Method and apparatus for negotiating master station

1. A method for negotiating a master station, the method comprising:

receiving from the master station a management frame that carries a master identity, wherein the management frame is a first beacon frame sent by the master station according to a Distributed Coordination Function (DCF) contention access mechanism after the master station waits for a short timeslot, wherein, before the receiving from the master station the management frame that carries the master identity, waiting for a short timeslot after arrival of a start point of each Beacon Interval (BI);

obtaining a maximum time interval between receiving the management frame and receiving a next management frame from the master station; and

determining, according to a preset policy, a local station as a new master station if no more management frame is received after the maximum time interval, wherein determining the local station as a new master station according to the preset policy comprises:

sending an Announcement Master Indication Message (AMIM) frame according to the DCF contention access mechanism to declare the local station as a new master station; and

sending a second beacon frame without backoff delay at the start point of a next BI if no NOWAY frame that negates the declaration is received within the BI, wherein the second beacon frame is used to determine the local station as a new master station.

2. The method according to claim 1 , further comprising returning an Acknowledge (ACK) message to a sending station of the NOWAY frame after receiving the NOWAY frame that negates the declaration.

3. The method according to claim 2 , wherein the NOWAY frame is sent by a receiving station of the AMIM frame according to a contention access mechanism.

4. The method according to claim 1 , wherein sending the AMIM frame according to the DCF contention access mechanism to declare the local station as a new master station comprises:

sending the AMIM frame in a nearest Announcement Traffic Indication Message (ATIM) window in power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station.

5. The method according to claim 2 , wherein sending the AMIM frame according to the DCF contention access mechanism to declare the local station as a new master station comprises:

sending the AMIM frame in the BI in non-power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station.

6. The method according to claim 3 , wherein sending the AMIM frame according to the DCF contention access mechanism to declare the local station as a new master station comprises:

sending the AMIM frame in a nearest Announcement Traffic Indication Message (ATIM) window in power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station; or

sending the AMIM frame in the BI in non-power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station.

7. The method according to claim 1 , further comprising keeping active within the BI in power-saving mode.

8. An apparatus for negotiating a master station, the apparatus comprising:

a receiving module, configured to receive from a master station a management frame that carries a master identity, wherein the management frame is a beacon frame;

an obtaining module, configured to obtain a maximum time interval between receiving of the management frame and receiving of a next management frame from the master station; and

a negotiating module, configured to determine, according to a preset policy, a local station itself as a new master station if the receiving module receives no more management frame after the maximum time interval obtained by the obtaining module, wherein the negotiating module further comprises:

a declaring unit, configured to send an Announcement Master Indication Message (AMIM) frame to declare the local station as a new master station according to a Distributed Coordination Function (DCF) contention access mechanism if the receiving module receives no more management frame after the maximum time interval obtained by the obtaining module; and

a sending unit, configured to send the beacon frame without backoff delay at a start point of a next Beacon Interval (BI) if no NOWAY frame that negates the declaration is received within the BI, wherein the beacon frame is used to determine the local station as a new master station.

9. The apparatus according to claim 8 , wherein the apparatus further comprises a responding module, configured to return an Acknowledge (ACK) message to a sending station of the NOWAY frame after receiving the NOWAY frame that negates the declaration.

10. The method according to claim 1 , wherein sending the AMIM frame according to the DCF contention access mechanism to declare the local station as a new master station comprises:

sending the AMIM frame in the BI in non-power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station.

11. The method according to claim 2 , wherein sending the AMIM frame according to the DCF contention access mechanism to declare the local station as a new master station comprises:

sending the AMIM frame in a nearest Announcement Traffic Indication Message (ATIM) window in power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station; or

sending the AMIM frame in the BI in non-power-saving mode according to the DCF contention access mechanism to declare the local station as a new master station.

12. A method for negotiating a master station, the method comprising:

receiving from the master station a management frame that carries a master identity;

obtaining a maximum time interval between receiving the management frame and receiving a next management frame from the master station; and

determining, according to a preset policy, a local station as a new master station if no more management frame is received after the maximum time interval,

wherein determining the local station as a new master station according to the preset policy comprises:

sending an Announcement Master Indication Message (AMIM) frame according to the DCF contention access mechanism to declare the local station as a new master station; and

sending a first beacon frame without backoff delay at the start point of a next Beacon Interval (BI) if no NOWAY frame that negates the declaration is received within the BI, wherein the first beacon frame is used to determine the local station as a new master station.

13. The method according to claim 12 , wherein the management frame is a second beacon frame.

14. The method according to claim 13 , wherein the second beacon frame is sent by the master station according to a Distributed Coordination Function (DCF) contention access mechanism after the master station waits for a short timeslot.

15. The method according to claim 14 , wherein before the receiving from the master station the management frame that carries the master identity, the method further comprises waiting for a short timeslot after arrival of a start point of each Beacon Interval (BI).

16. The method according to claim 12 , further comprising returning an Acknowledge (ACK) message to a sending station of the NOWAY frame after receiving the NOWAY frame that negates the declaration.

17. The method according to claim 16 , wherein the NOWAY frame is sent by a receiving station of the AMIM frame according to a contention access mechanism.

18. The method according to claim 12 , wherein the management frame is a probe frame.

19. The method according to claim 18 , wherein the probe frame is sent by the master station at preset intervals.

20. The method according to claim 19 , wherein:

the probe frame further carries a list of stations arranged according to control capabilities of the stations; and

the determining the local station as a new master station according to the preset policy comprises determining the local station as a new master station according to the list of stations.