RADIO COMMUNICATION SYSTEM, METHOD AND PROGRAM

• US 20100267378A1
• Filed: 11/07/2008
• Published: 10/21/2010
• Est. Priority Date: 11/09/2007
• Status: Active Grant

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hamabe, Kojiro, Lee, Jinsock
• Granted Patent: US 8,565,753 B2
• Time in Patent Office: Days
• US Class Current: 455/423
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/305 Handover due to radio link failure control signalling for hand-off failure H04W36/0079

Abstract

When a mobile terminal experienced a radio link failure in a first cell and establishes a re-connection in a second cell within a predefined time and/or within a preset movement distance from the time of the radio link failure, the mobile terminal reports at least one of the information regarding a first cell and the information regarding a second cell.

Claims

1. A mobile terminal comprising:

a unit that, after an occurrence of a radio link failure, tries to re-connect to a network; and

a unit that, performs at least one of

(A) reporting, in case at least one of a relation that an elapsed time from the radio link failure until the re-connection is less than or equal to a preset time length, and a relation that a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection is less than or equal to a preset distance value, holds,

cell information of at least one of a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection; and

(B) reporting, at least one of the elapsed time from the radio link failure until the re-connection and the movement distance during the time period from the radio link failure until the re-connection.

2. The mobile terminal according to claim 1, wherein the cell information includes at least cell location information.

3. The mobile terminal according to claim 1, wherein the cell information of the cell where the radio link failure occurred includes at least one of

an identification information of the cell;

a reception quality of a pilot signal from a base station immediately before the radio link failure; and

a location information.

4. The mobile terminal according to claim 3, wherein the cell information of the cell wherein the mobile terminal establishes the re-connection includes at least one of

an identification information of the cell;

a reception quality of a pilot signal from a base station on a location of the re-connection; and

a location information.

5. The mobile terminal according to claim 1, comprising:

a unit that exercises control to start measurement of a reception quality of a second cell when a reception quality of a first cell is below a preset threshold value, the measurement control unit setting

the threshold value to a higher value, based on a measurement instruction from the base station, to allow the measurement of the reception quality of the second cell to be started at an earlier time point.

6. The mobile terminal according to claim 1, wherein the location information has a location accuracy finer than a cell area.

7. The mobile terminal according to claim 1, wherein the location information has a location accuracy on a per cell basis.

8. The mobile terminal according to claim 1, comprising:

a unit that acquires a location information;

a unit that measures a reception quality of a pilot signal from a base station;

a unit that controls the radio link failure and the re-connection;

a unit that measures the elapsed time from the radio link failure until the re-connection;

a unit that stores a threshold value for the elapsed time from the radio link failure until the re-connection;

a unit that compares the elapsed time from the radio link failure until the re-connection with the threshold value, when re-connection is established after the radio link failure, and prepares, in case the elapsed time is less than or equal to the preset threshold value, a report including at least one of the reception quality of a pilot signal from a base station immediately before the radio link failure, the reception quality of a pilot signal from a base station at a location of the re-connection, respective location information and respective cell identification information; and

a unit that transmits the report to the base station.

9. The mobile terminal according to claim 1, comprising:

a unit that obtains a location information;

a unit that measures a reception quality of a pilot signal from a base station;

a unit that controls a radio link failure and a re-connection;

a unit that measures a movement distance during the time period from the radio link failure until the re-connection;

a unit that stores a threshold value for the movement distance during the time period from the radio link failure until the re-connection;

a unit that compares the movement distance during the time period from the radio link failure until the re-connection with the threshold value, when the re-connection is established after the radio link failure, and that prepares, in case the movement distance is less than or equal to the threshold value, a report including at least one of the reception quality of a pilot signal from a base station immediately before the radio link failure, the reception quality of a pilot signal from a base station at a location of the re-connection, respective location information and respective cell identification information; and

a unit that transmits the report to the base station.

10. A base station comprising:

a unit that controls a mobile terminal; and

a unit that receives a report from the mobile terminal that, after experiencing a radio link failure followed by a re-connection thereof, performs at least one of

(A) reporting, in case at least one of a relation that an elapsed time from the radio link failure until the re-connection is less than or equal to a predetermined preset time length and a relation that a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection is less than or equal to a predetermined preset distance value, holds,

cell information of at least one of a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection; and

(B) reporting, at least one of the elapsed time from the radio link failure until the re-connection and the movement distance during the time period from the radio link failure until the re-connection.

11. The base station according to claim 10, comprising:

a unit that exercises control to allow for or facilitate a handover between a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection, in case at least one of

a relation that the elapsed time from the radio link failure until the re-connection of the mobile terminal being less than or equal to a preset threshold value, and

a relation that the movement distance during the time period from the radio link failure until the re-connection of the mobile terminal being less than or equal to a preset threshold value, holds.

