, a GCR primary link set for which a plurality of GCR-MLO group members are available on at least one link within the GCR primary link set during a GCR frame transmission, and an association identifier (AID) corresponding to the group address. 
 
 
     
     
       2. The AP MLD of  claim 1 , wherein the GCR frame delivery time is based on a non-GCR-service period (SP). 
     
     
       3. The AP MLD of  claim 2 , wherein when the GCR frame delivery time is based on the non-GCR-SP, the GCR frame delivery time occurs after a delivery traffic indication message (DTIM) beacon. 
     
     
       4. The AP MLD of  claim 1 , wherein the processor is further configured to:
 assign the AID as an AID_ GcR  corresponding to a first GCR-MLO group; and 
 allocate a resource unit (RU) for transmission of a group addressed frame to the first GCR-MLO group identified by the AID_ GCR . 
 
     
     
       5. The AP MLD of  claim 1 , wherein the processor is further configured to:
 transmit, via the transceiver, an aggregate-Medium Access Control (MAC) Protocol Data Unit (A-MPDU) comprising an aggregated payload with aggregated GCR frames corresponding to two or more traffic identifiers (TIDs), wherein the two or more TIDs correspond to two or more concealment addresses. 
 
     
     
       6. The AP MLD of  claim 1 , wherein the GCR request is received from a first member of the group address via any link of the AP MLD, and wherein the GCR response is transmitted to the first member via any link of the AP MLD. 
     
     
       7. The AP MLD of  claim 6 , wherein the processor is further configured to:
 transmit, via the transceiver, a GCR frame corresponding to the group address via the GCR primary link set. 
 
     
     
       8. The AP MLD of  claim 1 , wherein the processor is further configured to:
 transmit, via the transceiver, a solicited or unsolicited GCR update signal comprising: an updated delivery time, an updated GCR primary link set, or an updated AID_ GCR . 
 
     
     
       9. The AP MLD of  claim 1 , wherein the AID is an AID_ GCR  corresponding to a first GCR-MLO group, and wherein a GCR-MLO retransmission policy comprises a block acknowledgement (BA), the processor is further configured to:
 transmit a group addressed data frame to the first GCR-MLO group; 
 transmit a GCR Multi-User (MU)-BA request (BAR) trigger frame comprising resource unit (RU) allocations for a first non-AP MLD GCR member and a second non-AP MLD GCR member of the first GCR-MLO group, subsequent to transmitting the group addressed data frame; and 
 receive a first BA frame from the first non-AP MLD GCR member and a second BA frame from the second non-AP MLD GCR member responsive to the GCR MU-BAR trigger frame. 
 
     
     
       10. The AP MLD of  claim 9 , wherein the first GCR-MLO group comprises a legacy single link device (SLD) GCR member that does not support GCR MU-BAR, the processor is configured to:
 transmit a single user (SU) BAR frame comprising an RU allocation for the legacy SLD GCR member; and 
 receive a third BA frame from the legacy SLD GCR member responsive to the SU BAR frame. 
 
     
     
       11. A non-access point (AP) multi-link device (MLD) station, comprising:
 a transceiver; and 
 a processor communicatively coupled to the transceiver, configured to:
 receive, via the transceiver, an advertisement indicating an availability of a group cast with retries (GCR)-multi-link operation (MLO) service for a group address, wherein the non-AP MLD station is a member of the group address; 
 transmit, via the transceiver, a GCR request comprising the group address associated with GCR-MLO service, wherein the group address corresponds to a GCR-MLO group for which at least one member is not available on a common link during a GCR frame delivery time; and 
 receive, via the transceiver, a GCR response comprising: the group address, a GCR primary link set for which a plurality of GCR-MLO group members are available on at least one link within the GCR primary link set during a GCR frame transmission, and an association identifier (AID) corresponding to the group address. 
 
 
     
     
       12. The non-AP MLD station of  claim 11 , wherein the processor is further configured to:
 transmit via the transceiver, a first value for a GCR operation parameter in the GCR request; 
 receive, via the transceiver, a second value for the GCR operation parameter in the GCR response, wherein the first value and the second value are different. 
 
     
     
       13. The non-AP MLD station of  claim 11 , wherein the processor is further configured to:
 receive, via the transceiver, a solicited or unsolicited GCR update signal comprising: an updated delivery time, an updated GCR primary link set, or an updated AID_ GCR . 
 
     
     
       14. A non-transitory computer-readable medium storing instructions that, when executed by a processor of a first electronic device, cause the first electronic device to perform operations for an access point (AP) multi-link device (MLD), the operations comprising:
 transmitting an advertisement indicating an availability of a group cast with retries (GCR)-multi-link operation (MLO) service for a group address; 
 receiving a GCR request comprising: the group address associated with GCR-MLO service, wherein the group address corresponds to a GCR-MLO group for which at least one member is not available on a common link during a GCR frame delivery time; and 
 transmitting a GCR response comprising: the group address, a GCR primary link set for which a plurality of GCR-MLO group members are available on at least one link within the GCR primary link set during a GCR frame transmission, and an association identifier (AID) corresponding to the group address. 
 
     
     
       15. The non-transitory computer-readable medium of  claim 14 , wherein when a GCR-MLO retransmission policy comprises unsolicited retry, the operations further comprise:
 determining a maximum number of retries of a GCR frame corresponding to the group address; and 
 transmitting retransmissions of the GCR frame corresponding to the maximum number of retries. 
 
     
     
       16. The non-transitory computer-readable medium of  claim 14 , wherein a GCR-MLO retransmission policy comprises a block acknowledgement (BA), the operations further comprise:
 determining that a first non-AP MLD operates on more than one link of the GCR primary link set; 
 determining a nominal link of the GCR primary link set on which to receive a GCR BA request (BAR); and 
 transmitting to the first non-AP MLD, the nominal link. 
 
     
     
       17. The non-transitory computer-readable medium of  claim 14 , wherein the operations further comprise:
 receiving from a first member of the group address, a first value for a GCR operation parameter in the GCR request; 
 based at least on the first value and input from another member of the group address, assigning a second value for the GCR operation parameter that is different than the first value; and 
 transmitting to the first member, the second value for the GCR operation parameter in the GCR response. 
 
     
     
       18. The non-transitory computer-readable medium of  claim 14 , wherein the operations further comprise:
 transmitting a GCR frame subject to a GCR-MLO agreement corresponding to the group address in a GCR-service period (SP), wherein the GCR frame comprises an indication enabling recipient stations to enter a doze state before a maximum duration of the GCR-SP. 
 
     
     
       19. The non-transitory computer-readable medium of  claim 14 , wherein the AID is an AID_ GCR  corresponding to a first GCR-MLO group, and wherein a GCR-MLO retransmission policy comprises a block acknowledgement (BA), the operations further comprise:
 transmitting a group addressed data frame to the first GCR-MLO group; 
 transmitting a GCR Multi-User (MU)-BA request (BAR) trigger frame comprising resource unit (RU) allocations for a first non-AP MLD GCR member and a second non-AP MLD GCR member of the first GCR-MLO group, subsequent to transmitting the group addressed data frame; and 
 receiving a first BA frame from the first non-AP MLD GCR member and a second BA frame from the second non-AP MLD GCR member responsive to the GCR MU-BAR trigger frame. 
 
     
     
       20. The non-transitory computer-readable medium of  claim 19 , wherein the first GCR-MLO group comprises a legacy single link device (SLD) GCR member that does not support GCR MU-BAR, the operations further comprise:
 transmitting a single user (SU) BAR frame comprising an RU allocation for the legacy SLD GCR member; and 
 receiving a third BA frame from the legacy SLD GCR member responsive to the SU BAR frame.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of U.S. Provisional Patent Application No. 63/224,797, filed on Jul. 22, 2021, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND 
     Field 
     The embodiments relate generally to wireless devices for transmitting group cast with retries (GCR) in a wireless communication system. 
     Related Art 
     Group cast with retries (GCR) is defined in IEEE P802.11REVme_D0.0, Draft Standard for Information technology—Telecommunications and information exchange between systems Local and metropolitan area networks—Specific requirements, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications “IEEE P802.11REVme” for single-link operation (SLO) to improve the reliability and/or to reduce the latency of the delivery of group addressed frames. 
     SUMMARY 
     Some embodiments include an apparatus, method, and computer program product for group cast with retries (GCR) for multi-link operation (MLO) in a multi-link system such as a Wireless LAN (WLAN) system. Some embodiments include an access point (AP) multi-link device (MLD) that obtains membership of a multicast group (e.g., obtains membership of a group address.) GCR service enables transmission and retransmission of medium access control (MAC) service data units (MSDUs) or aggregate MSDU (A-MSDU) to a destination that is a group address. GCR service increases reliability by enabling retransmissions where the retransmitted group address is concealed from GCR-incapable stations (e.g., legacy GCR-incapable stations.) GCR-MLO enables AP MLD and non-AP MLD to take advantage of multiple links of a MLD for retransmission of group addressed frames while maintaining backward compatibility with legacy devices (e.g., legacy GCR-incapable stations) as well as GCR-capable single link device (SLD) stations. 
     An AP MLD can establish a group cast with retries (GCR) agreement at the MLD level (e.g., modifying a Direct Multicast Service (DMS) Request/Response frame exchange) used by GCR-single link operation (SLO) to set up a GCR-MLO agreement; or other signaling method to exchange GCR-MLO parameters.) The AP MLD can operate in at least two modes: Mode 1 where all members of a GCR-MLO group are available on a common link, the GCR primary link, during GCR frame delivery time; and mode 2 where all members of a GCR-MLO group are not on available on a common link during GCR frame delivery time. Thus, mode 2 includes a GCR primary link set that includes two or more primary links over which GCR frames can be delivered to members of the GCR-MLO group. 
     In some embodiments, the AP MLD arranges a GCR-service period (SP) for low latency service where SPs are link specific. For example, the AP MLD can initiate a GCR-SP on a link and terminate the GCR-SP on the link before the scheduled duration of the GCR-SP ends. In addition, SPs (e.g., a target wake time (TWT) SP) can overlap with GCR-SPs. The AP MLD can communicate indications with members of a GCR-MLO group and/or stations corresponding with the overlapping TWT SP to terminate respective SPs individually or in combination with other SPs. 
     In some embodiments, the AP MLD can define a sequence number space (SNS) for GCR frames at the MLD level for sequence number assignment for GCR frames subjected to an GCR-MLO Unsolicited Retry policy, or GCR frames subjected to an GCR-MLO Block Ack retry policy. The AP MLD can perform duplicate GCR frame detection at the MLD level, and also discard duplicate GCR frames at the MLD level. The AP MLD can generate a group temporal key (GTK) for GCR-MLO at the MLD level for encryption/decryption of GCR frames. In addition, the AP MLD can perform GCR-MLO functions while enabling backward compatibility with: legacy GCR-SLO-capable STAs; GCR-MLO-capable non-AP MLDs; and/or legacy GCR-incapable STAs. When all members of a group address support GCR-MLO, the AP MLD can map one group address to one or more GCR sub-groups. 
     Some embodiments for GCR-MLO improve link-specific performance by including, but not limited to: assigning associated identifiers (AIDs) for GCR frame transmission; implementing multi-traffic identifier (TID) A-MAC protocol data unit (A-MPDU) aggregated payloads; and managing early termination for link-specific GCR-SPs including GCR-SPs that overlap with other SPs (e.g., TWT SPs). 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The accompanying drawings, which are incorporated herein and form part of the specification, illustrate the presented disclosure and, together with the description, further serve to explain the principles of the disclosure and enable a person of skill in the relevant art(s) to make and use the disclosure. 
         FIG.  1    illustrates an example system for group cast with retries (GCR) for multi-link operation (MLO), in accordance with some embodiments of the disclosure. 
         FIG.  2    illustrates a block diagram of an example wireless system supporting GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  3 A  illustrates an example system supporting GCR-MLO including a GCR primary link (mode 1), according to some embodiments of the disclosure. 
         FIG.  3 B  illustrates an example system supporting GCR-MLO including a GCR primary link set (mode 2), according to some embodiments of the disclosure. 
         FIG.  4 A  illustrates an example of GCR-MLO non-GCR-service period (SP) delivery time, according to some embodiments of the disclosure. 
         FIG.  4 B  illustrates an example of GCR-MLO GCR-SP delivery time, according to some embodiments of the disclosure. 
         FIG.  5    illustrates an example of Association Identifier (AID) assignment for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  6    illustrates an example method for GCR-MLO agreement setup and updates, according to some embodiments of the disclosure. 
         FIG.  7 A  illustrates an example of GCR Multi-User (MU) Block Acknowlegement Request (BAR) for early SP termination, according to some embodiments of the disclosure. 
         FIG.  7 B  illustrates another example of GCR MU BAR for early SP termination, according to some embodiments of the disclosure. 
         FIG.  8    illustrates an example of GCR-SP management for GCR-MLO with overlapping SPs, according to some embodiments of the disclosure. 
         FIG.  9 A  illustrates an example of GCR frame transmission for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  9 B  illustrates an example of a non-GCR frame format, according to some embodiments of the disclosure. 
         FIG.  10 A  illustrates an example of GCR-MLO Unsolicited Retry—mode 1, with a legacy non-GCR member, according to some embodiments of the disclosure. 
         FIG.  10 B  illustrates an example of GCR-MLO Unsolicited Retry—mode 2, with a legacy non-GCR member, according to some embodiments of the disclosure. 
         FIG.  11 A  illustrates an example of GCR-MLO Block Ack—mode 1, with a legacy single link device (SLD) GCR member, according to some embodiments of the disclosure. 
         FIG.  11 B  illustrates an example of GCR-MLO Block Ack—mode 2, with a legacy SLD GCR member, according to some embodiments of the disclosure. 
         FIG.  12    illustrates an example of a frame exchange with GCR multi-user (MU)-Block Ack Request (BAR) for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  13    illustrates an example of creating multiple GCR subgroups that correspond to one single group address, according to some embodiments of the disclosure. 
         FIG.  14    illustrates an example method for an access point (AP) multi-link device (MLD) for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  15    illustrates another example method for an AP MLD for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  16    illustrates an example method for a non-AP MLD for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  17    illustrates another example method for a non-AP MLD for GCR-MLO, according to some embodiments of the disclosure. 
         FIG.  18    is an example computer system for implementing some embodiments or portion(s) thereof. 
     
    
    
