System and method for hyperband cell interoperability in a cellular telecommunications network

• US 5,839,070 A
• Filed: 10/13/1995
• Issued: 11/17/1998
• Est. Priority Date: 10/13/1995
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Brunner, Richard, Lupien, Francis
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/542,879
• Time in Patent Office: 1,131 Days
• Field of Search: 455/422, 455/436, 455/437, 455/438, 455/439, 455/440, 455/441, 455/442, 455/443, 455/444, 455/450, 455/451, 455/62, 455/67.1, 455/426, 370/331, 370/332
• US Class Current: 455/440
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/008355 Determination of target cell based on user equipment [UE] properties, e.g. UE service capabilities
• CPC Class Codes: H04W 36/0085 Hand-off measurements

Abstract

A system for providing seamless interoperability for a multi-hyperband capable mobile station roaming between cells within a cellular telecommunications network having a mobile switching center and a plurality of base stations that transmit and receive radio signals in a plurality of frequency hyperbands. The system comprises a plurality of location and verification devices within each of the plurality of base stations, Each of the plurality of location and verification devices operates in a different one of the plurality of frequency hyperbands. The system builds a neighbor list of candidate cells for handoff that includes cells operating in different ones of the plurality of frequency hyperbands, identifies the best candidate cell for communication with the mobile station, and verifies the presence of the mobile station in the identified candidate cell.

Claims

1. A system for providing seamless interoperability for mobile stations capable of operating in a first hyperband, mobile stations capable of operating in a second hyperband, and multi-hyperband capable mobile stations, each such mobile station roaming between cells within a cellular telecommunications network having a mobile switching center and a plurality of frequency hyperbands, said system comprising:

a serving cell in which said mobile station is operating, said serving cell having a serving base station;

means for building a neighbor list of cells neighboring said serving cell, wherein if said mobile station is one capable of operation in said first hyperband, including neighbor cells operating in the first hyperband, if said mobile station is one capable of operation in said second hyperband, including neighbor cells operating in the second hyperband, and if said mobile station is one that is multi-hyperband capable, said neighbor list including neighbor cells operating in frequency hyperbands supported by said multi-hyperband capable mobile station;

means for measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list;

means for determining the best candidate cell for communication with said mobile station; and

means for handing off said mobile station to said best candidate cell for communication with said mobile station.

2. The system for providing seamless interoperability of claim 1 further comprising means for verifying that said mobile station is present in said best candidate cell for communication with said mobile station prior to handing off said mobile station.

3. The system for providing seamless interoperability of claim 2 wherein said means for measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list includes a location and verification device that measures signal strengths in said plurality of frequency hyperbands.

4. The system for providing seamless interoperability of claim 2 wherein said means for measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list includes a plurality of location and verification devices within each of said plurality of base stations, each of said plurality of location and verification devices operating in a different one of said plurality of frequency hyperbands.

5. The system for providing seamless interoperability of claim 2 wherein said means for measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list includes means within said mobile station for measuring said signal strengths.

6. The system for providing seamless interoperability of claim 5 further comprising means within said mobile switching center for requesting said mobile station to measure said signal strengths.

7. The system for providing seamless interoperability of claim 6 further comprising means within said mobile station for reporting said measured signal strengths to said serving base station.

8. The system for providing seamless interoperability for a mobile station of claim 2 wherein said means for building a neighbor list includes:

means for determining the frequency hyperbands in which said mobile station is capable of communicating; and

means for selectively building a neighbor list that includes only cells operating in said frequency hyperbands in which said mobile station is capable of communicating.

9. The system for providing seamless interoperability for a mobile station of claim 8 further comprising means for providing said neighbor list to said mobile station.

10. The system for providing seamless interoperability for a mobile station of claim 9 wherein said means for determining the best candidate cell for communication with said mobile station includes means for identifying a cell with the best radio reception characteristics for said mobile station.

11. The system for providing seamless interoperability for a mobile station of claim 10 wherein said means for identifying a cell with the best radio reception characteristics for said mobile station includes means within said mobile station for measuring signal strength and bit error rate on said mobile station'"'"'s assigned radio channel.

12. The system for providing seamless interoperability for a mobile station of claim 10 wherein said means for identifying a cell with the best radio reception characteristics for said mobile station includes means within said serving base station and said cells in said neighbor list for measuring signal strength and bit error rate on said mobile station'"'"'s assigned radio channel.

13. The system for providing seamless interoperability for a mobile station of claim 12 wherein said means for identifying a cell with the best radio reception characteristics for said mobile station includes means for comparing each of said measured signal strengths with predetermined parameters to determine whether to hand off said mobile station to an identified cell.

