Method and system for autonomously allocating a frequency hopping traffic channel in a private radio system

• US 6,009,332 A
• Filed: 04/24/1997
• Issued: 12/28/1999
• Est. Priority Date: 08/28/1996
• Status: Expired due to Term

• Current Assignee: Blackberry Limited, United Microelectronics Corporation
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Haartsen, Jacobus C.
• Primary Examiner(s): Vo, Nguyen
• Assistant Examiner(s): Aoki, Makoto
• Application Number:
  US08/847,524
• Time in Patent Office: 978 Days
• Field of Search: 455/450, 455/451, 455/452, 455/464, 455/509, 455/513, 455/444, 370/329, 370/330
• US Class Current: 455/450
• 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 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point
• CPC Class Codes: H04W 36/304 due to measured or perceived resources with higher communication quality
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02
• 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-interfered communications link between a cellular mobile station and a private radio base station within a cellular system is disclosed. A set of candidate carrier frequencies are first selected and ordered by the amount of interference present within the cellular system, and a subset thereof selected. A second set of candidate frequencies and associated timeslots are then selected from the subset and ordered by the amount of interference present in the private radio system environment, and a second subset thereof selected. A plurality of discrete hop lists for each timeslot are then formed, and one of the hop lists exhibiting the least amount of interference is then selected to be applied in the communications link.

Claims

1. A method for determining a least-interfered communications link between a private radio base station and a cellular mobile station, said private radio base station located within an area of said cellular mobile station, said private radio base station and said cellular mobile station sharing a multiplicity of frequencies for communication therein, said method comprising the steps of:

determining a first set of candidate frequencies for use by said private radio base station within said area of the cellular mobile station;

ordering said first set of candidate frequencies into a second set of candidate frequencies pursuant to a first interference measurement;

expanding said second set of candidate frequencies into a third set containing a multiplicity of frequency and timeslot pairings pursuant to a second interference measurement, each candidate frequency in said second set having a plurality of timeslots associated therewith;

selecting a subset of said pairings from said third set, said candidate frequencies within said third set pairings having an associated signal interference value less than a given interference value being selected for said pairings subset, said pairings subset comprising said plurality of frequency hop lists in said step of dividing;

reordering said frequency/timeslot pairings within said pairings subset;

dividing said third set of said pairings into a plurality of frequency hop lists, each of said frequency hop lists containing a plurality of frequencies from said third set associated with a particular timeslot within said pairings, wherein said step of dividing said third set further comprises another averaging of the signal strengths of said frequency/timeslot pairings within said third set over a plurality of seconds; and

selecting one of said frequency hop lists as the least-interfered communications link for said private radio base station.

2. The method according to claim 1, wherein said determination of said first set of candidate frequencies is made within said private radio base station.

3. The method according to claim 1, wherein said first set of candidate frequencies are forwarded to said private radio base station by a remote device, said determination of said first set of candidate frequencies being made within said remote device.

4. The method according to claim 3, wherein said remote device forwards said first set of candidate frequencies to said private radio base station via a wireless communication.

5. The method according to claim 1, wherein said first interference measurement comprises a combination of uplink and downlink measurements carried out within said private radio base station.

6. The method according to claim 1, wherein, in said step of ordering, each said candidate frequency in said second set includes a signal strength value associated therewith.

7. The method according to claim 6, further comprising, after said step of ordering, selecting a first subset of said second set of candidate frequencies, said candidate frequencies within said second set having an associated signal strength value less than a threshold signal strength value being selected for said first subset, said first subset being utilized in said step of expanding.

8. The method according to claim 1, wherein, in said step of expanding said second set into said third set of pairings, said second interference measurement comprises an averaging of the signal strengths of said frequency/timeslot pairings over a plurality of minutes.