     The presented disclosure is described with reference to the accompanying drawings. In the drawings, generally, like reference numbers indicate identical or functionally similar elements. Additionally, generally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears. 
     DETAILED DESCRIPTION 
     Some multilink devices (MLD) such as an access point (AP) MLD can utilize one or more radios for communications over multiple links to a non-AP MLD station (e.g., an extremely high throughput (EHT) station (STA)). The multiple links can be multiple channels in a same frequency band or multiple channels in different frequency bands. Further, an AP MLD can use a radio of two or more radios to communicate with a legacy station over a link of the multiple links. 
       FIG.  1    illustrates example system  100  for group cast with retries (GCR) for multi-link operation (MLO), in accordance with some embodiments of the disclosure. System  100  includes AP MLD  110  that provides non-AP MLDs  120   a ,  120   b ,  120   c , legacy single link device (SLD) station  130 , and legacy non-GCR capable station  140  (e.g., not a multi-link device) with access to network  150 . Non-AP MLDs  120   a - 120   c , legacy SLD station  130 , and legacy non-GCR capable station  140  can be electronic devices that may include but are not limited to a cellular phone, a smart phone, a tablet, a personal digital assistant (PDA), or a laptop. Network  150  may include but is not limited to, any of or any combination of local area networks (LANs), metropolitan area networks (MANs), wireless local area networks (WLANs), and/or the Internet. Non-AP MLDs  120   a - 120   c , legacy SLD station  130 , and legacy non-GCR capable station  140  in proximity to AP MLD  110  may associate with AP MLD  110 . In some embodiments, AP MLD  110  obtains membership of a multicast group corresponding to a group address. GCR service enables transmission and retransmission of medium access control (MAC) service data units (MSDUs) or aggregate MSDUs (A-MSDUs) to a destination that is the group address. GCR service increases reliability by enabling retransmissions where the retransmitted group address is concealed from GCR-incapable stations (e.g., legacy non-GCR capable station  140 .) In some embodiments, AP MLD  110  and non-AP MLD stations  120   a - 120   c  can perform GCR-MLO to take advantage of multiple links of a MLD for retransmission of group addresses while maintaining backward compatibility with legacy devices (e.g., legacy non-GCR capable station  140 ) as well as GCR-capable SLD stations (e.g., legacy SLD station  130 .) 
       FIG.  2    illustrates a block diagram of example wireless system  200  supporting GCR-MLO, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  2    may be described with reference to elements from  FIG.  1   . For example, system  200  may be any of the electronic devices (e.g., AP MLD  110 , non-AP MLDs  120   a ,  120   b ,  120   c , legacy SLD station  130 , and legacy non-GCR capable station  140 ) of system  100 . System  200  includes one or more processors  265 , transceiver(s)  270 , communication interface  275 , communication infrastructure  280 , memory  285 , and antenna  290 . Memory  285  may include random access memory (RAM) and/or cache, and may include control logic (e.g., computer instructions) and/or data. One or more processors  265  can execute the instructions stored in memory  285  to perform operations enabling wireless system  200  to transmit and receive wireless communications, including the operations for performing GCR-MLO functions herein. In some embodiments, one or more processors  265  can be “hard coded” to perform the functions herein. Transceiver(s)  270  transmits and receives wireless communications signals including wireless communications supporting GCR-MLO according to some embodiments, and may be coupled to one or more antennas  290  (e.g.,  290   a ,  290   b ). In some embodiments, a transceiver  270   a  (not shown) may be coupled to antenna  290   a  and different transceiver  270   b  (not shown) can be coupled to antenna  290   b . Communication interface  275  allows system  200  to communicate with other devices that may be wired and/or wireless. Communication infrastructure  280  may be a bus. Antenna  290  may include one or more antennas that may be the same or different types. 
       FIG.  3 A  illustrates example system  300  supporting GCR-MLO including a GCR primary link (mode 1), according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  3    may be described with reference to elements from  FIGS.  1  and  2   . For example, AP MLD  310  can correspond to AP MLD  110  of  FIG.  1   , and non-AP MLD A  320   a , non-AP MLD B  320   b , and non-AP MLD C  320   c  can correspond to non-AP MLD  120   a ,  120   b ,  120   c  of  FIG.  1   . 
     AP MLD  310  can include multiple APs, each identified by a specific link. For example, AP1  313  can communicate via 2.4 GHz identified by link1  391 ; AP2  315  can communicate via 5 GHz identified by link2  395 , and AP3  317  can communicate via 6 GHz identified by link3  397 . In system  300 , AP1  313 , AP2  315 , and AP3  317  may each have a radio transceiver that operates independently from the other radio transceivers. AP MLD  310  can utilize one or more radios (e.g.,  3  transceivers) to communicate over multiple links (e.g., over one or more frequency bands) to non-AP MLD A  320   a . For example, AP MLD  310  can utilize transceivers of AP1  313 , AP2  315 , and/or AP3  317  to communicate with non-AP MLD A  320   a  via link1  391 , link2  395 , and/or link3  397 . AP MLD  310  can utilize transceivers of AP1  313  and/or AP2  315  to communicate with non-AP MLD B  320   b  via link1  391  and/or link2  395 . AP MLD  310  can utilize the transceiver of AP1  313  to communicate with non-AP MLD C  320   c  via link1  391 . 
     Non-AP MLD A  320   a  can scan and identify AP MLD  310  across all three links. After associating with AP MLD  310 , non-AP MLD A  320   a  can communicate via any of the links link1  391 , link2  395 , and/or link3  397  that are available in, for example, three different frequency bands, e.g., 2.4 GHz, 5 GHz, and 6 GHz. If one link is busy, non-AP MLD A  320   a  or AP MLD  310  selects another link that is first available. 
     AP MLD  310  can operate in GCR-MLO with at least the following retransmission policies: unsolicited retry and block acknowledgement (BA). GCR frames transmitted in GCR-MLO utilize sequence numbers of a sequence number space (SNS) that is determined at the MLD level including but not limited to: SNS_GCR-MLO_Unsolicited Retry  360  and SNS_GCR-MLO-BlockAck  365 . When SNS_GCR-MLO_Unsolicited Retry  360  is implemented, sequence numbers generated at the MLD level and other parameters (e.g., group address (e.g., a group address corresponding to a GCR-MLO agreement and/or a GCR-MLO group), concealment address) in GCR frames can be used to detect duplicate GCR frames. The detection can be performed at the MLD level, and any duplicate GCR frame detected is discarded at the MLD level. In some embodiments, SNS_GCR-MLO_Unsolicited Retry may be the same as the general SNS that is used to deliver the group addressed frames delivery that are not subject to a GCR agreement. When SNS_GCR-MLO-BlockAck  365  is implemented, sequence numbers generated at the MLD level and other parameters (e.g., group address, concealment address, and/or traffic identifier (TID) in GCR frames can be used to detect duplicate GCR frames. The detection can be performed at the MLD level, and any duplicate GCR frame detected is discarded at the MLD level. 
     In some embodiments, when a GCR-MLO retry policy type transitions between Unsolicited Retry and Block Ack, AP MLD  310  transmits to a non-AP MLD (e.g., non-AP MLD A  320   a ) the last sequence number of the MPDU corresponding to the GCR traffic flow that is being updated that was delivered prior to the GCR-MLO retry policy transition, to facilitate detection of any duplicate GCR frame caused by the GCR-MLO retry policy transition. 
     In some embodiments, SNS_GCR_MLO_Unsolicited Retry  360  allows multiplicity and is indexed by &lt;address 1&gt;. In some embodiments, SNS_GCR-MLO_BlockAck allows multiplicity and is indexed by &lt;address 1, TID&gt;. For example, when SNS_GCR-MLO_BlockAck is implemented the BlockAck can be specific to the GCR address as well as to the TID. In some embodiments, the BlockAck can be agnostic to the TID. In some embodiments, SNS_GCR_MLO_BlockAck can be merged with SNS2 in that is currently defined in IEEE P802.11REVme. For example, a modified SNS2 of IEEE P802.11REVme can be used by both unicast QoS (data) and GCR Block Ack frames, and the modified SNS2 can allow multiplicity, indexed by &lt;address 1, TID&gt;. 
     In addition, AP MLD  310  can generate group temporal keys (GTK) at the MLD level (e.g., GTK_GCR-multi-link (ML)  370 ) to encrypt and decrypt GCR frames at the MLD level as described below in Table 1. GCR-MLO Security. The corresponding replay attack detection/PN (packet number) check can be performed at the MLD level as well. To deliver a group addressed data frame that is not subject to a GCR agreement, GTK_link_i can be used for communication on link_i where i is an integer greater than zero. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 GCR-MLO Security 
               
            
           
           
               
               
               
               
            
               
                   
                   
                   
                 Group Key  
               
               
                 Example 
                 GTK_link_i 
                 GTK GCR-ML 
                 Generation Method 
               
               
                   
               
               
                 1. 
                 GTK-ML is 
                 GTK_GCR-ML = 
                 GTK-ML is generated 
               
               
                   
                 generated at the 
                 GTK-ML = 
                 using the method in 
               
               
                   
                 MLD level; 
                 GTK_link_i, for  
                 12.7.1.4 [IEEE 
               
               
                   
                 GTK_link_i = 
                 all i 
                 P802.11REVme], where 
               
               
                   
                 GTK-ML, for all i 
                   
                 AA = AP MLD’s MAC 
               
               
                   
                   
                   
                 address 
               
               
                 2. 
                 GTK-ML is 
                 GTK_GCR-ML = 
                 GTK-ML is generated 
               
               
                   
                 generated at the 
                 GTK-ML 
                 using the method in 
               
               
                   
                 MLD level; 
                   
                 12.7.1.4 [IEEE 
               
               
                   
                 GTK_link_i = 
                   
                 P802.11REVme], where 
               
               
                   
                 GTK-ML or a 
                   
                 AA = AP MLD’s MAC 
               
               
                   
                 truncated version  
                   
                 address 
               
               
                   
                 of GTK-ML 
                   
                   
               
               
                 3. 
                 GTK_link_i is 
                 GTK_GCR-ML is 
                 GTK_link_i is 
               
               
                   
                 independent on  
                 independent of 
                 generated using the 
               
               
                   
                 each link i 
                 GTK_link_i 
                 method in 12.7.1.4 
               
               
                   
                   
                   
                 [IEEE P802.11REVme], 
               
               
                   
                   
                   
                 where AA = AP_i’s 
               
               
                   
                   
                   
                 MAC address 
               
               
                   
                   
                   
                 GTK-GCR-ML is 
               
               
                   
                   
                   
                 generated using the 
               
               
                   
                   
                   
                 method in 12.7.1.4 
               
               
                   
                   
                   
                 [IEEE P802.11REVme], 
               
               
                   
                   
                   
                 where AA = AP MLD’s 
               
               
                   
                   
                   
                 MAC address, and 
               
               
                   
                   
                   
                 GTK-GCR-ML, instead 
               
               
                   
                   
                   
                 of GTK, is generated. 
               
               
                   
               
            
           
         
       
     
     In examples 1, 2 and 3 in the table above, GTK_link_i is the group key used for the delivery of group addressed data frames that are not subjected to a GCR agreement (e.g., non-GCR group addressed frames) on link i. GTK_GCR-ML is the group key used for the delivery of group addressed frames that are subject to a GCR agreement on all links. 
     Example 1 in the table above illustrates that the GTK-multi-link (ML) is generated at the MLD level, and the GTK for each link i, is equal to the GTK-ML for all links, i. For example, the GTK-ML generated at the MLD level is shown as GTK_GCR-ML  370  in system  300 . The GTK_link_1 (e.g., Link1  391 ) used by AP1  313  can be GTK_GCR-ML  373  (which is identical to GTK_GCR-ML  370 ). Thus, GTK_GCR-ML  370  can be used to encrypt and decrypt GCR frames that are transmitted and received. AP2  315  can use GTK_GCR-ML  375  (which is identical to GTK_GCR-ML  370 ) to encrypt and decrypt GCR frames that are transmitted and received. AP3  317  can use GTK_GCR-ML  377  (which can be identical to GTK_GCR-ML  370 ) to encrypt and decrypt GCR frames that are transmitted and received. 
     Example 2 illustrates that the GTK-ML is generated at the MLD level, and the GTK for each link i, is equal to the GTK-ML or a truncated version of GTK-ML for all links, i. For example, each GTK_link_i, for all i, is either identical to or a truncated version of GTK-ML. The GTK-ML generated at the MLD level is shown as GTK_GCR-ML  370  in system  300 . The GTK_link_1 (e.g., link1  391 ) used by AP1  313  can be identical to or a truncated version of GTK_GCR-ML  373  (which is identical to GTK_GCR-ML  370 ). Thus, GTK_GCR-ML  370  or a truncated version of GTK_GCR-ML  370  can be used to encrypt and decrypt group addressed frames that are not subject to a GCR agreement and are transmitted and received on link1  391 . Similarly, the GTK link_2 (e.g., link2  395 ) used by AP2  315  can be identical to or a truncated version of GTK_GCR-ML  375  (which is identical GTK_GCR-ML  370 ). Thus, GTK_GCR-ML  370  or a truncated version of GTK_GCR-ML  370  can be used to encrypt and decrypt GCR group addressed frames that are not subject to a GCR agreement and are transmitted and received on link2  395 . The GTK_link_3 (e.g., link3  397 ) used by AP3  317  can be identical to or a truncated version of GTK_GCR-ML  375  (which is identical GTK_GCR-ML  370 ). Thus, GTK_GCR-ML  370  or a truncated version of GTK_GCR-ML  370  can be used to encrypt and decrypt GCR group addressed frames that are not subject to a GCR agreement and are transmitted and received on link3  397 . AP1  313  can use GTK_GCR-ML  373  (which is identical to GTK_GCR-ML  370 ) to encrypt and decrypt GCR frames that are transmitted and received on link1  315 . AP2  315  can use GTK_GCR-ML  375  (which is identical to GTK_GCR-ML  370 ) to encrypt and decrypt GCR frames that are transmitted and received on link2  395 . AP3  317  can use GTK_GCR-ML  377  (which can be identical to GTK_GCR-ML  370 ) to encrypt and decrypt GCR frames that are transmitted and received on link3  397 . 
     Example 3 illustrates that the GTK for links i are independent and is generated at each AP level instead of the MLD level. For group addressed frames not subject to a GCR-MLO agreement (e.g., non-GCR group addressed frames), AP1  313  can use a link-specific GTK (e.g., GTK_1  383 ) independent of GTK_GCR-ML  370  generated at the MLD level, to encrypt and decrypt group addressed frames that are not subject to a GCR agreement and are transmitted and received on link1  391 . AP2  315  can use a link-specific GTK (e.g., GTK_2  385 ), independent of GTK_GCR-ML  370  generated at the MLD level to encrypt and decrypt group addressed frames that are not subjected to a GCR agreement and are transmitted and received on link2  395 . AP3  317  can use a link-specific GTK (e.g., GTK_3  387 ), independent of GTK_GCR-ML  370  generated at the MLD level, to encrypt and decrypt group addressed frames that are not subject to a GCR agreement and are transmitted and received on link3  397 . 
     AP MLD  310  can operate in at least two modes: Mode 1 with a GCR primary link, and mode 2 with a GCR primary link set, where a GCR primary link or GCR primary link set is where the initial GCR frame transmission occurs. Retransmitted GCR frames can occur either on a GCR primary link, GCR primary link sets, or non-primary links. Assume that a GCR-MLO group includes non-AP MLD A  320   a , non-AP MLD B  320   b , and non-AP MLD C  320   c  that are each subject to a GCR-MLO agreement with AP MLD  310 . When all members of the GCR-MLO group are available on a common link (e.g., link1  391 ) during a GCR frame delivery time, AP MLD  310  can assign link1  391  as the GCR primary link. Thus, non-AP MLD B  320   b , and non-AP MLD C  320   c  can receive an initial GCR frame transmitted via link1  391 , the GCR primary link, during a GCR frame delivery time, and retransmitted GCR frames via primary link1  391  or non-primary link2  395  or non-primary link3  397 . Non-AP MLD A  320   a , non-AP MLD B  320   b , and non-AP MLD C  320   c  all can detect and discard a duplicate GCR frame received on any or all links at the MLD level. 
       FIG.  3 B  illustrates example system  350  supporting GCR-MLO including a GCR primary link set (mode 2), according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  3    may be described with elements from  FIGS.  1 ,  2 , and  3 A . For example, AP MLD  310  can correspond to AP MLD  110  of  FIG.  1   , and descriptions with the same labels as system  300  are not repeated here. Non-AP MLD A  322 , non-AP MLD B  324 , and non-AP MLD C  326  can correspond to non-AP MLD  120   a ,  120   b ,  120   c  of  FIG.  1   . 
     Assume that a GCR-MLO group includes non-AP MLD A  322 , non-AP MLD B  324 , and non-AP MLD C  326  that are each subject to a GCR-MLO agreement with AP MLD  310 . In system  350 , for example, members of the GCR-MLO group are not available on a common link. For example, only non-AP MLD A  322  can communicate via link1  393 . Since all members of the GCR-MLO group are not available on a common link during a GCR frame delivery time, AP MLD  310  can assign one or more links (e.g., link2  395  and link3  397 ) as primary links of the GCR primary link set  390 . Thus, during a GCR frame delivery time, non-AP MLD A  322  and/or non-AP MLD B  324  can receive an initial GCR frame transmitted from AP MLD  310  via link2  395 , while non-AP MLD C  326  and/or non-AP MLD B  324  can receive an initial GCR frame transmitted from AP MLD  310  via link3  397 , and non-AP MLD A  322  can receive retransmitted GCR frames on link1  393  or link2  395 , non-AP MLD B  324  can receive retransmitted GCR frames on link2  395  or link3  397 , non-AP MLD C  326  can receive retransmitted GCR on link3  397 . Non-AP MLD A  322 , non-AP MLD B  324 , and non-AP MLD C  326  all can detect and discard a duplicate GCR frame at the MLD level. 
     Referring back to  FIG.  1   , AP MLD  110  can obtain membership of a multicast group corresponding to a group address. For example, AP MLD  110  can transmit a Group membership Request frame to request the content of the dot11GroupAddressTable of the associated stations per IEEE 802.11 methods, or utilize another method outside of IEEE 802.11. AP MLD  110  can establish a GCR-MLO agreement at the MLD level. A non-AP MLD (e.g., non-AP MLD  120   a  can transmit or receive frames to establish or update a GCR-MLO agreement on any link (e.g., link2  395  or link3  397  of  FIGS.  3 A and  3 B .) After the GCR-MLO agreement is established, the GCR frames can be delivered on links (e.g., link1  391 ) that may not be the same link used to establish the GCR-MLO agreement. If a GCR-MLO group contains members that are pre-EHT legacy devices that support single-link operation (e.g., legacy SLD station  130 ), the GCR primary link (as in mode 1) or one link of the GCR primary link set (as in mode 2) needs to be the same link where the pre-11be legacy device that support single-link operation operates. 
     AP MLD  110  can exchange information with each member of the multicast group that supports GCR-MLO to setup and/or update GCR-MLO agreements. A multicast group that includes one or more non-AP MLD members (e.g., non-AP MLD  120   a - 120   c ) that establish a GCR-MLO agreement with an AP MLD (e.g., AP MLD  110 ) can be called a GCR-MLO group, and the corresponding group address can be called a GCR group address. The GCR-MLO group can include legacy stations that are GCR-incapable (e.g., legacy non-GCR station  140 ). For example, legacy non-GCR station  140  can receive the group addressed frames that are not retransmitted (e.g., no-Ack/No-retry transmission of the group addressed frames), but does not support GCR (e.g., group recast with retries). When the group addressed frame is to be retransmitted per the GCR-MLO agreement, AP MLD  110  can conceal the group address from legacy stations (e.g., by assigning and containing a concealment address in an aggregate medium access control (MAC) service data unit (A-MSDU) frame). See  FIG.  9 A  below. 
       FIG.  6    illustrates example method  600  for GCR-MLO agreement setup and updates, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  6    may be described with reference to elements from other figures within the disclosure. For example, AP MLD  610  can correspond to AP MLD  110  of  FIG.  1   , and non-AP MLD  620  can correspond to non-AP MLD  120   a ,  120   b ,  120   c  of  FIG.  1   . The information exchanged between AP MLD  610  and non-AP MLD  620  is shown below in Table 2. GCR-MLO Agreement Setup &amp; Updates. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 GCR-MLO Agreement Setup &amp; Updates 
               
