Linked equivalent cell header-based approach and protocol for organizing an ad-hoc network

• US 20070115897A1
• Filed: 11/22/2005
• Published: 05/24/2007
• Est. Priority Date: 11/22/2005
• Status: Active Grant

• Current Assignee: Telcordia Technologies Incorporated (Telefonaktiebolaget LM Ericsson), Toyota Infotechnology Center Co., Ltd. (Toyota Motor Corporation)
• Original Assignee: Toyota Infotechnology Center Co., Ltd. (Toyota Motor Corporation)
• Inventors: Lee, John, Pang, Marcus, Chen, Wai, Hikita, Toshiro, Cai, Shengwei
• Granted Patent: US 8,554,920 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 92/02 Inter-networking arrangements

Abstract

Establishing and maintaining a moving ad-hoc network is provided. The ad-hoc network includes a plurality of equivalent cells communicationally linked together to form a linked equivalent cell network. An equivalent cell header manages each equivalent cell. Additionally, regular nodes, scattered throughout the equivalent cell network, may be provided. Regular nodes have restricted communication privileges compared to the equivalent cell headers. However, equivalent cell headers can be demoted to regular nodes and regular nodes can be promoted to equivalent cell headers as required by equivalent cell network.

Claims

1. A method for establishing and maintaining a mobile ad-hoc network between a plurality of moving wireless devices, said method comprising:

operating a first device of said plurality of moving wireless devices as a first equivalent cell header (ECH), said ECH having a radio coverage range;

establishing a first equivalent cell (EC) for said first ECH, said first EC being formed centralized within an area of a radio coverage range of said first ECH and dimensioned to occupy a portion of said area, said EC being managed by said ECH;

broadcasting ECH information (ECH_HELLO) message from said first ECH, said ECH_HELLO message announcing that said one device of said plurality of moving wireless devices is the first ECH, said ECH_HELLO message broadcasts occurring at randomly determined fixed intervals;

receiving, by said first wireless device, at least second ECH_HELLO messages broadcast from at least a second moving wireless device operating as at least a second ECH;

creating a linked equivalent cell network between said first and second ECHs, if said second ECH is the only other ECH_HELLO message received or if two or more received ECH_HELLO messages belong to unlinked ECHs; and

operating said first device as a regular node in said linked equivalent cell network, if two or more received ECH_HELLO messages belong to a unified chain of linked ECHs, said regular node being part of said linked equivalent cell network, and said regular nodes having restricted communication privileges in comparison to an ECH.

2. The method as in claim 1, wherein said regular node becomes a new ECH when said regular node receives only one ECH_HELLO message, said new ECH links with an ECH that transmitted said received ECH_HELLO message, and wherein said regular node becomes a new ECH when said regular node receives at least one ECH_HELLO message from an unlinked ECH.

3. The method as in claim 1, wherein said regular node becomes a new ECH when said regular node receives at least two ECH_HELLO messages from at least two different ECH nodes belonging to different networks, said new ECH links said at least two different ECH nodes belonging to different EC networks together to create one unified network.

4. The method as in claim 1, wherein an ECH provide a communication link between said ECH and other ECHs and between regular nodes from different equivalent cells belonging to said linked EC network.

5. The method as in claim 1, wherein said area of said radio coverage range includes multiple other equivalent cells in addition to said centralized equivalent cell, each EC being managed by a unique ECH.

6. The method as in claim 5, wherein each linked ECH is aware of a relative position of itself with respect to other ECH nodes in said linked EC network, said relative position being determined from at least one list of ECH nodes in communication, each list of said at least one list of ECH nodes being indicative of an order of ECH nodes along one communication path of said linked equivalent cell network.

7. The method as in claim 1, further comprising the steps of detecting mobility of an ECH belonging to said equivalent cell network and electing a new ECH based upon a predetermined election criterion.

8. The method as in claim 7, wherein said ECH election is performed by selectively promoting a regular node to an ECH, said regular node being selected based on a position of said regular node relative to said equivalent cell managed by said detected ECH.

9. The method as in claim 7, said mobility includes:

a new ECH joining said EC network, a linked ECH leaving said EC network, and a linked ECH moving into an EC managed by another ECH of the same EC network.

10. The method as in claim 1, wherein at least one device of said plurality of moving wireless devices is installed or embedded in a vehicle.

