Apparatus and method for managing state of terminal in wireless communication system

1. A method of operating a base station in a wireless communication system, the method comprising:

performing, by the base station, a data communication with a terminal that is in a first sub-state of a radio resource control (RRC) connected state; and

controlling, by the base station, to change a state of the terminal from the first sub-state to a second sub-state of the RRC connected state, based on whether data related to the terminal is obtained during a transfer duration,

wherein the first sub-state is a state in which a resource for context information of the terminal related to the data communication is allocated in a first layer and all of a plurality of second layers,

wherein the second sub-state is a state in which the resource for the context information of the terminal related to the data communication is allocated in the first layer and is released in at least one of the plurality of second layers, and wherein the first layer comprises a RRC layer,

the plurality of second layers comprises a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a media access control (MAC) layer, and

wherein the controlling to change the state of the terminal from the first sub-state to the second sub-state comprises:

monitoring whether the data related to the terminal is obtained during the transfer duration; and

based on a determination that the data related to the terminal is not obtained during the transfer duration, controlling to change the state of the terminal from the first sub-state to the second sub-state.

2. The method of claim 1 , wherein the context information of the terminal comprises at least one of a bearer identifier for the data communication, a cell-radio network temporary identifier (C-RNTI) of the terminal, an inactivity timer, a packet data unit (PDU) sequence number, or scheduling information associated with the terminal.

3. The method of claim 1 , further comprising:

monitoring whether the data related to the terminal is obtained during a release duration;

based on a determination that the data related to the terminal is obtained during the release duration, controlling to change the state of the terminal from the second sub-state to the first sub-state; and

based on a determination that the data related to the terminal is not obtained during the release duration, controlling to change the state of the terminal from the second sub-state to a RRC idle state.

4. The method of claim 3 , wherein the controlling to change the state of the terminal from the second sub-state to the first sub-state comprises:

generating terminal context information for the plurality of second layers, based on terminal context information for the first layer; and

allocating a resource for the generated terminal context information for the plurality of second layers.

5. The method of claim 4 , further comprising:

receiving a random access request from the terminal and detecting that uplink data is obtained from the terminal;

transmitting a random access response to the terminal in response to the received random access request; and

re-establishing a radio connection with the terminal.

6. The method of claim 1 , wherein the controlling to change the state comprises identifying the transfer duration in case that a number of radio bearers is greater than a threshold.

7. The method of claim 6 , further comprising:

transmitting, to the terminal, a timing alignment (TA) command for releasing a physical uplink control channel (PUCCH) resource allocated to the terminal after receiving a last packet,

wherein the transfer duration is initiated according to a reception of the last packet.

8. The method of claim 7 , wherein the transfer duration is shorter than a duration for transferring from the RRC connected state to a RRC idle state.

9. An apparatus of a base station for a wireless communication system, the apparatus comprising:

a transceiver configured to perform data communication with a terminal in a first sub-state of a radio resource control (RRC) connected state; and

at least one processor configured to control to change a state of the terminal from the first sub-state to a second sub-state of the RRC connected state, based on whether data related to the terminal is obtained during a transfer duration,

wherein the first sub-state is a state in which a resource for context information of the terminal related to the data communication is allocated in a first layer and all of a plurality of second layers,

wherein the second sub-state is a state in which the resource for the context information of the terminal related to the data communication is allocated in the first layer, and is released in at least one of the plurality of second layers,

wherein the first layer comprises a RRC layer, and the plurality of second layers comprises a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a media access control (MAC) layer,

wherein the transceiver is further configured to monitor whether the data related to the terminal is obtained during the transfer duration; and

wherein the at least one processor is further configured to control to change the state of the terminal from the first sub-state to the second sub-state based on a determination that the data related to the terminal is not obtained during the transfer duration.

10. The apparatus of claim 9 , wherein the context information of the terminal comprises at least one of a bearer identifier for the data communication, a cell-radio network temporary identifier (C-RNTI) of the terminal, an inactivity timer, a packet data unit (PDU) sequence number, or scheduling information associated with the terminal.

11. The apparatus of claim 9 , wherein:

the transceiver is further configured to monitor whether the data related to the terminal is obtained during a release duration; and

the at least one processor is further configured to control to change the state of the terminal from the second sub-state to the first sub-state based on a determination that the data related to the terminal is obtained during the release duration, and to control to change the state of the terminal from the second sub-state to a RRC idle state based on a determination that the data related to the terminal is not obtained during the release duration.

12. The apparatus of claim 11 , wherein the at least one processor is further configured to generate terminal context information for the plurality of second layers, based on terminal context information for the first layer, and allocate a resource for the generated terminal context information for the plurality of second layers.

13. The apparatus of claim 12 , wherein:

the at least one processor is further configured to receive a random access request from the terminal, and to detect that uplink data is obtained from the terminal; and

the transceiver is further configured to transmit a random access response to the terminal in response to the random access request, and re-establish a radio connection with the terminal.

14. The apparatus of claim 9 , wherein the controlling to change the state comprises identifying the transfer duration in case that a number of radio bearers is greater than a threshold.

15. The apparatus of claim 14 ,

the transceiver is further configured to transmit, to the terminal, a timing alignment (TA) command for releasing a physical uplink control channel (PUCCH) resource allocated to the terminal after receiving a last packet,

wherein the transfer duration is initiated according to a reception of the last packet.

16. The apparatus of claim 15 , wherein the transfer duration is shorter than a duration for transferring from the RRC connected state to a RRC idle state.