Group cast with retries (GCR) for multi-link operation (MLO)
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.
1. An access point (AP) multi-link device (MLD), comprising:
a transceiver; and
a processor communicatively coupled to the transceiver, configured to:
generate a Group Temporal Key (GTK)_Group Cast with Retries (GCR)_Multi-link (ML) at a MLD level for transmission of a GCR frame, wherein the GCR frame includes a group address subject to a GCR-multi-link operation (MLO) agreement;
encrypt the GCR frame using the GTK_GCR_ML; and
transmit, via the transceiver, the encrypted GCR frame.
2. The AP MLD of claim 1 , wherein the GCR frame comprises a sequence number assigned from a sequence number space (SNS)_GCR_MLO defined at the MLD level.
3. The AP MLD of claim 2 , wherein the processor is further configured to:
transition between an Unsolicited Retry policy and a Block Ack (BA) policy for the group address.
4. The AP MLD of claim 2 , wherein the GCR frame corresponds to a GCR-MLO group comprising a legacy GCR-incapable station member, the processor is further configured to:
transmit, via the transceiver, a group addressed frame corresponding to the GCR-MLO group on all links of the AP MLD using a No-Ack/No-Retry group addressed frame format, wherein the group addressed frame using the No-Ack/No-Retry group addressed frame format includes the sequence number at the MLD level.
5. The AP MLD of claim 1 , wherein the processor is further configured to:
use the GTK_GCR_ML for encryption of the GCR frame for all links of the AP MLD.
6. The AP MLD of claim 1 , wherein the processor is further configured to:
use a truncated version of the GTK_GCR_ML for encryption and decryption of a group addressed frame that is not subject to a GCR agreement for a link of the AP MLD.
7. The AP MLD of claim 1 , wherein the processor is further configured to:
establish the GCR-MLO agreement comprising a GCR primary link on which members of a GCR-MLO group commit to be available to receive the GCR frame, wherein an initial GCR frame is transmitted via the GCR primary link; and
determine a maximum number of retry times for the GCR frame.
8. The AP MLD of claim 1 , wherein the processor is further configured to:
establish the GCR-MLO agreement comprising a GCR primary link set on which members of a GCR-MLO group commit to be available to receive the GCR frame on a link of the GCR primary link set, wherein an initial GCR frame is transmitted via links of the GCR primary link set; and
determine a maximum number of retry times for the GCR frame.
9. 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:
generating a Group Temporal Key (GTK)_Group Cast with Retries (GCR) Multi-link (ML) at a MLD level for transmission of a GCR frame, wherein the GCR frame includes a group address subject to a GCR-multi-link operation (MLO) agreement;
encrypting the GCR frame using the GTK_GCR ML; and
transmitting, the encrypted GCR frame.
10. The non-transitory computer-readable medium of claim 9 , wherein the GCR frame comprises a sequence number assigned from a sequence number space (SNS)_GCR_MLO defined at the MLD level.
11. The non-transitory computer-readable medium of claim 9 , wherein the GCR frame corresponds to a GCR-MLO group comprising one or more GCR-MLO capable non-AP MLDs that support multi-user (MU) BlockAckRequest (BAR)/BlockAck (BA), the operations further comprise:
initiating 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, transmitting a MU-BAR to request BA for multiple traffic identifiers (TIDs).
12. The non-transitory computer-readable medium of claim 11 , wherein a legacy GCR-single link operation (SLO) station member of the GCR-MLO group does not support the MU-BAR, the operations further comprise:
initiating the block negotiation with the legacy SLO station member; and
subsequent to transmitting the GCR frame, transmitting a BAR to request BA from the legacy SLO station member.
13. The non-transitory computer-readable medium of claim 11 , wherein the operations further comprise:
retransmitting the GCR frame based at least on: a BlockAck from members of the GCR-MLO group; a missing BlockAck frame; or an availability of a member of the GCR-MLO group on a link of a GCR primary link or a GCR primary link set, or other links.
14. A method for an access point (AP) multi-link device (MLD), comprising:
generating a Group Temporal Key (GTK)_Group Cast with Retries (GCR)_Multi-link (ML) at a MLD level for transmission of a GCR frame, wherein the GCR frame includes a group address subject to a GCR-multi-link operation (MLO) agreement;
encrypting the GCR frame using the GTK_GCR ML; and
transmitting the encrypted GCR frame.
15. The method of claim 14 , wherein the GCR frame comprises a sequence number assigned from a sequence number space (SNS)_GCR_MLO defined at the MLD level.
16. The method of claim 15 , further comprising transitioning between an Unsolicited Retry policy and a Block Ack (BA) policy for the group address.
17. The method of claim 15 , wherein the GCR frame corresponds to a GCR-MLO group comprising a legacy GCR-incapable station member, the method further comprises transmitting a group addressed frame corresponding to the GCR-MLO group on all links of the AP MLD using a No-Ack/No-Retry group addressed frame format, wherein the group addressed frame using the No-Ack/No-Retry group addressed frame format includes the sequence number at the MLD level.
18. The method of claim 14 , further comprising using the GTK_GCR ML for encryption of the GCR frame for all links of the AP MLD.
19. The method of claim 14 , further comprising using a truncated version of the GTK_GCR_ML for encryption and decryption of a group addressed frame that is not subject to a GCR agreement for a link of the AP MLD.
20. The method of claim 14 , further comprising:
establishing the GCR-MLO agreement comprising a GCR primary link set on which members of a GCR-MLO group commit to be available to receive the GCR frame on a link of the GCR primary link set, wherein an initial GCR frame is transmitted via links of the GCR primary link set; and
determining a maximum number of retry times for the GCR frame.