14. The system for providing seamless interoperability of claim 13 wherein said means for verifying that said mobile station is present in said best candidate cell for communication with said mobile station prior to handing off said mobile station includes:

means for measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell; and

means for receiving a supervisory audio tone (SAT) to verify the mobile station'"'"'s identity.

15. The system for providing seamless interoperability of claim 13 wherein said means for verifying that said mobile station is present in said best candidate cell for communication with said mobile station prior to handing off said mobile station includes:

means for measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell; and

means for decoding a digital verification color code (DVCC) to verify the mobile station'"'"'s identity.

16. The system for providing seamless interoperability of claim 15 wherein said means for measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell includes means for utilizing said location and verification devices to measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell.

17. The system for providing seamless interoperability of claim 16 wherein said location and verification devices include means for measuring the signal strength of the mobile station'"'"'s signal for purposes of presence verification independently of measuring the signal strength of the mobile station for purposes of identifying a cell with the best radio reception characteristics for said mobile station.

18. The system for providing seamless interoperability of claim 1 wherein said plurality of frequency hyperbands includes an 800-MHz cellular telephone frequency hyperband and a 1900-MHz personal communication services (PCS) frequency hyperband.

19. A method of providing seamless interoperability for mobile stations capable of operating in a first hyperband, mobile stations capable of operating in a second hyperband, and for multi-hyperband capable mobile stations, each mobile station roaming between cells within a cellular telecommunications network having a mobile switching center and a plurality of base stations that transmit and receive radio signals in a plurality of frequency hyperbands, said method comprising the steps of:

operating a plurality of location and verification devices within each of said plurality of base stations, each of said plurality of location and verification devices operating in a different one of said plurality of frequency hyperbands;

for each base station, building a neighbor list of neighbor cells that includes cells operating in different ones of said plurality of frequency hyperbands;

identifying the best candidate cell for communication with said mobile station, wherein if said mobile station is one that is capable of operating in said first frequency hyperband, said best candidate cell is selected from a neighbor list having only cells operating in said first frequency hyperband, if said mobile station is one that is capable of operating in said second frequency hyperband, said best candidate cell is selected from a neighbor list having only cells operating in said second frequency hyperband, and if said mobile station is one that is multi-hyperband capable, said best candidate cell is selected from a neighbor list having cells capable of operating in either said first frequency hyperband or said second frequency hyperband;

determining whether said mobile station is in said best candidate cell; and

handing off said mobile station to said best candidate cell upon determining that said mobile station is in said best candidate cell.

20. The method of providing seamless interoperability for a mobile station of claim 19 wherein said step of operating a plurality of location and verification devices within each of said plurality of base stations includes operating a plurality of location and verification devices, each of which includes a signal strength receiver tuned to a different one of said plurality of frequency hyperbands.

21. The method of providing seamless interoperability for a mobile station of claim 20 wherein said step of building a neighbor list includes the steps of:

determining the frequency hyperbands in which said mobile station is capable of communicating; and

selectively building a neighbor list that includes only cells operating in said frequency hyperbands in which said mobile station is capable of communicating.

22. The method of providing seamless interoperability for a mobile station of claim 21 further comprising the step of providing said neighbor list to said mobile station.

23. The method of providing seamless interoperability for a mobile station of claim 22 wherein said step of identifying the best candidate cell for communication with said mobile station includes identifying a cell with the best radio reception characteristics for said mobile station.

24. The method of providing seamless interoperability for a mobile station of claim 23 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes measuring within said mobile station, a signal strength and bit error rate on said mobile station'"'"'s assigned radio channel.

25. The method of providing seamless interoperability for a mobile station of claim 24 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes measuring a signal strength of a signal from said mobile station received in said neighboring cells.

26. The method of providing seamless interoperability for a mobile station of claim 24 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes sending a measurement order to said mobile station ordering said mobile station to measure signal strengths of radio channels in said neighboring cells.

27. The method of providing seamless interoperability for a mobile station of claim 26 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes comparing each of said measured signal strengths with predetermined parameters to determine whether to hand off said mobile station to an identified cell.

