System and method for geocasting in a mobile ad hoc network

• US 20090046628A1
• Filed: 08/17/2007
• Published: 02/19/2009
• Est. Priority Date: 08/17/2007
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Hall, Robert
• Granted Patent: US 8,149,801 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/021 Services related to particular areas, e.g. point of interest [POI] services, venue services or geofences
• CPC Class Codes: H04W 4/023 using mutual or relative location information between multiple location based services [LBS] targets or of distance thresholds
• CPC Class Codes: H04W 40/20 based on geographic position or location

Abstract

Disclosed is a wireless terminal that determines whether to retransmit a received packet. The wireless terminal is configured to determine a first distance from the wireless terminal to a point (e.g., the center point) in a geocast region. The wireless terminal is also configured to determine a plurality of distances between the point and each of a plurality of wireless terminals from which the wireless terminal has previously received a packet having an identifier that is the same as an identifier of the received packet. The wireless terminal is configured to retransmit the received packet if the first distance is less than each of the plurality of distances.

Claims

1. A method for determining whether a wireless terminal will retransmit a received packet, said method comprising:

determining a first distance from said wireless terminal to a point in a geocast region;

determining a plurality of distances between said point and each of a plurality of wireless terminals from which said wireless terminal has previously received a packet having an identifier that is the same as an identifier of said received packet; and

retransmitting said received packet if said first distance is less than each of said plurality of distances.

2. The method of claim 1 further comprising storing said received packet in a transmit queue.

3. The method of claim 2 further comprising assigning a priority to said received packet.

4. The method of claim 3 wherein said priority is based on differences between said first distance and each of said plurality of distances.

5. The method of claim 3 wherein said retransmitting further comprises retransmitting said received packet before another packet stored in said transmit queue when said received packet has a priority higher than said another packet.

6. The method of claim 1 further comprising discarding said received packet if said first distance is not less than each of said plurality of distances.

7. The method of claim 1 wherein said point in said geocast region is the center of the geocast region.

8. A wireless terminal configured to determine whether to retransmit a received packet comprising:

means for determining a first distance from said wireless terminal to a point in a geocast region;

means for determining a plurality of distances between said point and each of a plurality of wireless terminals from which said wireless terminal has previously received a packet having an identifier that is the same as an identifier of said received packet; and

means for retransmitting said received packet if said first distance is less than each of said plurality of distances.

9. The wireless terminal of claim 8 further comprising means for storing said received packet in a transmit queue.

10. The wireless terminal of claim 9 further comprising means for assigning a priority to said received packet.

11. The wireless terminal of claim 10 wherein said priority is based on differences between said first distance and each of said plurality of distances.

12. The wireless terminal of claim 10 wherein said means for retransmitting further comprises means for retransmitting said received packet before another packet stored in said transmit queue when said received packet has a priority higher than said another packet.

13. The wireless terminal of claim 8 further comprising means for discarding said received packet if said first distance is not less than each of said plurality of distances.

14. The wireless terminal of claim 8 wherein said point in said geocast region is the center of the geocast region.

15. A computer readable medium comprising computer program instructions capable of being executed in a processor and defining the steps comprising:

determining a first distance from said wireless terminal to a point in a geocast region;

determining a plurality of distances between said point and each of a plurality of wireless terminals from which said wireless terminal has previously received a packet having an identifier that is the same as an identifier of said received packet; and

retransmitting said received packet if said first distance is less than each of said plurality of distances.

16. The computer readable medium of claim 15 further comprising the step of storing said received packet in a transmit queue.

17. The computer readable medium of claim 16 further comprising the step of assigning a priority to said received packet.

18. The computer readable medium of claim 17 wherein said priority is based on differences between said first distance and each of said plurality of distances.

19. The computer readable medium of claim 17 wherein said retransmitting step further comprises the step of retransmitting said received packet before another packet stored in said transmit queue when said received packet has a priority higher than said another packet.

20. The computer readable medium of claim 15 further comprising the step of discarding said received packet if said first distance is not less than each of said plurality of distances.