12. A management server comprising:

a unit that controls a mobile terminal via a base station; and

a unit that receives, via the base station, a report from the mobile terminal that, after experiencing a radio link failure followed by a re-connection thereof, performs at least one of

(A) reporting, in case at least one of a relation that an elapsed time from the radio link failure until the re-connection is less than or equal to a predetermined preset time length and a relation that a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection is less than or equal to a predetermined preset distance value, holds,

cell information of at least one of a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection; and

(B) reporting, at least one of the elapsed time from the radio link failure until the re-connection and the movement distance during the time period from the radio link failure until the re-connection.

13. The management server according to claim 12, comprising:

a unit that exercises control to allow for or facilitate a handover between the cell where the radio link failure occurred and the cell where the mobile terminal establishes the re-connection, in case at least one of

a relation that the elapsed time from the radio link failure until the re-connection of the mobile terminal being less than or equal to a preset threshold value; and

a relation that the movement distance of the mobile terminal during the time period from the radio link failure until the re-connection thereof being less than or equal to a preset threshold value,

holds.

14. A method for radio communication, comprising:

a mobile terminal, after experiencing a radio link failure, establishing a re-connection thereof; and

,

the mobile terminal performing, at least one of

(A) reporting, in case at least one of a relation that an elapsed time from the radio link failure until the re-connection is less than or equal to a predetermined preset time length and a relation that a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection is less than or equal to a predetermined preset distance value, holds,

cell information of at least one of a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection; and

(B) reporting, at least one of the elapsed time from the radio link failure until the re-connection and the movement distance during the time period from the radio link failure until the re-connection.

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29. A radio communication system comprising:

one or more cells; and

a mobile terminal that, in case of experiencing a radio link failure and then establishing a re-connection, performs at least one of

(A) reporting, in case at least one of a relation that an elapsed time from the radio link failure until the re-connection is less than or equal to a predetermined preset time length and a relation that a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection is less than or equal to a predetermined preset distance value, holds,

cell information of at least one of a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection; and

(B) reporting to the base station, at least one of the elapsed time from the radio link failure until the re-connection and the movement distance during the time period from the radio link failure until the re-connection.

30. The radio communication system according to claim 29, wherein the cell information includes at least cell location information.

31. The radio communication system according to claim 29, wherein the cell information regarding the first cell where the radio link failure occurred includes at least one of

an identification information of the first cell;

a reception quality of a pilot signal from a base station immediately before the radio link failure; and

a location information.

32. The radio communication system according to claim 29, wherein the cell information regarding the second cell where the re-connection occurred includes at least one of

an identification information of the second cell;

a reception quality of a pilot signal from a base station on a location of the re-connection; and

a location information.

33. The radio communication system according to claim 29, in which, when the reception quality of the first cell has become lower than a preset threshold value, measurement of a reception quality of the second cell of the handover destination is controlled to be started,

the threshold value for the reception quality being set to a higher value, based on a measurement instruction from a base station, to allow the measurement of the reception quality of the second cell to be started at an earlier time point.

34. The radio communication system according to claim 29, wherein whether or not a handover is to be allowed or facilitated between the cell where the mobile terminal experienced the radio link failure and the cell where the mobile terminal establishes the re-connection is determined based on the report.

35. The radio communication system according to claim 29, wherein in case the distance between the location where the mobile terminal experienced the radio link failure and the location where the mobile terminal re-connects to a network is less than or equal to a preset value, a handover between the cell where the radio link failure occurred and the cell the re-connection of the mobile terminal to the network is allowed or facilitated, using the information regarding the location where the mobile terminal experienced the radio link failure and the information regarding the location of the re-connection of the mobile terminal to the network.

36. The radio communication system according to claim 35, wherein the mobile terminal reports the information regarding the location of the radio link failure and the information regarding the location of the re-connection to the network.

37. The radio communication system according to claim 35, wherein if, in case the location information is given by a limited number of dimensions, the time from the radio link failure of the mobile terminal until the re-connection thereof between two cells where a handover is not allowed or nor facilitated is less than or equal to a preset threshold, the handover is allowed or facilitated between the cell where the radio link failure occurred and the cell where re-connection has occurred.

38. The radio communication system according to claim 29, wherein when, in case the mobile terminal experienced the radio link failure, the elapsed time from the radio link failure until the re-connection of the mobile terminal is less than or equal to a preset threshold value, a handover between the cell where the radio link failure occurred and the cell of re-connection is allowed or facilitated.

39. The radio communication system according to claim 29, wherein when, in case the mobile terminal experienced the radio link failure, the elapsed time from the radio link failure until the re-connection of the mobile terminal is less than or equal to a preset threshold value, and the movement distance during the time period from the radio link failure until the re-connection of the mobile terminal is less than or equal to a preset threshold value, a handover between a cell of the radio link failure and a cell of re-connection is allowed or facilitated.

40. The radio communication system according to claim 34, further comprising:

a unit that is operative in case of the reception quality of a cell becoming lower than a preset threshold value to control starting the measurement of the reception quality of another cell, as a handover destination;

the threshold value for the reception quality being set to a higher value to allow the measurement of the reception quality of the another cell to be started at an earlier time point to facilitate the handover.