            
           
           
               
               
               
               
            
               
                 Exemplary 
                   
                   
                   
               
               
                 Frame 
                 Transmitter 
                 Purpose 
                 Exemplary Frame Content 
               
               
                   
               
               
                 GCR 
                 AP MLD 
                 Advertise the 
                 Group address, delivery time (e.g., 
               
               
                 Advertisement 
                   
                 availability of 
                 non-GCR-SP or GCR-SP info), 
               
               
                   
                   
                 GCR service for 
                 retry method (e.g., unsolicited retry 
               
               
                   
                   
                 a group address 
                 or BA), GCR primary link or GCR 
               
               
                   
                   
                   
                 primary link set 
               
               
                 GCR Request 
                 Non-AP 
                 Request to use 
                 Group address, requested delivery 
               
               
                   
                 MLD 
                 GCR-MLO 
                 time (e.g., non-GCR-SP or GCR- 
               
               
                   
                   
                 service for a 
                 SP), retry method (e.g., unsolicited 
               
               
                   
                   
                 group address 
                 retry or BA), GCR primary link or 
               
               
                   
                   
                   
                 GCR primary link set 
               
               
                 GCR 
                 AP MLD 
                 Response to a 
                 Group address, concealment 
               
               
                 Response 
                   
                 GCR request 
                 address, assigned delivery time 
               
               
                   
                   
                 with assigned 
                 (e.g., non-GCR-SP or GCR-SP), 
               
               
                   
                   
                 GCR-MLO 
                 retry method (e.g., unsolicited retry 
               
               
                   
                   
                 operation 
                 or BA), SP details if GCR-SP, GCR 
               
               
                   
                   
                 parameters 
                 primary link or GCR primary link 
               
               
                   
                   
                   
                 set, AID_ GCR   
               
               
                 GCR update 
                 Non-AP 
                 Request to 
                 Group address, requested updated 
               
               
                 request 
                 MLD 
                 change in GCR 
                 delivery time (e.g., non-GCR-SP or 
               
               
                   
                   
                 operation 
                 GCR-SP info.), retry method (e.g., 
               
               
                   
                   
                 parameters 
                 unsolicited retry or BA), GCR 
               
               
                   
                   
                   
                 primary link or GCR primary link 
               
               
                   
                   
                   
                 set 
               
               
                 GCR update 
                 AP MLD 
                 GCR operation 
                 Group address, concealment 
               
               
                 (solicited or 
                   
                 parameter 
                 address, assigned updated delivery 
               
               
                 unsolicited) 
                   
                 updates, either as 
                 time (e.g., non-GCR-SP or GCR-SP 
               
               
                   
                   
                 a response to an 
                 info.), retry method (e.g., 
               
               
                   
                   
                 update request 
                 unsolicited retry or BA), SP details 
               
               
                   
                   
                 and transmitted 
                 if GCR-SP, GCR primary link or 
               
               
                   
                   
                 unsolicited 
                 GCR primary link set, AID_ GCR   
               
               
                   
               
            
           
         
       
     
     At  630 , AP MLD  610  transmits a GCR Advertisement that is received by non-AP MLD  620 . The GCR Advertisement advertises the availability of GCR service for a group address. The GCR Advertisement can include but is not limited to: Group address, delivery time (e.g., non-GCR-service (SP) or GCR-SP information), retry method (e.g., unsolicited retry or block acknowledgement (BA)), GCR primary link (mode 1) or GCR primary link set (mode 2). 
     At  635 , non-AP MLD  620  transmits a GCR Request that can be received by AP MLD  110 . The GCR Request requests GCR-MLO service for the group address. The GCR Request can include but is not limited to: Group address, requested delivery time (e.g., non-GCR-SP or GCR-SP), retry method (e.g., unsolicited retry or BA), and/or GCR primary link or GCR primary link set. 
     At  640 , AP MLD  610  transmits a GCR Response that can be received by non-AP MLD  620 . The GCR Response informs non-AP MLD  620  of the GCR-MLO operation parameters that AP MLD  610  has selected. The GCR-MLO operation parameters may be different than the information that non-AP MLD  620  included in the GCR Request. The GCR Response can include but is not limited to: Group address, concealment address, assigned delivery time (e.g., non-GCR-SP or GCR-SP), retry method (e.g., unsolicited retry or BA), SP details if GCR-SP, GCR primary link or GCR primary link set, and/or an association identifier (AID) for GCR, AID_ GCR . 
     An AP MLD can use one or more of the currently reserved AID values to assign an AID to be used for a GCR frame transmission in a DL MU PPDU. The AID assignment types are described in Table 3. AID Assignment Types below. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 AID Assignment Types 
               
            
           
           
               
               
               
            
               
                   
                 AID 
                   
               
               
                   
                 assignment 
                   
               
               
                 Option 
                 type 
                 Description 
               
               
                   
               
               
                 1 
                 GCR group 
                 AP MLD assigns an AID for a specific  
               
               
                   
                 specific AID 
                 GCR group with the corresponding group  
               
               
                   
                 assignment 
                 address, called “AID_ GCR ”, and transmit  
               
               
                   
                   
                 such an AID_ GCR  in a GCR Response frame  
               
               
                   
                   
                 during the GCR-MLO agreement setup.  
               
               
                   
                   
                 The RU allocation for this AID_ GCR    
               
               
                   
                   
                 in a DL MU PPDU is only used for  
               
               
                   
                   
                 the transmission of GCR frames with a 
               
               
                   
                   
                 particular group address, which is in turn  
               
               
                   
                   
                 associated with this AID_ GCR . 
               
               
                 2 
                 Common AID 
                 An AID (e.g., specified in the IEEE  
               
               
                   
                 for all GCR 
                 802.11be spec) where the RU allocation  
               
               
                   
                 groups 
                 for this AID is used for GCR frame  
               
               
                   
                   
                 transmission for all GCR groups. 
               
               
                   
               
            
           
         
       
     
     In option 1, the AID_ GCR  corresponds to a specific GCR-MLO group. For example, AP MLD  610  can assign an AID for a specific GCR-MLO group corresponding to the group address. AP MLD  610  can transmit the AID_ GCR  in GCR Response  640  during method  600  for GCR-MLO agreement setup and updates. AIDs are used to assign Resource Units (RUs) to receivers in RU allocations. The RU allocation corresponding to a particular AID_ GCR  in a downlink (DL) multi-user (MU) Physical Layer Convergence Protocol (PLCP) protocol data unit (PPDU) corresponds to the respective group address corresponding to the particular AID_ GCR . Thus, the RU allocation corresponding to the particular AID_ GCR  is used only for the transmission of a GCR frame corresponding to the respective group address. The designated RU for a particular GCR group (option 1) facilitates the GCR frame delivery corresponding to the GCR group when there are a large number of group addressed frames in the network. 
       FIG.  5    illustrates example  500  of AID assignment for GCR-MLO, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  5    may be described with reference to elements from other figures within the disclosure. For example, AP MLD  610  can assign a first AID_ GCR  for a first GCR-MLO group corresponding to GCR group address #1, and a second AID_ GCR  for a second GCR-MLO group corresponding to GCR group address #2. GCR group address #1 can be a first group address subject to a first GCR-MLO agreement and GCR group address #2 can be a second group address subject to a second GCR-MLO agreement. 
     AP MLD  610  can transmit an MU PPDU that is received by a non-AP MLD (e.g., non-AP MLD  620 ). For example, non-AP MLD  620  can receive the following in one MU PPDU: i) 2 RUs corrresponding to AID_ GCR  assignments: e.g., RU #1  530  for GCR_ AID1  &amp; RU #2  535  for GCR AID2; ii) one RU corresponding to one AID_ GCR  assignment and one RU of an individually addressed data frame: e.g., RU #2  535  for GCR_ AID2  and RU #3  540  for individual addressed data; or iii) 2 RUs of individually addressed data frames: e.g., RU #4  545  and RU #3  540 . 
     In option 2, the AID is common for all GCR groups. Thus, the AID_ GCR  may be common to any and all GCR groups. 
     Returning to  FIG.  6   , at  645 , non-AP MLD  620  can transmit a GCR Update Request that can be received by AP MLD  610 . The GCR Update Request can request a change in GCR operation parameters. The GCR Update Request can include but is not limited to: Group address, requested updated delivery time (e.g., non-GCR-SP or GCR-SP information), retry method (e.g., unsolicited retry or BA), and/or GCR primary link or GCR primary link set. 
     At  650 , AP MLD  610  can transmit a GCR Update/Advertisement that can be solicited (e.g., in response to the received GCR Update Request  645 ) or unsolicited (e.g., based on changes in AP MLD  610  resources.) The GCR Update/Advertisement can be received by non-AP MLD  620  and can include but is not limited to: Group address, concealment address, assigned updated delivery time (e.g., non-GCR-SP or GCR-SP information), retry method (e.g., unsolicited retry or BA), SP details if GCR-SP, GCR primary link (mode 1) or GCR primary link set (mode 2), and/or AID_ GCR . 
     In some embodiments, method  600  can be performed by re-using and modifying a Direct Multicast Service (DMS) Request/Response frame exchanged used by GCR-single link operation (SLO) to set up a GCR-MLD agreement. For example, some embodiments include modifying Table 9-230 of IEEE P802.11REVme_D0.0 for the DMS Descriptor. AP MLD  610  can use one of the reserved subelement IDs (e.g., reserved value “2”) defined to be a “GCR-MLO Request” to contain GCR operation parameters that are only applicable to multi-link operation in GCR Request  635 . In addition, some embodiments include using the existing “subelement ID=1” to carry operation parameters pertinent to both single-link operation and multi-link operation. 
     Some embodiments include modifying Table 9-234 of IEEE P802.11REVme_D0.0 for the DMS Status. AP MLD  610  can use one of the reserved subelement IDs (e.g., reserved value “2”) defined to be a “GCR-MLO Response” to contain GCR operation parameters that are only applicable to multi-link operation in GCR Response  640 . Some embodiments include using the existing “subelement ID=1” to carry operation parameters pertinent to both single-link and multi-link operation, including the SP description in the “Schedule Element” field of the “GCR Response” subelement (as shown in FIG. 9-480 of IEEE P802.11REVme_D0.0.) 
     A GCR-MLO agreement established between AP MLD  610  and non-AP MLD can include a combination of delivery methods and retransmission (ReTx) policies as shown below in Table 4. GCR-MLO Agreement Types. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 GCR-MLO Agreement Types 
               
            
           
           
               
               
            
               
                   
                 ReTx policy 
               
            
           
           
               
               
               
            
               
                   
                 GCR-MLO 
                   
               
               
                   
                 unsolicited 
                 GCR-MLO 
               
               
                 Delivery method 
                 retry 
                 block ack 
               
               
                   
               
               
                 non-GCR-SP 
                 Type 1 
                 Type 2 
               
               
                 (GCR frames delivered after No-Ack/No- 
                   
                   
               
               
                 Retry group addressed frames after DTIM 
                   
                   
               
               
                 beacons) 
                   
                   
               
               
                 GCR-SP 
                 Type 3 
                 Type 4 
               
               
                 (GCR frames delivered at scheduled time) 
               
               
                   
               
            
           
         
       
     
     Only one of the four types of GCR-MLO agreement types is active at a time for frames subject to one group address. Two types of retransmission policies include GCR-MLO unsolicited retry and GCR-MLO block acknowledgement (BA). When GCR-MLO unsolicited retry is implemented, AP MLD  610  can determine a number of retries for a GCR frame. When GCR-MLO BA is implemented, AP MLD  610  can send a BA Request (BAR) to non-AP MLD  620  to obtain a BA from non-AP MLD  620 . AP MLD  610  can determine whether to retransmit a GCR frame based on the received BA. 
       FIG.  4 A  illustrates example  400  of GCR-MLO non-GCR-service period (SP) delivery time, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  4 A  may be described with reference to elements from other figures in the disclosure. For example, AP MLD  310  of  FIG.  3    can transmit Delivery Traffic Indication Message (DTIM) Beacon1  412  immediately before the non-GCR-SP delivery time  414 . Further, Link1  410  and Link2 can correspond to Link2  395  and Link3  397  of GCR primary link set  390  of  FIG.  3 B . 
     Example  400  illustrates a non-GCR-SP delivery method. AP MLD  310  can transmit DTIM Beacon1  412  on Link1  410  followed (e.g., immediately followed) by non-GCR-SP delivery time  414 . Within non-GCR-SP delivery time  414 , No-Ack/No-Retry group addressed frames are transmitted followed by any GCR frame transmissions. After DTIM Beacon2  416  is transmitted, non-GCR-SP delivery time  418  begins. Any No-Ack/No-Retry group addressed frames are delivered followed by any GCR frame transmissions. Note that the GCR frames, as well as a number of retries of the respective GCR frames may be different in each of the non-GCR-SP delivery times  414  and  418 . A similar process occurs on Link2 of example  400 . In some embodiments, for agreement type 2 of Table 4. GCR-MLO Agreement Types above, non-GCR-SP with GCR-MLO BA, if all members of a GCR BA are awake (e.g., not asleep or in power save mode) at any particular time, AP MLD  310  can transmit GCR frames immediately, without waiting for the DTIM beacon. 
       FIG.  4 B  illustrates example  450  of GCR-MLO GCR-SP delivery time, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  4 B  may be described with elements from other figures in the disclosure. For example, AP MLD  310  of  FIG.  3    can transmit Beacon1  472  and use scheduled GCR-SPs  474   a - 474   e . Further, Link1  470  and Link2 can correspond to Link2  395  and Link3  397  of GCR primary link set  390  of  FIG.  3 B . Example  450  illustrates a GCR-SP delivery method where AP MLD  310  can deliver GCR frames within scheduled service periods (SP). 
     For example, AP MLD  310  can transmit Beacon1  472  on Link1  470  and transmit GCR frames within the scheduled GCR-SPs  474   a - 474   e . Similarly, AP MLD  310  can transmit Beacon2  476  and subsequently transmit one or more GCR frames within scheduled GCR-SP  478   a  and so on. The GCR frames can be different in each of the GCR SPs  474   a - 474   e  and  478   a . A similar process occurs on Link2 of example  450 . 
     GCR operation parameters described in Table 2. GCR-MLO Agreement Setup &amp; Updates can be further described in Table 5. GCR Operation Parameters below. The inclusion of a single GCR primary link information indicates the operation is in mode 1, and the inclusion of a GCR primary link set indicates the operation is in mode 2 as described with regard to  FIGS.  3 A and  3 B . In some embodiments, the GCR operation parameters assigned by AP MLD  610  in a GCR-Response/Update/Advertisement frame (e.g.,  640 ,  650 ,  630  of  FIG.  6   ) may not be the same as the parameters requested by a particular station (e.g., non-AP MLD  620  in GCR Request  635  of  FIG.  6   .) AP MLD  610  chooses the operations parameters based at least on inputs received from members of a GCR-MLO group and AP MLD  610 &#39;s resource limitations. For example, AP MLD  610  may receive a GCR Request  635  from non-AP MLD  620  requesting a GCR-SP duration of 5 msec. AP MLD  610  may also receive another GCR Request (not shown) from another non-AP MLD requesting a GCR-SP duration of 3 msec. Based on the GCR Requests received as well as AP MLD  610 &#39;s resources, AP MLD  610  may set the GCR-SP duration to be 5 msec. 
     
