Radio communication system, radio base station, and communication control method

• US 9,148,793 B2
• Filed: 05/27/2011
• Issued: 09/29/2015
• Est. Priority Date: 05/27/2010
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Kusano, Yoshimasa, Yamazaki, Chiharu, Nakayama, Taku, Joko, Shingo, Nakamura, Kazutaka
• Primary Examiner(s): Kincaid, Lester
• Assistant Examiner(s): Gu, Andy
• Application Number:
  US13/700,125
• Publication Number:
  US 20130072184A1
• Time in Patent Office: 1,586 Days
• Field of Search: 455/423
• US Class Current: 1/1
• CPC Class Codes: H04W 16/28 using beam steering
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 36/00 Hand-off or reselection arrangements
• CPC Class Codes: H04W 92/20 between access points

Abstract

Upon receipt of an RLF Indication message indicating a failure in a handover where a radio base station eNB10-1 is the handover source from the other radio base station eNB, the radio base station eNB10-1 can recognize that its coverage is not adjusted appropriately by referring to the RLF Indication message. Moreover, the radio base station eNB10-1 can adjust coverage appropriately by expanding the radiation area of the antenna 101 whose radiation area is directed toward the other radio base station eNB being the handover target, among the antennas 101 included in the radio base station eNB10-1.

Claims

1. A radio communication system comprising:

a first radio base station;

a second radio base station, wherein the second radio base station comprises a transmitter configured to send the first radio base station handover failure information indicating that a failure occurs in a handover in which the first radio base station is involved;

wherein the first radio base station comprises;

an antenna;

a receiver configured to receive the handover failure information from the second radio base station;

and a controller configured to;

determine a handover failure rate calculated based on a history of the handover failure information received by the receiver,

adjust the radiation area of the antenna according to the handover failure rate, and wherein the controller is configured to make the adjustment in proportionality to the handover failure rate so that the larger the rate of handover failure indicated by the history of the first handover failure information, the wider the radiation area of the antenna is expanded.

2. A radio base station comprising:

an antenna;

a receiver configured to receive first handover failure information from a first other radio base station, the first handover failure information is information indicating that a failure occurs in a handover in which the radio base station is involved;

and a controller configured to;

determine a handover failure rate calculated based on a history of the first handover failure information received by the receiver,

adjust the radiation area of the antenna according to the handover failure rate, and wherein the controller is configured to make the adjustment in proportionality to the handover failure rate so that the larger the rate of handover failure indicated by the history of the first handover failure information, the wider the radiation area of the antenna is expanded.

3. The radio base station according to claim 2 further comprising a transmitter configured to send second handover failure information to a second other radio base station, wherein

the second handover failure information is information indicating that a failure occurs in a handover in which the second other radio base station is involved.

4. The radio base station according to claim 2, wherein the controller adjusts the radiation area of the antenna corresponding to a certain sector among sectors of the radio base station, according to the first handover failure information.

5. The radio base station according to claim 2, wherein the controller adjusts a tilt angle of the antenna to adjust the radiation area of the antenna.

6. A communication control method for a radio base station including an antenna, comprising the steps of:

receiving, at the radio base station, handover failure information from another radio base station, wherein the handover failure information is information indicating that a failure occurs in a handover in which the radio base station is involved;

determining a handover failure rate calculated based on a history of the received handover failure information;

and adjusting a radiation area of the antenna in proportionality to the handover failure rate, so that the larger the rate of handover failure indicated by the history of the handover failure information, the wider the radiation area of the antenna is expanded.