Method and apparatus for changing connection state of UE

1. A method of changing a connection state by a User Equipment (UE), the method comprising:

receiving indication information indicating a connection change into a specific RRC state from a Base Station (BS);

configuring a connection state of the UE into the specific RRC state based on the indication information and performing a cell reselection operation according to a movement of the UE; and

changing the connection state of the UE into an RRC idle state based on at least one piece of i) information on whether an RRC resume procedure is initiated, ii) system information of a cell selected by the cell reselection operation, and iii) radio access technology information,

wherein the specific RRC state is a state distinguished from an RRC connection state and the RRC idle state;

wherein the specific RRC state is a light connection state or an RRC inactive state in which an S1 connection is maintained between the BS and a core network entity for the specific RRC state; and

wherein the changing of the connection state comprises, when a PLMN id of the cell selected by the cell reselection operation is different from a PLMN id of a cell having configured the specific RRC state, changing the connection state of the UE into the RRC idle state.

2. The method of claim 1 , wherein the specific RRC state is the light connection state or the RRC inactive state in which UE context of the UE is stored and an RAN initiation paging operation is supported.

3. The method of claim 1 , wherein the changing of the connection state comprises, when radio access technology of the cell selected by the cell reselection operation is different from that of the cell having configured the specific RRC state, changing the connection state of the UE into the RRC idle state.

4. The method of claim 1 , wherein the changing of the connection state comprises, when the UE initiates the RRC resume procedure for a transition to the RRC connection state before the cell reselection operation, changing the connection state of the UE into the RRC idle state.

5. A method of controlling a change in a connection state of a User Equipment (UE) by a Base Station (BS), the method comprising:

transmitting information on whether a corresponding cell provided by the BS supports a specific RRC state through system information;

transmitting indication information indicating a state change into the specific RRC state to a UE within the corresponding cell; and

configuring the connection state of the UE as the specific RRC state,

wherein the specific RRC state is a state distinguished from an RRC connection state and an RRC idle state;

wherein the specific RRC state is a light connection state or an RRC inactive state in which an S1 connection is maintained between the BS and a core network entity for the specific RRC state; and

wherein the UE in the specific RRC state is configured to:

perform a cell reselection operation according to a movement of the UE;

change the specific RRC state into the RRC idle state when a PLMN id of a cell selected by the cell reselection operation is different from a PLMN id of the cell having configured the specific RRC state.

6. The method of claim 5 , wherein the specific RRC state is the light connection state or the RRC inactive state in which UE context of the UE is stored and an RAN initiation paging operation is supported.

7. The method of claim 5 , wherein when radio access technology of the cell selected by the cell reselection operation is different from that of the cell provided by the BS, the UE in the specific RRC state changes the connection state of the UE into the RRC idle state.

8. A User Equipment (UE) for changing a connection state, the UE comprising:

a receiver configured to receive indication information indicating a state change into a specific RRC state from a Base Station (BS); and

a controller configured to configure a connection state of the UE as the specific RRC state based on the indication information and perform a cell reselection operation according to a movement of the UE,

wherein the controller changes the connection state of the UE into an RRC idle state based on at least one piece of i) information on whether an RRC resume procedure is initiated, ii) system information of a cell selected by the cell reselection operation, and iii) radio access technology information;

wherein the specific RRC state is a state distinguished from an RRC connection state and the RRC idle state;

wherein the specific RRC state is a light connection state or an RRC inactive state in which an S1 connection is maintained between the BS and a core network entity for the specific RRC state; and

wherein when a PLMN id of the cell selected by the cell reselection operation is different from a PLMN id of a cell having configured the specific RRC state, the controller changes the connection state of the UE into the RRC idle state.

9. The UE of claim 8 , wherein the specific RRC state is the light connection state or the RRC inactive state in which UE context of the UE is stored and an RAN initiation paging operation is supported.

10. The UE of claim 8 , wherein, when radio access technology of the cell selected by the cell reselection operation is different from that of the cell having configured the specific RRC state, the controller changes the connection state of the UE into the RRC idle state.

11. The UE of claim 8 , wherein, when the UE initiates the RRC resume procedure for a transition to the RRC connection state before the cell reselection operation, the controller changes the connection state of the UE into the RRC idle state.