Method and system for autonomously allocating a cellular communications channel for communication between a cellular terminal and a telephone base station

• US 5,884,145 A
• Filed: 08/28/1996
• Issued: 03/16/1999
• Est. Priority Date: 08/28/1996
• Status: Expired due to Term

• Current Assignee: Blackberry Limited
• Original Assignee: Telefon Akmebolget Lm Ericsson
• Inventors: Haartsen, Jacobus C.
• Primary Examiner(s): Cuchlinski, Jr., William A.
• Assistant Examiner(s): ARTHUR JEANGLAUDE, GERTRUDE
• Application Number:
  US08/704,846
• Time in Patent Office: 930 Days
• Field of Search: 455/33.1, 455/33.2, 455/34.1, 455/34.2, 455/54.1, 455/56.1, 455/62, 455/63, 455/67.1, 455/33.4, 455/422, 455/444, 455/450, 455/452, 455/451, 455/455, 455/454 , 455/464, 455/509, 455/426, 455/434, 455/437, 455/513
• US Class Current: 455/63.2
• CPC Class Codes: H04W 16/10 Dynamic resource partitioning
• CPC Class Codes: H04W 16/12 Fixed resource partitioning
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence

Abstract

An allocation method and system for allocating a least-interference communications channel between a cellular system and a private radio system within the cellular system. A set of candidate channels are first selected and ordered by the amount of interference present within the cellular system, and a subset thereof is selected. A second set of candidate channels are then selected from the subset and ordered by the amount of interference present in the private radio system environment, and a safe channel subset thereof is selected. That channel exhibiting the least amount of interference is then selected from the safe channel subset as the communications channel.

Claims

1. A method for allocating a least-interfered communication channel between a private radio system and a cellular terminal, said private radio system and said cellular terminal being located within an area covered by said cellular system, where said private radio system and said cellular system share channels, said method comprising the steps of:

determining, within said private radio system, a first set of candidate channels for use by said private radio system within said area;

ordering said first set of candidate channels into an ordered set pursuant to a first interference measurement, said first interference measurement being associated with the amount of interference encountered by the respective channels of said first set within said area;

determining, within said private radio system, a second set of candidate channels pursuant to a second interference measurement, said second set being a subset of said first set of candidate channels, said second interference measurement being associated with the amount of interference encountered by the respective channels of said second set within said area;

performing averaging measurements on a plurality of candidate channels within said second set;

ordering said plurality of candidate channels within said second set into an ordered set pursuant to said second interference measurement; and

selecting one of said plurality of candidate channels within said second set as the least-interfered communication channel for use by said private radio system.

2. The method according to claim 1, wherein said step of determining said first set of candidate channels comprises:

performing signal strength measurements, within a mobile station in communication with said private radio system, on channels between said mobile station and said private radio system;

transferring said signal strength measurements to said private radio system; and

determining, within said private radio system, said first set of candidate channels.

3. The method according to claim 2, wherein said first interference measurement in said step of ordering said first set of candidate channels comprises weighing portions of said signal strength measurements more heavily during a particular time of the day.

4. The method according to claim 2, wherein said first interference measurement in said step of ordering said first set of candidate channels comprises combining a plurality of uplink and downlink signal strength measurements between said private radio system and said cellular system.

5. The method according to claim 4, wherein said plurality of downlink signal strength measurements are weighed more heavily in the combination.

6. The method according to claim 1, wherein said averaging measurements in said step of performing are performed over a range of about one to five seconds.

7. The method according to claim 1, further comprising:

updating said second set of candidate channels pursuant to changes within the private radio system.

8. The method according to claim 1, further comprising:

handing over said least-interfered communication channel to another channel when the quality of said least-interfered communication channel deteriorates, said another channel selected in accordance with said method.

9. The method according to claim 8, wherein said another channel is at a frequency different from said communication channel.

10. The method according to claim 8, wherein said another channel is in a timeslot different from said least-interfered communication channel.

11. The method according to claim 1, further comprising:

updating said first set of candidate channels pursuant to changes within the cellular system.

12. The method according to claim 1, wherein said step of determining said second set of candidate channels comprises:

performing averaging measurements, within a mobile station in communication with said private radio system, on channels between said mobile station and said private radio system;

transferring said averaging measurements to said private radio system; and

determining, within said private radio system, said second set of candidate channels.