9. The method according to claim 1, wherein said frequency/timeslot pairings signal strengths after said another averaging differ from said frequency/timeslot pairings signal strengths prior to said another averaging, wherein a first frequency/timeslot in said pairings subset has a signal strength greater than the signal strength of a second frequency/timeslot prior to said averaging and less than the signal strength of said second frequency/timeslot after said averaging, and wherein said step of reordering is performed if the difference in signal strengths between said first frequency/timeslot pairing and said second frequency/timeslot pairing after said averaging is greater than a threshold margin.

10. The method according to claim 1, wherein said cellular network system is a digital Frequency Division Multiple Access (FDMA) system.

11. The method according to claim 1, wherein said cellular network system is a digital Frequency Division Multiple Access/Time Division Multiple Access (FDMA/TDMA) system.

12. The method according to claim 1, wherein said frequencies are expressed in Absolute Radio Frequency Channel Numbers.

13. A method for determining a least-interfered communications link between a private radio base station and a cellular mobile station, said private radio base station located within an area of said cellular mobile station, said private radio base station and said cellular mobile station sharing a multiplicity of frequencies for communication therein, said method comprising the steps of:

determining a first set of candidate frequencies for use by said private radio base station within said area of the cellular mobile station;

ordering said first set of candidate frequencies into a second set of candidate frequencies pursuant to a first interference measurement;

expanding said second set of candidate frequencies into a third set containing a multiplicity of frequency and timeslot pairings pursuant to a second interference measurement, each candidate frequency in said second set having a plurality of timeslots associated therewith;

dividing said third set of said pairings into a plurality of frequency hop lists, each of said frequency hop lists containing a plurality of frequencies from said third set associated with a particular timeslot within said pairings, wherein, in said step of dividing said third set, the number of said plurality of frequency hop lists equals the number of timeslots in a multislot digital transmission frame; and

selecting one of said frequency hop lists as the least-interfered communications link for said private radio base station.

14. The method according to claim 13, wherein said determination of said first set of candidate frequencies is made within said private radio base station.

15. The method according to claim 13, wherein said first set of candidate frequencies are forwarded to said private radio base station by a remote device, said determination of said first set of candidate frequencies being made within said remote device.

16. The method according to claim 15, wherein said remote device forwards said first set of candidate frequencies to said private radio base station via a wireless communication.

17. The method according to claim 13, wherein said first interference measurement comprises a combination of uplink and downlink measurements carried out within said private radio base station.

18. The method according to claim 13, wherein, in said step of ordering, each said candidate frequency in said second set includes a signal strength value associated therewith.

19. The method according to claim 13, wherein, in said step of expanding said second set into said third set of pairings, said second interference measurement comprises an averaging of the signal strengths of said frequency/timeslot pairings over a plurality of minutes.

20. The method according to claim 13, wherein said cellular network system is a digital Frequency Division Multiple Access (FDMA) system.

21. The method according to claim 13, wherein sad cellular network system is a digital Frequency Division Multiple Access/Time Division Multiple Access (FDMA/TDMA) system.

22. The method according to claim 13, wherein said frequencies are expressed in Absolute Radio Frequency Channel Numbers.

23. In a communication system having a cellular mobile station and a private radio base station, said private radio base station being located within an area of said cellular mobile station, circuitry within said private radio base station for allocating a least-interfered communications link between said private radio base station and said cellular mobile station, where said private radio base station and said cellular mobile station share frequencies, said circuitry comprising:

a first determining means for determining a first set of candidate frequencies for use by said private radio system within said area of said cellular mobile station;

a first ordering means for ordering said first set of candidate channels into second set of candidate frequencies pursuant to a first interference measurement;

expanding means for expanding said second set of candidate frequencies into a third set containing a multiplicity of frequency and timeslot pairings pursuant to a second interference measurement, each candidate frequency in said second set having a plurality of timeslots associated therewith;

a dividing means for dividing said third set of pairings into a plurality of frequency hop lists, each of said frequency hop lists containing a plurality of frequencies from said third set associated with a particular timeslot within said pairings, wherein said dividing means further comprises an averaging means for averaging the signal strengths of said frequency/timeslot pairings within said third set over a plurality of seconds, wherein said frequency/timeslot pairings within said pairings subset are reordered;

a second selecting means for selecting a subset of said pairings from said third set, said candidate frequencies within said third set pairings having an associated signal interference value less than a given interference value being selected for said pairings subset, said pairings subset comprising said plurality of frequency hop lists for said dividing means; and

selecting means for selecting one of said frequency hop lists as the least-interfered communications link for said private radio base station.

