Patent ID: 7701889

Claim:
An access point (AP) apparatus for allocating a transmission period in a frame period in a wireless network system, the apparatus comprising: a processor which generates a first power save multi-poll (PSMP) frame allocating a downlink period and an uplink period to a station (STA), and generates a subsequent PSMP frame allocating at least one of an additional downlink period and an additional uplink period to the STA after the downlink period and uplink period; and a transceiver which transmits data to the STA during the downlink period and receives data from the STA during the uplink period, and retransmits data to the STA during the additional downlink period in response to there being data to be retransmitted and receives data retransmitted from the STA during the additional uplink period in response to there being data to be retransmitted from the STA, wherein the subsequent PSMP frame is an additional PSMP frame to follow the first PSMP frame in the frame period having periodic duration.