Patent ID: 8023480

Claim:
A method of preventing a plurality of stations in a wireless local area network (WLAN) from colliding with each other when attempting to access a medium, the method comprising: determining transmission capabilities of the plurality of stations in the WLAN; arranging a frame of a station to prevent the plurality of stations from colliding with each other when attempting to access the medium according to a result of the determining the transmission capabilities; and transmitting the arranged frame to be used in the WLAN to the other stations, wherein, if the result of the determining the transmission capabilities of the plurality of stations indicates that at least one high throughput (HT) station and at least one legacy station coexist in the WLAN or that at least two HT stations using channel bandwidths which are different from each other coexist in the WLAN, the arranging the frame comprises determining that a data frame which has an HT format should contain time information in a predetermined field that is a legacy format and is included in a physical layer (PHY) header of the data frame, wherein the time information indicates how long the plurality of stations, other than a sending station transmitting the data frame and a destination station receiving the transmitted data frame, must wait and refrain from attempting to access the medium.