13. The method according to claim 1, wherein, upon loss of communication between said private radio system and a mobile terminal, said step of selecting selects an escape communication channel.

14. The method according to claim 13, wherein said escape communication channel is the second least-interfered communication channel within said second set.

15. In a communication system having a cellular system and a private radio system, said private radio system being located within an area covered by said cellular system, circuitry within said private radio system for allocating a least-interfered communication channel for said private radio system where said private radio system and said cellular system share channels, said circuitry comprising:

a first determining means, within said private radio system, for determining a first set of candidate channels for use by said private radio system within said area, said first set of candidate channels being determined pursuant to a first interference averaging measurement;

a first ordering means for ordering said first set of candidate channels into an ordered set pursuant to said first interference averaging measurement, said first interference averaging measurement being associated with the amount of interference encountered by the respective channels of said first set within said area;

a second determining means, within said private radio system, for determining a second set of candidate channels pursuant to a second interference averaging measurement, said second set being a subset of said first set of candidate channels, said second interference averaging measurement being associated with the amount of interference encountered by the respective channels of said second set within said area;

a second ordering means for ordering said second set of candidate channels into an ordered set pursuant to said second interference averaging measurement; and

selecting means for selecting a given candidate channel within said ordered second set as the least-interfered communications channel for use by said private radio system.

16. The circuitry according to claim 15, wherein said first determining means receives signal strength measurements, from a mobile station in communication with the private radio system, of a plurality of channels between said mobile station and said private radio system, and determines said first set of candidate channels from said plurality of channels.

17. The circuitry according to claim 15, wherein said second determining means is within a mobile station in communication with the private radio system.

18. The communication system according to claim 15, wherein, upon loss of communication between said private radio system and a mobile terminal, said selecting means selects an escape communication channel.

19. The communication system according to claim 18, wherein said escape communication channel is the second least-interfered communication channel within said second set.

20. A private base station within a private radio system, said private base station being in communication with a plurality of mobile phones, said private radio system being located within an area covered by a cellular system, circuitry within said private base station for allocating a least-interfered traffic channel between a given one of said plurality of mobile phones and said private base station, said circuitry comprising:

a first channel selection means for selecting a first set of candidate channels for use by said private radio system within said area pursuant to a first interference averaging measurement, said first interference averaging measurement being associated with the amount of interference encountered by the respective channels of said first set within said area;

a second channel selection means for selecting a second set of candidate channels for use by said private radio system within said area of the cellular system pursuant to a second interference averaging measurement, said second set being a subset of the first set, said second interference averaging measurement being associated with the amount of interference encountered by the respective channels of said second set within said area; and

selecting means for selecting a given one of said candidate channels within the second set as the least-interfered traffic channel.

21. The private base station according to claim 20, wherein said first set of candidate channels are selected from a generic list of candidate channels within said private base station.

22. The private base station according to claim 21, wherein said generic list is placed within said private base station at the time of manufacture of said private base station.

23. The private base station according to claim 21, wherein said generic list is placed within said private base station at the time of installation of said private base station within said area.

24. The private base station according to claim 21, wherein said generic list is forwarded to the private base station via a wireline connection to a remote operator.

25. The private base station according to claim 21, wherein said generic list is forwarded to the private base station via a wireless communication.

26. The private base station according to claim 25, wherein said generic list is forwarded to the private base station via a short message service communication.

27. The private base station according to claim 25, wherein said generic list is forwarded to the private base station via a communications link with one of said mobile phones.

28. The private base station circuitry according to claim 20, wherein said first channel selection means further comprises a first ordering means for ordering the respective candidate channels within said first set into an ordered set pursuant to the amount of interference encountered by the respective candidate channels of said first set within said area.

29. The private base station circuitry according to claim 28, wherein said first channel selection means further comprises averaging means for averaging, pursuant to said first interference averaging measurement, the amount of interference encountered by the respective channels of said first set over a given period of time.

30. The private base station circuitry according to claim 29, wherein said averaging means includes uplink measurements of a plurality of said respective channels.

31. The private base station circuitry according to claim 30, wherein said averaging means also includes downlink measurements of a plurality of said respective channels, said uplink and downlink channels being coupled.

32. The private base station circuitry according to claim 31, wherein said downlink channels are weighted by said averaging means more heavily than said uplink channels.

