Handover method in mobile communications system

• US 5,530,910 A
• Filed: 12/27/1994
• Issued: 06/25/1996
• Est. Priority Date: 12/27/1993
• Status: Expired due to Term

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Taketsugu, Masanori
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): BANKS HAROLD, MARSHA DENISE
• Application Number:
  US08/364,462
• Time in Patent Office: 546 Days
• Field of Search: 455/33.1, 455/33.2, 455/33.4, 455/34.1, 455/54.1, 455/56.1, 379/58, 379/59, 379/60
• US Class Current: 455/444
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data

Abstract

The handover method disclosed relates to a mobile communication system in which, based on the number of handovers in mobile units, the size of the radio zone to be assigned to a mobile unit is selected. The mobile switching center measures the number of handovers in each of the mobile units engaging in communication and, during the handover in the mobile unit, the handover target radio zone is assigned based on the measured value of the number of handovers. The target handover of mobile units is determined by the target determination controller based the number of handovers memorized in the handover number recorder. The assignment of the appropriate size radio zone prevents an excess load on the mobile switching center and the capacity to accommodate subscribers in the mobile communication system is enhanced.

Claims

1. A handover method in a mobile communication system which comprises a plurality of radio base stations for communication with a plurality of mobile units using radio channels, said plurality of radio base stations covering a plurality of radio zones whose sizes are different from one another, and a mobile switching center for controlling said plurality of radio base stations, said radio zones having different sizes being overlapped thereby constituting a multi-radio zone environment, said handover method comprising the steps of:

measuring, by said mobile switching center, the number of handovers in each of said mobile units engaging in communication; and

assigning, during the handover in said mobile unit, a handover target radio zone based on the measured value of said number of handovers.

2. A handover method in a mobile communication system which comprises a plurality of radio base stations for communication with a plurality of mobile units using radio channels, said plurality of radio base stations covering a plurality of radio zones whose sizes are different from one another, and a mobile switching center for controlling said plurality of radio base stations, said radio zones having different sizes being overlapped thereby constituting a multi-radio zone environment, said handover method comprising the steps of:

measuring, by said mobile switching center, the number of handovers in each of said mobile units engaging in communication; and

assigning, during the handover in said mobile unit, a handover target radio zone based on the measured value of said number of handovers;

in which, in the step of assigning the handover target radio zone, if the measured value of said number of handovers is higher than a threshold value, the handover target radio zone to be assigned is a zone whose size is larger than that of the radio zone with which said mobile unit is in communication.

3. A handover method in a mobile communication system which comprises a plurality of radio base stations for communication with a plurality of mobile units using radio channels, said plurality of radio base stations covering a plurality of radio zones whose sizes are different from one another, and a mobile switching center for controlling said plurality of radio base stations, said radio zones having different sizes being overlapped thereby constituting a multi-radio zone environment, said handover method comprising the steps of:

measuring, by said mobile switching center, the number of handovers in each of said mobile units engaging in communications, and

assigning, during the handover in said mobile unit, a handover target radio zone based on the measured value of said number of handovers;

in which, in the step of assigning the handover target radio zone, if the measured value of said number of handovers is lower than a threshold value, the handover target radio zone to be assigned is a zone whose size is smaller than that of the radio zone with which said mobile unit is in communication.

4. A handover method in a mobile communication system which comprises a plurality of radio base stations for communication with a plurality of mobile units using radio channels, said plurality of radio base stations covering a plurality of radio zones whose sizes are different from one another and a mobile switching center for controlling said plurality of radio base stations, said radio zones having different sizes being overlapped thereby constituting a multi-radio zone environment, said handover method comprising the steps of:

measuring, by each of said plurality of mobile units, the number of handovers that have taken place in each of said plurality of mobile units; and

assigning, during the handover in each of said plurality of mobile units, a handover target radio zone based on the measured value of said number of handovers that have taken place in the mobile unit itself.

5. A handover method in a mobile communication system which comprises a plurality of radio base stations for communication with a plurality of mobile units using radio channels, said plurality of radio base stations covering a plurality of radio zones whose sizes are different from one another and a mobile switching center for controlling said plurality of radio base stations, said radio zones having different sizes being overlapped thereby constituting a multi-radio zone environment, said handover method comprising the steps of:

measuring, by each of said plurality of mobile units, the number of handovers that have been taken place in each of said plurality of mobile units; and

assigning, during the handover in each of said plurality of mobile units, a handover target radio zone based on the measured value of said number of handovers that have taken place in the mobile unit itself;

in which, in the step of assigning the handover target radio zone, if the measured value of said number of handovers that have taken place in the mobile unit itself is higher than a threshold value, the handover target radio zone assigned is a zone whose size is larger than that of the radio zone with which said mobile unit is in communication.

6. A handover method in a mobile communication system which comprises a plurality of radio base stations for communication with a plurality of mobile units using radio channels, said plurality of radio base stations covering a plurality of radio zones whose sizes are different from one another and a mobile switching center for controlling said plurality of radio base stations, said radio zones having different sizes being overlapped thereby constituting a multi-radio zone environment, said handover method comprising the steps of:

measuring, by each of said plurality of mobile units, the number of handovers that have been taken place in each of said plurality of mobile units; and

assigning, during the handover in each of said plurality of mobile units, a handover target radio zone based on the measured value of said number of handovers that have taken place in the mobile unit itself;

in which, in the step of assigning the handover target radio zone, if the measured value of said number of handovers that have taken place in the mobile unit itself is lower than a threshold value, the handover target radio zone assigned is a zone whose size is smaller than that of the radio zone with which said mobile unit is in communication.