NON-INTERFERENCE TECHNIQUE FOR SPATIALLY AWARE MOBILE AD HOC NETWORKING

• US 20130242956A1
• Filed: 05/02/2013
• Published: 09/19/2013
• Est. Priority Date: 11/01/2005
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property II LP (AT&T, Inc.)
• Inventors: Hall, Robert J.
• Granted Patent: US 9,788,329 B2
• Time in Patent Office: Days
• US Class Current: 370/336
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

A system and method for reducing interference between wireless terminals communicating in a mobile ad-hoc network (MANET). Interference is reduced by dividing the MANET into a number of geographical areas having a specific size and shape. Each geographical area is assigned a time slot during which wireless terminals located in the respective geographical area may transmit to other wireless terminals. The time slots are assigned such that geographical areas having the same time slot are far enough away from each other that wireless terminals located in such same time slot geographical areas are outside the interference range of each other.

Claims

1. A method comprising:

calculating a ratio R equal to a ratio of an interference range to a detection range of a device;

determining a number of time slots based on the ratio R; and

assigning each geographical area of a plurality of geographical areas one of the time slots of the number of time slots, wherein;

a device located in a geographical area transmits only during a time interval assigned to a time slot assigned to a respective geographical area; and

a device located in a geographical area having a given time slot may not interfere with a device located in another geographical area having the same time slot.

2. The method of claim 1, wherein at least one of the geographical areas is hexagonal in shape.

3. The method of claim 1, wherein at least one of the geographical areas has a diameter equal to a detection range of at least one device.

4. The method of claim 1, wherein at least one of the geographical areas is rectangular in shape.

5. The method of claim 1, wherein at least one of the geographical areas is triangular in shape.

6. The method of claim 1, wherein at least one of the geographical areas is circular in shape.

7. The method of claim 1, wherein:

each geographical area has a hexagonal shape with a diameter equal to a detection range of at least one of the devices; and

no gaps exist between geographical areas.

8. An device comprising:

a processor; and

memory coupled to the processor, the memory comprising executable instructions that when executed by the processor cause the processor to effectuate operations comprising;

determining a geographical location of the device;

based on mapping information, determining which geographical area of a predefined plurality of geographical areas, in which the device is located, the mapping information comprising;

the plurality of predefined plurality geographical areas each of which is assigned one of a set of time slots wherein a device located anywhere in a geographical area having a given time slot may not interfere with a device located in another geographical area having the same time slot; and

a number of the set of time slots based on a ratio, R, equal to a ratio of an interference range to a detection range of a device; and

transmitting during the time slot assigned to the geographical area in which the device is located.

9. The device of claim 8, wherein the geographical location of the device is determined via global positioning system.

10. The device of claim 8, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a hexagonal shape.

11. The device of claim 8, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a rectangular shape.

12. The device of claim 8, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a triangular shape.

13. The device of claim 8, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a circular shape.

14. The device of claim 8, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a diameter equal to the detection range of the device.

15. The device of claim 8, wherein each geographical area of the predefined plurality of geographical areas has a hexagonal shape with a diameter equal to the detection range of the device.

16. An device comprising:

a processor; and

memory coupled to the processor, the memory comprising executable instructions that when executed by the processor cause the processor to effectuate operations comprising;

determining which geographical area of a plurality of geographical areas in which the device is located;

determining at least one time slot assigned to the determined geographical area; and

transmitting during the at least one time slot assigned to the determined geographical area, wherein;

the device has an interference range and a detection range;

each geographical area is assigned at least one of a set of time slots;

the time slots are assigned to the geographical areas such that a device located anywhere in a geographical area having a given time slot assigned may not interfere with a device located in another geographical area having the same time slot assigned; and

a number of the set of time slots is based on a ratio R equal to the ratio of the interference range to the detection range of the device.

17. The device of claim 16, wherein the geographical location of the device is determined via global positioning system.

18. The device of claim 16, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a diameter equal to the detection range of the device.

19. The device of claim 16, wherein each geographical area of the predefined plurality of geographical areas has a hexagonal shape with a diameter equal to the detection range of the device.

20. The device of claim 16, wherein at least one of the geographical areas of the predefined plurality of geographical areas has a one of:

a hexagonal shape;

a rectangular shape;

a triangular shape;

or

a circular shape.