COMMUNICATION TERMINAL AND COMMUNICATION METHOD

• US 20120289274A1
• Filed: 01/13/2011
• Published: 11/15/2012
• Est. Priority Date: 01/15/2010
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Matsuo, Hidenori, Aoyama, Takahisa, Tamura, Takashi
• Granted Patent: US 9,031,594 B2
• Time in Patent Office: Days
• US Class Current: 455/509
• CPC Class Codes: H04W 36/32 by location or mobility data, e.g. speed data
• CPC Class Codes: H04W 36/324 by mobility data, e.g. speed data
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions
• CPC Class Codes: H04W 48/06 based on traffic conditions
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

A communication terminal includes: a notification information acquiring section which acquires notification information containing information related to all frequencies allocated to cells provided by a base station that provides access-restricted cells; a frequency information storing section which stores cell information containing information contained in the notification information; a frequency selecting section which selects one arbitrary frequency from a plurality of frequencies provided by an access-restricted base station to be accessible in a past when detecting that the communication terminal approximates to a cell of the access-restricted base station to be accessible in the past, based on the notification information and the cell information; and a transmitting section which transmits the proximity indication message containing the frequency selected by the frequency selecting section, to the base station that provides the currently connected cell.

Claims

1. A communication terminal which transmits a proximity indication message to a base station that provides a currently connected cell when approximating to an access-restricted cell provided by a base station that provides a plurality of access-restricted cells at different frequencies, the communication terminal comprising:

a notification information acquiring section which acquires notification information containing information related to all frequencies allocated to the access-restricted cells provided by the base station that provides the access-restricted cells;

a frequency information storing section which stores cell information containing information contained in the notification information;

a frequency selecting section which selects one arbitrary frequency from a plurality of frequencies provided by an access-restricted base station to be accessible in the past when detecting that the communication terminal approximates to an access-restricted cell of the access-restricted base station to be accessible in the past, based on the notification information acquired by the notification information acquiring section and the cell information stored by the frequency information storing section; and

a transmitting section which transmits the proximity indication message containing the frequency selected by the frequency selecting section, to the base station that provides the currently connected cell.

2. The communication terminal according to claim 1, wherein

the notification information contains frequency priority information indicating a priority to each frequency of access-restricted cells provided by the base station that provides the access-restricted cells, and

the frequency selecting section selects one frequency having a highest priority which is indicated by the frequency priority information, from the plurality of frequencies provided by the base station that provides the access-restricted cells.

3. The communication terminal according to claim 1, wherein

the notification information contains coverage information indicative of a coverage of each of the access-restricted cells provided by the base station that provides the access-restricted cells, and,

the frequency selecting section selects one frequency corresponding to an access-restricted cell having the largest coverage from the plurality of frequencies provided by the base station that provides the access-restricted cells.

4. The communication terminal according to claim 1, comprising:

a frequency determining section which determines whether the frequency of the currently connected cell is contained in the plurality of frequencies provided by the base station that provides the access-restricted cell to which the communication terminal approximates or not; and

a traveling speed determining section which determines a traveling speed of the communication terminal, wherein

the notification information contains coverage information which is information related to a coverage of each of the access-restricted cells provided by the base station that provides the access-restricted cells,

when the frequency of the currently connected cell is contained in the plurality of frequencies provided by the base station that provides the access-restricted cells, the frequency selecting section selects one frequency corresponding to an access-restricted cell having a largest coverage, from the plurality of frequencies provided by the base station that provides the access-restricted cells, and

when the frequency of the currently connected cell is not contained in the plurality of frequencies provided by the base station that provides the access-restricted cells, the frequency selecting section selects one frequency corresponding to an access-restricted cell having a smallest coverage, from the plurality of frequencies provided by the base station that provides the access-restricted cells when a traveling speed of the communication terminal is equal to or larger than a predetermined threshold, and the frequency selecting section selects one frequency corresponding to an access-restricted cell having a largest coverage, from the plurality of frequencies provided by the base station that provides the access-restricted cells when the traveling speed of the communication terminal is smaller than the predetermined threshold.

5. The communication terminal according to claim 1, wherein

the notification information contains a selection inhibition flag which is added to the frequency that should not be notified by the communication terminal by means of the proximity indication message, and

the frequency selecting section selects one frequency from the plurality of frequencies provided by the base station that provides the access-restricted cells, except for the frequency indicated by the selection inhibition flag.

6. The communication terminal according to claim 1, wherein

the notification information contains a selection flag which is added to the frequency which should be notified by the communication terminal by means of the proximity indication message, and

the frequency selecting section selects a frequency indicated by the selection flag from the plurality of frequencies provided by the base station that provides the access-restricted cells.

7. A communication method which is executed by a communication terminal which transmits a proximity indication message to a base station that provides a currently connected cell when approximating to an access-restricted cell provided by a base station that provides a plurality of access-restricted cells at different frequencies, the communication method comprising:

a notification information acquiring step of acquiring notification information containing information related to all frequencies allocated to the access-restricted cells provided by the base station that provides the access-restricted cells;

a frequency information storing step of storing cell information containing information contained in the notification information;

a frequency selecting step of selecting one arbitrary frequency from a plurality of frequencies provided by an access-restricted base station to be accessible in a past, when detecting that the communication terminal approximates to an access-restricted cell of the access-restricted base station to be accessible in a past, based on the notification information acquired in the notification information acquiring step and the cell information stored in the frequency information storing step; and

a transmitting step of transmitting the proximity indication message containing the frequency selected in the frequency selecting step, to the base station that provides the currently connected cell.