Method and device for performing handover using location information

• US 6,876,853 B2
• Filed: 10/17/2001
• Issued: 04/05/2005
• Est. Priority Date: 04/30/1999
• Status: Expired due to Fees

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Networks (Nokia Corporation)
• Inventors: Hokkanen, Tuomo
• Primary Examiner(s): Nguyen, Lee
• Assistant Examiner(s): Yun, Eugene
• Application Number:
  US09/982,589
• Publication Number:
  US 20020072371A1
• Time in Patent Office: 1,266 Days
• Field of Search: 455/436, 455/440, 455/446, 455/438, 455/439, 455/456.1, 455/414.2, 455/434
• US Class Current: 455/440
• 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

In the present invention, a method for performing a handover procedure for a movable mobile station communicating in a communication network is disclosed. The communication network includes a plurality of base transceiver stations adapted to communicate with mobile stations within its coverage area. The method includes processing location information related to the mobile station and position information related to the base transceiver stations. The method also includes deciding, based on the result of the processing, whether a first handover condition is fulfilled and designating a next base transceiver station in the network to communicate with the mobile station. When the first handover condition is fulfilled, a handover of the mobile station from the current base transceiver station to the next designated base transceiver station is triggered. A corresponding device for controlling handover is also disclosed. Base transceiver stations that do not permanently transmit a broadcast control channel or base stations which can be turned off when no subscribers are within the coverage area may be used.

Claims

1. A method for performing a handover procedure for a

mobile station communicating in a communication network and being movable

therein,

said communication network comprising

a plurality of base transceiver stations being adapted to perform a communication with said mobile station within a coverage area of a respective one of said base transceiver stations, said method comprising the steps of

processing location information related to the mobile station by comparing position information of the mobile station with position information related to the base transceiver stations,

deciding on the basis of the result of said processing of said location information, whether a first handover condition based on said location information is fulfilled or not, wherein said first handover condition is based on said location information and indicates that a handover is necessary for establishing or maintaining the communication between the mobile station and the communication network,

when the first handover condition is not fulfilled, checking subscriber specifications, whether or not another measurement, which is related to a handover and is not based on said location information, is to be performed, wherein said another measurement results in a determination of a second handover condition indicating that a handover is necessary for establishing or maintaining the communication between the mobile station and the communication network,

selecting a measurement of availability of traffic channels as the type of the further measurement, if the another measurement is to be performed,

executing the measurement of availability of traffic channels selected in said selecting step,

verifying, whether the measurement of availability of traffic channels results in a second handover condition, and if the result of said verifying step indicates that the second handover condition is fulfilled,

designating a next base transceiver station in said communication network, to which the communication with said mobile station is to be directed from a current base transceiver station, when the first handover or the second handover condition is fulfilled,

triggering a handover of the communication connection of the mobile station from the current base transceiver station to the next base transceiver station designated in said designating step, and

performing the handover.

2. A method according to claim 1, wherein

in said processing step at least one additional parameter is processed together with said location information related to the mobile station and position information related to the base transceiver stations.

3. A method according to claim 2, wherein

said additional parameter is based on a signal quality.

4. A method according to claim 1, further comprising a location information obtaining step comprising

a step of determining said location information related to the mobile station and

a step of transmitting said determined location information to a respective network device adapted to perform said processing step.

5. A method according to claim 4, wherein said step of determining said location information related to the mobile station is executed in the mobile station.

6. A method according to claim 4, wherein said step of determining said location information related to the mobile station is executed in a network element on the network infrastructure side.

7. A method according to claim 4, wherein said step of determining said location information related to the mobile station is based on at least one of the following methods:

locating by a global positioning system;

locating by a time of arrival;

locating by an observed time difference.

8. A method according to claim 4, wherein said location information obtaining step is executed periodically.

9. A method according to claim 4, wherein said location obtaining step is executed upon predetermined occasions.

10. A method according to claim 9, wherein said predetermined occasion is an attachment procedure of the mobile station to the communication network.

11. A method according to claim 1, wherein a coverage area of the base transceiver station designated in said designating step and to which the communication connection is to be directed is a coverage area adjacent to the coverage area of the current base transceiver station.

12. A method according to claim 1, wherein a coverage area of the base transceiver station designated in said designating step and to which the communication connection is to be directed is a coverage area not adjacent to the coverage area of the current base transceiver station.

13. A method according to claim 12, wherein the coverage area not adjacent to the coverage area of the current base transceiver station to which the communication is to be directed is known to the communication network.

14. A method according to claim 13, wherein the base transceiver station with the coverage area not adjacent to the coverage area of the current base transceiver station, to which the communication connection is to be directed, is a predetermined base transceiver station.

15. A method according to claim 14, wherein the position information of the predetermined base transceiver station is stored in a subscriber identity module or in the mobile station.

16. A device for controlling a handover procedure for a mobile station communicating in a communication network and being movable therein,

said communication network comprising

a plurality of base transceiver stations being adapted to perform a communication with said mobile station within a coverage area of a respective one of said base transceiver stations, said device comprising

a processing means for processing location information related to said mobile station by comparing position information of the mobile station with position information related to base transceiver stations, and for deciding on the basis of the result of said processing of said location information, whether a first handover condition based on said location information is fulfilled or not, wherein said first handover condition is based on said location information and indicates that a handover is necessary for establishing or maintaining the communication between the mobile station and the communication network, for checking, when the first handover is not fulfilled, subscriber specifications, whether or not another measurement which is related to a handover and is not based on said location information is to be performed, wherein said another measurement results in a determination of a second handover condition indicating that a handover is necessary for establishing or maintaining the communication between the mobile station and the communication network, and for designating a next base transceiver station in said communication network, to which the communication with said mobile station is to be directed from a current base transceiver station, when the first handover condition or the second handover condition is fulfilled, and

a triggering means for triggering a handover of the communication connection of the mobile station from the current base transceiver station to the next base transceiver station designated by said designating means

the device further comprising

a measurement means being responsive to the subscriber specifications and adapted to

check, whether the another measurement is to be performed,

select a measurement of availability of traffic channels as the type of the further measurement, if the another measurement is to be performed,

execute the measurement of availability of traffic channels selected,

verify, whether the measurement of availability of traffic channels results in a second handover condition,

and if the result of the verification indicates that the second handover condition is fulfilled, forward the measurement result to said handover condition processing means for performing the handover.

17. A device according to claim 16, wherein

in said processing means at least one additional parameter is processed together with said location information related to the mobile station and position information related to the base transceiver stations.

18. A device according to claim 17, wherein

said additional parameter is based on a signal quality.

19. A device according to claim 16, further comprising means

for determining location information related to the mobile station and

for transmitting said determined location information to a respective network device performing said processing.

20. A device according to claim 19, further comprising a memory means for memorizing location information related to the mobile station and position information related to the base transceiver stations.

21. A device according to claim 19, wherein said means for determining location information related to the mobile station and for transmitting said determined location information to a respective network device performing said processing are located in the mobile station.

22. A device according to claim 19, wherein said means for determining location information related to the mobile station and for transmitting said determined location information to a respective network device performing said processing are located in a network element on the network infrastructure side.

23. A device according to claim 19, wherein said means for determining the location information related to the mobile station is adapted to perform said determination according to at least one of the following methods:

locating by a global positioning system;

locating by time of arrival;

locating by an observed time difference.