       
         
           
               
             
               
                 TABLE 5 
               
             
            
               
                   
               
               
                 GCR Operation Parameters 
               
            
           
           
               
               
               
            
               
                 GCR  
                   
                 Method/Mode- 
               
               
                 Method/Mode 
                 Common Parameters 
                 Specific Parameters 
               
               
                   
               
               
                 GCR-MLO  
                 Concealment address 
                 GCR primary link 
               
               
                 Unsolicited 
                 Delivery time 
                 max number of retry 
               
               
                 Retry/Mode 1 
                 If GCR-SP is used, the 
                   
               
               
                 GCR-MLO  
                 specific information on  
                 GCR primary link set 
               
               
                 Unsolicited 
                 the SPs (e.g., start time 
                 max number of retry 
               
               
                 Retry/Mode 2 
                 expressed by TSF or offset 
                   
               
               
                 GCR-MLO Block  
                 to Beacon Transmit Time 
                 GCR primary link 
               
               
                 Ack/Mode 1 
                 or other methods, duration, 
                   
               
               
                 GCR-MLO Block  
                 cadence) 
                 GCR primary link set 
               
               
                 Ack/Mode 2 
                 If GCR-SP is used, 
                 the nominal link to 
               
               
                   
                 whether non-AP MLD  
                 receive GCR BAR 
               
               
                   
                 will skip some SPs. 
                 and transmit BA if a 
               
               
                   
                 AID assignment 
                 non-AP MLD 
               
               
                   
                 corresponding to either a 
                 operates on more than 
               
               
                   
                 specific GCR group or all 
                 one link of the GCR 
               
               
                   
                 GCR groups. 
                 primary link set 
               
               
                   
               
            
           
         
       
     
     In some embodiments, other signaling/frames methods may be used to exchange the GCR-MLO parameters described in  FIG.  6   , Table 2. GCR-MLO Agreement Setup &amp; Updates, and Table 5. GCR Operation Parameters. For example, broadcast or group cast frames, instead of individually addressed frames, can be used for establishing a GCR-SP. A broadcast approach (e.g., including the container of the information, such as an element, subelement, in the beacons/Probe Responses) can be used if channel access protection for the SP is desired. In some embodiments, a Broadcast TWT element can be modified to indicate that a particular Broadcast TWT SP is used for transmission of GCR frames subject to a particular GCR-MLO agreement, by including a GCR-MLO agreement identifier (e.g., a concealment address, or GCR group ID) in a container for information on a specific Broadcast TWT SP. When a GCR-SP is used for low latency service, a scheduling method for low latency service (e.g., restrictive TWT) can be modified for the GCR-SP establishment. For example, a container that includes an rTWT schedule can include an indication (e.g., a field, subfield, subelement, etc) to indicate such an rTWT schedule is used for GCR transmission. In some embodiments, a groupcast or unicast approach can be used. For example, GCR-SP information can be transmitted to GCR group members in a group addressed frame or an individually addressed frames. 
     A GCR-SP is necessary for low latency service. GCR SP can be setup with broadcast signaling, group cast, or unicast signaling as described above. Service periods (SPs) are link specific. Each SP can be initiated and terminated separately in their respective link. Different links may have SPs operating at the same time (e.g., overlapping in time.) For mode 2 of both GCR-MLO unsolicited retry and GCR-MLO Block Ack, when a GCR-SP is used for low latency service (e.g., agreement types 3 and 4 of Table 4. GCR-MLO Agreement Types), the Service Periods on all links (e.g., all the primary links) of the GCR primary link set should be synchronized or semi-synchronized to render low latency delivery of traffic, where the semi-synchronized GCR-SPs on different links enable the delivery of latency sensitive traffic on different links to be close in time so that the low latency requirement is met. For example, a GCR frame is delivered on one link at time  1  and on another link at time  2 , and the time gap between time  1  and time  2  is sufficiently small so that reception on both links can meet the low latency requirement. In some embodiments, AP MLD  110  schedules SPs based on non-AP MLD  120   a - 120   c  and/or legacy SLD station  130 &#39;s inputs (e.g., service requirements delivered in their traffic specification (TSPEC) or by other means.) 
       FIG.  7 A  illustrates example  700  of GCR Multi-User (MU) Block Acknowlegement Request (BAR) for early SP termination, according to some embodiments of the disclosure.  FIG.  7 B  illustrates example  750  of GCR MU BAR for early SP termination, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIGS.  7 A and  7 B  may be described with reference to elements from other figures in the disclosure. For example, the AP may be AP MLD  310  of  FIG.  3    that can transmit Beacon1  472  and delivers GCR frames within for example, GCR-SP  475   a  of  FIG.  4 B . In examples  700  and  750 , a GCR-SP is of maximum SP duration length, t1. In some embodiments, STA include stations that are a member of a GCR-MLO group such as non-AP MLD stations: STA1, STA2, STA3, STA4, and STA5 that have BA agreements with the AP. In some embodiments, some non-AP MLD STAs may return to power save modes at the end of a GCR-SP, or earlier if the non-AP MLD STA receives one or more of the following information or indications during a GCR-SP and/or a Target Wake Time (TWT) SP:
         More Trigger Frame (TF)=0 in Trigger frame: member stations (STAs) of the GCR-MLO group that have no resource unit (RU) allocation in the trigger frame may go to doze;   End of service period (EOSP)=1 or More Data (MD)=0 in a GCR Data (e.g., GCR frame) or a QoS Null frame;   A GCR-SP termination indication.       

     After receiving one or more of the indications, a receiving non-AP MLD STA can return to doze (e.g., a power save mode.) Example  700  is described further below: 
     At  705 , the AP can transmit GCR data frames, indications MD=1, eosp=0, and the GCR Address (e.g., addressed to the GCR-MLO group) during a GCR-SP of maximum SP duration length, t1. 
     At  710 , subsequent to transmitting data frames  705 , the AP can transmit a GCR MU BAR trigger frame that include Resource Unit (RU) allocations for STA1, STA2, STA3, STA4, and STA5. In addition, the AP indicates More TF=1. 
     At  715 , STA4 and STA5 signal in their BA that they have received the GCR frames correctly. STA1, STA2, and STA3 indicate in their BA that they have not received their GCR frames correctly. 
     At  720 , the AP retransmits the missed data and indicates MD=1, eosp=0. 
     At  725 , subsequent to transmitting data frames  720 , the AP can transmit a GCR MU BAR trigger frame that include RU allocations for STA1, STA2, STA3. In addition, the AP indicates More TF=0. There are no RU allocations for STA  4  and STA  5 , thus STA  4  and STA  5  can return to doze. In other words, the GCR SP is terminated for STA  4  and STA  5 . 
     At  730 , STA1, STA2, and STA3 signal in their BA that they have received their GCR frames correctly. 
     At  735 , the AP can transmit a GCR frame or a QoS Null frame indicating MD=0 and eosp=1 that terminates the GCR-SP for all stations (e.g., STA1, STA2, and STA3.) Thus, the GCR-SP can end for stations before the maximum SP duration, t1. 
       FIG.  7 B  illustrates another example of GCR MU BAR for early SP termination, according to some embodiments of the disclosure. Example  750  is described further below: 
     At  755 , the AP can transmit GCR data frames, indications MD=1, eosp=0, and the GCR Address (e.g., addressed to the GCR-MLO group) during a GCR-SP of maximum SP duration length, t1. 
     At  760 , subsequent to transmitting data frames  755 , the AP can transmit a GCR MU BAR trigger frame that include Resource Unit (RU) allocations for STA1, STA2, STA3, STA4, and STA5. In addition, the AP indicates More TF=0. The GCR MU BAR trigger frame may contain the sequence number of the last transmitted GCR MPDU. If a STA receives all MDPUs from the sequence signaled in the last transmitted GCR data frame (e.g., at  755 ), then a station may return to doze. Otherwise, a STA remains awake. 
     At  765 , STA4 and STA5 signal in their BA that they have received the GCR frames correctly. Accordingly, STA4 and STA5 may terminate their SP and return to doze. STA1, STA2, and STA3 indicate in their BA that they have not received their GCR frames correctly, so they remain awake. 
     At  770 , the AP retransmits the missed data and indicates MD=1, eosp=0. 
     At  775 , subsequent to transmitting data frames  770 , the AP can request BA from STA1, STA2, and STA3 by transmitting a GCR MU BAR trigger frame that include RU allocations for STA1, STA2, STA3. In addition, the AP indicates More TF=0. 
     At  780 , STA1, STA2, and STA3 signal in their BA that they have received their GCR frames correctly and they can return to doze. In some embodiments, the More TF=0 terminates the SP. Any STA that have RU allocations terminate SP after receiving their GCR frames correctly. Thus, the GCR-SP can end for stations before the maximum SP duration, t1. 
     A summary of Receive Address (RA) use is shown in Table 6. Receive Address (RA) Usage below. 
     
       
         
           
               
             
               
                 TABLE 6 
               
             
            
               
                   
               
               
                 Receive Address (RA) Usage 
               
            
           
           
               
               
               
               
               
            
               
                 Receiver 
                   
                   
                   
                   
               
               
                 Address 
                   
                   
                   
                   
               
               
                 (RA) in a 
                   
                   
                   
                   
               
               
                 Trigger 
                 Recipient of 
                 RA in a BAR 
                 TW TSP termination if 
                   
               
               
                 Frame 
                 the Trigger 
                 (Block-Ack 
                 the Trigger Frame has 
                   
               
               
                 Header 
                 Frame 
                 Request) 
                 “More TF = 0” 
                 Benefit 
               
               
                   
               
               
                 Individual 
                 Trigger 
                 Set to the 
                 No effect. Resource Unit 
                 — 
               
               
                 Address 
                 Frame is 
                 GCR Address 
                 (RU) always allocated to 
                   
               
               
                   
                 received only 
                 corresponding 
                 the STA 
                   
               
               
                   
                 by the STA 
                 to the BARs 
                   
                   
               
               
                 Broadcast 
                 Trigger 
                   
                 If the Trigger Frame does 
                 May 
               
               
                 Address 
                 Frame is 
                   
                 not allocate RU for a STA, 
                 terminate 
               
               
                   
                 received by 
                   
                 then the TWT SP of the 
                 legacy 
               
               
                   
                 all STAs 
                   
                 STA is terminated; 
                 TWT SPs 
               
               
                   
                   
                   
                 GCR SP corresponding to a 
                 and GCR 
               
               
                   
                   
                   
                 GCR Address is terminated 
                 SPs 
               
               
                   
                   
                   
                 for STAs for which the 
                   
               
               
                   
                   
                   
                 Trigger Frame does not 
                   
               
               
                   
                   
                   
                 allocate RU 
                   
               
               
                 GCR 
                 Trigger 
                   
                 GCR SP of GCR Address is 
                 Reduces 
               
               
                 Address 
                 Frame is 
                   
                 terminated for STAs for 
                 the number 
               
               
                   
                 received by 
                   
                 which the Trigger Frame 
                 of 
               
               
                   
                 STAs in the 
                   
                 does not allocate RU 
                 receiving 
               
               
                   
                 GCR group 
                   
                   
                 STAs 
               
               
                 MAC 
                 Trigger 
                   
                 GCR SP of GCR Address is 
                 Reduces 
               
               
                 Address that 
                 Frame is 
                   
                 terminated for STAs for 
                 the number 
               
               
                 is agreed to 
                 received by 
                   
                 which the Trigger Frame 
                 of 
               
               
                 be common 
                 all STAs that 
                   
                 does not allocate RU 
                 receiving 
               
               
                 for all GCR 
                 belong to any 
                   
                   
                 STA 
               
               
                 Addresses 
                 GCR group 
               
               
                   
               
            
           
         
       
     
