Method and apparatus for selecting neighbor cells in mobile communication system
A neighbor cell search method and apparatus of a User Equipment (UE) is provided for performing the cell search procedure with the utilization of a Physical Cell Identity (PCI) list of PCIs used by evolved Node Bs (eNBs) for a Closed Subscriber Group (CSG) which is from an eNB in a Long Term Evolution (LTE) system. The cell search method includes selecting a cell of a base station, receiving system information including a Physical Cell Identity (PCI) list used by neighbor Closed Subscribed Group (CSG) cells of the base station, determining whether the terminal is in an any cell selection state for selecting any cell, and searching, when the terminal is in the any cell selection state, neighbor cells without application of the PCI list. The cell search method and apparatus are capable of performing the cell search procedure to appropriate eNBs, resulting in improvement of network attachment efficiency.
1. A method for selecting/reselecting a cell by a terminal in a mobile communication system, the method comprising:
receiving system information including a set of physical cell identities reserved for closed subscriber group (CSG) cells;
determining whether the terminal is in an any cell selection state; and
selecting a first cell among a plurality of cells including the CSG cells if the terminal is in the any cell selection state;
wherein the terminal is in the any cell selection state, if the terminal fails finding a suitable cell or is rejected by a selected public land mobile network (PLMN).
2. The method of claim 1 , further comprising:
selecting a second cell among the plurality of cells with an exception of the CSG cells if the terminal is not in the any cell selection state.
3. The method of claim 1 , further comprising:
starting, if the system information is received, a timer having a length of a first time duration; and
selecting a second cell among the plurality of cells with an exception of the CSG cells before the timer expires.
4. The method of claim 1 , wherein the set of physical cell identities is included in a csg-PhysCellIdRange parameter of the system information.
5. A terminal for selecting/reselecting a cell in a mobile communication system, the terminal comprising:
a transceiver configured to transmit and receive signals to and from a base station; and
a controller configured to:
receive system information including a set of physical cell identities reserved for closed subscriber group (CSG) cells,
determine whether the terminal is in an any cell selection state, and
select a first cell among a plurality of cells with an exception of the CSG cells if the terminal is in the any cell selection state based on the determination,
wherein the terminal is in the any cell selection state if the terminal fails finding a suitable cell or is rejected by a selected public land mobile network (PLMN).
6. The terminal of claim 5 , wherein the controller is further configured to select a second cell among the plurality of cells with an exception of the CSG cells if the terminal is not in the any cell selection state.
7. The terminal of claim 5 , wherein the controller is further configured to:
select, if the system information is received, a timer having a length of a first time duration, and
select a second cell among the plurality of cells with an exception of the CSG cells before the timer expires.
8. The terminal of claim 5 , wherein the set of physical cell identities is included in a csg-PhysCellIdRange parameter of the system information.
9. A method for selecting/reselecting a cell by a terminal in a mobile communication system, the method comprising:
receiving first system information including a set of physical cell identities reserved for closed subscriber group (CSG) cells on a first cell;
receiving second system information including public land mobile network (PLMN) information on a second cell;
determining whether a PLMN identity of the first cell and a PLMN identity of the second cell is different based on the PLMN information; and
selecting a cell among a plurality of cells including the CSG cells if the PLMN of the first cell and the PLMN of the second cell is different.
10. The method of claim 9 , further comprising:
selecting a cell among the plurality of cells with an exception of the CSG cells if the PLMN of the first cell and the PLMN of the second cell is identical.
11. A terminal for selecting/reselecting a cell by a terminal in a mobile communication system, the terminal comprising:
a transceiver configured to transmit and receive signals to and from a base station; and
a controller configured to:
receive first system information including a set of physical cell identities reserved for closed subscriber group (CSG) cells on a first cell,
receive second system information including public land mobile network (PLMN) information on a second cell,
determine whether a PLMN identity of the first cell and a PLMN identity of the second cell is different or not based on the PLMN information, and
to select a cell among a plurality of cells including the CSG cells if the PLMN of the first cell and the PLMN of the second cell is different.
12. The terminal of claim 11 , wherein the controller is further configured to select a cell among the plurality of cells with an exception of the CSG cells if the PLMN of the first cell and the PLMN of the second cell is identical.