Extreme-high-throughput fast initial link setup support in multi-link operation in wireless communications

1. A method, comprising:

performing a fast initial link setup (FILS) procedure to establish wireless communications between an access point (AP) multi-link device (MLD) and a non-AP station (STA) MLD over a plurality of links; and

communicating over one or more links of the plurality of links upon completion of the FILS procedure,

wherein the communicating comprises communicating a retransmitted frame with a Key identifier (ID) field in a Galois/Counter Mode Protocol (GCMP) header of the frame being equal to a Key ID field of a first transmitted medium access control (MAC) protocol data unit (MPDU), and

wherein the performing of the FILS procedure comprises the AP MLD performing an association or reassociation procedure by:

generating an association or reassociation response frame by constructing a Key Delivery element indicating:

a current group temporal key (GTK) and key receive sequence counter (RSC) associated with each link of the plurality of links,

a current integrity group temporal key (IGTK) and IGTK packet number (IPN) associated with each link of the plurality of links in an event that management frame protection is enabled, and

a current beacon integrity group temporal key (BIGTK) and BIGTK packet number (BIPN) associated with each link of the plurality of links in an event that beacon protection is enabled; and

transmitting the association or reassociation response frame to the non-AP STA MLD.

2. The method of claim 1 , wherein a Multiple Links Presence Indicator subfield of a FILS Discovery frame transmitted in the FILS procedure indicates whether an SSID of the AP MLD is different from the SSID of the AP of the plurality of APs in the AP MLD transmitting the FILS Discovery frame.

3. The method of claim 2 , wherein a FILS Discovery Information field that contains the Multiple Links Presence Indicator subfield further comprises a Short MLD SSID subfield containing a 4-octet short SSID of the AP MLD.

4. The method of claim 1 , wherein the performing of the FILS procedure comprises the non-AP STA MLD performing the association or reassociation procedure with higher-layer protocol (HLP) encapsulation by:

constructing a FILS HLP Container element to form a HLP packet; and

transmitting the FILS HLP Container element in an association or reassociation request frame to the AP MLD,

wherein the FILS HLP Container element comprises a destination medium access control (MAC) address, a source MAC address, and the HLP packet in a MAC service data unit (MSDU) format, and

wherein the source MAC address comprises an MLD MAC address of the non-AP STA MLD.

5. The method of claim 4 , wherein the performing of the FILS procedure further comprises the AP MLD receiving and decapsulating the HLP packet by:

extracting the destination MAC address, the source MAC address, and the HLP packet from the FILS HLP Container element;

determining whether the extracted source MAC address matches the MLD MAC address of the non-AP STA MLD associated with the source MAC address of the association or reassociation request frame; and

responsive to determining that the extracted source MAC address matches the MLD MAC address of the non-AP STA MLD:

constructing a frame containing the HLP packet; and

delivering the frame to an upstream network or a basic service set (BSS),

wherein the FILS HLP Container element is discarded by the AP MLD responsive to determining that the extracted source MAC address does not match the MLD MAC address of the non-AP STA MLD.

6. The method of claim 1 , wherein the performing of the FILS procedure comprises performing an authentication procedure with one public key across the plurality of links by the plurality of APs in the AP MLD and by a plurality of STAs in the non-AP STA MLD across the plurality of links.

7. The method of claim 6 , wherein Diffie-Hellman values in the plurality of APs in the AP MLD are common across the plurality of links, and wherein Diffie-Hellman values in the plurality of STAs in the non-AP STA MLD are common across the plurality of links.

8. The method of claim 1 , wherein the performing of the FILS procedure comprises performing an authentication procedure using a pairwise master key (PMK) and a PMK identifier (PMKID), and wherein each of the PMK and PMKID is generated using MLD-level information related to the AP MLD and the non-AP STA MLD.

9. The method of claim 1 , wherein the performing of the FILS procedure comprises the non-AP STA MLD performing an authentication procedure by:

generating an authentication frame by:

encoding an MLD medium access control (MAC) address of the non-AP STA MLD which is a wireless medium (WM) MAC address for each link of one or more supported links among the plurality of links; and

including the encoded MAC address in a Multiple Link Address element of the authentication frame; and

transmitting the authentication frame to the AP MLD.

10. The method of claim 1 , wherein the performing of the FILS procedure comprises the AP MLD performing an authentication procedure by:

generating an authentication frame by:

encoding an MLD medium access control (MAC) address of the AP MLD which is a wireless medium (WM) MAC address for each link of one or more supported links among the plurality of links; and

including the encoded MAC address in a Multiple Link Address element of the authentication frame; and

transmitting the authentication frame to the non-AP STA MLD.

11. The method of claim 1 ,

wherein the Key Delivery element contains a key data encapsulation (KDE) List field comprising a multi-link GTK KDE, a multi-link IGTK KDE, and a multi-link BIGTK KDE associated with each link of one or more links among the plurality of links on which the Key Delivery element is transmitted.