       FIG.  8    illustrates example  800  of GCR-SP management for GCR-MLO with overlapping SPs, according to some embodiments of the disclosure. For explanation purposes and not a limitation,  FIG.  8    may be described with reference to elements from other figures in the disclosure. For example, AP MLD  310  of  FIG.  3    may transmit frames within target wake time (TWT) SPs and GCR-SPs that overlap on Link1, e.g., Link2  395  of GCR primary link set  390  of  FIG.  3   . 
     Example  800  illustrates TWT #2 SP  840  in which downlink (DL) individually addressed data to a STA (not shown) is transmitted. A STA may receive multiple TWT flows (e.g., TWT #1 SP  850  and TWT #2 SP  840 ) and each TWT flow may have SPs at a different schedule (e.g., different SP Start time, SP end time and SP interval). Thus, two or more TWT SPs can overlap. All overlapping TWT SPs can be terminated early with the same signaling indication shown in example  800  at TWT SP early termination  810 . A GCR-SP carries GCR frames that have the same group address in a destination address field. (See  FIG.  9 A .) The group address can be associated with a GCR-MLO group, and the group address can be subject to a corresponding GCR-MLO agreement. Each GCR-SP (e.g., GCR #1 SP and GCR #2 SP) is terminated separately (e.g., shown at GCR #2 SP early termination  820  and GCR #1 SP early termination  830 ) because GCR #1 SP and GCR #2 SP carry different data. Further, a GCR-SP termination does not terminate TWT SPs for individual data. 
     In some embodiments, STAs may have TWT SPs for individually addressed frames transmission ongoing at the same time as GCR SP. EOSP=1 or MD=0 in the MAC header of MPDU transmitted to a group address terminates only the specific GCR-SP. EOSP=1 or MD=0 in the MAC Header of the individually addressed frame terminates all TWT SPs. Expiration of the GCR-SP duration terminates only that GCR-SP. For example, after GCR #2 Early termination  820  does not affect other GCR-SPs, such a subsequent GCR #2 SP. A trigger frame with the More TF=0 terminates the GCR SPs and Individual SPs of the STAs that did not have allocated RU by the Trigger frame. 
       FIG.  9 A  illustrates example  900  of a GCR frame transmission for GCR-MLO, according to some embodiments of the disclosure.  FIG.  9 A  may be described with elements from other figures in the disclosure. For example, an AP MLD (e.g., AP MLD  110  of  FIG.  1   ) can transmit example  900  of a GCR frame transmission that can be received by a non-AP MLD (e.g., non-AP MLD  120   a - 120   c  of  FIG.  1   ) that is a member of a GCR-MLO group. A GCR frame is a group addressed frame subject to a GCR-MLO agreement between AP MLD  110  and at least one non-AP MLD  120  (e.g., non-AP MLD  120   a - 120   c ) within an infrastructure basic service set (BSS) or between peer mesh stations in a mesh BSS. 
     GCR frame transmission  900  uses an aggregate medium access control (MAC) service data unit (A-MSDU) frame format that includes A-MSDU MAC header  910  and subframe  920 . A-MSDU MAC header  910  can include: retry field  912  set to “1” for GCR retransmissions (ReTx); Address1 field  914  can include a concealment address assigned by AP MLD  110 . The concealment address prevents GCR frames from being processed by legacy GCR-incapable stations (e.g., legacy non-GCR capable station  140 ); Sequence Control field  916  can include a Sequence Number Space (SNS) defined at the MLD level (e.g., SNS_GCR-MLO_Unsolicited Retry  360  and SNS_GCR-MLO-BlockAck  365  of  FIG.  3 A .) Subframe field  920  includes the GCR frame format that includes destination address (DA) field  922 . DA field  922  includes the group address that is concealed. The group address can be subject to a GCR-MLO agreement. 
     GCR frames may be aggregated in an aggregate-MAC protocol data unit (A-MPDU). A-MPDUs include the aggregation of multiple MPDUs, and result in larger transmitted payloads. GCR frames (also called GCR data) may be aggregated similarly as individually addressed data frames by adding A-MPDU headers. A-MPDU aggregation used for GCR data can include a single traffic identifier (TID) A-MPDU Aggregation. For example, a single TID A-MPDU aggregated payload includes aggregated frames corresponding to a single concealment address (that corresponds to a single group address.) All of these aggregated frames will belong to the same TID (e.g., share a same TID value.) The support for such single-TID aggregation is mandatory for all GCR capable extremely high throughput (EHT) stations (e.g., non-AP MLD  120   a - 120   c .) 
     Some embodiments include a multi-TID A-MPDU aggregated payload that include aggregated frames from two or more concealment addresses (that correspond to two or more group addresses) within the transmitted PPDU. If multi-TID A-MPDU aggregation is used, then all receivers (e.g., non-AP MLD  120   a - 120   c ) are capable of receiving multi-TID A-MPDU aggregation, and AP MLD  110  is capable of transmitting multi-TID A-MPDU aggregation. In some embodiments, AP MLD  110  uses a single indication to indicate its support of transmitting multi-TID A-MPDU of both individually addressed frames and multi-TID A-MPDU of GCR frames. In some embodiments, AP MLD  110  indicates separately (e.g., using two separate indications) AP MLD  110  support of transmtting multi-TID A-MPDU of individually addressed frames and its support of transmitting multi-TID A-MPDU of GCR frames In some embodiments, AP MLD  110  can assign a concealment address to each group address subject to a GCR-MLO agreement. All the receivers of a multi-TID A-MPDU of GCR frames (e.g., non-AP MLD  120   a - 120   c ) have established GCR agreements (each corresponding to one GCR concealment address subject to such A_MPDU) with AP MLD  110 . 
       FIG.  9 B  illustrates example  950  of a non-GCR (e.g., No-Ack/No-Retry) group addressed frame format, according to some embodiments of the disclosure.  FIG.  9 B  may be described with elements from other figures in the disclosure. For example, an AP MLD (e.g., AP MLD  110  of  FIG.  1   ) can transmit example  950  of a no-Ack/no-Retry group addressed frame format that can be received by a legacy non-GCR station (e.g., legacy non-GCR station  140  of  FIG.  1   ) that is also a member of the GCR-MLO group. The no-Ack/no-Retry group addressed frame can be a group addressed frame where the group address is subject to a GCR-MLO agreement between AP MLD  110  and at least one non-AP MLD  120  (e.g., non-AP MLD  120   a - 120   c ) within an infrastructure basic service set (BSS) or between peer mesh stations in a mesh BSS. 
     In some embodiments, frames subject to GCR agreements are also transmitted using no-Ack/no-Retry group addressed frame format if at least one group member does not perform GCR. For example, a GCR-MLO group may include a legacy GCR-incapable station (e.g., legacy non-GCR capable station  140  of  FIG.  1   .) To accommodate the legacy GCR-incapable station, AP MLD  110  can transmit a no-Ack/no-Retry group addressed frame format illustrated in example  950  across each of the links of AP MLD  110  to serve at least legacy non-GCR capable station  140 . Any subsequent GCR frames transmitted by AP MLD  110  include the concealment address that is not recognized by legacy non-GCR capable station  140  (e.g., not passed up to a MAC service access point (SAP) of legacy non-GCR capable station  140 .) Example  950 , a no-Ack/no-Retry group addressed frame format, can be called a non-GCR group addressed frame format, and includes MAC header  960 . MAC header  960  can include retry field  962  set to “0”, Address1 field  964  set to the group address which may be the group address of DA  922  of  FIG.  9 A  that is concealed from legacy non-GCR capable station  140 . Sequence control field  966  uses SNS1 as described in IEEE P802.11REVme_D0.0. 
       FIG.  10 A  illustrates example  1000  of GCR-MLO Unsolicited Retry—mode 1, with a legacy non-GCR member, according to some embodiments of the disclosure.  FIG.  10 A  may be described with reference to elements from other figures in the disclosure. For example, AP MLD  1010  can be AP MLD  110  of  FIG.  1    or AP MLD  310  of  FIG.  3   . AP1  1013 , AP3  1015 , and AP3  1017  can correspond to AP1  313 , AP3  315 , and AP3  317 . Non-AP MLD A  1020   a , non-AP MLD B  1020   b , and non-AP MLD C  1020   c  can correspond to non-AP MLD  120   a - 120   c  of  FIG.  1    or non-AP MLD  320   a - 320   c  of  FIG.  3 A . Legacy SLD GCR member  1030  and legacy non-GCR member  1040  may correspond respectively, to legacy SLD station  130  and legacy non-GCR capable station  140  of  FIG.  1   . 
     Systems operating GCR-MLO Unsolicited Retry can support backward compatibility with legacy devices. GCR-MLO Unsolicited Retry operations are possible even when some members of a GCR-MLO group corresponding to a group address has group members that support GCR and some group members that do not support GCR. Frames subject to GCR Unsolicited Retry agreements are also transmitted using a no-Ack/no-Retry frame format if at least one group member does not perform GCR. For example, when a GCR-MLO group (corresponding to one group address and one concealment address) contains (a) GCR-MLO-capable non-AP MLD (e.g., non-AP MLD  120   a ,  120   b , or  120   c ) and (b) a legacy GCR-incapable station (e.g., legacy non-GCR capable station  140 ), some embodiments utilize GCR-MLO Unsolicited Retry as a retransmission policy. The GCR-MLO Unsolicited Retry group may also include (c) a legacy GCR-SLO-capable station (e.g., legacy SLD station  130 .) Copies of the group addressed frames are first transmitted using a no-Ack/no-Retry format (e.g., example  950  of a non-GCR frame format) on each link of the AP MLD  110  that is intended to be received by the legacy GCR-incapable stations  140 . Any GCR frames can be transmitted via a GCR primary link (e.g., link1  391  of  FIG.  3   ) or via a link (e.g., link2  395 , link 3  397  of  FIG.  3   ) of a GCR primary link set (e.g., GCR primary link set  390 .) 
     For both GCR-MLO Unsolicited Retry and GCR-MLO Block Ack, when a GCR group contains both (a) legacy GCR-SLO-capable stations (e.g., legacy SLD GCR member  1030 ), and (b) GCR-MLO-capable non-AP MLDs, the legacy GCR-SLO-capable station operates on either the GCR primary link (e.g., link1  1091 ) or one link (e.g., link2  1095  or link3  1097 ) of the GCR primary link set (e.g., GCR primary link set  1090 ), and the following conditions need to be met to enable backward compatibility with legacy GCR-SLO-capable STAs: i) no use of either option of GCR-SLO/MLO AID assignment described in Table 3. AID Assignment Types is not used; ii) use of GCR-MLO agreement setup/update signaling described in paragraphs [0065] and [0065]; and iii) option 1 described in Table 1. GCR-MLO Security is used. 
     For both GCR-MLO Unsolicited Retry and GCR-MLO Block Ack, when a GCR group contains only GCR-MLO-capable non-AP MLDs, all options described in this disclosure can be used. 
     In  FIG.  10 A , a GCR-MLO group includes the following members: non-AP MLD A  1020   a , non-AP MLD B  1020   b , non-AP MLD C  1020   c , legacy SLD GCR member D  1030 , and legacy non-GCR member  1040 . A GCR-MLO agreement may be established between AP MLD  1010  and each of non-AP MLD A  1020   a , non-AP MLD B  1020   b , non-AP MLD C  1020   c . A GCR-SLO agreement may be established between AP MLD  1010  and legacy SLD GCR member D  1030 , while no GCR agreement is established with legacy non-GCR member  1040 . For mode 1, during the GCRF (GCR frame) delivery times, the GCR-MLO group members are committed to be available on the GCR primary link, link1  1091 . 
     GCRF  1005  refers to a GCR frame that is subject to a GCR agreement (e.g., GCR-MLO). Based on the GCR-MLO group membership, AP MLD  1010  implements GCR-MLO Unsolicited Retry as a retransmission policy for GCRF and determines a number of retry times for GCRF  1005 . In addition, AP MLD  1010  determines and assigns a concealment address corresponding to the group address. Since legacy non-GCR member  1040  does not support GCR, AP MLD  1010  transmits GCRF data using a no-Ack/no-Retry group addressedframe format (e.g., example  950  of a non-GCR frame format) on all links of AP MLD  1010  shown as GCRF_SN=n  1045   a  on link1  1091 , GCRF_SN=n  1045   b  on link2  1095 , GCRF_SN=n  1045   c  on link3  1097 , where Address1 field  964  is equal to the group address, and uses the respective GTKs corresponding to the links: GTK_1  1083 , GTK_2  1085 , GTK_3  1087 , and a sequence number assigned from SNS_GCR-MLO_Unsolicited Retry  1060  in Sequence Control field  916 . 
     AP MLD  1010  may retransmit GCRF data Retry GCRF_SN=n  1007  on GCR primary link, link1  1091 , using a GCR frame format (as shown in example  900 ) to legacy SLD GCR member  1030 , non-AP MLD A  1020   a , non-AP MLD B  1020   b , and non-AP MLD C  1020   c . The GCR frame format of Retry GCRF_SN=n  1007  can include the concealment address in Address1 field  914 , a sequence number assigned from SNS_GCR-MLO_Unsolicited Retry  1060  in Sequence Control field  916 , and the group address in DA field  922 . Retry GCRF_SN=n  1007  can be retransmitted multiple times, where the number of retry times is set by AP MLD  1010 . The GCR frames are transmitted using GTK_GCR-ML  1070   
     AP MLD  1010  and non-AP MLDs  1020   a - 1020   c  take advantage of their multiple links using the Unsolicited Retry as a retransmission policy for GCRF  1005  by transmitting Retry GCRF_SN=n  1007  in GCR frame format (e.g., example  900  of a GCR frame transmission for GCR-MLO) on non-GCR primary link, link2  1095  or link3  1097  when AP MLD  1010  obtains information that non-AP MLD A  1020   a , MLD B  1020   b , or non-AP MLD C is temporarily unavailable on the primary link1  1091 , but available on a non-primary link (e.g., link2,  1095  or link3  1097 ), using GTK_GCR-ML  1073 . 
       FIG.  10 B  illustrates example  1050  of GCR-MLO Unsolicited Retry—mode 2, with a legacy non-GCR member, according to some embodiments of the disclosure.  FIG.  10 B  may be described with reference to elements from other figures in the disclosure. For example, AP MLD  1010  can be AP MLD  110  of  FIG.  1    or AP MLD  310  of  FIG.  3   . AP1  1013 , AP3  1015 , and AP3  1017  can correspond to AP1  313 , AP3  315 , and AP3  317 . Non-AP MLD A  1022 , non-AP MLD B  1024 , and non-AP MLD C  1026  can correspond to non-AP MLD  120   a - 120   c  of  FIG.  1    or non-AP MLD  320   a - 320   c  of  FIG.  3 A . Legacy SLD GCR member  1030  and legacy non-GCR member  1040  may correspond respectively, to legacy SLD station  130  and legacy non-GCR capable station  140  of  FIG.  1   . 
     Example  1000  focused on mode 1; example  1050  is similar, but focuses on mode 2. In example  1050 , a GCR-MLO group includes the following members: non-AP MLD A  1022 , non-AP MLD B  1024 , non-AP MLD C  1026 , legacy SLD GCR member D  1030 , and legacy non-GCR member  1040 . A GCR-MLO agreement may be established between AP MLD  1010  and each of non-AP MLD A  1022 , non-AP MLD B  1024 , non-AP MLD C  1026 . A GCR-SLO agreement may be established between AP MLD  1010  and legacy SLD GCR member D  1030 , while no GCR agreement is established with legacy non-GCR member  1040 . 
     In example  1050 , GCRF  1002  refers to a GCR frame that is subject to a GCR agreement (e.g., GCR-MLO). Based on the GCR-MLO group membership, AP MLD  1010  implements GCR-MLO Unsolicited Retry as a retransmission policy for GCRF and determines a number of retry times for GCRF  1002 . In addition, AP MLD  1010  determines and assigns a concealment address corresponding to the group address. For mode 2, during the GCRFs (GCR frames) delivery times, the GCR-MLO group members are committed to be available on at least one link (e.g., link2  1095  and/or link3  1097 ) within the GCR primary link set  1090 . In some embodiments, if GCR-MLO group members converge to a single link of GCR primary link set  1090 , then example  1050  transitions to mode 1. 
     Since legacy non-GCR member  1040  does not support GCR, AP MLD  1010  transmits GCRF data using a non-GCR frame format (e.g., example  950  of a non-GCR frame format) on all links of AP MLD  1010  shown as GCRF_SN=n  1045   a  on link1  1093 , GCRF_SN=n  1045   b  on link2  1095 , GCRF_SN=n  1045   c  on link3  1097 , where Address1 field  964  is equal to the group address, and using the respective GTKs corresponding to the links: GTK_1  1083 , GTK_2  1085 , GTK_3  1087 . 
     AP MLD  1010  may retransmit GCRF data (e.g., Retry GCRF_SN=n (GCR frame format)  1004  and  1006 ) on all links (e.g., link2  1095  and link3  1097 ), of GCR primary link set  1090 , using a GCR frame format to legacy SLD GCR member  1030 , non-AP MLD A  1022 , non-AP MLD B  1024  and non-AP MLD C  1026 ). The GCR frame format is similar to example  900  in that an Address1 field would include the concealment address corresponding to the group address and a DA field would include the group address. The GCR-SLO frame format Sequence Control field, however, would use SNS1 (explained in IEEE P802.11REVme.) The GCRF data in the GCR-SLO frame format can be retransmitted multiple times, where the number of retry times is set by AP MLD  1010 . The GCR frame formats of Retry GCRF_SN=n  1004  and Retry GCRF_SN=n  1006  can include the concealment address in Address1 field  914 , a sequence number assigned from SNS_GCR-MLO_Unsolicited Retry  1060  in Sequence Control field  916 , and the group address in DA field  922 . Retry GCRF_SN=n  1004  and Retry GCRF_SN=n  1006  can be retransmitted multiple times, where the number of retry times is set by AP MLD  1010 . The GCR frames are transmitted using GTK_GCR-ML  1070 . 
     AP MLD  1010  and non-AP MLDs  1022 ,  1024 , 1026  take advantage of their multiple links using the Unsolicited Retry as a retransmission policy for GCRF  1002  by transmitting Retry GCRF_SN=n  1004  and Retry GCRF_SN=n  1006  on a link that does not belong to the primary link set in GCR frame format (e.g., example  900  of a GCR frame transmission for GCR-MLO), when AP MLD  1010  obtains information that non-AP MLD A  1021   a , MLD B  1024 , or non-AP MLD C  1026  is temporarily unavailable on a link of the primary link set  1090  but available on a link that is not of a primary link set (e.g., link1,  1093 ), using GTK_GCR-ML  1070 . 
     Table 7. GCR-MLO: Unsolicited Retry—Mode 1 &amp; 2 summarizes the transmission types described above. If all members of a GCR-MLO group are non-AP MLDs (e.g., EHT/11be capable) and option 1 of the GCR-SLO/MLO AID assignment described in Table 3. AID Assignment Types is used, then an AID_ GCR  assigned to a GCR group uniquely identifies the GCR group (corresponding to a group address), the concealment address for this GCR group may not be generated by the AP MLD and transmitted to the group members during the GCR agreement setup. Instead, the frame format of No-Ack/No-Retry transmission of group address frames, may be used for GCR transmission instead of the GCR frame format. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 GCR-MLO: Unsolicited Retry - Mode 1 &amp; 2 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Delivery 
                   
                   
                   
                   
                   
               
               
                 Tx Type 
                 Method 
                 Tx Time 
                 Tx Link 
                 Frame Format 
                 SNS 
                 Group Key 
               
               
                   
               
               
                 No- 
                 Non- 
                 The DTIM 
                 All links 
                 Frame format of 
                 SNS_GCR- 
                 GTK_link_i 
               
               
                 Ack/No- 
                 GCR-SP 
                 Beacon 
                   
                 No-Ack/No-Retry 
                 MLO_un- 
               
               
                 Retry 
                   
                 before the 
                   
                 transmission of 
                 solicited 
               
               
                 transmission 
                   
                 GCRF 
                   
                 group addressed 
                 retry 
               
               
                   
                   
                 delivery 
                   
                 frames 
                 (defined at 
               
               
                   
                 GCR-SP 
                 The DTIM 
                   
                   
                 ML level) 
               
               
                   
                   
                 beacon 
               
               
                   
                   
                 before or 
               
               
                   
                   
                 after the 
               
               
                   
                   
                 GCRF 
               
               
                   
                   
                 delivery in 
               
               
                   
                   
                 SPs 
               
               
                 GCR- 
                 Non- 
                 Immediately 
                 Nominally, 
                 GCR frame 
                   
                 GTK_GCR- 
               
               
                 transmission 
                 GCR-SP 
                 after a 
                 transmit on 
                 format (the same 
                   
                 ML 
               
               
                   
                   
                 DTIM 
                 the primary 
                 as GCR-SLO 
               
               
                   
                   
                 Beacon after 
                 link (as in 
                 frame format 
               
               
                   
                   
                 the delivery 
                 mode 1) or 
                 depicted), with 
               
               
                   
                   
                 of no- 
                 primary link 
                 “SNS_GCR- 
               
               
                   
                   
                 Ack/no- 
                 set (as in 
                 MLO_unsolicited 
               
               
                   
                   
                 retry copy 
                 mode 2) 
                 retry”, instead of 
               
               
                   
                   
                 of the same 
                 Optionally, 
                 SNS1, being used 
               
               
                   
                   
                 frames 
                 transmits on 
                 to generate the 
               
               
                   
                 GCR-SP 
                 During the 
                 the links that 
                 sequence number 
               
               
                   
                   
                 GCR 
                 are not 
                 contained in the 
               
               
                   
                   
                 Service 
                 primary link 
                 “sequence 
               
               
                   
                   
                 Periods 
                 or link set due 
                 control” field. 
               
               
                   
                   
                   
                 to temporary 
               
               
                   
                   
                   
                 unavailability 
               
               
                   
                   
                   
                 of one or 
               
               
                   
                   
                   
                 more non-AP 
               
               
                   
                   
                   
                 MLD(s) on 
               
               
                   
                   
                   
                 the primary 
               
               
                   
                   
                   
                 link or link 
               
               
                   
                   
                   
                 set. 
               
