Method and system for real-time channel management in a radio telecommunications system

• US 5,867,789 A
• Filed: 12/30/1996
• Issued: 02/02/1999
• Est. Priority Date: 12/30/1996
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Olds, Keith Andrew, Davieau, Gerald Joseph
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): Kincaid, Lester G.
• Application Number:
  US08/777,434
• Time in Patent Office: 764 Days
• Field of Search: 455/450, 455/452, 455/453, 455/62, 455/63, 455/442, 455/443, 455/446, 455/447, 455/448, 455/449, 455/509, 455/512, 455/12.1, 455/436
• US Class Current: 455/453
• CPC Class Codes: H04B 7/18541 for handover of resources
• CPC Class Codes: H04W 16/06 Hybrid resource partitioning, e.g. channel borrowing
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 36/08 Reselecting an access point
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/20 between access points

Abstract

A channel management process (68) is performed by a parent base station (36) of a radio telecommunications system (20) that exchanges channel usage data with neighbor base stations (38) within its local group (34). When channel usage data indicates a channel assignment conflict, that conflict is resolved in the base station (22) having the lesser loading of the pair of conflicting base stations (22). Channel usage requests received by a base station (22) are prioritized and sequentially processed, channels (58) being assigned for inter-cell handoff requests, then intra-cell handoff requests after inter-cell handoff requests, even when that assignment creates a conflict, and then channels (58) being assigned to new call requests after handoff requests if that assignment does not create a conflict.

Claims

1. A method for managing channel usage at a first base station in a radio telecommunication system, said method comprising the steps of:

(a) receiving data which identify channels in use at a second base station;

(b) obtaining a channel usage request, said channel usage request requesting use of a channel at said first base station;

(c) determining whether said second base station is carrying less call traffic than said first base station; and

(d) if said second base station is carrying less call traffic, using a channel at said first base station which is in use at said second base station.

2. A method as claimed in claim 1, wherein said step (b) obtains a plurality of channel usage requests, and said method additionally comprises the steps of:

sequentially processing said channel usage requests by performing said step (c) and said step (d) for each of said channel usage requests; and

prioritizing said channel usage requests to indicate an order in which to sequentially process said channel usage requests.

3. A method as claimed in claim 2, wherein:

said method additionally comprises the step of evaluating data which characterize said channel usage requests as inter-cell handoff requests and intra-cell handoff requests; and

said prioritizing step gives priority to processing said inter-cell handoff requests before processing said intra-cell handoff requests.

4. A method as claimed in claim 3, wherein:

said evaluating step evaluates data which characterize said channel usage requests as inter-cell handoff requests, intra-cell handoff requests, and new call requests; and

said prioritizing step gives priority to processing said inter-cell handoff requests and said intra-cell handoff requests before processing said new call requests.

5. A method as claimed in claim 2, wherein:

said method additionally comprises the step of evaluating data which characterize said channel usage requests as handoff requests and new call requests; and

said prioritizing step gives priority to processing said handoff requests before processing said new call requests.

6. A method as claimed in claim 5, wherein:

said step (d) uses channels at said first base station which are in use at said second base station in response to said handoff requests; and

said step (d) refrains from using channels at said first base station which are in use at said second base station in response to said new call requests.

7. A method as claimed in claim 1, additionally comprising the step of refraining, at said first base station, from determining a presence of or resolving interference conflicts between channels in use at said first and second base stations when said second base station is carrying less call traffic than said first base station.

8. A method as claimed in claim 1, additionally comprising the step of determining, if said second base station is carrying more call traffic than said first base station, whether a conflict exists between a first existing call using a first base station channel and a second existing call using a second base station channel.

9. A method as claimed in claim 8, additionally comprising the step of handing off, if said conflict exists, said first call to a first base station channel which does not conflict with channels in use at said second base station.

10. A method as claimed in claim 1, additionally comprising the step of identifying whether a non-interfering channel is available for use at said first base station, said non-interfering channel being a first base station channel which does not interfere with channels in use at said first base station and does not interfere with channels in use at said second base station.

11. A method as claimed in claim 10, wherein said step (d) uses said non-interfering channel at said first base station when said non-interfering channel is available for use at said first base station.

12. A method as claimed in claim 1, additionally comprising the step of sending data from said first base station to said second base station, said data being configured to identify said channel used at said first base station.

13. A method as claimed in claim 1, additionally comprising the step of placing said first base station in a moving orbit around the earth.

14. A method as claimed in claim 1, wherein:

said first base station manages a first plurality of channels, including said channel used in said step (d);

said first plurality of channels are grouped into reuse units;

each of said reuse units includes a second plurality of said channels;

each reuse unit is placed in use when any channel included therein is placed in use and is placed out of use when all channels included therein are placed out of use; and

said method additionally comprises the step of handing off a call from a first one of said reuse units to a second one of said reuse units to place said first one of said reuse units out of service.

