Method and apparatus for processing a circuit-switched (CS) call while camped on a CSG cell

1. A method of processing a Circuit-Switched (CS) call by a User Equipment (UE), the method comprising:

registering, by the UE, with a manually selected Closed Subscriber Group (CSG) cell of a Public Land Mobile Network (PLMN), which is different from a Registered PLMN (RPLMN) of the UE;

detecting the CS call; and

processing the CS call in a non-CSG cell, when the UE loses coverage of the manually selected CSG cell,

wherein processing the CS call in the non-CSG cell comprises:

sending a request to process the CS call to the manually selected CSG cell;

receiving a redirect request message from the manually selected CSG cell requesting the UE to initiate a Circuit Switched Fall Back (CSFB) procedure in order to select the non-CSG cell; and

initiating the CSFB procedure to select the non-CSG cell for processing the CS call.

2. The method of claim 1 , wherein the non-CSG cell supports at least one of a Global System for Mobile communications (GSM) Edge Radio Access Network (GERAN), and a Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN).

3. The method of claim 1 , further comprising:

identifying that the CS call is ended; and

camping on and registering with the manually selected CSG cell using a pre-stored parameter associated with the manually selected CSG cell.

4. The method of claim 3 , wherein the pre-stored parameter comprises at least one of Evolved UTRA (EUTRA) Absolute Radio Frequency Channel Number (EARFCN) information of the manually selected CSG cell, a CSG Identifier (ID), and a cell ID.

5. The method of claim 3 , wherein camping on and registering with the manually selected CSG cell comprises:

initiating a search to identify the manually selected CSG cell;

determining whether the manually selected CSG is available, based on the search; and

camping on and registering with manually selected CSG cell, in response to determining that the manually selected CSG is available.

6. The method of claim 5 , further comprising:

camping on and registering with the RPLMN using a stored duplicate value of the RPLMN, in response to determining that the manually selected CSG is unavailable, based on the search.

7. The method of claim 1 , wherein the CS call includes one of a Mobile Originated (MO) call and a Mobile Terminated (MT) call.

8. A User Equipment (UE) for processing a Circuit-Switched (CS) call, the UE comprising:

a memory; and

a controller configured to:

register the UE with a manually selected Closed Subscriber Group (CSG) cell of a Public Land Mobile Network (PLMN), which is different from a Registered PLMN (RPLMN) of the UE;

detect the CS call; and

process the CS call in a non-CSG cell, when the UE loses coverage of the manually selected CSG cell,

wherein the controller is configured to process the CS call in the non-CSG cell by:

sending a request to process the CS call to the manually selected CSG cell;

receiving a redirect request message from the manually selected CSG cell requesting the UE to initiate a Circuit Switched Fall Back (CSFB) procedure in order to select the non-CSG cell; and

initiating the CSFB procedure to select the non-CSG cell for processing the CS call.

9. The UE of claim 8 , wherein the CS call comprises one of:

a Mobile Originated (MO) call; and

a Mobile Terminated (MT) call.

10. The UE of claim 8 , wherein the controller is further configured to:

identify that the CS call is ended; and

camp on and register with the manually selected CSG cell using a pre-stored parameter from the memory, which are associated the manually selected CSG cell.

11. The UE of claim 10 , wherein the controller is configured to camp on and register with the manually selected CSG cell by:

initiating a search to identify the manually selected CSG cell;

determining whether the manually selected CSG is available, based on the search; and

camp on and register with manually selected CSG cell, in response to determining that the manually selected CSG is available.

12. The UE of claim 10 , wherein the controller module is further configured to:

camp on and register with the RPLMN using a stored duplicate value of the RPLMN from the memory, in response to determining that the manually selected CSG is unavailable, based on the search.

13. The UE of claim 10 , wherein the pre-stored parameter comprises Evolved UTRA (EUTRA) Absolute Radio Frequency Channel Number (EARFCN) information of the manually selected CSO cell, a CSG IDentifier (ID), and a cell ID.