Method and apparatus for paging terminal in a light connection state in wireless communication system
A light connection state is different from a substate of a radio resource control connection (RRC) state or the RRC connection state, and is a state which allows free movement of a UE in a plurality of cells without involving a handover process controlled by a network. A terminal in the RRC connection state, which has received a cell radio network temporary identity (C-RNTI) from a first cell, enters the light connection state and then moves to a second cell. The terminal in the light connection state receives, from the second cell, a random access reply including a temporary C-RNTI during a random access process, and replaces the C-RNTI received from the first cell with the temporary C-RNTI.
1. A method for operating a user equipment (UE) in a light connection state in a wireless communication system, the method comprising:
while being in a first state, receiving a cell radio network temporary identity (C-RNTI) from a first cell;
entering from the first state to a second state;
while being in the second state, moving to a second cell;
during a random access procedure, receiving a random access response including a temporary C-RNTI from the second cell; and
replacing the C-RNTI received from the first cell with the temporary C-RNTI included in the random access response,
wherein the first state is a RRC_CONNECTED state,
wherein the second state is the light connection state, which is either a substate of the RRC_CONNECTED state or a different state than the RRC_CONNECTED state, and
wherein, in the second state, the UE is allowed to move autonomously across a plurality of cells without a handover procedure controlled by a network.
2. The method of claim 1 , further comprising receiving a cell list including the plurality of cells from the first cell.
3. The method of claim 1 , further comprising monitoring a physical downlink control channel (PDCCH) addressed by a paging RNTI (P-RNTI) to receive a paging message transmitted from the second cell.
4. The method of claim 3 , wherein the paging message includes an identity (ID) of the UE.
5. The method of claim 4 , wherein the ID of the UE is a combination of an ID of the first cell and the C-RNTI.
6. The method of claim 3 , further comprising receiving the paging message transmitted from the second cell.
7. The method of claim 1 , further comprising transmitting a message 3 including the C-RNTI received from the first cell to the second cell, during the random access procedure.
8. The method of claim 1 , wherein the C-RNTI received from the first cell is replaced with the temporary C-RNTI included after the random access procedure is successfully completed.
9. The method of claim 1 , wherein the plurality of cells includes the second cell.
10. A user equipment (UE) in a light connection state in a wireless communication system, the UE comprising:
a memory;
a transceiver; and
a processor, operably coupled to the memory and the transceiver, that:
while being in a first state, controls the transceiver to receive a cell radio network temporary identity (C-RNTI) from a first cell,
enters from the first state to a second state,
while being in the second state, moves to a second cell,
during a random access procedure, controls the transceiver to receive a random access response including a temporary C-RNTI from the second cell, and
controls the transceiver to replace the C-RNTI received from the first cell with the temporary C-RNTI included in the random access response,
wherein the first state is a RRC_CONNECTED state,
wherein the second state is the light connection state, which is either a substate of the RRC_CONNECTED state or a different state than the RRC_CONNECTED state, and
wherein, in the second state, the UE is allowed to move autonomously across a plurality of cells without a handover procedure controlled by a network.
11. The UE of claim 10 , wherein the processor controls the transceiver to receive a cell list including the plurality of cells from the first cell.
12. The UE of claim 10 , wherein the processor monitors a physical downlink control channel (PDCCH) addressed by a paging RNTI (P-RNTI) to receive a paging message transmitted from the second cell.
13. The UE of claim 12 , wherein the paging message includes an identity (ID) of the UE.
14. The UE of claim 10 , wherein the processor controls the transceiver to transmit a message 3 including the C-RNTI received from the first cell to the second cell, during the random access procedure.