Systems and methods for multicast retransmission over a secure wireless LAN

摘要

Systems and methods for broadcast and multicast retransmissions within a protected wireless communications system are described. Retransmitted broadcast or multicast frames are designated by modification of fields or subfields in the MAC header of the frame which are constituent parts of the additional authentication data used to generate encryption keys. Such modifications cause legacy receivers to disregard the retransmitted frames or render legacy receivers to be unable to decrypt the retransmitted frame, avoiding the generation of duplicate frames. Non-legacy receivers recognizing the modification conventions can restore the MAC header to the original state and can reconstruct the original encryption keys and decrypt the retransmitted frames. A non-legacy transmitter can retransmit a frame without the need to re-encrypt the frame.