Group address frames replay protection in multi-link and other improvements to multi-link system

A method of performing wireless communication in a network to protect against group address replay attacks, comprising:

• (a) utilizing a multiple-link devices (MLD), having stations (STAs) connected to a first link (link A) and a second link (link B), and configured for performing frame transmissions between the medium access control (MAC) layers of an IEEE 802.11 network as an access point (AP) MLD or a non-AP MLD, for wirelessly communicating with other STAs using a carrier sense multiple access/collision avoidance (CSMA/CA) mechanism on a wireless local area network (WLAN) in which enhanced distributed channel access (EDCA) is utilized for random channel access on all the links to perform steps of a wireless communications protocol for said MLD;
• (b) wherein a non-AP MLD has multiple affiliated non-AP STAs operating over multiple links and is associated with an AP MLD on multiple links, with the AP which is always in an awake state on link A and link B;
• (c) wherein the non-AP MLD monitors a link A and is in doze state on another link B, and can switch to monitor link B and be in doze state on link A;
• wherein when the non-AP MLD is in doze state on a specific link, it is unable to receive group addressed or broadcast frames on that specific link;
• (d) receiving a signaling message from the associated AP MLB, prior to either link A or link B going into a doze state, for updating replay counters associated with that specific link beacon integrity group temporal key (BIGTK), or integrity group temporal key (IGTK), or group temporal key (GTK), by the non-AP MLD when monitoring a specific link, based on the received group addressed/broadcast frames on that specific link;
• (e) wherein upon link A going into a doze state and thus being unable to receive either group addressed or broadcast frames on link A, then link B receives group frames which include a sequence identifier and a packet identifier;
• and
• (f) sending signaling messages from the non-AP MLD between its link A and link B for synchronizing packet identifiers for group addressed and broadcast frames;
• wherein upon switching roles between link A and link B wherein link A is now receiving group frames and link B is going into a doze state, then link A determines an expected last packet identifier from the signaling between link A and link B to in detecting replay attacks, despite sequence identifier wrap-around events.

An apparatus for wireless communication in a network, the apparatus comprising:

• (a) a wireless multiple-link device (MLD), having stations (STAs) connected to a first link (link A) and a second link (link B), and configured for performing frame transmissions between the medium access control (MAC) layers of an IEEE 802.11 network as an access point (AP) MLD or a non-AP MLD, for wirelessly communicating with other STAs using a carrier sense multiple access/collision avoidance (CSMA/CA) mechanism on a wireless local area network (WLAN) in which enhanced distributed channel access (EDCA) is utilized for random channel access on all the links;
• (b) a processor coupled to said MLD for operating on the WLAN;
• (c) a non-transitory memory storing instructions executable by the processor for communicating with other STAs;
• and
• (d) wherein said instructions, when executed by the processor, perform steps of a wireless communications protocol for said MLD to protect against group address replay attacks, comprising:
• (i) wherein a non-AP MLD has multiple affiliated non-AP STAs operating over multiple links and is associated with an AP MLD on multiple links, with the AP always in an awake state on link A and link B;
• (ii) wherein the non-AP MLD monitors a link A and is in doze state on another link B, and can switch to monitor link B and be in doze state on link A;
• wherein when the non-AP MLD is in doze state on a specific link, it is unable to receive group addressed or broadcast frames on that specific link;
• (iii) updating replay counters associated with that specific link beacon integrity group temporal key (BIGTK), or integrity group temporal key (IGTK), or group temporal key (GTK), by the non-AP MLD when monitoring a specific link, based on the received group addressed/broadcast frames on that specific link;
• (iv) wherein the non-AP MLD receives a signaling message on link A, which includes a packet identifier or a portion of a packet identifier, or a difference of values of packet identifier in comparison to the identifier of the same type of frame, of the group addressed/broadcast frame on link B, from an AP MLD which has recently sent, or is about to send, a group addressed or broadcast frame on link B;
• (v) wherein the non-AP MLD receives a signaling message on a link it was not previously monitoring, said signaling message including a packet identifier or a portion of a packet identifier of the group addressed/broadcast frame, as sent by an AP MLD that sent, or will send, a group addressed/broadcast frame;
• (vi) wherein the expected last packet identifier or a portion of the expected last packet identifier of the signaling message sent on link B, is derived by the receiver of the message with a certain accuracy as selected from one or more of the following:
• (a) the expected transmission frequency/periodicity of the signaling message;
• (b) the starting value of a packet identifier and a starting time;
• and (c) the elapsed number of periods based on the expected transmission frequency from the starting time;
• and
• (vii) wherein the non-AP MLD identifies the expected last packet identifier of a signaling message on link B, and the replay counter for the signaling message is updated by the expected last packet identifier;
• wherein the non-AP MLD uses the updated replay counter to determine the validity of the signaling message received on link B.