Patent ID: 7489666
Filing Date: 2009-02-10
Classification: H04W

Abstract:
1. A media access control (MAC) apparatus comprising: a first transmission queue exclusively storing a voice transmission frame; a second transmission queue storing a general transmission frame and not storing voice transmission frames; a frame handler extracting user priority information from a frame input from an upper layer, mapping the frame to a relevant access category (AC), and storing the frame in the first transmission queue or the second transmission 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 performing a separate backoff operation for each AC using a predetermined backoff count value; a contention resolution unit, which transmits the voice frame having a higher user priority first and gives up transmission of the general frame when two ACs simultaneously end the backoff operations; a frame detector, which determines whether or not to transmit an acknowledgment (ACK) frame by checking an ACK policy bit from a header of the received frame when a frame is received from a physical layer; a receive queue storing the received frame and transmitting the frame to the upper layer; and wherein the apparatus flexibly receives an ACK response based on the determination by the frame detector whether or not to transmit the ACK frame, but does not receive the ACK response if the received frame is the voice frame, wherein the frame handler maps the received frame to an AC[3] when the received frame is a voice frame and to one of AC[0]-AC[2] when the received frame is a general frame, wherein the MAC controller performs