               
                   
               
            
           
         
       
     
     GCR-MLO Block Ack in mode 1 &amp; 2 can be established when all members of a group corresponding to a group address support GCR. During the GCR agreement set up, an AP MLD establishes a GCR primary link (mode 1) or links of the GCR primary link set (mode 2). During the GCRF delivery times, the GCR member STAs are committed to be available on the GCR primary link or a link of the GCR primary link set. If a GCR-MLO group includes a legacy GCR-SLD member (e.g., legacy SLD GCR member  1130 ), the legacy GCR-SLD member operates operate on either the GCR primary link (mode 1) or one link of the GCR primary link set (mode 2), and the following are met to ensure backwards compatibility with legacy GCR-SLO-capable STAs 
       FIG.  11 A  illustrates example  1100  of GCR-MLO Block Ack—mode 1, with a legacy single link device (SLD) GCR member, according to some embodiments of the disclosure.  FIG.  11 A  may be described with reference to elements from other figures in the disclosure. For example, AP MLD  1110  can be AP MLD  110  of  FIG.  1    or AP MLD  310  of  FIG.  3   . AP1  1113 , AP3  1115 , and AP3  1117  can correspond to AP1  313 , AP3  315 , and AP3  317 . Non-AP MLD A  1120   a , non-AP MLD B  1120   b , and non-AP MLD C  1120   c  can correspond to non-AP MLD  120   a - 120   c  of  FIG.  1    or non-AP MLD  320   a - 320   c  of  FIG.  3 A . Legacy SLD GCR member D  1130  may correspond to legacy SLD GCR member  130  of  FIG.  1   . 
       FIG.  11 A  illustrates example  1100  of GCR-MLO Block Ack—mode 1, with a legacy SLD GCR member, according to some embodiments of the disclosure. Assume a GCR-MLO group includes the following members: non-AP MLD A  1120   a , non-AP MLD B  1120   b , non-AP MLD C  1120   c , and legacy SLD GCR member D  1130 . A GCR-MLO agreement may be established between AP MLD  1110  and each of non-AP MLD A  1120   a , non-AP MLD B  1120   b , non-AP MLD C  1120   c . A GCR-SLO agreement may be established between AP MLD  1110  and legacy SLD GCR member D  1130 . In addition, all of the GCR-MLO group members establish a GCR BA agreement with AP MLD  1110 . For mode 1, during the GCRF (GCR frame) delivery times, the GCR-MLO group members are committed to be available on the GCR primary link, link1  1191 . 
     AP MLD  1110  can transmit initial GCR frames, GCRFs_SN=n, (n+1), . . . x . . . m,  1107  using the GCR frame format. The transmission nominally, is on the GCR primary link (e.g., link1  1191 ) for mode 1 or on a link (e.g., link2  1195  or link3  1197 ) of the GCR primary link set (e.g., GCR primary link set  1190  of  FIG.  11 B ) for mode 2. The GCR frame format of GCRFs GCRF_SN=n, (n+1), , , , , x, . . . m,  1107  can include the concealment address in Address1 field  914 , a sequence number assigned from SNS_GCR-MLO_Block Ack  1165  in Sequence Control field  916 , and the group address in DA field  922 . 
     In some embodiments, AP MLD  1110  can perform the initial GCR transmission on the links (e.g., link2  1195  or link3  1197 ) that are not the GCR primary link or not a link (e.g., link1  1193  of  FIG.  11 B ) of the GCR primary link set due to a temporary unavailability of one or more non-AP MLD(s) on the GCR primary link or a link of the GCR primary link set. AP MLD  1110  and non-AP MLDs  1120   a - 1120   c  take advantage of their multiple links using the BlockAck Retry as a retransmission policy. AP MLD  1110  can perform a retransmission on a link (a GCR primary link, a link of the GCR primary link set, or otherwise) that AP MLD  1110  selects based on but not limited to: a BlockAck bitmap from each member; a missing BlockAck frame; and/or a member&#39;s availability on various links. 
     Example  1100  shows that after the initial transmission GCRFs GCRF_SN=n, (n+1), , , , , , x, . . . m,  1107 , AP MLD  1110  transmit a BAR (Block-Ack Request) frame to each of the members, non-AP MLD A  1120   a , non-AP MLD B  1120   b , non-AP MLD C  1120   c , and legacy SLD GCR member D  1130 . Based on the Ack frame received from these GCR group members, AP MLD  1110  learns that the GCR frame with the sequence number (SN) that is equal to x (e.g., Retry GCRF_SN=x (GCR frame format)  1107  needs to be retransmitted on link1  1191 . The GCR frame format of GCRF_SN=n, (n+1), . . . x, . . . m,  1107  and GCRF Retry GCRF_SN=x  1107  can include example  900  of a GCR frame transmission for GCR-MLO using GTK_GCR-ML  1170 , and can include the concealment address in Address1 field  914 , a sequence number assigned from SNS_GCR-MLO_Block Ack  1165  in Sequence Control field  916 , and the group address in DA field  922 . 
     If all the members including legacy SLD GCR member D  1130  support multi-user (MU)-BlockAckReq/BlockAck (BAR/BA) exchange, then AP MLD  1110  can transmit a MU-BAR/A, B, C, D  1145  identifying non-AP MLD A  1120   a , non-AP MLD B  1120   b , non-AP MLD C  1120   c , and legacy SLD GCR member D  1130 , and can receive a corresponding BA response shown as MU-BA/A, B, C, D  1143 . In the event legacy SLD GCR member D  1130  does not support MU-BARBA, AP MLD  1110  can transmit and receive separate BAR/BA exchanges shown as: MU-BAR/A, B, C  1125 ; MU-BA/A, B, C  1123 ; and BAR/SLD D  1135  and BA/SLD D  1133 . Other GCRF retransmissions are shown as GCRFs_SN  1107   m.    
       FIG.  11 B  illustrates example  1150  of GCR-MLO Block Ack—mode 2, with a legacy SLD GCR member, according to some embodiments of the disclosure.  FIG.  11 B  illustrates an example of GCR-MLO Block Ack—mode 2, with a legacy SLD GCR member, according to some embodiments of the disclosure.  FIG.  11 B  may be described with elements from other figures in the disclosure. For example, AP MLD  1110  can be AP MLD  110  of  FIG.  1    or AP MLD  310  of  FIG.  3   . AP1  1113 , AP3  1115 , and AP3  1117  can correspond to AP1  313 , AP3  315 , and AP3  317 . Non-AP MLD A  1122 , non-AP MLD B  1124 , and non-AP MLD C  1126  can correspond to non-AP MLD  120   a - 120   c  of  FIG.  1    or non-AP MLD  320   a - 320   c  of  FIG.  3 A . Legacy SLD GCR member D  1130  may correspond to legacy SLD GCR member  130  of  FIG.  1   . 
     Assume a GCR-MLO group includes the following members: non-AP MLD A  1122 , non-AP MLD B  1124 , non-AP MLD C  1126 , and legacy SLD GCR member  1130 . A GCR-MLO agreement may be established between AP MLD  1110  and each of non-AP MLD A  1122 , non-AP MLD B  1124 , and non-AP MLD C  1126 . A GCR-SLO agreement may be established between AP MLD  1110  and legacy SLD GCR member D  1130 . In addition, all of the GCR-MLO group members establish a GCR BA agreement with AP MLD  1110 . For mode 2, during the GCRFs (GCR frames) delivery times, the GCR-MLO group members are committed to be available on at least one link (e.g., link2  1195  or link3  1197 ) of GCR primary link set  1190 . 
     Example  1150  shows that after the initial transmission of GCRF_SN=n, (n+1), . . . x, . . . m  1104  on link 2  1995  and  1106  on link 3, using GCR frame format, AP MLD  1110  transmits BAR (Block Ack Request) frame to each of the members, non-AP MLD A  1122 , non-AP MLD B  1124 , non-AP MLD C  1126 , and legacy SLD GCR member D  1130 . Based on the Ack frame received from these GCR group members, AP MLD  1110  learns that the GCR frame with the sequence number x (e.g., Retry GCRF_SN=x (GCR frame format)  1104  needs to be retransmitted on link 2  1195  and the GCR frame with the sequence number y (e.g., Retry GCRF_SN=x (GCR frame format)  1106  needs to be retransmitted on link 3  1197 . The GCR frame format of GCRF_SN=n, (n+1), . . . x, . . . m  1104 , GCRF Retry GCRF_SN=x  1104  and GCRF Retry GCRF_SN=y  1106  can include example  900  of a GCR frame transmission for GCR-MLO using GTK_GCR-ML  1170 , and can include the concealment address in Address1 field  914 , a sequence number assigned from SNS_GCR-MLO Block Ack  1165  in Sequence Control field  916 , and the group address in DA field  922 . 
     If all the members including legacy SLD GCR member D  1130  support multi-user (MU)-BlockAckReq/BlockAck (BAR/BA) exchange, then AP MLD  1110  can transmit on link3  1197 , MU-BAR/C, D  1144  identifying non-AP MLD C  1126  and legacy SLD GCR member D  1130 , and can receive a corresponding BA response shown as MU-BA/C, D  1142 . 
     In the event legacy SLD GCR member D  1130  does not support MU-BAR/BA, AP MLD  1110  can transmit and receive separate BAR/BA exchanges on link3  1197  shown as: BAR/SLD D  1134  and BA/SLD  1132 ; and single user (SU)-BAR/C  1138  and BA/C  1136 . Other GCRF retransmissions are shown as GCRFs_SN  1106   m.    
     AP MLD  1110  can transmit on link2  1195 , MU-BAR/A, B  1148  identifying non-AP MLD A  1122  and non-AP MLD B  1124 , and can receive a corresponding BA response shown as MU-BA/A, B  1146 . Other GCRF retransmissions are shown as GCRFs_SN  1104   m.    
     Table 8. GCR-MLO: Block Ack—Mode 1 &amp; 2 summarizes the discussions above. If all members of a GCR-MLO group are non-AP MLDs (e.g., EHT/11be capable) and option 1 of the GCR-SLO/MLO AID assignment described in Table 3. AID Assignment Types is used, then an AID_ GCR  assigned to a GCR group uniquely identifies the GCR group (corresponding to a group address), the concealment address for this GCR group may not be generated by the AP MLD and transmitted to the group members during the GCR agreement setup. Instead, the frame format of No-Ack/No-Retry transmission of group address frames, may be used for GCR transmission instead of the GCR frame format. 
     
       
         
           
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 GCR-MLO: Block Ack - Mode 1 &amp; 2 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Delivery 
                   
                   
                   
                   
                   
               
               
                 Tx Type 
                 Method 
                 Tx Time 
                 Tx Link 
                 Frame Format 
                 SNS 
                 Group Key 
               
               
                   
               
            
           
           
               
               
            
               
                 No- 
                 Not used 
               
               
                 Ack/No- 
               
               
                 Retry 
               
               
                 Tx 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 GCR- 
                 Non- 
                 Immediately 
                 Initial tx: 
                 GCR frame 
                 SNS_GCR- 
                 GTK_GCR- 
               
               
                 Tx 
                 GCR-SP 
                 after a 
                 Nominally, is on 
                 format (e.g., 
                 MLO_block 
                 ML 
               
               
                   
                   
                 DTIM 
                 the GCR primary 
                 GCR-SLO 
                 ack (defined 
               
               
                   
                   
                 Beacon 
                 link (as in mode 1) 
                 frame format 
                 at ML level) 
               
               
                   
                 GCR-SP 
                 During the 
                 or a link of the 
                 with 
               
               
                   
                   
                 GCR 
                 GCR primary link 
                 “SNS_GCR- 
               
               
                   
                   
                 Service 
                 set (as in mode 2) 
                 MLO_block 
               
               
                   
                   
                 Periods 
                 Optionally, 
                 ack”, instead 
               
               
                   
                   
                   
                 transmits on the 
                 of SNS1, 
               
               
                   
                   
                   
                 links that are not 
                 being used to 
               
               
                   
                   
                   
                 the GCR primary 
                 generate the 
               
               
                   
                   
                   
                 link or a link of the 
                 sequence 
               
               
                   
                   
                   
                 GCR primary link 
                 number 
               
               
                   
                   
                   
                 set due to 
                 contained in 
               
               
                   
                   
                   
                 temporary 
                 the 
               
               
                   
                   
                   
                 unavailability of 
                 “sequence 
               
               
                   
                   
                   
                 one or more non- 
                 control” field 
               
               
                   
                   
                   
                 AP MLD(s) on the 
               
               
                   
                   
                   
                 GCR primary link 
               
               
                   
                   
                   
                 or a link of the 
               
               
                   
                   
                   
                 GCR primary link 
               
               
                   
                   
                   
                 set. 
               
               
                   
                   
                   
                 Retransmission: 
               
               
                   
                   
                   
                 On a link (primary 
               
               
                   
                   
                   
                 link or otherwise) 
               
               
                   
                   
                   
                 that AP MLD 
               
               
                   
                   
                   
                 selects based on: 
               
               
                   
                   
                   
                 BlockAck 
               
               
                   
                   
                   
                 bitmap from each 
               
               
                   
                   
                   
                 member. 
               
               
                   
                   
                   
                 Missing 
               
               
                   
                   
                   
                 BlockAck frame 
               
               
                   
                   
                   
                 Member&#39;s 
               
               
                   
                   
                   
                 availability on 
               
               
                   
                   
                   
                 various links 
               
               
                   
               
            
           
         
       
     