28. A method of providing seamless interoperability for mobile stations capable of operating in a first hyperband, mobile stations capable of operating in a second hyperband, and for a multi-hyperband capable mobile stations, each mobile station roaming between cells within a cellular telecommunications network having a mobile switching center and a plurality of base stations that transmit and receive radio signals in a plurality of frequency hyperbands, said method comprising the steps of:

designating a cell in which said mobile station is operating as a serving cell, said serving cell having a serving base station;

building a neighbor list of cells that neighbor said serving cell, said neighbor cells including cells operating in frequency hyperbands supported by said multi-hyperband capable mobile station;

measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list;

determining the best candidate cell for communication with said mobile station, wherein if said mobile station is one that is capable of operating in said first frequency hyperband, said best candidate cell is selected from a neighbor list having only cells operating in said first frequency hyperband, if said mobile station is one that is capable of operating in said second frequency hyperband, said best candidate cell is selected from a neighbor list having only cells operating in said second frequency hyperband, and if said mobile station is one that is multi-hyperband capable, said best candidate cell is selected from a neighbor list having cells capable of operating in either said first frequency hyperband or said second frequency hyperband; and

handing off said mobile station to said best candidate cell for communication with said mobile station.

29. The method of providing seamless interoperability of claim 28 further comprising the step of verifying that said mobile station is present in said best candidate cell for communication with said mobile station prior to handing off said mobile station.

30. The method of providing seamless interoperability of claim 29 wherein said step of measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list includes the step of measuring signal strengths in said plurality of frequency hyperbands with a location and verification device.

31. The method of providing seamless interoperability of claim 29 wherein said step of measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and said serving base station, and between said mobile station and said cells in said neighbor list includes the step of measuring signal strengths in said plurality of frequency hyperbands with a plurality of location and verification devices within each of said plurality of base stations, each of said plurality of location and verification devices operating in a different one of said plurality of frequency hyperbands.

32. The method of providing seamless interoperability of claim 29 wherein said step of measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and a serving base station, and between said mobile station and said cells in said neighbor list of candidate cells for handoff includes the step of measuring said signal strengths within said mobile station.

33. The method of providing seamless interoperability of claim 32 further comprising the step of sending a message from said mobile switching center to said mobile station, said message requesting said mobile station to measure said signal strengths.

34. The method of providing seamless interoperability of claim 33 further comprising the step of sending a message from said mobile station to said serving base station, said message reporting said measured signal strengths to said serving base station.

35. The method of providing seamless interoperability for a mobile station of claim 29 wherein said step of building a neighbor list includes:

determining the frequency hyperbands in which said mobile station is capable of communicating; and

selectively building a neighbor list that includes only cells operating in said frequency hyperbands in which said mobile station is capable of communicating.

36. The method of providing seamless interoperability for a mobile station of claim 35 further comprising the step of providing said neighbor list to said mobile station.

37. The method of providing seamless interoperability for a mobile station of claim 36 wherein said step of determining the best candidate cell for communication with said mobile station includes the step of identifying a cell with the best radio reception characteristics for said mobile station.

38. The method of providing seamless interoperability for a mobile station of claim 37 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes the step of measuring within said mobile station, signal strength and bit error rate on said mobile station'"'"'s assigned radio channel.

39. The method of providing seamless interoperability for a mobile station of claim 37 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes the step of measuring within said serving base station and within said cells in said neighbor list, signal strength and bit error rate on said mobile station'"'"'s assigned radio channel.

40. The method of providing seamless interoperability for a mobile station of claim 39 wherein said step of identifying a cell with the best radio reception characteristics for said mobile station includes the step of comparing each of said measured signal strengths with predetermined parameters to determine whether to hand off said mobile station to an identified cell.

41. The method of providing seamless interoperability of claim 40 wherein said step of verifying that said mobile station is present in said best candidate cell for communication with said mobile station prior to handing off said mobile station includes:

measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell; and

receiving a supervisory audio tone (SAT) to verify the mobile station'"'"'s identity.

42. The method of providing seamless interoperability of claim 40 wherein said step of verifying that said mobile station is present in said best candidate cell for communication with said mobile station prior to handing off said mobile station includes:

measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell; and

decoding a digital verification color code (DVCC) to verify the mobile station'"'"'s identity.

43. The method of providing seamless interoperability of claim 42 wherein said step of measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell includes the step of utilizing said location and verification devices to measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell.

44. The method of providing seamless interoperability of claim 42 wherein said step of utilizing said location and verification devices to measuring the signal strength of the mobile station'"'"'s signal in said best candidate cell includes measuring the signal strength of the mobile station'"'"'s signal for purposes of presence verification independently of measuring the signal strength of the mobile station'"'"'s signal for purposes of identifying a cell with the best radio reception characteristics for said mobile station.

45. The method of providing seamless interoperability of claim 28 wherein said step of measuring signal strengths in each of said plurality of frequency hyperbands between said mobile station and a serving base station, and between said mobile station and said cells in said neighbor list of candidate cells for handoff includes measuring signal strengths in an 800-MHz cellular telephone frequency hyperband and in a 1900-MHz personal communication services (PCS) frequency hyperband.