33. The private base station circuitry according to claim 29, wherein said averaging means includes downlink measurements of a plurality of said respective channels.

34. The private base station circuitry according to claim 33, wherein said downlink measurements are carried out in a given one of said mobile phones and forwarded to said private base station.

35. The private base station circuitry according to claim 29, wherein said averaging means comprises an exponent-forget a averaging algorithm.

36. The private base station circuitry according to claim 28, wherein said first ordering means reorders the respective candidate channels within said first set pursuant to subsequent amounts of interference encountered by said respective candidate channels within said area.

37. The private base station circuitry according to claim 36, wherein said first ordering means reorders said first set in accordance with interference measurements forwarded by a given one of said mobile phones.

38. The private base station circuitry according to claim 36, wherein said reordering of said first ordering means is continuous, said reordering between two of said candidate channels within said first set being performed if the difference in interference measurements for said two candidate channels is greater than a first threshold.

39. The private base station circuitry according to claim 38, wherein said first threshold is predetermined.

40. The private base station circuitry according to claim 38, wherein said first threshold is variable.

41. The private base station circuitry according to claim 20, wherein said first channel selection means excludes from said first set a plurality of control channels utilized within said area.

42. The private base station circuitry according to claim 20, wherein said second channel selection means further comprises a second ordering means for ordering the respective candidate channels within said second set into another ordered set pursuant to the amount of interference encountered by the respective candidate channels of said second set within said area.

43. The private base station circuitry according to claim 42, wherein said second channel selection means further comprises averaging means for averaging, pursuant to said second interference averaging measurement, the amount of interference encountered by the respective channels of said second set over a given period of time.

44. The private base station circuitry according to claim 43, wherein said averaging means includes uplink measurements of a plurality of said respective channels.

45. The private base station circuitry according to claim 44, wherein said averaging means also includes downlink measurements of a plurality of said respective channels, said uplink and downlink channels being coupled.

46. The private base station circuitry according to claim 45, wherein said downlink channels are weighted by said averaging means more heavily than said uplink channels.

47. The private base station circuitry according to claim 43, wherein said averaging means includes downlink measurements of a plurality of said respective channels.

48. The private base station circuitry according to claim 47, wherein said downlink measurements are carried out in a given one of said mobile phones and forwarded to said private base station.

49. The private base station circuitry according to claim 43, wherein said averaging means comprises an exponential-forget averaging algorithm.

50. The private base station circuitry according to claim 20, wherein said first channel selection means excludes from said first set a plurality of control channels utilized within said area.

51. The private base station circuitry according to claim 20, wherein if, during a communications link between said private base station and a given one of said mobile phones on a given traffic channel, said link is severed, said second channel selection means selects another of said candidate channels within the second set as the least-interfered traffic channel.

52. The private base station circuitry according to claim 51, wherein said another candidate channel is determined prior to said severing and stored within said private base station and said given mobile phone.

53. The private base station circuitry according to claim 20, wherein, during a communications link between said private base station and a given one of said mobile phones on a given traffic channel, said link is severed whenever the amount of interference encountered by said given traffic channel within said area of the cellular system exceeds an interference margin, and said second channel selection means selects another of said candidate channels within the second set as the least-interfered traffic channel.

54. The private base station circuitry according to claim 20, wherein the interference encountered by the respective candidate channels of said first and second sets within said area is interference from a plurality of channels of said cellular system.

55. The private base station circuitry according to claim 54, wherein the interference encountered within said area further includes interference from a plurality of channels of other private radio systems.

56. The private base station circuitry according to claim 20, wherein the interference encountered by the respective candidate channels of said first and second sets within said area is interference from a plurality of channels of other private radio systems.

57. The private base station circuitry according to claim 20, wherein said candidate channels comprise frequencies.

58. The private base station circuitry according to claim 57, wherein said cellular system is a Frequency Division Multiple Access system.

59. The private base station circuitry according to claim 57, wherein said candidate channels comprise a frequency and timeslot combination.

60. The private base station circuitry according to claim 59, wherein said cellular system is a member of the group consisting of a Frequency Division Multiple Access system, a Time Division Multiple Access system and a combination thereof.

61. The private base station circuitry according to claim 20, wherein each of said candidate channels are associated with a respective Absolute Radio Frequency Channel Number.