US Patent 7489648 Optimizing 802.11 power-save for VLAN

A method for an access point to provide immediate delivery of low-latency data packets to one virtual local area network when there are one or more associated stations operating in Power-Save-Protocol on another virtual local area network. The access point observes all the virtual local area networks to which it provides access to associated stations. The access point then determines which of the virtual local area networks contains only active stations. The access point then tracks the virtual local area network having only active stations and immediately transmits to the network incoming multicast/broadcast data packets.