15. A method for managing radio channel usage among a plurality of base stations in a radio telecommunication system, said method comprising the steps of:

placing channels in use at each of said base stations to support calls from each of said base stations;

notifying other ones of said base stations that said channels have been placed in use;

monitoring, at each of said base stations, call traffic in more than one of said base stations; and

identifying possible interference conflicts between channels placed in use at pairs of said base stations;

wherein, for each pair of said base stations, said identifying step is performed at said base station which is experiencing less call traffic within said pair of base stations.

16. A method as claimed in claim 15, additionally comprising, for each pair of said base stations, the step of placing in use, at said base station which is experiencing more call traffic within said pair of said base stations, a channel which interferes with a channel already placed in use at said base station which is experiencing less call traffic within said pair of said base stations.

17. A method as claimed in claim 15, wherein said placing step places channels in use in response to channel usage requests, said requests being configured as handoff requests and new call requests, and said method additionally comprises the steps of:

sequentially processing, at each of said base stations, said channel usage requests; and

prioritizing said channel usage requests to process said handoff requests before processing said new call requests.

18. A method as claimed in claim 15, wherein said placing step places channels in use in response to channel usage requests, said requests being configured as handoff requests and new call requests, and said placing step comprises the steps of:

selecting, at said base station which is experiencing more call traffic within said pair of said base stations, channels which interfere with channels already placed in use at said base station which is experiencing less call traffic within said pair of said base stations, said selecting step being performed in response to said handoff requests; and

refraining, at said base station which is experiencing more call traffic within said pair of said base stations, from placing into use channels which interfere with channels already placed in use at said base station which is experiencing less call traffic within said pair of said base stations, said refraining step being performed in response to said new call requests.

19. A method as claimed in claim 15, additionally comprising the step of refraining, at said base station which is experiencing more call traffic within said pair of said base stations, from performing said identifying step.

20. A method as claimed in claim 15, additionally comprising the step of performing an intra-cell handoff at said base station which is experiencing less call traffic within said pair of said base stations to resolve conflicts identified in said identifying step.

21. A method as claimed in claim 15, wherein:

channels supported by each of said base stations are grouped into reuse units;

each reuse unit is placed in use when any channel included therein is placed in use and is placed out of use when all channels included therein are placed out of use; and

said method additionally comprises the step of performing, at each of said base stations, an intra-cell handoff between two of said reuse units to place one of said two reuse units out of service.

22. A method for managing radio channel usage between first and second base stations within a radio telecommunication system, said first and second base stations supporting first and second cells, respectively, and said first cell being located proximate said second cell so that communications in said first and second cells potentially interfere, said method comprising the steps of:

(a) receiving channel usage requests at said first and second base stations, said channel usage requests requesting use of channels at said first and second base stations, and said requests being configured as handoff requests and new call requests;

(b) performing pre-usage interference conflict checking at said first and second base stations in response to each of said channel usage requests;

(c) monitoring call traffic at said first and second base stations to identify a greater call-traffic-carrying one of said first and second base stations and a lesser call-traffic-carrying one of said first and second base stations;

(d) if, in response to said step (b), channels appear to be non-interfering, using said apparently non-interfering channels at said greater and lesser call-traffic-carrying base stations to support calls conducted in said first and second cells;

(e) if, in response to said step (b), no channel appears to be non-interfering, refraining from using any channel in response to new call requests at said greater and lesser call-traffic-carrying base stations; and

(f) if, in response to said step (b), no channel appears to be non-interfering, using apparently interfering channels at said greater call-traffic-carrying base station to support calls conducted in said first cell.

23. A method as claimed in claim 22, additionally comprising the steps of:

(g) notifying said second base station of channels placed in use and removed from use at said first base station;

(h) notifying said first base station of channels placed in use and removed from use at said second base station; and

(i) performing usage interference conflict checking at said lesser call-traffic-carrying base station, said step (i) being performed with respect to channels placed in use at said first and second base stations.

24. A method as claimed in claim 23, additionally comprising the step of:

(j) if said step (i) identifies a usage interference conflict at said lesser call-traffic-carrying base station, performing an intra-cell handoff at said lesser call-traffic-carrying base station to resolve said usage interference conflict.

25. A system comprising:

a plurality of neighbor base stations, each carrying an amount of call traffic; and

a parent base station that is capable of communicating with each of the neighbor base stations to receive the amount of call traffic from each of the neighbor base stations, passing conflict resolution to a neighbor base station if the neighbor base station has a lesser amount of the call traffic than the parent base station, and resolving a conflict if the neighbor base station has a greater amount of the call traffic and the conflict exists.

26. A parent base station comprising:

means for communicating with each of the neighbor base stations to receive an amount of call traffic of each of a plurality of neighbor base stations;

means for passing conflict resolution to a neighbor base station if the neighbor base station has a lesser amount of the call traffic than the parent base station; and

means for resolving a conflict if the neighbor base station has a greater amount of the call traffic than the parent base station and the conflict exists.