Patent ID: 8693380

Claim:
A method for transmitting data in a wireless local area network, the method comprising: buffering, at an access point, frames including data to be transmitted to stations capable of operating in a power-saving state; prior to sending a beacon frame, the access point dividing an interval between beacon frames into a number of time slices; and transmitting, by the access point, the beacon frame which includes information about a time slice included within the number of time slices when buffered frames destined for particular stations will be sent; assigning an association identifier to each station and each multicast group associated with the access point, wherein a multicast group is assigned a MAC address; indicating, in the transmitting step, if there are buffered frames for each station and each multicast group by using the association identifier; and maintaining a mapping between association identifiers and MAC addresses; wherein the transmitting step includes transmitting a slicing index providing a relative starting position of the time slices assigned to a destination corresponding to a specific MAC address and a slicing control field which indicates the number of bits in each slicing index.