SYNCHRONIZED, SEMI-DYNAMIC FREQUENCY HOPPING METHOD FOR WRAN AND OTHER WIRELESS NETWORKS

• US 20070249341A1
• Filed: 04/23/2007
• Published: 10/25/2007
• Est. Priority Date: 04/25/2006
• Status: Active Grant

• Current Assignee: SRC Computers, Inc., STMicroelectronics Incorporated (STMicroelectronics NV)
• Original Assignee: STMicroelectronics Incorporated (STMicroelectronics NV)
• Inventors: Chu, Liwen, Hu, Wendong, Vlantis, George
• Granted Patent: US 7,826,422 B2
• Time in Patent Office: Days
• US Class Current: 455/434
• CPC Class Codes: H04W 16/02 Resource partitioning among network components, e.g. reuse partitioning
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 84/20 Master-slave selection or change arrangements

Abstract

A method for creating and maintaining semi-dynamic frequency hopping communities. Each community is a set of neighboring cells, such as wireless regional area networks (WRANs) according to IEEE 802.22, that follow a protocol defining coordinated frequency hopping operations, e.g., hopping is performed by community members according to a leader-defined hopping pattern rather than to channels selected in the prior operation period. Each community has one leader base station and one or more community member base stations. The leader determines membership, calculates hopping patterns for all members, and distributes the hopping information to the community members. Members provide their neighborhood and channel availability information, e.g., information about their sensing results and channel usage of neighboring WRANs. In exemplary communities, the community members are one-hop neighbors, each community member is configured to perform sensing concurrently with data transmissions, and the number of available channels is greater than the number of members.

Claims

1. A communication system for managing use of channels in a frequency spectrum having available channels and unavailable channels in use by incumbent services, comprising:

a base station wirelessly communicating with a first plurality of consumer premise equipment sites and functioning as a leader of a frequency hopping community; and

a set of base stations each wirelessly communicating with a second plurality of consumer premise equipment sites and each functioning as a member base station of the frequency hopping community;

wherein the leader base station generates a hopping pattern defining a dwell time for data transmissions operation periods and start times for the operation periods on each one of a working set of channels for the leader base station and for the member base stations and defining when each of the leader base station and the member base stations switch to another one of the channels in the working set, whereby only one of the set of base stations operates on one of the channels in the working set at a time;

wherein the leader base station transmits the hopping pattern to each of the member base stations; and

wherein the leader base station and the member base stations communicate with the consumer premise equipment sites according to the hopping pattern.

2. The system of claim 1, wherein the base station functioning at the leader selects a subset of available channels as the working set of channels.

3. The system of claim 1, wherein the base station functioning as the leader receives an identification of the available channels from the base stations functioning as members.

4. The system of claim 1, wherein the base station functioning as the leader is selected as the leader based upon a priority relative to at least one other base station in the frequency hopping community.

5. The system of claim 1, wherein the base station function as the leader is selected as the leader based upon an absence of other relative neighbor base station in the frequency hopping community.

6. The system of claim 1, wherein the base station functioning as the leader includes a leader priority number MAC address and the leader is selected as the leader based upon the leader priority number MAC address relative to priority number MAC addresses of other base stations in the frequency hopping community.

7. The system of claim 1, wherein the base station functioning as the leader generates a new frequency hopping pattern responsive to a change in active status of base stations in the frequency hopping community.

8. The system of claim 1, wherein the base station functioning as the leader determines whether the frequency hopping community will accept another base station into the frequency hopping community.

9. The system of claim 8, wherein the base station functioning as the leader makes the determination based upon whether the another base station is capable of fitting into a new hopping pattern for the frequency hopping community.

10. The system of claim 8, wherein the base station functioning as the leader makes the determination based upon whether the another base station is a one-hop neighbor of the base stations in the frequency hopping community.

11. The system of claim 1, wherein the base station functioning as the leader makes the determination whether a base station has left the frequency hopping community.

12. A base station functioning as a leader of a frequency hopping community to manage operations of base stations wirelessly communicating with end users in cells over available channels, comprising:

memory storing a set of available channels determined to be vacant and a list of base stations including the leader base station that are members of the frequency hopping community;

a processor managing the memory and executing one or more software modules;

a community manager software module executed by the processor selecting a subset of the available channels as a working set and generating a hopping pattern for the frequency hopping community; and

a communication software module executed by the processor transmitting a message to other ones of the member base stations including the generated hopping pattern.

13. The base station of claim 12, wherein the community manager software module generates a new frequency hopping pattern responsive to a change in active status of base stations in the frequency hopping community.

14. The base station of claim 12, wherein the communication software module operates to receive messages from the other ones of the member base stations including sensing information for available channels, the community manager software module responding by updating the stored set of available channels, choosing a new working set of the available channels, and repeating the hopping pattern generated using the new working set.

