Mobile communications system, mobile station, control method and recording medium

• US 6,947,746 B2
• Filed: 08/26/2002
• Issued: 09/20/2005
• Est. Priority Date: 08/29/2001
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Watanabe, Akira
• Primary Examiner(s): Trost, William
• Assistant Examiner(s): RAMPURIA, SHARAD K
• Application Number:
  US10/227,476
• Publication Number:
  US 20030045291A1
• Time in Patent Office: 1,121 Days
• Field of Search: 455436-439, 455/435.1, 455/442
• US Class Current: 455/438
• CPC Class Codes: H04W 60/04 using triggered events

Abstract

A mobile station that can suppress repetitive location registration. If a cell reselection instruction is issued for a cell, the mobile Station determines whether the new cell is listed in a history of cells in which the mobile station has existed before. If the new cell lies in the history, the control circuit suppresses the transfer. If a count value of cell reselection instructions in the mobile station reaches a predetermined value, the control circuit performs the transfer without referring to the history. In this manner, repetitive zone transfers are suppressed, so that the location registration process is also suppressed, and so the repetition of location registration can be suppressed.

Claims

1. A mobile communication system for code division multiple access communication, said system comprising a mobile station and a plurality of base stations, each base station comprising a plurality of cells, the mobile station communicating through a cell of one of the base stations, wherein said mobile station comprises a suppression control section for suppressing transferring of the mobile station to a different cell selected by a transfer process in accordance with a history of cells in which said mobile station has existed before, when a cell selection instruction is issued.

2. The mobile communication system according to claim 1, wherein said suppression control section suppresses the transfer process, if the transferred cell lies in the history.

3. The mobile communication system according to claim 2, wherein said suppression control section performs the transfer process, if the cell selection instruction is issued a predetermined number of times.

4. The mobile communication system according to claim 3, wherein said suppression control section comprises a counting unit for counting the cell selection instruction, and said suppression control section controls the transfer process in accordance with a comparison result that is obtained by comparing a count value of said counting unit and the predetermined number of times.

5. The mobile communication system according to claim 3, wherein the predetermined number of times comprises a value corresponding to the frequency of the cell selection instruction.

13. The mobile communication system according to claim 1, wherein said suppression control section comprises a cell selection instruction generating unit for generating the cell selection instruction by detecting deterioration in a received signal from the base station of a cell in which said mobile station exists at present.

6. A mobile communication system for code division multiple access communication, said system comprising a mobile station and a plurality of base stations, each base station comprising a plurality of cells, the mobile station communicating through a cell of one of the base stations, wherein said mobile station comprises a suppression control section for suppressing transferring of the mobile station to a different cell selected by a transfer process in accordance with the number of times a cell selection instruction has been issued within a predetermined time period and a history of cells in which said mobile station has existed before.

7. The mobile communication system according to claim 6, wherein said suppression control section suppresses the transfer process until the number of times the cell selection instruction has been issued reaches a predetermined number, if the transferred cell lies in the history at the time the cell selection instruction is issued within the predetermined time period.

8. The mobile communication system according to claim 7, wherein said suppression control section performs the transfer process if the number of times the cell selection instruction has been issued reaches the predetermined number of times.

9. The mobile communication system according to claim 7, wherein said suppression control section directly makes the transfer process if the transferred cell does not lie in the history at the time the cell selection instruction is issued within the predetermined time period.

10. The mobile communication system according to claim 6, wherein said suppression control section initializes the history after the elapse of the predetermined time period.

11. The mobile communication system according to claim 6, wherein said suppression control section comprises a clock unit for timing the predetermined time period, and starts said clock unit when the transfer process is suppressed.

12. The mobile communication system according to claim 7, wherein the predetermined time period and the predetermined number of times are based on values corresponding to the frequency of the cell selection instruction.

14. A mobile station for use in a mobile communication system for code division multiple access communication, wherein the system comprises said mobile station and a plurality of base stations, each base station comprises a plurality of cells, and said mobile station communicates through a cell of one of the base stations, said mobile station comprising a suppression control section for suppressing transferring of said mobile station to a different cell selected by a transfer process in accordance with a history of cells in which said mobile station has existed before, when a cell selection instruction is issued.

15. The mobile station according to claim 14, wherein said suppression control section suppresses the transfer process, if the transferred cell lies in the history.

16. The mobile station according to claim 15, wherein said suppression control section performs the transfer process, if the cell selection instruction is issued a predetermined number of times.

17. The mobile station according to claim 16, wherein said suppression control section comprises a counting unit for counting the cell selection instruction, and said suppression control section controls the transfer process in accordance with a comparison result that is obtained by comparing a count value of said counting unit and the predetermined number of times.

18. The mobile station according to claim 16, wherein the predetermined number of times comprises a value corresponding to the frequency of the cell selection instruction.

26. The mobile station according to claim 14, wherein said suppression control section comprises a cell selection instruction generating unit for generating the cell selection instruction by detecting deterioration in a received signal from the base station of a cell in which said mobile station exists at present.

19. A mobile station for use in a mobile communication system for code division multiple access communication, wherein the system comprises said mobile station and a plurality of base stations, each base station comprises a plurality of cells, and said mobile station communicates through a cell of one of the base stations, said mobile station comprising a suppression control section for suppressing transferring of said mobile station to a different cell selected by a transfer process in accordance with the number of times a cell selection instruction has been issued within a predetermined time period and a history of cells in which said mobile station has existed before.

20. The mobile station according to claim 19, wherein said suppression control section suppresses the transfer process until the number of times the cell selection instruction has been issued reaches a predetermined number, if the transferred cell lies in the history at the time the cell selection instruction is issued within the predetermined time period.

