Base station, mobile station and target cell determination method

• US 8,311,553 B2
• Filed: 08/14/2007
• Issued: 11/13/2012
• Est. Priority Date: 08/22/2006
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Iwamura, Mikio, Ishii, Minami, Abeta, Sadayuki
• Primary Examiner(s): Patel, Ajit
• Assistant Examiner(s): Navar, Erica
• Application Number:
  US12/377,347
• Publication Number:
  US 20100056172A1
• Time in Patent Office: 1,918 Days
• Field of Search: 455405-409, 4554221-425, 455/432.1, 4554351-4353, 455436-445, 455449-453, 455/485, 455/461, 455/466
• US Class Current: 455/453
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point
• CPC Class Codes: H04W 36/22 for handling the traffic
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like

Abstract

One feature of the present invention relates to a base station for operating multiple cells each having a predefined bandwidth, including: a load measurement unit configured to measure traffic status in each of the cells; a redirected cell determination unit configured to determine either a redirected cell or a cell layer as redirected cell information for redirecting a mobile station based on the traffic status, the redirected cell and the cell layer to which the mobile station is to be redirected; and a transmission unit configured to transmit the redirected cell information to the mobile station in a paging channel.

Claims

1. A base station for operating multiple cells each having a predefined bandwidth, comprising:

a load measurement unit configured to measure traffic status in each of the cells;

a redirected cell determination unit configured to determine either a redirected cell or a cell layer as redirected cell information for redirecting a mobile station operating in standby mode based on the traffic status and a type of service received by the mobile station, the redirected cell and the cell layer to which the mobile station is to be redirected; and

a transmission unit configured to transmit the redirected cell information to the mobile station in a paging channel to enable the mobile station to establish a connection to the redirected cell or a cell selected from the cell layer in response to call reception from the base station,

wherein the redirected cell determination unit determines the redirected cell or the cell layer based on whether the service is available to the mobile station even in delay occurrence.

2. The base station as claimed in claim 1, wherein the redirected cell determination unit is configured to determine either the redirected cell or the cell layer based on a remaining radio resource in each of the cells.

3. The base station as claimed in claim 1, wherein the transmission unit is configured to transmit paging channels including uniform redirected cell information at a uniform timing in cells with uniform central frequency and bandwidth between sectors resulting from division of an area covered by the base station.

4. A mobile station, comprising:

a reception quality measurement unit configured to measure reception quality in either a redirected cell or a cell layer specified by a base station; and

a control plane processing unit configured to establish a connection to either the redirected cell or a cell selected from the cell layer if the measured reception quality satisfies a predefined threshold,

wherein the base station operates multiple cells each having a predefined bandwidth, measures traffic status of each of the cells, determines either the redirected cell or the cell layer for the mobile station operating in standby mode based on the traffic status and a type of service received by the mobile station and transmits either the redirected cell or the cell layer determined in a paging channel to enable the mobile station to establish a connection to the redirected cell or a cell selected from the cell layer in response to call reception from the base station, and

wherein the base station determines the redirected cell or the cell layer based on whether the service is available to the mobile station even in delay occurrence.

5. A method of determining a redirected cell, comprising:

measuring traffic status of multiple cells at a base station, each of the cells having a predefined bandwidth and operated by the base station;

determining either a redirected cell or a cell layer at the base station as redirected cell information for redirecting a mobile station operating in standby mode based on the traffic status and a type of service received by the mobile station, the redirected cell and the cell layer to which the mobile station is to be redirected; and

transmitting the redirected cell information from the base station to the mobile station in a paging channel to enable the mobile station to establish a connection to the redirected cell or a cell selected from the cell layer in response to call reception from the base station,

wherein the determining comprises determining the redirected cell or the cell layer based on whether the service is available to the mobile station even in delay occurrence.