MOBILE COMMUNICATION SYSTEM, RADIO CONTROLLER, BASE STATION, AND MOBILITY CONTROL METHOD

• US 20130143567A1
• Filed: 06/03/2011
• Published: 06/06/2013
• Est. Priority Date: 06/04/2010
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Hosono, Hiroyuki, Terayama, Takeshi, Okamoto, Takeshi, Nagato, Rie
• Granted Patent: US 8,996,010 B2
• Time in Patent Office: Days
• US Class Current: 455/436
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/304 due to measured or perceived resources with higher communication quality
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/242 taking into account path loss
• CPC Class Codes: H04W 52/243 taking into account interferences

Abstract

A radio controller 100 includes a transmission power acquisition unit 111 configured to acquire a neighboring cell transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the neighboring cell, an offset determination unit 115 configured to determine a power offset of the neighboring cell to be added to the predetermined transmission power value, based on a difference between the predetermined transmission power value and the neighboring cell transmission power value acquired by the transmission power acquisition unit, and an offset notification unit 117 configured to notify the power offset determined by the offset determination unit to the mobile station.

Claims

1. A mobile communication system configured to control mobility of a mobile station from a predetermined cell to a neighboring cell of the predetermined cell on the basis of a path loss value based on a predetermined transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the predetermined cell and a reception power value of the radio signal in the mobile station, the system comprising:

a transmission power detection unit configured to detect a neighboring cell transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the neighboring cell;

an offset determination unit configured to determine a power offset of the neighboring cell to be added to the predetermined transmission power value, based on a difference between the predetermined transmission power value and the neighboring cell transmission power value detected by the transmission power detection unit; and

an offset notification unit configured to notify the power offset determined by the offset determination unit to the mobile station.

2. The mobile communication system according to claim 1, wherein the transmission power detection unit receives notification including a transmission power value of a common control channel transmitted by the neighboring cell, and detects the neighboring cell transmission power value based on the received notification.

3. The mobile communication system according to claim 1, wherein the offset determination unit determines a difference between the predetermined transmission power value and the neighboring cell transmission value as the power offset.

4. A radio controller configured to control mobility of a mobile station from a predetermined cell to a neighboring cell of the predetermined cell on the basis of a path loss value based on a predetermined transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the predetermined cell and a reception power value of the radio signal in the mobile station, the radio controller comprising:

a transmission power acquisition unit configured to acquire a neighboring cell transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the neighboring cell;

an offset determination unit configured to determine a power offset of the neighboring cell to be added to the predetermined transmission power value, based on a difference between the predetermined transmission power value and the neighboring cell transmission power value acquired by the transmission power acquisition unit; and

an offset notification unit configured to notify the power offset determined by the offset determination unit to the mobile station.

5. The radio controller according to claim 4, wherein the offset determination unit determines a difference between the predetermined transmission power value and the neighboring cell transmission value as the power offset.

6. A base station configured to control mobility of a mobile station from a predetermined cell to a neighboring cell of the predetermined cell on the basis of a path loss value based on a predetermined transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the predetermined cell and a reception power value of the radio signal in the mobile station, the base station comprising:

a transmission power detection unit configured to detect a neighboring cell transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the neighboring cell;

an offset determination unit configured to determine a power offset of the neighboring cell to be added to the predetermined transmission power value, based on a difference between the predetermined transmission power value and the neighboring cell transmission power value detected by the transmission power detection unit; and

an offset notification unit configured to notify the power offset determined by the offset determination unit to the mobile station.

7. The base station according to claim 6, wherein the offset determination unit determines a difference between the predetermined transmission power value and the neighboring cell transmission value as the power offset.

8. A mobility control method for controlling mobility of a mobile station from a predetermined cell to a neighboring cell of the predetermined cell on the basis of a path loss value based on a predetermined transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the predetermined cell and a reception power value of the radio signal in the mobile station, the method comprising the steps of:

detecting a neighboring cell transmission power value that is a transmission power value of a radio signal transmitted from a base station forming the neighboring cell;

determining a power offset of the neighboring cell to be added to the predetermined transmission power value, based on a difference between the predetermined transmission power value and the detected neighboring cell transmission power value; and

notifying the determined power offset to the mobile station.

9. The mobility control method according to claim 8, wherein in the power offset determining step, a difference between the predetermined transmission power value and the neighboring cell transmission value is determined as the power offset.