21. The mobile station according to claim 20, wherein said suppression control section performs the transfer process if the number of times the cell selection instruction has been issued reaches the predetermined number of times.

22. The mobile station according to claim 20, wherein said suppression control section directly makes the transfer process if the transferred cell does not lie in the history at the time the cell selection instruction is issued within the predetermined time period.

23. The mobile station according to claim 19, wherein said suppression control section initializes the history after the elapse of the predetermined time period.

24. The mobile station according to claim 19, wherein said suppression control section comprises a clock unit for timing the predetermined time period, and starts said clock unit when the transfer process is suppressed.

25. The mobile station according to claim 20, wherein the predetermined time period and the predetermined number of times are based on values corresponding to the frequency of the cell selection instruction.

27. A control method for a mobile station in a mobile communication system for code division multiple access communication, wherein the system comprises the mobile station and a plurality of base stations, each base station comprises a plurality of cells, and the mobile station communicates through a cell of one of the base stations, the method comprising suppressing transferring of the mobile station to a different cell selected by a transfer process in accordance with a history of cells in which said mobile station has existed before, when a cell selection instruction is issued.

28. The control method according to claim 27, wherein the transfer process is suppressed if the transferred cell lies in the history.

29. The control method according to claim 28, wherein the transfer process is performed if the cell selection instruction is issued a predetermined number of times.

30. The control method according to claim 29, wherein performing the transfer process comprises counting the cell selection instruction, and controlling the transfer process in accordance with a comparison result that is obtained by comparing a count value of the counting and the predetermined number of times.

31. The control method according to claim 29, wherein the predetermined number of times comprises a value corresponding to the frequency of the cell selection instruction.

39. The control method according to claim 27, further comprising generating the cell selection instruction by detecting deterioration in a received signal from the base station of a cell in which said mobile station exists at present.

32. A control method for a mobile station in a mobile communication system for code division multiple access communication, wherein said system comprises the mobile station and a plurality of base stations, each base station comprises a plurality of cells, and the mobile station communicates through a cell of one of the base stations, the method comprising suppressing transferring of the mobile station to a different cell selected by a transfer process in accordance with the number of times a cell selection instruction has been issued within a predetermined time period and a history of cells in which said mobile station has existed before.

33. The control method according to claim 32, wherein the transfer process is suppressed until the number of times the cell selection instruction has been issued reaches a predetermined number, if the transferred cell lies in the history at the time the cell selection instruction is issued within the predetermined time period.

34. The control method according to claim 33, further comprising performing the transfer process if the number of times the cell selection instruction has been issued reaches the predetermined number of times.

35. The control method according to claim 33, further comprising directly making the transfer process if the transferred cell does not lie in the history at the time the cell selection instruction is issued within the predetermined time period.

36. The control method according to claim 32, further comprising initializing the history after the elapse of the predetermined time period.

37. The control method according to claim 32, further comprising timing the predetermined time period, starting when the transfer processing is suppressed.

38. The control method according to claim 33, wherein the predetermined time period and the predetermined number of times are based on values corresponding to the frequency of the cell selection instruction.

40. A recording medium storing a program that is to be executed on a computer to implement a control method for a mobile station in a mobile communication system for code division multiple access communication, wherein the system comprises the mobile station and a plurality of base stations, each base station comprises a plurality of cells, and the mobile station communicates through a cell of one of the base stations, said method comprising a suppressing transferring of the mobile station to a different cell selected by a transfer process in accordance with a history of cells in which said mobile station has existed before, when a cell selection instruction is issued.

41. The recording medium according to claim 40, wherein the method suppresses the transfer process if the transferred cell lies in the history.

42. The recording medium according to claim 41, wherein the method further comprises performing the transfer process if the cell selection instruction is issued a predetermined number of times.

43. The recording medium according to claim 42, wherein said transfer process comprises counting the cell selection instruction, and controlling the transfer process in accordance with a comparison result that is obtained by comparing a count value of the counting and the predetermined number of times.

44. The recording medium according to claim 42, wherein the predetermined number of times comprises a value corresponding to the frequency of the cell selection instruction.

52. The recording medium according to claim 40, wherein the method further comprises generating the cell selection instruction by detecting deterioration in a received signal from the base station of a cell in which said mobile station exists at present.

45. A recording medium storing a program that is to be executed on a computer to implement a control method for a mobile station in a mobile communication system for code division multiple access communication, wherein the system comprises the mobile station and a plurality of base stations, each base station comprises a plurality of cells, and the mobile station communicates through a cell of one of the base stations, said method comprising suppressing transferring of the mobile station to a different cell selected by a transfer process in accordance with the number of times a cell selection instruction has been issued within a predetermined time period and a history of cells in which said mobile station has existed before.

46. The recording medium according to claim 45, wherein the method suppresses the transfer process until said the number of times the cell selection instruction has been issued reaches a predetermined number, if the transferred cell lies in the history at the time the cell selection instruction is issued within the predetermined time period.

47. The recording medium according to claim 46, wherein the method further comprises performing the transfer process if the number of times the cell selection instruction has been issued reaches the predetermined number of times.

48. The recording medium according to claim 46, wherein the method further comprises directly making the transfer process if the transferred cell does not lie in the history at the time the cell selection instruction is issued within the predetermined time period.

49. The recording medium according to claim 45, wherein the method further comprises initializing the history after the elapse of the predetermined time period.

50. The recording medium according to claim 45, wherein the method further comprises timing the predetermined time period, starting when the transfer processing is suppressed.

51. The recording medium according to claim 46, wherein the predetermined time period and the predetermined number of times are based on values corresponding to the frequency of the cell selection instruction.