System and method for determining the mobility of nodes in a wireless communication network

• US 20060160540A1
• Filed: 12/21/2005
• Published: 07/20/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Bison Patent Licensing, LLC
• Original Assignee: MeshNetworks, Inc. (Motorola Solutions, Inc.)
• Inventors: Ramachandran, Shyamal, Strutt, Guenael
• Granted Patent: US 7,830,842 B2
• Time in Patent Office: Days
• US Class Current: 455/440
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system and method for determining the mobility of a node (102) in a wireless communication network (102). The system and method determine the distance between the node (102) and at least one stationary neighboring node (102, 106, 107) at at least two or more time points, using at least two moving average filters, to arrive at two distance values. The system and method then determine the relative velocity based on the at least two distance values, and thus determine whether the node (102) is mobile.

Claims

1. A method for determining mobility of a node in a wireless communication network, the method comprising:

determining distance information representing a change in distance between the node and at least one other node in the wireless communication network;

receiving information from the other node pertaining to mobility of the other node; and

identifying the node as mobile or stationary based on a value relating to the distance information and the information received from the other node.

2. A method as claimed in claim 1, further comprising:

periodically performing the determining step and the information receiving step to determine further changes in distance between the node and the other node in view of additional information received from the other node pertaining to the mobility of the other node; and

periodically confirming whether the node is to remain identified as mobile or stationary based on values pertaining to the further changes in distance and the additional information.

3. A method as claimed in claim 2, wherein:

the periodically performing and confirming steps are performed at times when the node is about to transmit a message and at time when the node receives a communication from the other node.

4. A method as claimed in claim 1, further comprising:

operating the node to transmit information indicating whether the node is identified as mobile or stationary.

5. A method as claimed in claim 1, wherein:

the change in distance determining step comprises mathematically processing the distance information to generate the value.

6. A method as claimed in claim 5, wherein:

the value represents a relative velocity between the node and the other node; and

the identifying step comprises identifying the node as mobile or stationary based on the relative velocity and the information received from the other node.

7. A method as claimed in claim 1, wherein:

the information received from the other node indicates whether the other node is identified as mobile or stationary.

8. A method as claimed in claim 1, wherein:

the identifying step identifies the node as mobile when the value and the information indicate a likelihood that the node is moving and the other node is stationary; and

the identifying step identifies the node as stationary when the value and the information indicate a likelihood that the other node is moving.

9. A method as claimed in claim 1, wherein:

the identifying step comprises determining a likelihood that the node is stationary based on an average of relative velocities of the node with respect to neighboring nodes and a skewness of the average of the relative velocities, and determining whether to identify the node as stationary based on the determined likelihood.

10. A method as claimed in claim 1, wherein:

the identifying step comprises setting a value for a verification time based on a likelihood that the node is stationary, and assessing whether the node is stationary or mobile during the verification time.

11. A method for determining mobility of a node in a wireless communication network, the method comprising:

operating the node to receive respective information from each of a plurality of other nodes in the network, each respective information indicating whether the respective other node is identified as a mobile node or a stationary node;

operating the node to determine its respective relative velocity with respect to each of a plurality of other nodes in the network; and

operating the node to determine whether it should be identified as mobile or stationary based on the respective relative velocities and the respective information.

12. A method as claimed in claim 11, wherein:

the node performs the operating steps to determine its respective velocity and to determine whether it should be identified as mobile or stationary at each time that the node receives the respective information from a respective other node.

13. A method as claimed in claim 11, further comprising:

operating the node to periodically determine whether it should remain identified as mobile or stationary.

14. A method as claimed in claim 11, further comprising:

operating the node to transmit information indicating that it is identified as mobile or stationary.

15. A node, adapted for communication in a wireless network, comprising:

a transceiver; and

a controller, adapted to control the transceiver to communicate with at least one other node in the wireless communication network, and being further adapted to determine distance information representing a change in distance between the node and the other node in the wireless communication network based on the communication, and to identify the node as mobile or stationary based on a value relating to the distance information and information included in the communication received from the other node.

16. A node as claimed in claim 15, wherein:

the controller is further adapted to control the transceiver to periodically communicate with the other node; and

the controller is further adapted to periodically determine further changes in distance between the node and the other node in view of additional information received from the other node pertaining to the mobility of the other node during the periodic communication, and to periodically confirm whether the node is to remain identified as mobile or stationary based on values pertaining to the further changes in distance and the additional information.

17. A node as claimed in claim 16, wherein:

the controller is further adapted to confirm whether the node is to remain identified as mobile or stationary at times when the transceiver is about to transmit a message and at time when the transceiver receives a communication from the other node.

18. A node as claimed in claim 15, wherein:

the controller is further adapted to control the transceiver to transmit information indicating whether the node is identified as mobile or stationary.

19. A node as claimed in claim 15, wherein:

the controller is further adapted to mathematically process the distance information to generate the value.

20. A node as claimed in claim 19, wherein:

the value represents a relative velocity between the node and the other node; and

the controller is further adapted to identify the node as mobile or stationary based on the relative velocity and the information received from the other node.

21. A node as claimed in claim 15, wherein:

the information received from the other node indicates whether the other node is identified as a mobile or stationary.

22. A node as claimed in claim 15, wherein:

the controller is adapted to identify the node as mobile when the value and the information indicate a likelihood that the node is moving and the other node is stationary, and is further adapted to identify the node as stationary when the value and the information indicate a likelihood that the other node is moving.

23. A node as claimed in claim 15, wherein:

the controller is adapted to determine a likelihood that the node is stationary based on an average of relative velocities of the node with respect to neighboring nodes and a skewness of the average of the relative velocities, and determine whether to identify the node as stationary based on the determined likelihood.

24. A node as claimed in claim 15, wherein:

the controller is adapted to set a value for a verification time based on a likelihood that the node is stationary, and assess whether the node is stationary or mobile during the verification time.