12. The method of claim 11 , wherein the multi-link GTK KDE comprises:

a Key identifier (ID) field indicating a value of a GTK key identifier,

a Transmit field indicating a link on which the GTK is transmitted,

a Link ID field indicating a link on which the GTK is being installed, and

a Key RSC field containing a RSC for the GTK being installed on the link indicated by the Link ID field,

wherein the GTK key identifier is MLD-level for the AP MLD and the non-AP STA MLD supporting a same key identifier.

13. The method of claim 11 , wherein the multi-link IGTK KDE comprises:

a Key identifier (ID) field indicating a value of an IGTK key identifier,

a Link ID field indicating a link on which the IGTK is being installed, and

an IPN field corresponding to a last packet number used by a transmitter on the link indicated by the Link ID field and used by a receiver as an initial value for a Broadcast Integrity Protocol (BIP) replay counter for the IGTK,

wherein the IGTK key identifier is MLD-level for the AP MLD and the non-AP STA MLD supporting a same key identifier.

14. The method of claim 11 , wherein the multi-link BIGTK KDE comprises:

a Key identifier (ID) field indicating a value of an BIGTK key identifier,

a Link ID field indicating a link on which the BIGTK is being installed, and

a BIPN field corresponding to a BIPN value carried in a Management Message Integrity Check (MIC) element (MME) of a last protected beacon frame on the link indicated by the Link ID field and used by a receiver as an initial value for a Broadcast Integrity Protocol (BIP) replay counter for the BIGTK,

wherein the BIGTK key identifier is MLD-level for the AP MLD and the non-AP STA MLD supporting a same key identifier.

15. An apparatus, comprising:

a transceiver configured to communicate wirelessly; and

a processor coupled to the transceiver and configured to perform operations comprising:

performing, via the transceiver, a fast initial link setup (FILS) procedure to establish wireless communications between an access point (AP) multi-link device (MLD) and a non-AP station (STA) MLD over a plurality of links; and

communicating, via the transceiver, over one or more links of the plurality of links upon completion of the FILS procedure,

wherein, in communicating, the processor is configured to communicate a retransmitted frame with a Key identifier (ID) field in a Galois/Counter Mode Protocol (GCMP) header of the frame being equal to a Key ID field of a first transmitted medium access control (MAC) protocol data unit (MPDU), and

wherein, in performing the FILS procedure, the processor, implemented in the AP MLD, performs an association or reassociation procedure by:

generating an association or reassociation response frame by constructing a Key Delivery element indicating:

a current group temporal key (GTK) and key receive sequence counter (RSC) associated with each link of the plurality of links,

a current integrity group temporal key (IGTK) and IGTK packet number (IPN) associated with each link of the plurality of links in an event that management frame protection is enabled, and

a current beacon integrity group temporal key (BIGTK) and BIGTK packet number (BIPN) associated with each link of the plurality of links in an event that beacon protection is enabled; and

transmitting the association or reassociation response frame to the non-AP STA MLD.

16. The apparatus of claim 15 , wherein a Multiple Links Presence Indicator subfield of a FILS Discovery frame transmitted in the FILS procedure indicates whether the SSID of the AP MLD is different from the SSID of the AP of the plurality of APs in the AP MLD transmitting the FILS Discovery frame, and wherein a FILS Discovery Information field that contains the Multiple Links Presence Indicator subfield further comprises a Short MLD SSID subfield containing a 4-octet short SSID of the AP MLD.

17. The apparatus of claim 15 , wherein:

when implemented in the AP MLD, in performing the FILS procedure, the processor receives and decapsulating the HLP packet by:

extracting the destination MAC address, the source MAC address, and the HLP packet from the FILS HLP Container element;

determining whether the extracted source MAC address matches the MLD MAC address of the non-AP STA MLD associated with the source MAC address of the association or reassociation request frame; and

responsive to determining that the extracted source MAC address matches the MLD MAC address of the non-AP STA MLD:

constructing a frame containing the HLP packet; and

delivering the frame to an upstream network or a basic service set (BSS), or

responsive to determining that the extracted source MAC address does not match the MLD MAC address of the non-AP STA MLD, discarding the FILS HLP Container element.

18. The apparatus of claim 15 , wherein, in performing the FILS procedure, the processor performs an authentication procedure with one public key across the plurality of links by the plurality of APs in the AP MLD and by a plurality of STAs in the non-AP STA MLD across the plurality of links, wherein Diffie-Hellman values in the plurality of APs in the AP MLD are common across the plurality of links, and wherein Diffie-Hellman values in the plurality of STAs in the non-AP STA MLD are common across the plurality of links.

19. The apparatus of claim 15 ,

wherein the Key Delivery element contains a key data encapsulation (KDE) List field comprising a multi-link GTK KDE, a multi-link IGTK KDE, and a multi-link BIGTK KDE associated with each link of one or more links among the plurality of links on which the Key Delivery element is transmitted.