SYSTEM AND METHOD FOR WIRELESS MULTI-HOP NETWORK SYNCHRONIZATION AND MONITORING

• US 20090303895A1
• Filed: 07/27/2007
• Published: 12/10/2009
• Est. Priority Date: 07/28/2006
• Status: Abandoned Application

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Naden, James Mark, Zhang, Hang, Tong, Wen, Zhu, Peiying, Fong, Mo-Han, Yu, Derek, Steer, David, Bahceci, Israfil, Senarath, Nimal Gamini
• Application Number:
  US12/375,478
• Publication Number:
  US 20090303895A1
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels
• CPC Class Codes: H04W 56/002 Mutual synchronization

Abstract

A wireless communication system and method for wireless communication in a multi-hop network. A first preamble is transmitted using a first repetition cycle. Monitoring for a second preamble is done in a second repetition cycle. The first repetition cycle is different than the second repetition cycle.

Claims

1. A method for wireless communication in a multi-hop network, the method comprising:

transmitting a first preamble using a first repetition cycle;

monitoring for a second preamble in a second repetition cycle, the first repetition cycle being different than the second repetition cycle.

2. The method of claim 1, wherein the second repetition cycle varies from node to node in one of a deterministic or random manner.

3. The method of claim 2, wherein the second repetition cycle is divided into at least two sub-cycles in which at least one sub-cycle is used for synchronization and at least other sub-cycle is used for neighbor monitoring.

4. The method of claim 2, wherein the second repetition cycle is divided into at least two sub-cycles, wherein the sub-cycles are distinguished by separation in their respective transmission periods by at least one of:

a different location within a frame; and

locations in different ones of a plurality of frames in which the plurality of frames comprise a multi-frame.

5. The method of claim 1, wherein transmitting using the first repetition cycle includes transmitting in a first predetermined frame, p, and transmitting each successive 2*Nth frame, wherein N is an integer and p<

N.

6. The method of claim 5, wherein monitoring in a second repetition cycle includes monitoring for the second preamble in a second predetermined frame, q, different from the first predetermined frame and monitoring each successive 2*Nth frame, wherein q<

N.

7. The method of claim 6, wherein the first and second preambles are synchronization preambles.

8. The method of claim 7, wherein transmitting a third preamble for neighbor monitoring in a third frame other than the first frame and the second frame.

9. The method of claim 8, wherein a plurality of frames are arranged as a multi-frame, a predetermined frame within the multi-frame being allocated for monitoring the third preamble.

10. A method for wireless communication in a multi-hop network using a first preamble type for synchronization and a second preamble type for neighbor monitoring, the method comprising:

transmitting a first preamble of the first preamble type using a fixed transmission frequency;

transmitting a second preamble of the second preamble type using a non-fixed transmission frequency.

11. The method of claim 10, further comprising:

monitoring the first preamble; and

monitoring the second preamble,

wherein the monitoring for the first preamble is done on a random basis and the monitoring for the second preamble is done on a random basis.

12. The method of claim 10, further comprising:

monitoring the first preamble; and

monitoring the second preamble only when there is a change to the network.

13. The method of claim 10, further comprising:

determining whether a relay node is one of a fixed relay node or a mobile relay node;

monitoring the first preamble; and

monitoring the second preamble,

wherein monitoring for the second preamble is performed at a first frequency if the relay node is a fixed relay node and at a second frequency if the relay node is a mobile relay node, the first frequency being less than the second frequency.

14. The method of claim 10, wherein the fixed transmission frequency is modified such that the first preamble is randomly not transmitted during certain periods.

15. The method of claim 10, further comprising:

selecting a monitoring cycle;

allocating a set of monitoring slots within the monitoring cycle;

monitoring the first preamble and monitoring the second preamble during the allocated set of monitoring slots.

16. The method of claim 10, further comprising:

identifying relay nodes and base stations having a level of interference above a predetermined level;

transmitting monitoring slot information to the identified relay nodes and base stations monitoring slot information;

assigning a monitoring slot based on the monitoring slot information.

17. The method of claim 10, further comprising:

establishing a list of neighbor nodes;

obtaining monitoring slot information for the list of neighbor nodes;

selecting a non-colliding monitoring slot from the monitoring slot information; and

monitoring the first preamble and the second preamble based on the selected non-colliding monitoring slot.

18. The method of claim 10, further comprising:

monitoring the first preamble; and

monitoring the second preamble,

wherein monitoring times to monitor the first preamble and the second preamble are pre-determined.

19. A wireless communication system, comprising:

a first relay node, the first relay node transmitting a first preamble using a first repetition cycle and monitoring for a second preamble in a second repetition cycle, the first repetition cycle being different than the second repetition cycle.

20. The system of claim 19, further comprising a second relay node, the second relay node transmitting the second preamble using the second repetition cycle and monitoring for the first preamble in the first repetition cycle.

21. The system of claim 20, wherein the system is an IEEE 802.16j system.

22. The system of claim 19, wherein transmitting using the first repetition cycle includes transmitting in a first predetermined frame, p, and transmitting each successive 2*Nth frame, wherein N is an integer and p<

N.

23. The system of claim 22, wherein monitoring in a second repetition cycle includes monitoring for the second preamble in a second predetermined frame, q, different from the first predetermined frame and monitoring each successive 2*Nth frame, wherein q<

N.

24. The system of claim 23, wherein the first and second preambles are synchronization preambles.