       FIG.  12    illustrates example  1200  of a frame exchange with GCR multi-user (MU)-Block Ack Request (BAR) for GCR-MLO, according to some embodiments of the disclosure. As a convenience and not a limitation,  FIG.  12    may be described with reference to elements from other figures in the disclosure. For example, example  1200  may include elements from  FIG.  11 B  such as AP MLD  1110 , non-AP MLD A  1122 , non-AP MLD B  1124 , non-AP MLD C  1126 , and legacy SLD GCR member D  1130 . 
     When a GCR-MLO agreement is established, AP MLD  1110  can immediately initiate a Block negotiation with the non-AP STAs of the group. For a GCR BlockAckReq Variant, TID_INFO=0 as described in IEEE P802.11REVme. To unify the Block Ack operation for unicast and group cast, some embodiments allow the GCR BlockAckReq to be TID specific (e.g., TID_INFO is not always 0): Option 1: revise the existing GCR BlockAckReq variant. Option 2: create a new GCR BlockAckReq variant, with exemplary name such as “TID-specific GCR BlockAckReq variant.” For both Option 1 and Option 2 above, the new GCR BlockAckReq variant is capable of using a single BlockAckReq to request Block Ack for multiple TIDs. 
     Example  1200  illustrates AP MLD  1110  transmitting data and subsequently transmitting GCR MU-BAR Trigger  1148  corresponding to non-AP MLD A  1122  and non-AP MLD B  1124 . Non-AP MLD A  1122  and non-AP MLD B  1124  respond with respective Block Acks  1223  and  1227 . If legacy SLD GCR member D  1130  does not support GCR MU-BAR, AP MLD  1110  can transmit a GCR MU BAR Trigger  1138  corresponding to non-AP MLD C  1126 , where GCR MU BAR Trigger  1138  only allocates RU to a non-AP MLD C  1126 . Non-AP MLD C  1126  can respond with respective Block Ack  1243 . AP MLD  1110  can transmit a single user (SU) Block Ack Req  1134  corresponding to legacy SLD GCR member D  1130 . Legacy SLD GCR member D  1130  can respond with Block Ack  1265 . Based on the received Block Acks, AP MLD  1110  determines whether additional retransmissions are needed. 
       FIG.  13    illustrates example  1300  of creating multiple GCR subgroups that correspond to one single group address, according to some embodiments of the disclosure. As a convenience and not a limitation,  FIG.  13    may be described with reference to elements from other figures in the disclosure. For example, AP MLD  110  of  FIG.  1    or processor(s)  265  of system  200  of  FIG.  2    that executes instructions stored in memory  285  can perform the functions described in example  1300 . In some embodiments, all group members corresponding to a group address support GCR-MLO, and AP MLD  110  can map one group address  1310  to one or more concealment addresses concealment address 1  1320 , concealment address 2  1322 , . . . concealment address N  1340 , where N is an integer greater than 1. A concealment address (e.g., concealment address 1  1320  can correspond to a GCR sub-group identified by a GCR Group ID (e.g., GCR ID1  1360 , GCR ID 2  1362 , . . . GCR ID N  1380 .) Further, Concealment address_x can be used for duplicate detection (e.g., duplicate frame.) Each GCR sub-group (e.g., GCR ID 2  1362 ) may use a corresponding separate GTK_GCR-ML (sub-group n). 
       FIG.  14    illustrates an example method  1400  for an access point (AP) multi-link device (MLD) for GCR-MLO service, according to some embodiments of the disclosure. As a convenience and not a limitation, method  1400 , can be described with reference to elements of other figures in the disclosure. For example, method  1400  can be performed by AP MLD  110  of  FIG.  1   , or processor(s)  265  of system  200  of  FIG.  2    that executes instructions stored in memory  285 . 
     At  1405 , AP MLD  110  exchanges signals with a non-AP MLD (e.g., non-AP MLD station  120   a ) to setup and/or update a GCR-MLO agreement. In some embodiments, AP MLD  110  can transmit a signal advertising the availability of a GCR-MLO service for a group address (e.g., a group address that can be subject to the GCR-MLO agreement), and a GCR primary link or a GCR primary link set of the AP MLD. AP MLD  110  can receive a signal including the group address, and the GCR primary link or the GCR primary link set. In response to the receiving, AP MLD  110  can transmit to non-AP MLD  120   a , the GCR-MLO group address, the GCR primary link or the GCR primary link set, and an association identifier (AID) that corresponds to the group address. Some functions of signals exchanged are described in  1415 ,  1420 ,  1425 ,  1430 ,  1435 , and  1440  and the order of the functions may vary. 
     At  1415 , AP MLD  110  can assign the AID as an AID_ GCR  corresponding to the GCR-MLO group. AP MLD  110  can allocate a resource unit (RU) according to the AID_ GCR  corresponding to a GCR frame of the group address. In some embodiments, the AID is common among all GCR groups. 
     At  1420 , AP MLD  110  can receive parameter input (e.g., a request for certain parameters to be set at a value) from one or more members of the GCR-MLO group and assign one or more GCR operation parameters based on the received parameter inputs as well as AP MLD  110  resources. For example, AP MLD  110  can receive from a first member of the GCR-MLO group a first parameter (e.g., request GCR-SP duration of 3 msec) in a GCR-MLO Request signal, and based at least on the first parameter and input from another member of the group address, assign a GCR operation parameter (e.g., assign a GCR-SP duration of 5 msec) that is different than the first parameter. AP MLD  110  can then transmit to the first member the GCR operation parameter in a GCR-MLO Response signal. 
     At  1425 , AP MLD  110  can utilize a reserved value (e.g., Subelement ID=2) of the direct multicast service (DMS) status for the GCR-MLO Response frames. For example, AP MLD  110  can contain a GCR-MLO parameters including the group address, and the GCR primary link or the GCR primary link set, and the AID that corresponds to the group address in an subelement of the DMS Status where the subelement ID uses a reserved value (e.g., subelement ID=2) in REVme_D0.0. 
     At  1430 , AP MLD  110  can use a broadcast, groupcast or unicast approach to establish a GCR-MLO agreement with a station. For example, AP MLD  110  can transmit the SP schedule information using a broadcast or groupcast frame. In another example, AP MLD  110  can transmit the SP schedule information using a unicast frame. In some embodiments, the SP established using broadcast frames includes a broadcast target wake time (TWT) element that can include the group address corresponding to the GCR-MLO group, the corresponding concealment address, and/or an identifier of the GCR-MLO group (e.g., a GCR-MLO group ID) corresponding to the GCR-MLO agreement. When the GCR-SP is used for low latency service, AP MLD  110  can modify a restrictive TWT (rTWT) SP establishment method to establish GCR-MLO SP. In some embodiments,  1430  can occur any time after  1425 . 
     At  1435 , AP MLD  110  can synchronize or semi-synchronize SPs transmitted on links of a GCR primary link set (e.g., mode 2.) For example, when the group address corresponds to the GCR primary link set, AP MLD  110  can synchronize or semi-synchronize SPs on the links of the GCR primary link set. 
     At  1440 , when a GCR-MLO group includes a legacy GCR-single link operation (SLO) station member, AP MLD  110  can utilize a DMS status to establish the GCR-MLO agreement corresponding to the group address. For example, AP MLD  110  can contain GCR-MLO parameters including the group address, and the GCR primary link or the GCR primary link set, and the AID that corresponds to the group address in an subelement of the DMS Status where the subelement ID is a reserved value (e.g., subelement ID=2) in REVme_D0.0. 
     At  1445 , AP MLD  110  can establish a GCR-MLO agreement with a first member of the GCR-MLO group at a MLD level where the receiving and the transmitting can occur on different links of AP MLD  110 . For example, the receiving of the group address, and the GCR primary link or the GCR primary link set can be from the first member via any link of AP MLD  110 , and the transmitting the group address, a concealment address, the GCR primary link or the GCR primary link set, and the AID that corresponds to the group address, to the first member can be via any link of AP MLD  110 . Subsequently, AP MLD  110  can transmit a GCR frame corresponding to the group address via the GCR primary link or the GCR primary link set. 
     At  1450 , AP MLD  110  can transmit a solicited or unsolicited GCR update signal that includes: an updated delivery time, an updated concealment address, an updated GCR primary link or an updated GCR primary link set, and/or an updated AID_ GCR . This update can occur any time after the establishment of a GCR agreement  1445 . 
     At  1455 , AP MLD  110  can begin GCR frame delivery. Some functions of GCR frame delivery are described in  1460 ,  1465 ,  1470 ,  1480 ,  1485 , and  1490 . 
     At  1460 , AP MLD  110  utilizes the GCR primary link or the GCR primary link set to transmit a GCR frame during a GCR frame delivery time. When the group address corresponds to a GCR-MLO group where all members are available on a common link during a GCR frame delivery time, AP MLD  110  can utilize the common link as the GCR primary link during the GCR frame delivery time. The GCR frame delivery time can be based at least on: a non-GCR-SP or a GCR-SP. When the GCR frame delivery time is based on the non-GCR-SP, the GCR frame delivery time occurs after a delivery traffic indication message (DTIM) beacon and after a No-Ack/No-Retry group addressed frame delivery. 
     When the group address corresponds to a GCR-MLO group where members are not all available on a common link during a GCR frame delivery time, AP MLD  110  can utilize a GCR primary link set where each of the members is available on at least one link within the GCR primary link set during the GCR frame delivery time. 
     At  1465 , AP MLD  110  can transmit an aggregate-Medium Access Control (MAC) Protocol Data Unit (A-MPDU) including an aggregated payload with aggregated GCR frames that share a common traffic identifier (TID). For example, AP MLD  110  can determine that members of the GCR-MLO group are GCR-capable stations, and then transmit the A-MPDU that includes an aggregated payload with aggregated GCR frames that share a common TID. In some embodiments, AP MLD  110  can determine that members of the GCR-MLO group are capable of receiving aggregated GCR frames, and transmit an A-MPDU the includes an aggregated payload with aggregated GCR frames corresponding to two or more TIDs. 
     At  1470 , AP MLD  110  can implement: an unsolicited retry GCR-MLO retransmission policy, or a block acknowledgement (BA) GCR-MLO retransmission policy. For example, AP MLD  110  can determine a maximum number of retries of a GCR frame corresponding to the group address; and transmit the GCR frame according to the maximum number of retries. In some embodiments, AP MLD  110  can implement a block acknowledgement (BA) GCR-MLO retransmission policy. Accordingly, AP MLD  110  can determine that a first non-AP MLD  110  operates on more than one link of the GCR primary link set, determine a nominal link of the GCR primary link set on which to receive a GCR BA request (BAR), and transmit to the first non-AP MLD  110 , via the transceiver, the nominal link. 
     At  1480 , AP MLD  110  can provide indications to a non-AP MLD to end a GCR-SP sooner than the scheduled duration of the GCR-SP. Thus, the non-AP MLD can return to a power save mode before the scheduled duration of the GCR-SP. For example, AP MLD  110  can transmit on one link of the GCR primary link set, a first GCR-SP corresponding to the group address, and transmit an indication ending the first GCR-SP before a scheduled duration of the first GCR-SP ends. In some embodiments, the indication includes but is not limited to: a Cascade Indication=0 in a first trigger frame, or the first trigger frame is not targeted to a member of the GCR-MLO group; a More Trigger Frame (TF)=0 in a second trigger frame for stations that did not have a resource unit (RU) allocated by the second trigger frame; a Quality of Service (QoS) Null frame; an end of SP (EOSP)=1; More Data (MD)=0 in a GCR frame; and/or a GCR-SP termination indication. 
     At  1485 , AP MLD  110  can manage GCR-SPs that overlap with other SPs. For example, AP MLD  110  can transmit on the one link of the GCR primary link set, a TWT SP for an individually addressed frame that overlaps with the first GCR-SP corresponding to the group address. Subsequently, AP MLD  110  can transmit an indication ending the first GCR-SP before a maximum duration of the first GCR-SP, but not affecting the TWT SP. 
     In some examples, AP MLD  110  can transmit an indication that ends one GCR-SP but not another overlapping GCR-SP. For example, AP MLD  110  can transmit on one link of the GCR primary link set, a TWT SP for an individually addressed frame that overlaps with the first GCR-SP corresponding to the group address, and a second GCR-SP. Subsequently, AP MLD  110  can transmit, an indication ending the first GCR-SP before a maximum duration of the first GCR-SP, but not affecting the second GCR-SP. 
     At  1490 , AP MLD  110  can terminate one or more GCR-SPs and one or more TWT SPs using a trigger frame (TF) with More TF=0. For example, AP MLD  110  can transmit a trigger frame comprising More TF=0, terminating the first GCR-SP, the second GCR-SP, and the TWT SP, for stations that did not have a resource unit (RU) allocated by the trigger frame. 
       FIG.  15    illustrates another example method  1500  for an AP MLD for GCR-MLO, according to some embodiments of the disclosure. As a convenience and not a limitation, method  1500 , can be described with reference to elements of other figures in the disclosure. For example, method  1500  can be performed by AP MLD  110  of  FIG.  1   , or processor(s)  265  of system  200  of  FIG.  2    that executes instructions stored in memory  285 . 
     At  1505 , AP MLD  110  can generate a Group Temporal Key (GTK) at the MLD level for transmission of the GCR frame for GCR-MLO. For example AP MLD  110  can generate a GTK_GCR_ML at the MLD level, wherein the GTK_GCR_ML is used for encryption and decryption of the GCR frame. In some embodiments, to generate the GTK_GCR_ML at the MLD level, AP MLD  110  is further configured to: utilize a MAC address of the AP MLD as the Authenticator Address (AA). In some embodiments, AP MLD  110  can use the GTK_GCR_ML for encryption and decryption of the GCR frame for all links of AP MLD  110 . In some embodiments, AP MLD  110  can use a truncated version of the GTK_GCR_ML for encryption and decryption of the group addressed frames that are not subject to a GCR agreement for a link of AP MLD  110 . 
     At  1510 , AP MLD  110  can transmit a GCR frame for GCR-multi-link operation (MLO) that includes a sequence number assigned from a sequence number space (SNS) defined at the MLD level. For example, AP MLD  110  can transmit a GCR frame subject to a GCR-MLO agreement comprising a sequence number assigned from SNS_GCR_MLO where SNS_GCR_MLO is defined at a MLD level. In some embodiments the SNS_GCR_MLO can correspond to: a SNS_GCR_MLO Unsolicited Retry that allows multiplicity, and is indexed by an address; or a SNS_GCR_MLO_BlockAck that allows multiplicity, and is indexed by an address and a traffic identifier (TID). 
     At  1513 , some functions regarding GCR_MLO operations are described in  1515 ,  1520 ,  1525 ,  1535 ,  1540 , and/or  1545  in any order. 
     At  1515 , AP MLD  110  can transition between an Unsolicited Retry policy and a Block Ack (BA) policy for a group address, and use a sequence number assigned from SNS_GCR_MLO for duplicate detection. During the transition, AP MLD  110  can transmit via the transceiver, a last SNS_GCR_MLO sequence number corresponding to the group address, delivered prior to the transition. 
     At  1520 , AP MLD  110  can detect and discard a duplicate GCR frame using the SNS_GCR_MLO sequence number, where the detecting and the discarding are performed at the MLD level. 
     At  1525 , AP MLD  110  supports backward compatibility where a GCR-MLO group includes a legacy GCR-incapable station member. For example, when the GCR frame corresponds to a GCR-MLO group including a legacy GCR-incapable station member, AP MLD  110  can utilize a SNS_GCR_MLO Unsolicited Retry, use sequence number assigned from the SNS_GCR_MLO, and transmit a No-Ack/No-Retry group addressed frame corresponding to the GCR-MLO group on all links of AP MLD  110 . 
     In some embodiments, AP MLD  110  can establish the GCR-MLO agreement comprising a GCR primary link on which members of the GCR-MLO group commit to be available to receive the GCR frame, where the initial GCR frame is transmitted via the primary link. Further, AP MLD  110  can assign a number of retry times for the GCR frame. In some embodiments, AP MLD  110  can establish the GCR-MLO agreement including a GCR primary link set on which members of the GCR-MLO group commit to be available to receive the GCR frame on a link of the GCR primary link set, where the initial GCR frame is transmitted via the links of the GCR primary link set. AP MLD  110  can assign a number of retry times for the GCR frame. 
     At  1535 , AP MLD  110  supports backward compatibility where the GCR-MLO group includes a legacy GCR-single link operation (SLO) station member (e.g., a legacy GCR-single link device (SLD).) In some embodiments, AP MLD  110  can utilize a SNS_GCR_MLO_Unsolicited Retry, and use sequence number assigned from SNS_GCR_MLO for duplicate detection, where the initial GCR frame is transmitted via the GCR primary link or links of the GCR primary link set. In some embodiments, AP MLD  110  can utilize a SNS_GCR_MLO_BlockAck corresponding to the SNS_GCR_MLO sequence number, where the GCR frame is transmitted via the GCR primary link or links of the GCR primary link set. In some embodiments, AP MLD  110  can retransmit, via the transceiver, the GCR frame, based at least on: a BlockAck from members of the GCR-MLO group; a missing BlockAck frame; or availability of a member of the GCR-MLO group on a link of the GCR primary link or the GCR primary link set. 
     At  1540 , AP MLD  110  supports multi-user (MU)-BlockAckRequest (BAR)/BlockAck (BA) when the GCR-MLO group includes one or more GCR-MLO capable non-AP MLDs that support MU-BAR/BA. For example, AP MLD  110  can initiate a block negotiation with the one or more GCR-MLO capable non-AP MLDs that support MU-BAR/BA, and subsequent to transmitting the GCR frame, transmit a MU-BAR to request BA for one or more (e.g. multiple) TIDs. 
     At  1545 , AP MLD  110  includes backward compatibility when the legacy SLO station member does not support MU-BAR. For example, AP MLD  110  can initiate a block negotiation with the legacy SLO station member. Subsequent to transmitting the GCR frame, transmit a BAR to request BA from the legacy SLO station member. 
     At  1550 , AP MLD  110  can support GCR-MLO extension where the group address can be mapped to one or more concealment addresses. For example, AP MLD  110  can determine that all members of the GCR-MLO group support GCR-MLO. Based at least on the determination, AP MLD  110  can map a group address of the GCR-MLO group to one or more concealment addresses that correspond to respective one or more GCR sub-groups. In some embodiments, the respective one or more GCR sub-groups are identified by respective GCR IDs, wherein the respective GCR IDs correspond respective GTK_GCR-MLs that are different than the GTK_GCR_ML. In some embodiments, AP MLD  110  can detect and discard a duplicate concealment address of the one or more concealment addresses, wherein the detect and the discard are performed at the MLD level. 
       FIG.  16    illustrates an example method  1600  for a non-AP MLD for GCR-MLO service, according to some embodiments of the disclosure. As a convenience and not a limitation, method  1600 , can be described with reference to elements of other figures in the disclosure. For example, method  1600  can be performed by a non-AP MLD  120  (e.g.,  120   a - 120   c ) of  FIG.  1   , or processor(s)  265  of system  200  of  FIG.  2    that executes instructions stored in memory  285 . Some functions of signals exchanged are described in  1615 ,  1620 ,  1625 ,  1630 , and  1640 , and the order of the functions may vary. At  1605 , non-AP MLD station (e.g., non-AP MLD station  120   a ) exchanges signals with an AP MLD (e.g., AP MLD  110 ) to setup and/or update a GCR-MLO agreement. 
     At  1615 , non-AP MLD station  120   a  can receive an assigned AID as an AID_ GCR  corresponding to the GCR-MLO group. AP MLD  110  can allocate a resource unit (RU) according to the AID_ GCR  corresponding to a GCR frame of the group address. In some embodiments, the AID is common among all GCR groups. 
     At  1620 , non-AP MLD station  120   a  can transmit parameter input to AP MLD  110  (e.g., a request for certain parameters to be set at a value). Subsequently, AP MLD  110  assigns one or more GCR operation parameters based on the parameter input and other received parameter inputs as well as AP MLD  110  resources. For example, AP MLD  110  can receive from non-AP MLD station  120   a , a first member of the GCR-MLO group, a first parameter in a GCR-MLO Request signal, and based at least on the first parameter and input from another member of the GCR-MLO group corresponding to the group address, AP MLD  110  can assign a GCR operation parameter that is different than the first parameter. Non-AP MLD station  120   a  can receive the GCR operation parameter in a GCR-MLO Response signal from AP MLD  110 . 