24. The communication system circuitry according to claim 23, wherein said first determining means for determining said first set of candidate frequencies is within said private radio base station.

25. The communication system circuitry according to claim 23, wherein said first determining means for determining said first set of candidate frequencies is within a remote device.

26. The communication system circuitry according to claim 23, wherein said remote device forwards said first set of candidate frequencies to said private radio base station via a wireless communication.

27. The communication system circuitry according to claim 23, wherein said first interference measurement comprises a combination of uplink and downlink measurements carried out within said private radio base station.

28. The communication system circuitry according to claim 23, wherein said second set includes a signal strength value associated with each of said candidate frequencies.

29. The communication system circuitry according to claim 23, wherein said frequency/timeslot pairings signal strengths after said averaging in said averaging means differ from said frequency/timeslot pairings signal strengths prior to said averaging, wherein a first frequency/timeslot in said pairings subset has a signal strength greater than the signal strength of a second frequency/timeslot prior to said averaging and less than the signal strength of said second frequency/timeslot after said averaging, and wherein said frequency/timeslot pairing reordering is performed if the difference in signal strengths between said first frequency/timeslot pairings and said second frequency/timeslot pairing after said averaging is greater than a threshold margin.

30. The communication system circuitry according to claim 23, further comprising an escape communications link means, said link means used upon an occurrence of a link failure condition between said private radio base station and said cellular mobile station, said escape communication link means using a particular frequency hop list.

31. In a communication system having a cellular mobile station and a private radio base station, said private radio base station being located within an area of said cellular mobile station, circuitry within said private radio base station for allocating a least-interfered communications link between said private radio base station and said cellular mobile station, where said private radio base station and said cellular mobile station share frequencies, said circuitry comprising:

a first determining means for determining a first set of candidate frequencies for use by said private radio system within said area of said cellular mobile station;

a first ordering means for ordering said first set of candidate channels into second set of candidate frequencies pursuant to a first interference measurement;

expanding means for expanding said second set of candidate frequencies into a third set containing a multiplicity of frequency and timeslot pairings pursuant to a second interference measurement, each candidate frequency in said second set having a plurality of timeslots associated therewith;

a dividing means for dividing said third set of pairings into a plurality of frequency hop lists, each of said frequency hop lists containing a plurality of frequencies from said third set associated with a particular timeslot within said pairings, wherein the number of said plurality of frequency hop lists equals the number of timeslots in a multislot digital transmission frame; and

selecting means for selecting one of said frequency hop lists as the least-interfered communications link for said private radio base station.

32. The communication system circuitry according to claim 31, wherein said first determining means for determining said first set of candidate frequencies is within said private radio base station.

33. The communication system circuitry according to claim 31, wherein said first determining means for determining said first set of candidate frequencies is within a remote device.

34. The communication system circuitry according to claim 31, wherein said remote device forwards said first set of candidate frequencies to said private radio base station via a wireless communication.

35. The communication system circuitry according to claim 31, wherein said first interference measurement comprises a combination of uplink and downlink measurements carried out within said private radio base station.

36. The communication system circuitry according to claim 31, wherein said second set includes a signal strength value associated with each of said candidate frequencies.

37. The communication system circuitry according to claim 31, further comprising an escape communications link means, said link means used upon an occurrence of a link failure condition between said private radio base station and said cellular mobile station, said escape communication link means using a particular frequency hop list.