Method and apparatus for channel access in contention-based communication system and station
A method for accessing a channel by a station in a contention-based communication system, includes: starting a backoff timer to perform contention-based channel accessing; when the backoff timer expires, a delay timer starts; and when the delay timer expires, channel accessing is attempted. Coexistence of a station using a directional antenna and a station using a non-directional antenna is guaranteed in a contention-based communication system.
1. A method for accessing a channel by a station in a contention-based communication system, the method comprising:
starting a backoff timer to perform contention-based channel accessing;
starting a delay timer when the backoff timer expires, wherein a specific value for the delay timer is smaller than a value obtained by subtracting a transmission time duration of a directional RTS (Request To Send) frame from a transmission time duration of an omni-directional RTS frame; and
attempting the contention-based channel accessing when the delay timer expires.
2. The method of claim 1 , wherein attempting the contention-based channel accessing comprises transmitting a directional RTS frame.
3. The method of claim 1 , wherein the backoff timer operates based on a slot time determined by an access point, and the slot time is determined by considering a time required for RTS frame transmission, wherein the RTS frame transmission is directional transmission performed by using a directional antenna.
4. The method of claim 1 , wherein the backoff timer operates based on a slot time determined by an access point, and the slot time is determined by considering a time required for RTS frame transmission, wherein the RTS frame transmission is omni-directional transmission performed by using an omni-directional antenna.
5. A station in a contention-based communication system, the station comprising:
a transceiver that transmits or receives a radio signal; and
a processor connected to the transceiver, the processor configured to:
start a backoff timer to perform contention-based channel accessing,
start a delay timer when the backoff timer expires, wherein a specific value for the delay timer is smaller than a value obtained by subtracting a transmission time duration of a directional RTS (Request To Send) frame from a transmission time duration of an omni-directional RTS frame, and
attempt the contention-based channel accessing when the delay timer expires.
6. The station of claim 5 , further comprising:
a directional antenna connected to the transceiver, wherein the contention-based channel accessing is performed by transmitting a directional RTS frame.
7. A channel accessing method in a contention-based communication system, the method comprising:
starting a backoff timer to perform contention-based channel accessing;
attempting, by a non-steerable station, the contention-based channel accessing when the backoff timer expires, and
starting, by a steerable station, a delay timer; and
attempting, by the non-steerable station, the contention-based channel accessing when the delay timer expires,
wherein a specific value for the delay timer is smaller than a value obtained by subtracting a transmission time duration of a directional RTS (Request To Send) frame from a transmission time duration of an omni-directional RTS frame.
8. The station of claim 5 , wherein the backoff timer operates based on a slot time determined by an access point, and the slot time is determined by considering a time required for RTS frame transmission, wherein the RTS frame transmission is directional transmission performed by using a directional antenna.
9. The station of claim 5 , wherein the backoff timer operates based on a slot time determined by an access point, and the slot time is determined by considering a time required for RTS frame transmission, wherein the RTS frame transmission is omni-directional transmission performed by using an omni-directional antenna.
10. The channel accessing method of claim 7 , wherein the backoff timer operates based on a slot time determined by an access point, and the slot time is determined by considering a time required for RTS frame transmission, wherein the RTS frame transmission is directional transmission.
11. The channel accessing method of claim 7 , wherein the backoff timer operates based on a slot time determined by an access point, and the slot time is determined by considering a time required for RTS frame transmission, wherein the RTS frame transmission is omni-directional transmission.