UE mobility state detection apparatus and method for wireless communication system

• US 20100113019A1
• Filed: 11/04/2009
• Published: 05/06/2010
• Est. Priority Date: 11/05/2008
• Status: Active Grant

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Soeng Hun, Jung, Jung Soo, Jeong, Kyeong In
• Granted Patent: US 9,467,903 B2
• Time in Patent Office: Days
• US Class Current: 455/435.200
• CPC Class Codes: H04W 36/0005 Control or signalling for completing the hand-off
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/322 by location data

Abstract

A method for transmitting information required for user equipment mobility state detection is provided. The method includes broadcasting, at a base station, system information including frequency information and cell identifiers (IDs) of cells co-located with a current cell geographically; and transmitting, when an handover is detected, a handover command message including a handover factor indicator indicating whether the handover was triggered by movement of the user equipment, wherein the user equipment detects the mobility state based on the information provided by the system information and the handover command message. The apparatus and method of the present invention allows the UE to add the cell reselection/handover triggered by movement of the UE to the number of cell reselections/handovers and subtract the cell reselection/handover triggered by a non-mobility factor from the number of cell reselections/handovers used for determining the UE mobility state thereby improving accuracy of the UE mobility state detection.

Claims

1. A method for transmitting information required for user equipment mobility state detection in a wireless communication system, the method comprising:

broadcasting, at a base station, system information including frequency information and cell identifiers (IDs) of cells co-located with a current cell geographically; and

transmitting, when an handover is detected, a handover command message including a handover factor indicator indicating whether the handover is triggered by movement of a user equipment,

wherein the user equipment detects a mobility state based on the information provided by the system information and the handover command message.

2. The method of claim 1, wherein broadcasting system information comprises setting the system information based on a neighbor cell context stored in the base station.

3. The method of claim 2, wherein the handover factor indicator is set to a value indicating that the handover is triggered by a non-mobility factor, when the handover occurs for at least one of load balancing, service profile adaptation, user equipment capability adaption, and Radio Resource Management (RRM).

4. A mobility state detection method of a user equipment in a wireless communication system, the method comprising:

receiving system information;

determining, based on the system information, whether a reselected cell is co-located with a previous cell geographically;

subtracting, when the reselected cell is co-located with the previous cell, the cell reselection from a number of cell reselections and adding, when the reselected cell is not co-located with the previous cell, the cell reselection to the number of cell reselections; and

detecting a mobility state by comparing the number of cell reselections with at least one predetermined threshold value.

5. The mobility state detection method of claim 4, further comprising receiving frequency information and cell identifiers of the cells co-located with the current cell.

6. A mobility state detection method of a user equipment in a wireless communication, the method comprising:

subtracting, when a handover command message is received and the handover is triggered by a non-mobility factor, the handover from a number of handovers and, otherwise, adding the handover to the number of handovers; and

detecting a mobility state by comparing the number of handovers with at least one predetermined threshold value.

7. The mobility state detection method of claim 6, wherein the handover command message comprises a handover factor indicator which is set by a base station when a handover occurs.

8. The mobility state detection method of claim 6, further comprising subtracting, when system information is received and the system information indicates that a handover target cell is co-located with a serving cell, the handover from the number of handovers and, otherwise, adding the handover to the number of handovers.

9. The mobility state detection method of claim 8, further comprising receiving frequency information and cell identifiers of the cells co-located with the current cell.

10. A user equipment mobility state detection method for a wireless communication system, the method comprising:

receiving system information including information on cells co-located with a current cell geographically and, when a handover occurs, a handover command message including a handover factor indicator indicating whether the handover was triggered by movement of a user equipment;

subtracting, when a cell reselection occurs and the reselected cell is co-located with the previous cell geographically, the cell reselection from a number of cell reselections and, when the reselected cell is not co-located with the previous cell, adding the cell reselection to the number of cell reselections;

subtracting, when a handover command message is received and the handover is triggered by a non-mobility factor, the handover from a number of handovers and adding, when the handover is triggered by movement of the user equipment, the handover to the number of handovers; and

detecting a mobility state by comparing at least one of the number of cell reselections and the number of handovers with at least one predetermined threshold value.

11. The method of claim 10, further comprising:

subtracting, if the cell reselection is an inter-frequency cell reselection, the cell reselection from the number of cell reselections, and adding, if the cell reselection is not an inter-frequency cell reselection, the cell reselection/handover to the number of cell reselections.

12. The method of claim 10, further comprising:

subtracting, if the handover is an inter-frequency handover, the handover from the number of handovers, and adding, if the cell handover is not an inter-frequency handover, the handover to the number of handovers.

13. An apparatus for transmitting information required for user equipment mobility state detection in a wireless communication system, the apparatus comprising:

a handover unit configured to detect a handover of a user equipment based on at least one of a measurement report context the user equipment, a user equipment context, and a Radio Resource Management (RRM) context;

an information generator configured to generate system information comprising information on cells co-located with a current cell based on at least one of the RRM context and a neighbor cell context and to generate, when a handover occurs, a handover command message including a mobility factor indicator provided by the handover unit; and

a communication unit configured to broadcast the system information generated by the information generator and to transmit the handover message to the user equipment.

14. The apparatus of claim 13, wherein the information generator is configured to generate frequency information and cell identifiers of the cells co-located with the current cell.

15. The apparatus of claim 13, wherein the mobility factor indicator is set to a first value if the handover is triggered by movement of the user equipment and is set to a second value if the handover is triggered by a non-mobility factor.

16. The apparatus of claim 15, wherein the non-mobility factor includes least one of load balancing, service profile adaptation, user equipment capability adaption, and Radio Resource Management (RRM).

17. A user equipment mobility state detection apparatus for a wireless communication system, the apparatus comprising:

a communication unit configured to receive system information and a handover command message;

a information analysis unit configured to analyze the system information to determine whether a reselected cell is co-located with a previous cell geographically and to analyze the handover command message to determine whether a handover was triggered by movement of the user equipment; and

a mobility state detection unit configured to add, only when the reselected cell is not co-located with the previous cell geographically, the cell reselection to a number of cell reselections, and to add, only when the handover is triggered by mobility of the user equipment, the handover to the number of handovers.

18. The apparatus of claim 17, wherein the mobility state detection unit is further configured to detect a mobility state by comparing at least one of the number of cell reselections and the number of handovers with at least one predetermined threshold value.

19. The apparatus of claim 17, wherein the handover command message comprises a handover factor indicator that is set to a first value if the handover is triggered by movement of the user equipment and is set to a second value if the handover is triggered by a non-mobility factor.

20. The apparatus of claim 19, wherein the non-mobility factor includes least one of load balancing, service profile adaptation, user equipment capability adaption, and Radio Resource Management (RRM).