Patent ID: 7974302

Claim:
A media access control method of a wireless communication system, the method comprising: transmitting one or more frames based on a contention-free based media access protocol at a timing when receiving a predetermined frame from a media access controller, wherein the predetermined frame includes information to determine the timing; and transmitting one or more frames based on a carrier sense multiple access/collision avoidance protocol (CSMA/CA) when not receiving the predetermined frame from the media access controller, wherein the contention based media access protocol uses a plurality of inter frame spaces (IFSs), wherein the duration of IFS with a higher priority is shorter than the duration of IFS with a lower priority, wherein CSMA/CA protocol comprise: monitoring a state of a channel and transmitting a Request To Send frame to the media access controller when the channel is free during a predetermined duration of IFS, receiving a Clear to Send frame from the media access controller after the shortest IFS; and transmitting a frame to the media access controller after the shortest IFS.