USER EQUIPMENT AND METHOD USED IN MOBILE COMMUNICATION SYSTEM

• US 20100029283A1
• Filed: 12/26/2007
• Published: 02/04/2010
• Est. Priority Date: 01/05/2007
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Iwamura, Mikio
• Granted Patent: US 8,095,156 B2
• Time in Patent Office: Days
• US Class Current: 455/437
• CPC Class Codes: H04J 11/0069 Cell search, i.e. determining cell identity [cell-ID] design of multiplexing codes H04J13/00; processing access restriction or access information H04W48/16; discovery of network devices for network data management H04W8/005; sounding signals for channel estimation H04L25/0226; structure of reference signals in multicarrier modulation systems H04L27/2613; frame, time or carrier synchronisation in multicarrier modulation systems H04L27/2655
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information

Abstract

User equipment used in a mobile communication system is disclosed that includes a specifying unit specifying a tracking area of a serving cell based on broadcast information, a determination unit determining whether the user equipment is entitled to communicate in the private network, and a transmission unit transmitting a signal requesting to update the tracking area to a base station of the serving cell, in which the determination unit determines whether the specified tracking area is for the private network by checking a common identification which is common to private networks, and the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether the private network to which the serving cell belongs is the same as or different from a private network in which the user equipment is entitled to communicate.

Claims

1. A user equipment to be used in a mobile communication system, comprising:

a specifying unit configured to specify a tracking area of a serving cell based on broadcast information;

a determination unit configured to, when the specified tracking area is for a private network, determine whether the user equipment is entitled to communicate in the private network; and

a transmission unit configured to, when the user equipment is entitled to communicate in the private network, transmit a signal to a base station of the serving cell, the signal requesting that a tracking area be updated to a tracking area for the private network, wherein

the determination unit determines whether the specified tracking area is for the private network by checking a common identification which is common to private networks, and

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether the private network to which the serving cell belongs is the same as or different from a private network in which the user equipment is entitled to communicate.

2. The user equipment according to claim 1, wherein

the common identification is expressed by any number within a predetermined range of numbers and included in the broadcast information as an indicator indicating any number within the predetermined range of numbers.

3. The user equipment according to claim 2, wherein

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether a cell identification of the serving cell belonging to the private network is the same as or different from a cell identification of the private network in which the user equipment is entitled to communicate.

4. The user equipment according to claim 2, wherein

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether a tracking area identification of the private network to which the serving cell belongs is the same as or different from a tracking area identification of the private network in which the user equipment is entitled to communicate.

5. The user equipment according to claim 1, wherein

the common identification common to private networks indicates a value within one numeral range and a common identification common to non-private networks indicates a value within another numeral range.

6. The user equipment according to claim 5, wherein

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether a cell identification of the serving cell belonging to the private network is the same as or different from a cell identification of the private network in which the user equipment is entitled to communicate.

7. The user equipment according to claim 5, wherein

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether a tracking area identification of the private network to which the serving cell belongs is the same as or different from a tracking area identification of the private network in which the user equipment is entitled to communicate.

8. The user equipment according to claim 1, wherein

the common identification is expressed by using the tracking area identification commonly shared by the private networks.

9. The user equipment according to claim 8, wherein

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether a cell identification of the serving cell belonging to the private network is the same as or different from a cell identification of the private network in which the user equipment is entitled to communicate.

10. The user equipment according to claim 8, wherein

the determination unit determines whether the user equipment is entitled to communicate in the private network by determining whether a tracking area identification of the private network to which the serving cell belongs is the same as or different from a tracking area identification of the private network in which the user equipment is entitled to communicate.

11. A method to be used in a mobile communication system, comprising:

a specifying step of specifying a tracking area of a serving cell based on broadcast information;

a determination step of, when the specified tracking area is for a private network, determining whether the user equipment is entitled to communicate in the private network; and

a transmission step of, when the user equipment is entitled to communicate in the private network, transmitting a signal to a base station of the serving cell, the signal requesting that a tracking area be updated to a tracking area for the private network, wherein

in the determination step, the determination of whether the specified tracking area is for the private network is performed by checking a common identification which is common to private networks, and

in the determination step, the determination of whether the user equipment is entitled to communicate in the private network is performed by determining whether the private network to which the serving cell belongs is the same as or different from the private network in which the user equipment is entitled to communicate.

12. The method according to claim 11, further comprising:

an execution step of, when determining that the user equipment is not entitled to communicate in the private network, searching for a different frequency cell operating on a different frequency from the frequency of the serving cell, receiving the broadcast information from the different frequency cell, and executing the determination step again.

13. The method according to claim 11, wherein

the common identification is included in the MIB of the broadcast information, and

in the determination step, when the user equipment is entitled to communicate in any of the private networks, the determination of whether the user equipment is entitled to communicate in the private network is performed by determining whether the private network to which the serving cell belongs is the same as or different from the private network in which the user equipment is entitled to communicate based on a tracking area ID or a cell ID included in the SIB.

14. The method according to claim 13, further comprising:

an execution step of, when determining that the user equipment is not entitled to communicate in the private network, searching for a different frequency cell operating on a different frequency from the frequency of the serving cell, receiving the broadcast information from the different frequency cell, and executing the determination step again.

15. A method to be used in user equipment for a mobile communication system, comprising;

a search step of performing a cell search to search for a candidate cell to be a candidate of a handover destination cell;

a receiving step of receiving broadcast information from the candidate cell;

a determination step of, when the candidate cell belong to a private network, determining whether the user equipment is entitled to communicate in the private network; and

a transmission step of, when a tracking area of the candidate cell is not registered as a tracking area in which the user equipment is entitled to communicate, transmitting a signal to a base station, the signal requesting that a tracking area be updated, wherein

the determination of whether the cell belongs to the private network is performed by determining whether a cell ID of the cell corresponds to a predetermined cell ID, and

before the search step, whether a private network is to be included in a range where the cell search is performed is determined depending on whether the user equipment is entitled to communicate in any of the private networks.

16. The method according to claim 15, further comprising:

an execution step of, in a case where the user equipment is entitled to communicate in any of the private networks and when the user equipment is not entitled to communicate in the candidate cell belonging to the private network, the candidate cell being found in the cell search, searching for a different frequency cell operating on a different frequency from the frequency of the serving cell, receiving the broadcast information from the different frequency cell, and executing the determination step again.

17. The method according to claim 16, wherein

upon the different frequency cell being searched for, whether a private network is to be included in a range where the cell search is performed is determined depending on whether the user equipment is entitled to communicate in any of the private networks.

18. A method to be used in user equipment for a mobile communication system, comprising;

a search step of performing a cell search to search for a candidate cell to be a candidate of a handover destination cell;

a first determination step of determining whether the candidate cell belongs to a private network;

a second determination step of, when determining that the candidate cell belongs to a private network, receiving broadcast information from the candidate cell and determining whether the user equipment is entitled to communicate in the private network;

a transmission step of, when a tracking area of the candidate cell is not registered as a tracking area in which the user equipment is entitled to communicate, transmitting a signal to a base station, the signal requesting that a tracking area be updated, wherein

the determination of whether the cell belongs to the private network is performed by determining whether a cell ID of the cell corresponds to a predetermined cell ID.

19. The method according to claim 18, further comprising:

an execution step of, in a case where the user equipment is not entitled to communicate in any of the private networks and when the candidate cell belongs to the private network, searching for a different frequency cell operating on a different frequency from the frequency of the serving cell, receiving the broadcast information from the different frequency cell, and executing first and second determination steps again.