15. The base station of claim 12, wherein the community manager software module operates to determine whether the frequency hopping community will accept another base station into the frequency hopping community.

16. The base station of claim 15, wherein the determination of whether to accept another base station into the frequency hopping community is based upon whether the another base station is capable of fitting into a new hopping pattern for the frequency hopping community.

17. The base station of claim 15, wherein the determination of whether to accept another base station into the frequency hopping community is based upon whether the another base station is a one-hop neighbor of the base stations in the frequency hopping community.

18. The base station of claim 12, wherein the community manager software module operates to determine whether a base station has left the frequency hopping community.

19. A semi-dynamic frequency hopping method for use in wireless regional area network (WRAN) systems, comprising:

providing two or more WRANs each operated by base stations to wirelessly communicate with consumer premise equipment (CPE);

electing one of the base stations as a leader of a frequency hopping community having the base stations as members; and

operating the leader base station to determine a set of channels available for use by the frequency hopping community,

with the leader base station, selecting a subset of the available channels as a working set of channels and generating a hopping sequence.

20. The method of claim 19, wherein the operating of the base stations according to the hopping sequence is performed for a plurality of operation periods for each of the base stations without modifying the hopping sequence.

21. The method of claim 19, further comprising operating the leader base station to receive a message from one of the member base stations indicating one of the channels in the working set is unavailable and, in response, repeating the selecting, generating, and transmitting steps with the base station to generate a modified hopping sequence with a modified working set of the available channels without the unavailable channel.

22. The method of claim 19, further comprising with the leader base station receiving a request from another base station to join the frequency hopping community, operating the leader base station to repeat the selecting of a working set of channels, generating a new hopping sequence, and transmitting the new hopping sequence responsive to accepting the another base station into the frequency hopping community.

23. The method of claim 19 wherein the leader base station receives an identification of available channels from the base stations functioning as members.

24. The method of claim 19, wherein electing one of the base stations as the leader is based upon a priority relative to at least one other base station in the frequency hopping community.

25. The method of claim 19, wherein the base stations elected as the leader includes a leader MAC address and wherein electing the leader is based upon the leader MAC address relative to MAC addresses of other base stations in the frequency hopping community.

26. The method of claim 19, wherein the leader base station further operates to generate a new frequency hopping pattern responsive to a change in active status of base stations in the frequency hopping community.

27. The method of claim 19, wherein the leader base station operates to determine whether the frequency hopping community will accept another base station into the frequency hopping community based upon whether the another base station fits into the hopping sequence or is capable of fitting into a new hopping sequence for the frequency hopping community.

28. A method for managing operations of a community of frequency hopping base stations in wireless regional area network (WRAN) systems by an elected leader base station, the method comprising:

selecting a subset of available channels as a working set of channels;

generating a frequency hopping sequence defining for each of the members of the community of frequency hopping base stations a next one of the channels in the working set to operate upon, a time to make a switch to the next one of the channels, and a dwell time on the next one of the channels after the switch; and

transmitting the frequency hopping sequence to member base stations of the community of frequency hopping base stations for performing frequency hopping according to the frequency hopping sequence.

29. The method of claim 28, further comprising determining a set of channels available for use by the community of frequency hopping base stations.

30. The method of claim 28, further comprising receiving an identification of the available channels from the members of the community of frequency hopping base stations.

31. The method of claim 28, further comprising receiving a message from at least one of the member base stations indicating one of the channels in the working set is unavailable and, in response, repeating the selecting, generating, and transmitting steps to generate a modified hopping sequence with a modified working set of the available channels without the unavailable channel.

32. The method of claim 28, further comprising receiving a request from another base station to join the community of frequency hopping base stations, determining whether the frequency hopping community will accept the another base station.

33. The method of claim 32, wherein the elected leader base station makes the determination based upon whether the another base station fits into the hopping sequence or is capable of fitting into a modified hopping sequence of the frequency hopping community.

34. The method of claim 32, wherein the elected leader base station makes the determination based upon whether the another base station is a one-hop neighbor to member base stations of the community of frequency hopping base stations.

35. The method of claim 28, further comprising determining whether a base station has left the community of frequency hopping base stations.

36. A base station functioning as a member in a community of frequency hopping base stations in wireless regional area network (WRAN) communicating with end users in cells over available channels, comprising:

memory storing a set of available channels determined to be vacant and a list of base stations that are members of the frequency hopping community;

a processor managing the memory and executing one or more software modules;

a communication software module executed by the processor receiving a message wherein the message includes a hopping pattern and a subset of the available channels designated as a working set; and

a software module executed by the processor executing the hopping pattern for the frequency hopping community.

37. The base station of claim 36, wherein the communication software module operates to transmit a message to a leader base station including sensing information for identification of available channels, the leader base station responding by updating the stored set of available channels, and designating a new working set of the available channels for the hopping pattern.