Patent ID: 7616612
Filing Date: 2009-11-10
Classification: H04W

Abstract:
1. A media access control (MAC) apparatus comprising: a first transmit queue storing a voice frame; a second transmit queue storing a non-voice frame; a frame handler extracting a user priority, from a frame received from an upper layer, mapping the frame to an access category (AC), and storing the frame in the first transmit queue or the second transmit queue; a MAC controller determining a backoff operation timing and a frame transmission timing by checking a media status; a first arbitration inter-frame space (AIFS) timer and a second AIFS timer, each reducing a predetermined timer value set by the MAC controller by a predetermined value unit; a first backoff block and a second backoff block, each independently performing backoff operations for each AC using a predetermined backoff count value wherein the backoff count value corresponds to a contention window (CW) wherein the value of the contention window (CW) incrementally increases by CW a contention resolution unit, which transmits the voice frame having a higher priority first and gives up transmission of the non-voice frame when two ACs simultaneously end the backoff operations; a frame detector, which determines whether or not to transmit an ACK frame by checking an ACK policy bit from a header of the received frame when a frame is received from a physical layer; and a receive queue storing the received frame and transmitting the received frame to the upper layer.