# US 12,004,050 B2 · Group cast with retries (GCR) in a multi-link WLAN system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,004,050 B2 - Document ID: US12004050B2 - Status: Granted - Kind: B2 - Application number: 17/721,978 - Filed: 2022-04-15 - Published: 2023-02-02 - Granted: 2024-06-04 - Earliest claimed: 2021-07-22 - Assignees: Apple Inc. - Applicants: Apple Inc. - Inventors: Qi Wang; Jarkko L. Kneckt; Yong Liu; Jinjing Jiang; Yoel Boger; Tianyu Wu; Su Khiong Yong - Web page: https://patentgrep.com/patent/US12004050B2 ## CPC - H04W 4/06: Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services - H04W 76/11: Allocation or use of connection identifiers - H04L 1/08: by repeating transmission, e.g. Verdan system {(H04L1/1858 and H04L1/189 take precedence)} - H04W 72/30: Resource management for broadcast services - H04W 76/15: Setup of multiple wireless link connections - H04W 76/40: for selective distribution or broadcast - H04W 48/12: using downlink control channel - H04W 84/12: WLAN [Wireless Local Area Networks] - H04W 88/08: Access point devices - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## 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 ### Claim 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. ### Claim 2 (depends on 1) The AP MLD of claim 1, wherein the GCR frame delivery time is based on a non-GCR-service period (SP). ### Claim 3 (depends on 2) 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. ### Claim 4 (depends on 1) 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. ### Claim 5 (depends on 1) 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. ### Claim 6 (depends on 1) 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. ### Claim 7 (depends on 6) 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. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) 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. ### Claim 10 (depends on 9) 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. ### Claim 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. ### Claim 12 (depends on 11) 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. ### Claim 13 (depends on 11) 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. ### Claim 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. ### Claim 15 (depends on 14) 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. ### Claim 16 (depends on 14) 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. ### Claim 17 (depends on 14) 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. ### Claim 18 (depends on 14) 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. ### Claim 19 (depends on 14) 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. ### Claim 20 (depends on 19) 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.