Mobile terminal, communication system, and method for changing location registration

• US 20050003818A1
• Filed: 04/21/2004
• Published: 01/06/2005
• Est. Priority Date: 04/22/2003
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Chiba, Koji, Kanto, Hiroshi, Maeda, Fukiko
• Granted Patent: US 7,386,312 B2
• Time in Patent Office: Days
• US Class Current: 455/435.200
• CPC Class Codes: H04W 48/10 using broadcasted information
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 60/04 using triggered events
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A mobile terminal, which is registered to either a first mobile communication network or a second communication network, determines whether it is possible to register to the first mobile communication network on the basis of control information received from the second mobile communication network. Then, the mobile terminal attempts to register to the first mobile communication network a predetermined number of times in a case that it is determined that it is possible to register to the first mobile communication network.

Claims

1. A radio terminal comprising:

communication means having a communication function for using a first mobile communication network and a second mobile communication network;

determination means for determining, when said mobile terminal is registered to said second mobile communication network, whether it is possible to register to said first mobile communication network, on the basis of notification information transmitted from said second mobile communication network; and

attempt means for attempting, in a case that it is determined that it is possible to register to said first mobile communication network, to register to said first mobile communication network.

2. mobile terminal according to claim 1,

wherein notification information received by said communication means includes timing information indicating a maximum number of times for attempting to register to said first mobile communication network, and said attempt means attempts to register to said first mobile communication network on the basis of said timing information.

3. A communication system comprising:

a first mobile communication network;

a second mobile communication network having a base station for transmitting notification information indicating that it is possible to register to said first mobile communication network; and

a management device, in accordance with location registration of a mobile terminal to either said first mobile communication network or said second mobile communication network, for storing data in correlation with a identifier of the mobile terminal, the data indicating a mobile communication network to which the mobile terminal is registered.

4. A location registration changing method comprising:

a first step of determining in a mobile terminal whether it is possible to register to a first mobile communication network on the basis of notification information received from a second mobile communication network, the mobile terminal having a communication function for using the first mobile communication network and the second mobile communication network;

a second step of transmitting from said mobile terminal to said first mobile communication network, a notification including an identifier, in a case that said determination is positive; and

a third step of receiving in a management device a notification transmitted by the mobile terminal in said second step through said first mobile communication network, and storing in said management device data indicating that said mobile terminal is registered to said first mobile communication network, the mobile terminal being specified by an identifier included in said notification.