Method and apparatus for searching for radio station for wireless ad hoc communication network

• US 6,907,257 B1
• Filed: 11/06/2000
• Issued: 06/14/2005
• Est. Priority Date: 11/10/1999
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Shimotono, Susumu, Mizutani, Akihiko, Aihara, Toru
• Primary Examiner(s): Corsaro, Nick
• Assistant Examiner(s): Orgad, Edan
• Application Number:
  US09/706,660
• Time in Patent Office: 1,681 Days
• Field of Search: 455/446, 455/69, 455/452.1, 455/422.1, 455/507, 455/524, 455/517, 455/412, 455/411, 370/389, 370/335, 370/344, 370/445, 370/400, 370/330, 375/131
• US Class Current: 455/464
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/302 due to low signal strength
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system and method wherein a master node 710 comprises, as its primary components, a protocol stack 715, a transceiver 720, a search scheduler 725, communication volume prediction means 730 and outside-channel, signal induced interference intensity measuring means 735. A slave node 750 comprises, as its primary components, a protocol stack 760, a transceiver 765 and a search routine 755. The signal induced interference intensity read by the signal induced interference intensity measuring means 735 is transmitted to the search scheduler 725. The search scheduler 725 then employs the signal induced interference intensity to determine the total amount of the resources that are to be allocated for a search.

Claims

1. An apparatus in a node in a network, said node participating in a communication session for said node to initiate a search for a radio station during a communication session comprising:

signal monitoring component for detecting the strength of the communication signal; and

comparator component for comparing the detected strength of the signal to a predetermined reference, for establishing that deterioration of signal strength is an index of topological change in the network, and for generating an initiation signal for said node to initiate a search by said node for a radio station when deterioration of the strength of the communication signal indicates the appearance of a new radio station.

2. The apparatus of claim 1 wherein the communication session is wireless.

3. The apparatus of claim 1 wherein the communication session is an ad hoc communication network session.

4. The apparatus of claim 1 wherein the communication session is a multi-hop wireless communication session.

5. An apparatus in a node in a network, said node participating in a communication session for initiating a search for a radio station by said node during a communication session comprising:

interference detection component for detecting the intensity of interference in the session; and

comparator component for comparing the intensity of interference to a predetermined reference, for determining that a a change in the interference indicates a topological change in the network and for generating an initiation signal for said node to initiate said search when increased intensity of interference indicates the appearance of a new radio station.

6. The apparatus of claim 5 wherein the communication session is wireless.

7. The apparatus of claim 5 wherein the communication session is an ad hoc communication network session.

8. The apparatus of claim 5 wherein the communication session is a multi-hop wireless communication session.

9. An apparatus in a node in a network participating in a communication session for altering the frequency at which monitoring for radio stations is performed by said node during a communication session comprising:

signal monitoring component for detecting the strength of the communication signal; and

comparator component for comparing the detected strength of the signal to a predetermined reference, for determining that a change in signal strength is due to a topological change in the network and for generating a signal to alter the frequency of said monitoring by said node when deterioration of the strength of the communication signal indicates the appearance of at least one new radio station.

10. The apparatus of claim 9 wherein the communication session is a wireless communication session.

11. The apparatus of claim 9 wherein the communication session is an ad hoc communication network session.

12. The apparatus of claim 9 wherein the communication session is a multi-hop wireless communication session.

13. A method performed by a node in a network, said node participating in a communication sessions, for initiating a search for a radio station by said node during a communication session comprising the steps of said node:

detecting the strength of the communication signal;

comparing the detected strength of the signal to a predetermined reference;

determining that a change in the strength of the communication signal indicates the appearance of a new radio station; and

generating a initiation signal to initiate said search by said node when deterioration of the strength of the communication signal indicates the appearance of a new radio station.

14. A method performed by a node in a network participating in a communication session for initiating a search for a radio station by said node during a communication session comprising the steps of said node:

detecting the intensity of interference in the session;

comparing the intensity of interference to a predetermined reference;

determining that a change in interference is due to a topological change in the network; and

generating an initiation signal to initiate said search by said node when increased intensity of interference indicates the appearance of a new radio station.

15. A method performed by a network node participating in a communication session for altering the frequency at which monitoring for radio stations is performed by said node during a communication session comprising the steps at said node of:

detecting the strength of the communication signal;

comparing the detected strength of the signal to a predetermined reference as an indication of a topological change in the network; and

generating a signal to alter the frequency of said monitoring by said node when deterioration of the strength of the communication signal indicates the appearance of at least one new radio station.

16. The method of claim 15 wherein said altering comprising increasing frequency of monitoring to search for radio stations when the signal strength is less than a predetermined reference and decreasing the frequency when the signal strength exceeds the predetermined reference.

17. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for initiating a search for a radio station in a network by a node during a communication session, said method comprising the steps for said node of:

detecting the strength of the communication signal;

comparing the detected strength of the signal to a predetermined reference as an indication of a change in topology of said network; and

generating a initiation signal to initiate said search by said node when deterioration of the strength of the communication signal indicates the appearance of a new radio station.

18. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for initiating a search for a radio station in a network by a node during a communication session, said method comprising the steps for said node of:

detecting the intensity of interference in the session;

comparing the intensity of interference to a predetermined reference a an indicator of a change in topology of the network; and

generating an initiation signal to initiate said search by said node when increased intensity of interference indicates the appearance of a new radio station.

19. A program storage device readable by machine, tangibly embodying a program of instructions executable by the machine to perform method steps for altering the frequency at which monitoring for radio stations is performed in a network by a node during a communication session, said method comprising the steps for said node of:

detecting the strength of the communication signal;

comparing the detected strength of the signal to a predetermined reference as an indication of a topological change in the network; and

generating a signal to alter the frequency of said monitoring by said node when deterioration of the strength of the communication signal indicates the appearance of at least one new radio station.