Uplink and downlink data and context handling for roaming

An access point (AP) multi-link device (MLD) of a seamless mobility domain (SMD), comprising:

• a processor;
• two or more affiliated APs, each affiliated AP operative to establish a corresponding link with an affiliated station of a non-AP MLD, and
• a memory communicatively coupled to the processor, wherein the memory comprises a Multi-Link Operation (MLO) management logic configured to perform operations comprising:
• establishing, by the AP MLD, an association between a seamless mobility domain (SMD) and a non-AP MLD, wherein the SMD comprises the AP MLD and a second AP MLD, and wherein the association comprises at least one link between a first affiliated AP of the AP MLD and a first STA of the non-AP MLD;
• maintaining, by the AP MLD, a downlink (DL) transmit buffer comprising DL data MPDUs and corresponding sequence numbers for the DL data MPDUs, the MPDUs transmitted or to be transmitted to the non-AP MLD;
• maintaining a SN of a first unacknowledged DL data MPDU in the DL transmit buffer (WinStartO);
• receiving, by the AP MLD, a roaming request from the non-AP MLD, the roaming request indicating intent to roam to the second AP MLD;
• responsive to the roaming request, transferring, by the AP MLD, DL context information to the second AP MLD, the DL context information comprising a SN of the first unacknowledged DL data MPDU (WinStartO) and a next SN value indicating a SN corresponding to a first DL data MPDU that the second AP MLD is expected to transmit to the non-AP MLD;
• and
• transmitting, by the AP MLD, a roaming response to the non-AP MLD.

A non-transitory computer readable storage medium comprising instructions that when executed configure one or more processors of an access point (AP) multi-link device (MLD) to perform operations comprising:

• establishing, by the AP MLD, an association between a seamless mobility domain (SMD) and a non-AP MLD, wherein the SMD comprises the AP MLD and a second AP MLD, and wherein the association comprises at least one link between a first affiliated AP of the AP MLD and a first STA of the non-AP MLD;
• maintaining, by the AP MLD, a downlink (DL) transmit buffer comprising DL data MPDUs and corresponding sequence numbers for the DL data MPDUs, the MPDUs transmitted or to be transmitted to the non-AP MLD;
• maintaining a SN of a first unacknowledged DL data MPDU in the DL transmit buffer (WinStartO);
• receiving, by the AP MLD, a roaming request from the non-AP MLD, the roaming request indicating intent to roam to the second AP MLD;
• responsive to the roaming request, transferring, by the AP MLD, DL context information to the second AP MLD, the DL context information comprising a SN of the first unacknowledged DL data MPDU (WinStartO) and a next SN value indicating a SN corresponding to a first DL data MPDU that the second AP MLD is expected to transmit to the non-AP MLD;
• and
• transmitting, by the AP MLD, a roaming response to the non-AP MLD.