41. The radio communication system according to claim 29, wherein the location information has a location accuracy finer than a cell area.

42. The radio communication system according to claim 29, wherein the location information has a location accuracy on a per cell basis.

43. A computer readable recording medium storing a program for causing a computer composing a mobile terminal to execute the processing comprising,

establishing a re-connection, after experiencing a radio link failure;

and

performing at least one of

(A) reporting, in case at least one of a relation that an elapsed time from the radio link failure until the re-connection is less than or equal to a predetermined preset time length and a relation that a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection is less than or equal to a predetermined preset distance value, holds,

cell information of at least one of a cell where the radio link failure occurred and a cell where the mobile terminal establishes the re-connection; and

(B) reporting, at least one of the elapsed time from the radio link failure until the re-connection and the movement distance during the time period from the radio link failure until the re-connection.

44. The program according to claim 43, wherein the program causes the computer composing the mobile terminal to execute the processing comprising:

when a reception quality of a first cell has become lower than a preset threshold value,

exercising control to start measurement of a reception quality of a second cell, with setting the threshold value for the reception quality to a higher value, based on a measurement instruction from a base station, to allow the measurement of the reception quality of the second cell to be started at an earlier time point.

45. A radio communication system comprising:

one or more cells; and

a mobile terminal, wherein in case a distance between the location where the mobile terminal experienced the radio link failure and the location where the mobile terminal establishes a re-connection to a network is less than or equal to a preset value, a handover between a cell where the radio link failure occurred and a cell where the mobile terminal re-connects to the network is allowed or facilitated, using the information regarding the location where the mobile terminal experienced the radio link failure and the information regarding the location of the re-connection of the mobile terminal to the network.

46. The radio communication system according to claim 45, wherein the mobile terminal reports to a base station the information regarding the location of the radio link failure and the information regarding the location of the re-connection to the network.

49. The radio communication system according to claim 45, wherein in case of a reception quality of a cell becoming lower than a preset threshold value, the reception quality of another cell, as a handover destination, is controlled to be started;

the threshold value for the reception quality being set to a higher value to allow the measurement of the reception quality of the another cell to be started at an earlier time point to facilitate the handover.

47. A radio communication system, comprising:

a plurality of cells; and

a mobile terminal, wherein, when, in case the mobile terminal experienced a radio link failure, an elapsed time from the radio link failure until a re-connection of the mobile terminal is less than or equal to a preset threshold value, a handover between a cell of the radio link failure and a cell of the re-connection of the mobile terminal is allowed or facilitated.

48. A radio communication system, comprising:

a plurality of cells; and

a mobile terminal, wherein, when, in case a mobile terminal experienced a radio link failure, an elapsed time from the radio link failure until a re-connection of the mobile terminal is less than or equal to a preset threshold value, and a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection of the mobile terminal is less than or equal to a preset threshold value, a handover between a cell of the radio link failure and a cell of re-connection is allowed or facilitated.

50. A method for radio communication, comprising:

checking whether or not a distance between a location where a mobile terminal experienced a radio link failure and a location of a re-connection of the mobile terminal is less than or equal to a preset threshold value, and

in case the distance is less than or equal to the preset value, exercising control to allow or facilitate a handover between a cell where the radio link failure occurred and a cell where the radio link re-connects to a network, using the information regarding the location where the mobile terminal experienced the radio link failure and the information regarding the location of the re-connection of the mobile terminal to the network.

51. The method for radio communication according to claim 50, comprising:

the mobile terminal reporting to a base station the information regarding the location of the radio link failure and the information regarding the location of the re-connection of the mobile terminal to the network.

54. The method for radio communication according to claim 50, comprising:

the mobile terminal exercising control so that when a reception quality of a given cell has become lower than the preset threshold value, a measurement of a reception quality of another cell of the destination of a handover is started, wherein

the threshold value for the reception quality is set to a higher value to allow the measurement of the reception quality of the another cell to be started at an earlier time point to facilitate the handover.

52. A method for radio communication, comprising:

a mobile terminal experiencing a radio link failure;

the mobile terminal comparing an elapsed time from the radio link failure until a re-connection with a preset threshold value; and

if the elapsed time is less than or equal to the preset threshold value, control being exercised to allow or facilitate a handover between a cell of the radio link failure and a cell of the re-connection of the mobile terminal.

53. A method for radio communication, comprising:

a mobile terminal experiencing a radio link failure;

the mobile terminal comparing, an elapsed time from the radio link failure until a re-connection thereof with a first threshold value and comparing a movement distance of the mobile terminal during the time period from the radio link failure until the re-connection of the mobile terminal with a second threshold value; and

if the elapsed time is less than or equal to the first threshold value and the movement distance is less than or equal to the second threshold value, control being exercised to allow or facilitate a handover between a cell where the radio link failure occurred and a cell of the re-connection of the mobile terminal.