     At  1625 , non-AP MLD station  120   a  can contain a GCR-MLO parameters including the group address, and preferred GCR primary link or the GCR primary link set, in an subelement of the DMS Descriptor where the subelement ID uses a reserved value (e.g., subelement ID=2) in REVme_D0. 
     At  1630 , non-AP MLD station  120   a  can use a groupcast or unicast approach to establish a GCR-MLO agreement with AP MLD  110 . For example, non-AP MLD station  120   a  can receive a broadcast frame, groupcast frame or unicast frame that is used to establish an SP for delivery of GCR frames subject to a GCR-MLO agreement. In some embodiments, the broadcast SP includes a broadcast TWT SP that includes the group address corresponding to the GCR-MLO group, a concealment address, and/or an identifier of the GCR-MLO group (e.g., a GCR-MLO group ID) corresponding to the GCR-MLO agreement. When the GCR-SP enables low latency service, a restrictive TWT SP can be modified by AP MLD  110  for GCR-MLO SP establishment. In some embodiments, the SP established using broadcast frames includes a broadcast target wake time (TWT) element that can include the group address corresponding to the GCR-MLO group, the corresponding concealment address, and/or an identifier of the GCR-MLO group (e.g., a GCR-MLO group ID) corresponding to the GCR-MLO agreement. When the GCR-SP is used for low latency service, a non-AP MLD can receive such modified broadcast target wake time (TWT) element. 
     At  1640 , non-AP MLD station  120   a  can utilize a DMS descriptor to establish the GCR-MLO agreement corresponding to the group address. For example, non-AP MLD  120   a  can contain GCR-MLO parameters including the group address, and the preferred GCR primary link or the GCR primary link set, in an subelement of the DMS Descriptor where the subelement ID uses a reserved value (e.g., subelement ID=2) in REVme_D0.0. 
     At  1645 , non-AP MLD station  120   a  can be a first member of the GCR-MLO group and can establish a GCR-MLO agreement with AP MLD  110  at a MLD level. During establishment of the GCR-MLO agreement, the receiving and the transmitting can occur on different links of non-AP MLD station  120   a . For example, the transmitting of the group address, and the GCR primary link or the GCR primary link set can be via any link of non-AP MLD station  120   a , and the receiving of the group address, the corresponding concealment address, the GCR primary link or the GCR primary link set, and the AID that corresponds to the group address, by non-AP MLD station  120   a  can be via any link of non-AP MLD station  120   a . Subsequently, non-AP MLD station  120   a  can receive a GCR frame corresponding to the group address via the GCR primary link or the GCR primary link set. 
     At  1650 , non-AP MLD station  120   a  can receive a solicited or unsolicited GCR update signal that includes: an updated delivery time, an updated GCR primary link or an updated GCR primary link set, and/or an updated AID_ GCR . This update can occur at any time after the establishment of a GCR agreement. 
     At  1655 , non-AP MLD station  120  can begin receiving GCR frames. Some functions of GCR frame reception are described in  1660 ,  1665 ,  1670 ,  1680 ,  1685 , and  1690 . 
     At  1660 , non-AP MLD station  120   a  receives a GCR frame during a GCR frame delivery time via the GCR primary link or via a link of the GCR primary link set. The GCR frame delivery time can be based at least on: a non-GCR-SP or a GCR-SP. When the GCR frame delivery time is based on the non-GCR-SP, the GCR frame delivery time occurs after a DTIM beacon and after a No-Ack/No-Retry group addressed frame delivery. 
     At  1665 , non-AP MLD station  120   a  can receive an A-MPDU including an aggregated payload with aggregated GCR frames that share a common traffic identifier (TID). In some embodiments, non-AP MLD station  120   a  can receive an A-MPDU that includes an aggregated payload with aggregated GCR frames corresponding to two or more TIDs. 
     At  1670 , non-AP MLD station  120   a  can implement: an unsolicited retry GCR-MLO retransmission policy, or a block acknowledgement (BA) GCR-MLO retransmission policy. For example, AP MLD  110  can determine a maximum number of retries of a GCR frame corresponding to the group address; and non-AP MLD station  120   a  can receive the GCR frame according to the maximum number of retries. In some embodiments, non-AP MLD station  120   a  can implement a block acknowledgement (BA) GCR-MLO retransmission policy. Accordingly, AP MLD  110  can determine that a first non-AP MLD  110  operates on more than one link of the GCR primary link set, determine a nominal link of the GCR primary link set on which to receive a GCR BA request (BAR), and non-AP MLD station  120   a  can receive a BAR via the nominal link from AP MLD  110 . 
     At  1680 , non-AP MLD station  120   a  can receive indications from AP MLD  110  to end a GCR-SP sooner than the scheduled duration of the GCR-SP. Thus, non-AP MLD  120   a  can return to a power save mode before the scheduled duration of the GCR-SP. For example, non-AP MLD station  120   a  can receive on one link of the GCR primary link set, a first GCR-SP corresponding to the group address, and receive an indication ending the first GCR-SP before a scheduled duration of the first GCR-SP ends. In some embodiments, the indication received includes but is not limited to: a Cascade Indication=0 in a first trigger frame, or the first trigger frame is not targeted to a member of the GCR-MLO group; a More Trigger Frame (TF)=0 in a second trigger frame and non-AP MLD station  120   a  did not have a resource unit (RU) allocated by the second trigger frame; a Quality of Service (QoS) Null frame; an end of SP (EOSP)=1; More Data (MD)=0 in a GCR frame; and/or a GCR-SP termination indication. 
     At  1685 , non-AP MLD station  120   a  can receive GCR frames within GCR-SPs that overlap with other SPs. For example, AP MLD  110  can transmit on the one link of the GCR primary link set, a TWT SP for an individually addressed frame that overlaps with the first GCR-SP corresponding to the group address. Subsequently, AP MLD  110  can transmit an indication ending the first GCR-SP before a maximum duration of the first GCR-SP, but not affecting the TWT SP. 
     In some examples, non-AP MLD station  120   a  can receive an indication from AP MLD  110  that ends one GCR-SP but not another overlapping GCR-SP. For example, non-AP MLD station  120   a  can receive from AP MLD  110 , on one link of the GCR primary link set, a TWT SP for an individually addressed frame that overlaps with the first GCR-SP corresponding to the group address, and a second GCR-SP. Subsequently, non-AP MLD station  120   a  can receive from AP MLD  110 , an indication ending the first GCR-SP before a maximum duration of the first GCR-SP, but not affecting the second GCR-SP. 
     At  1690 , non-AP MLD station  120   a  can return to a power save mode after AP MLD  110  terminates one or more GCR-SPs and one or more TWT SPs corresponding to non-AP MLD station  120   a . For example, AP MLD  110  can transmit a trigger frame (TF) with More TF=0, terminating the first GCR-SP, the second GCR-SP, and the TWT SP, for non-AP MLD station  120   a  that did not have a resource unit (RU) allocated by the trigger frame. 
       FIG.  17    illustrates another example method  1700  for a non-AP MLD station (e.g., non-AP MLD station  120   a ) for GCR-MLO, according to some embodiments of the disclosure. As a convenience and not a limitation, method  1700 , can be described with reference to elements of other figures in the disclosure. For example, method  1700  can be performed by non-AP MLD station  120   a  of  FIG.  1   , or processor(s)  265  of system  200  of  FIG.  2    that executes instructions stored in memory  285 . 
     At  1705 , non-AP MLD station  120   a  can receive a GCR frame for GCR-multi-link operation (MLO) that includes a sequence number assigned by a sequence number space (SNS) defined at the MLD level. For example, non-AP MLD station  120   a  can receive a GCR frame subject to a GCR-MLO agreement comprising a SNS_GCR_MLO sequence number assigned at a MLD level. In some embodiments the SNS_GCR_MLO can correspond to: a SNS_GCR_MLO_Unsolicited Retry that allows multiplicity, and is indexed by an address (e.g., the group address corresponding to the GCR-MLO group); or a SNS_GCR_MLO_BlockAck that allows multiplicity, and is indexed by an address and a traffic identifier (TID). 
     At  1710 , non-AP MLD station  120   a  can utilize a Group Temporal Key (GTK) generated at the MLD level for the reception of a GCR frame. For example AP MLD  110  can generate a GTK_GCR_ML at the MLD level, wherein the GTK_GCR_ML is used for encryption and decryption of the GCR frame. In some embodiments, non-AP MLD station  120   a  can use the GTK_GCR_ML for encryption and decryption of the group addressed frames that are not subject to a GCR agreement for all links of non-AP MLD station  120   a . In some embodiments, non-AP MLD station  120   a  can use a truncated version of the GTK_GCR_ML for encryption and decryption of the group addressed frames that are not subject to a GCR agreement for a link of non-AP MLD station  120   a.    
     At  1713 , some functions regarding GCR MLO operations are described in  1715 ,  1720 ,  1525 , and/or  1740  in any order. 
     At  1715 , non-AP MLD station  120   a  can transition between an Unsolicited Retry policy and a Block Ack (BA) policy. For example, AP MLD  110  can transition between an Unsolicited Retry policy and a BA policy for a group address. During the transition, non-AP MLD station  120   a  can receive from AP MLD  110 , a last SNS_GCR_MLO sequence number corresponding to the group address, delivered prior to the transition. 
     At  1720 , non-AP MLD station  120   a  can detect and discard a duplicate GCR frame using a sequence number assigned by the SNS_GCR_MLO defined at the MLD level, where the detect and the discard are performed at the MLD level. 
     At  1740 , non-AP MLD station  120   a  can support multi-user (MU)-BlockAckRequest (BAR)/BlockAck (BA). For example, AP MLD  110  can initiate a block negotiation with the non-AP MLD station  120   a . Subsequent to receiving the GCR frame from AP MLD  110 , non-AP MLD station  120   a  can receive a MU-BAR to transmit BA for one or more (e.g. multiple) TIDs. 
     At  1750 , non-AP MLD station  120   a  can support GCR-MLO extension where the group address can be mapped to one or more concealment addresses. For example, AP MLD  110  can determine that all members of the GCR-MLO group support GCR-MLO. Based at least on the determination, AP MLD  110  can map a group address of the GCR-MLO group to one or more concealment addresses that correspond to respective one or more GCR sub-groups. In some embodiments, the respective one or more GCR sub-groups are identified by respective GCR IDs, wherein the respective GCR IDs correspond respective GTK_GCR-MLs that are different than the GTK_GCR_ML. In some embodiments, non-AP MLD station  120   a  can detect and discard a duplicate concealment address of the one or more concealment addresses, where the detecting and the discarding are performed at the MLD level. 
     Various embodiments can be implemented, for example, using one or more well-known computer systems, such as computer system  1800  shown in  FIG.  18   . Computer system  1800  can be any well-known computer capable of performing the functions described herein. For example, and without limitation, system  200  of  FIG.  2   , method  1400  of  FIG.  14   , method  1500  of  FIG.  15   , method  1600  of  FIG.  16   , method  1700  of  FIG.  17    (and/or other apparatuses and/or components shown in the figures) may be implemented using computer system  1800 , or portions thereof. 
     Computer system  1800  includes one or more processors (also called central processing units, or CPUs), such as a processor  1804 . Processor  1804  is connected to a communication infrastructure  1806  that can be a bus. One or more processors  1804  may each be a graphics processing unit (GPU). In an embodiment, a GPU is a processor that is a specialized electronic circuit designed to process mathematically intensive applications. The GPU may have a parallel structure that is efficient for parallel processing of large blocks of data, such as mathematically intensive data common to computer graphics applications, images, videos, etc. 
     Computer system  1800  also includes user input/output device(s)  1803 , such as monitors, keyboards, pointing devices, etc., that communicate with communication infrastructure  1806  through user input/output interface(s)  1802 . Computer system  1800  also includes a main or primary memory  1808 , such as random access memory (RAM). Main memory  1808  may include one or more levels of cache. Main memory  1808  has stored therein control logic (e.g., computer software) and/or data. 
     Computer system  1800  may also include one or more secondary storage devices or memory  1810 . Secondary memory  1810  may include, for example, a hard disk drive  1812  and/or a removable storage device or drive  1814 . Removable storage drive  1814  may be a floppy disk drive, a magnetic tape drive, a compact disk drive, an optical storage device, tape backup device, and/or any other storage device/drive. 
     Removable storage drive  1814  may interact with a removable storage unit  1818 . Removable storage unit  1818  includes a computer usable or readable storage device having stored thereon computer software (control logic) and/or data. Removable storage unit  1818  may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and/any other computer data storage device. Removable storage drive  1814  reads from and/or writes to removable storage unit  1818  in a well-known manner. 
     According to some embodiments, secondary memory  1810  may include other means, instrumentalities or other approaches for allowing computer programs and/or other instructions and/or data to be accessed by computer system  1800 . Such means, instrumentalities or other approaches may include, for example, a removable storage unit  1822  and an interface  1820 . Examples of the removable storage unit  1822  and the interface  1820  may include a program cartridge and cartridge interface (such as that found in video game devices), a removable memory chip (such as an EPROM or PROM) and associated socket, a memory stick and USB port, a memory card and associated memory card slot, and/or any other removable storage unit and associated interface. 
     Computer system  1800  may further include a communication or network interface  1824 . Communication interface  1824  enables computer system  1800  to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (individually and collectively referenced by reference number  1828 ). For example, communication interface  1824  may allow computer system  1800  to communicate with remote devices  1828  over communications path  1826 , which may be wired and/or wireless, and which may include any combination of LANs, WANs, the Internet, etc. Control logic and/or data may be transmitted to and from computer system  1800  via communication path  1826 . 
     The operations in the preceding embodiments can be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations in the preceding embodiments may be performed in hardware, in software or both. In some embodiments, a tangible, non-transitory apparatus or article of manufacture includes a tangible, non-transitory computer useable or readable medium having control logic (software) stored thereon is also referred to herein as a computer program product or program storage device. This includes, but is not limited to, computer system  1800 , main memory  1808 , secondary memory  1810  and removable storage units  1818  and  1822 , as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (such as computer system  1800 ), causes such data processing devices to operate as described herein. 
     Based on the teachings contained in this disclosure, it will be apparent to persons skilled in the relevant art(s) how to make and use embodiments of the disclosure using data processing devices, computer systems and/or computer architectures other than that shown in  FIG.  18   . In particular, embodiments may operate with software, hardware, and/or operating system implementations other than those described herein. 
     It is to be appreciated that the Detailed Description section, and not the Summary and Abstract sections, is intended to be used to interpret the claims. The Summary and Abstract sections may set forth one or more but not all exemplary embodiments of the disclosure as contemplated by the inventor(s), and thus, are not intended to limit the disclosure or the appended claims in any way. 
     While the disclosure has been described herein with reference to exemplary embodiments for exemplary fields and applications, it should be understood that the disclosure is not limited thereto. Other embodiments and modifications thereto are possible, and are within the scope and spirit of the disclosure. For example, and without limiting the generality of this paragraph, embodiments are not limited to the software, hardware, firmware, and/or entities illustrated in the figures and/or described herein. Further, embodiments (whether or not explicitly described herein) have significant utility to fields and applications beyond the examples described herein. 
     Embodiments have been described herein with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternate boundaries can be defined as long as the specified functions and relationships (or equivalents thereof) are appropriately performed. In addition, alternative embodiments may perform functional blocks, steps, operations, methods, etc. using orderings different from those described herein. 
     References herein to “one embodiment,” “an embodiment,” “an example embodiment,” or similar phrases, indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it would be within the knowledge of persons skilled in the relevant art(s) to incorporate such feature, structure, or characteristic into other embodiments whether or not explicitly mentioned or described herein. 
     The breadth and scope of the disclosure should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. 
     The present disclosure contemplates that the entities responsible for the collection, analysis, disclosure, transfer, storage, or other use of such personal information data will comply with well-established privacy policies and/or privacy practices. In particular, such entities should implement and consistently use privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining personal information data private and secure. Such policies should be easily accessible by users, and should be updated as the collection and/or use of data changes. Personal information from users should be collected for legitimate and reasonable uses of the entity and not shared or sold outside of those legitimate uses. Further, such collection/sharing should only occur after receiving the informed consent of the users. Additionally, such entities should consider taking any needed steps for safeguarding and securing access to such personal information data and ensuring that others with access to the personal information data adhere to their privacy policies and procedures. Further, such entities can subject themselves to evaluation by third parties to certify their adherence to widely accepted privacy policies and practices. In addition, policies and practices should be adapted for the particular types of personal information data being collected and/or accessed and adapted to applicable laws and standards, including jurisdiction-specific considerations. For instance, in the US, collection of, or access to, certain health data may be governed by federal and/or state laws, such as the Health Insurance Portability and Accountability Act (HIPAA); whereas health data in other countries may be subject to other regulations and policies and should be handled accordingly. Hence different privacy practices should be maintained for different personal data types in each country.

Metadata:
Filing Date: 20220415
Publication Date: 20240604
Grant Date: 20240604
Priority Date: 20210722
Inventors: WANG, QI
KNECKT, JARKKO L.
LIU, YONG
JIANG, JINJING
BOGER, YOEL
WU, TIANYU
YONG, SU KHIONG
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W4/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L1/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W76/11", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W4/06", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W84/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W4/06", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W76/15", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/40", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W72/30", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L1/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/08", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 82270659