Method and apparatus to perform synchronization in an AD-HOC network

• US 7,948,939 B2
• Filed: 02/23/2005
• Issued: 05/24/2011
• Est. Priority Date: 03/04/2004
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Morioka, Yuichi, Nishikawa, Kenzo, Sakoda, Kazuyuki, Suzuki, Mitsuhiro, Fujita, Chihiro, Sugaya, Shigeru
• Primary Examiner(s): Kincaid; Lester
• Assistant Examiner(s): Lai; Daniel
• Application Number:
  US11/062,952
• Publication Number:
  US 20060068820A1
• Time in Patent Office: 2,281 Days
• Field of Search: 370/468, 370/310, 370/477, 370/236, 370/336, 370/347, 370/350, 370/329, 370/330, 370/338, 455450-453, 455 411- 413, 455/336, 455/347
• US Class Current: 370/329
• CPC Class Codes: H04W 28/20 Negotiating bandwidth
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A wireless communication system in which each of communication stations performs networking operation in an autonomous, distributed manner, wherein each of the communication stations gathers information indicative of a band use situation in peripheral stations, grasps bands usable and unusable by the own station from the gathered information to set a band to be actually used by the own station, and mutually recognize bands to be used and unusable by the own station by informing to the peripheral stations.

Claims

1. A wireless communication system, comprising:

a plurality of communication stations configured to perform networking operation in an autonomous, distributed manner, each of the plurality of communication stations configured to gather information indicative of available communication slots with respect thereto, the available communication slots being portions of an ad-hoc managed bandwidth including communication slots available to others of the plurality of communication stations, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy, each station of the plurality of communication stations configured to inform others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication, the plurality of communication stations configured to rank reservation states with the predetermined hierarchy which includes at least a reserved slot and a transmit beacon slot, each station of the plurality of communication stations configured to determine unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations and inform the others of the plurality of communication stations of the determined unusable slots, and each station of the plurality of communication stations is configured to transmit a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon.

2. A wireless communication system, comprising:

a plurality of communication stations configured to perform networking operation in an autonomous, distributed manner, each of the plurality of communication stations configured to gather information indicative of available communication slots with respect thereto, the available communication slots being portions of an ad-hoc managed bandwidth including communication slots available to others of the plurality of communication stations, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy and, configured to inform others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication slots, the provision of beacon information describing information relating to a communication condition with respect thereto, and sets a communication slot which coincides with a beacon received from a peripheral station as an available slot unusable for communication in accordance with the predetermined hierarchy, the plurality of communication stations configured to rank reservation states with the predetermined hierarchy which includes at least a reserved slot and a transmit beacon slot, each station of the plurality of communication stations configured to determine unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations and inform the others of the plurality of communication stations of the determined unusable slots, and each station of the plurality of communication stations is configured to transmit a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon.

3. A wireless communication system, comprising:

a plurality of communication stations configured to perform networking operation in an autonomous, distributed manner, each of the plurality of communication stations configured to gather information indicative of available communication slots with respect thereto, the available communication slots being portions of an ad-hoc managed bandwidth including communication slots available to others of the plurality of communication stations, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy, and, configured to inform others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication slots, the plurality of communication stations configured to rank reservation states with the predetermined hierarchy which includes at least a reserved slot and a transmit beacon slot, each station of the plurality of communication stations configured to determine unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations and inform the others of the plurality of communication stations of the determined unusable slots, and each station of the plurality of communication stations is configured to transmit a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon,

wherein when a communication slot is utilized to perform a band reserved communication or a prioritized communication, each of the plurality of communication stations begins transmission after an offset time elapses, the offset time being a predetermined probability.

4. A wireless communication system, comprising:

a plurality of communication stations configured to perform networking operation in an autonomous, distributed manner, each of the plurality of communication stations configured to gather information indicative of available communication slots with respect thereto, the available communication slots being portions of an ad-hoc managed bandwidth including communication slots available to others of the plurality of communication stations, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy and, configured to inform others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication slots, for use in scheduling available time slots for use in communication, the plurality of communication stations configured to rank reservation states with the predetermined hierarchy which includes at least a reserved slot and a transmit beacon slot, each station of the plurality of communication stations configured to determine unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations and inform the others of the plurality of communication stations of the determined unusable slots, and each station of the plurality of communication stations is configured to transmit a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon,

wherein a respective one of the plurality of communication stations temporarily secures an available communication slot for performing band reserved communication, and does not temporarily secure communication slots identified as secured by a peripheral station in accordance with the hierarchy.

5. A wireless communication apparatus performing data transmission in a wireless communication environment, comprising:

a communication unit configured to transmit and/or receive wireless data on a communication channel;

an information gathering unit configured to gather information indicative of available communication channel slots with respect thereto, the available communication channel slots being portions of an ad-hoc managed bandwidth including communication slots available to others of a plurality of wireless communication apparatus, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy;

an identification unit configured to identify usable and unusable slots based upon the hierarchy, the identification unit configured to rank reservation states including at least a reserved slot and a transmit beacon slot with the predetermined hierarchy, the identification unit configured to determine unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations;

a setting unit configured to set available slots as usable and unusable by the wireless communication apparatus;

a controller configured to control communication operation based on the usable and unusable slots set; and

an informing unit configured to inform others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication slots and the determined unusable slots, the informing unit configured to transmit a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon.

6. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to provide beacon signal information designating the available communication slots corresponding thereto in accordance with the predetermined hierarchy, periodically.

7. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating implementation of a band-reserved communication in the available communication slots in accordance with the predetermined hierarchy.

8. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating reception of beacon information from the others of a plurality of wireless communication apparatus of the available communication slots in accordance with the predetermined hierarchy.

9. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating existence of beacon information from the others of the wireless communication apparatus of the available communication slots in accordance with the predetermined hierarchy.

10. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating implementation of prioritized transmission of the available communication slots in accordance with the predetermined hierarchy.

11. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating temporarily secured slots of the available communication slots in accordance with the predetermined hierarchy.

12. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating performing receiving operation relative to the available communication slots in accordance with the predetermined hierarchy.

13. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating that the others of the plurality of wireless communication apparatus has reserved slots of the available communication slots in accordance with the predetermined hierarchy.

14. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating a sleeping mode in the unusable slots.

15. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to describe information designating a band-reserved communication pursuant to an immediately preceding available slot in an available slot identified as unusable in accordance with the predetermined hierarchy.

16. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to set a reserved or prioritized available slot of a peripheral station as unusable in accordance with the predetermined hierarchy.

17. The wireless communication apparatus according to claim 5, wherein the informing unit is configured to set an available slot for receiving a beacon from a peripheral station as a band unusable in accordance with the predetermined hierarchy.

18. The wireless communication apparatus according to claim 5, further comprising:

a signal generating unit configured to generate an open signal describing a completion of slot utilization before a set and reserved slot scheduled as unusable expires.

19. The wireless communication apparatus according to claim 18, wherein the controller is configured to perform a predetermined access control after the completion when receiving the open signal from one of the others of the plurality of wireless communication apparatus.

20. The wireless communication apparatus according to claim 5, wherein the setting unit is configured to set a slot of the available slots for prioritized communication or a slot of the available slots for beacon reception;

and when transmission is not performed in these slots for a predetermined time interval, the controller is configured to allow others of the plurality of wireless communication apparatus to utilize these slots.

21. The wireless communication apparatus according to claim 5, wherein when performing transmission in an available slot set to perform a reserved communication or a prioritised communication in accordance with the predetermined hierarchy, the controller is configured to start the transmission after an offset time elapses, the offset time being a predetermined probability.

22. The wireless communication apparatus according to claim 5, wherein the setting unit is configured to temporarily secure an available slot for performing reserved communication, and does not temporarily secure communication slots identified as secured by a peripheral station in accordance with the hierarchy.

23. The wireless communication apparatus according to claim 5, wherein the identifying unit is configured to rank a strong reserved slot as higher priority than a transmit beacon slot based on the predetermined hierarchy.

24. The wireless communication apparatus according to claim 5, wherein the second reservation slots include weak reserved slots, the station transmitting the beacon being prohibited from transmitting during weak reserved slots until a predetermined time elapses.

25. A wireless communication method performing data transmission in a wireless communication environment, comprising:

gathering information indicative of available communication channel slots with respect thereto, the available communication channel slots being portions of an ad-hoc managed bandwidth including communication slots available to others of a plurality of wireless communication apparatus, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy as the information indicative of available communication slots, for use in scheduling available time slots for use in communication;

identifying available slots as unusable and usable slots based upon the hierarchy, the identifying including ranking reservation states including at least a reserved slot and a transmit beacon slot with the predetermined hierarchy, the identifying including determining unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations;

setting available slots as usable and unusable by the wireless communication apparatus;

controlling communication operation based on the usable and unusable slots set; and

informing others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication slots and the determined unusable slots, the informing including transmitting a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon.

26. A tangible computer readable storage medium encoded with computer instructions which causes a data processor to execute a method of controlling a wireless communication operation to implement data transmission in a wireless communication environment, said method comprising:

gathering information indicative of available communication channel slots with respect thereto, the available communication channel slots being portions of an ad-hoc managed bandwidth including communication slots available to others of a plurality of wireless communication apparatus, the information indicative of available communication slots identifying a current reservation state of the available communication slots based upon a predetermined hierarchy for use in scheduling available time slots for use in communication;

identifying available slots as unusable and usable slots based upon the hierarchy, the identifying including ranking reservation states including at least a reserved slot and a transmit beacon slot with the predetermined hierarchy, the identifying including determining unusable slots based on the current reservations states of available communication slots of others of the plurality of communication stations;

setting available slots as usable and unusable by the wireless communication apparatus;

controlling communication operation based on the usable and unusable slots set; and

informing others of the plurality of communication stations of current reservation states of available communication slots in accordance with the predetermined hierarchy as the information indicative of available communication slots and the determined unusable slots, the informing including transmitting a beacon to the others of the plurality of communication stations, the beacon including a status for every communication slot in each frame, the status indicating first reservation slots identifying slots reserved for a station transmitting the beacon and second reservation slots identifying slots reserved by neighboring stations other than the station transmitting the beacon.