11. A system for establishing a mobile ad-hoc network between a plurality of moving wireless devices, said system comprising:

means for operating a first device of said plurality of moving wireless devices as a first equivalent cell header (ECH), said ECH having a radio coverage range;

means for broadcasting ECH information (ECH_HELLO) message from said first ECH, said ECH_HELLO message announcing that said one device of said plurality of moving wireless devices is the first ECH, said ECH_HELLO message broadcasts occurring at randomly determined fixed intervals;

means for establishing a first equivalent cell (EC) for said first ECH, said first EC being formed centralized within an area of a radio coverage range of said first ECH and dimensioned to occupy a portion of said area, said EC being managed by said ECH;

means for receiving, by said first wireless device, at least second ECH_HELLO messages broadcast from at least a second moving wireless device operating as at least a second ECH;

means for creating a linked equivalent cell network between said first and second ECH nodes, if said second ECH is the only other ECH_HELLO message received or if two or more received ECH_HELLO messages belong to unlinked ECH nodes; and

means for operating said first device as a regular node in said linked equivalent cell network, if two or more received ECH_HELLO messages belong to a unified chain of linked ECH nodes, said regular node being part of said linked equivalent cell network, and said regular nodes having restricted communication privileges in comparison to an ECH.

12. The system as in claim 11, wherein said regular node becomes a new ECH when said regular node receives only one ECH_HELLO message, said new ECH links with an ECH that transmitted said received ECH_HELLO message, and wherein said regular node becomes a new ECH when said regular node receives at least one ECH_HELLO message from an unlinked ECH.

13. The system as in claim 11, wherein said regular node becomes a new ECH when said regular node receives at least two ECH_HELLO message from at least two different linked ECH nodes belonging to different networks, said new ECH links said at least two different linked ECH nodes belonging to different networks together to create one unified network.

14. The system as in claim 11, wherein each ECH provides a communication link between each other and between regular nodes from different equivalent cells belonging to said linked equivalent cell network.

15. The system as in claim 14, wherein said area of said radio coverage range includes multiple other equivalent cells in addition to said centralized equivalent cell, each equivalent cell being managed by a unique ECH and forming a linked equivalent cell network.

16. The system as in claim 11, wherein an ECH is aware of a relative position of an equivalent cell managed by said ECH, said relative position being determined from at least one list of ECHs in communication, each list of said at least one list of ECHs being indicative of ECHs in communication along one communication path of said linked equivalent cell network.

17. The system as in claim 11, further comprising means for detecting mobility of an ECH belonging to said equivalent cell network and means for electing a new ECH based upon a predetermined election criterion.

18. The system as in claim 17, wherein said ECH election is performed by selectively promoting a regular node to an ECH, said regular node being selected based on a position of said regular node relative to said equivalent cell managed by said detected ECH.

19. The system as in claim 11, wherein at least one device of said plurality of moving wireless devices is installed or embedded in a moving vehicle.

20. A computer-readable medium having a set of instructions executable by a processor for performing a method for establishing a mobile ad-hoc network between a plurality of moving wireless devices, said method comprising:

operating a first device of said plurality of moving wireless devices as a first equivalent cell header (ECH), said ECH having a radio coverage range;

establishing a first equivalent cell (EC) for said first ECH, said first EC being formed centralized within an area of a radio coverage range of said first ECH and dimensioned to occupy a portion of said area, said EC being managed by said ECH;

broadcasting ECH information (ECH_HELLO) message from said first ECH, said ECH_HELLO message announcing that said one device of said plurality of moving wireless devices is the first ECH, said ECH_HELLO message broadcasts occurring at randomly determined fixed intervals;

receiving, by said first wireless device, at least second ECH_HELLO messages broadcast from at least a second moving wireless device operating as at least a second ECH;

creating a linked equivalent cell network between said first and second ECH nodes, if said second ECH is the only other ECH_HELLO message received or if two or more received ECH_HELLO messages belong to unlinked ECH nodes; and

operating said first device as a regular node in said linked equivalent cell network, if two or more received ECH_HELLO messages belong to a unified chain of linked ECH nodes, said regular node being part of said linked equivalent cell network, and said regular nodes having restricted communication privileges in comparison to an ECH.

21. The computer-readable medium as in claim 20, wherein said method further comprises the steps of:

detecting mobility of an ECH belonging to said equivalent cell network; and

electing a new ECH based upon a predetermined election criterion, said ECH election is performed by selectively promoting a regular node to an ECH, said regular node being selected based on a position of said regular node relative to said equivalent cell managed by said detected ECH.

22. The computer-readable medium as in claim 20, wherein said computer-readable medium is a network and said instructions are signals transmittable over said network.