Radio resource control connection resume method of wireless communication system
An RRC connection resume method of a wireless communication system is provided. An RRC suspend message is received by a UE from a first base station. An RRC resume procedure is performed by the UE with a second base station in response to the RRC suspend message. An RRC resume response is received by the UE from the second base station.
1. A radio resource control (RRC) connection resume method of a wireless communication system, comprising:
receiving, by a user equipment (UE), an RRC suspend message from a first base station;
performing, by the UE, an RRC resume procedure with a second base station in response to the RRC suspend message; and
receiving, by the UE, an RRC resume response from the second base station,
wherein the RRC suspend message comprises:
a) target cell information, and
b) target radio access technology information comprising numerology information.
2. The RRC connection resume method of claim 1 , further comprising:
transmitting, by the second base station, a UE context fetch request to the first base station in response to the RRC resume procedure; and
receiving, by the second base station, a UE context fetch response from the first base station in response to the UE context fetch request;
wherein the first base station and the second base station is realized by different radio access numerologies, one of the first base station and the second base station is a wide-band numerology and another one is a narrow-band-Internet-of-Things numerology.
3. The RRC connection resume method of claim 1 , further comprising:
transmitting, by the second base station, a UE context fetch request to the first base station in response to the RRC resume procedure; and
receiving, by the second base station, a UE context fetch response from the first base station in response to the UE context fetch request;
wherein the first base station and the second base station is realized by different radio access technologies, and one of the first base station and the second base station is a narrow-band-Internet-of-Things numerology.
4. The RRC connection resume method of claim 1 , wherein the step of performing the RRC resume procedure with the second base station comprises:
transmitting, by the UE, an RRC resume request to the second base station;
wherein the RRC resume request comprises at least one of:
a) an RRC resume request cause; and
b) source cell information.
5. The RRC connection resume method of claim 1 , wherein the RRC resume response comprises at least one of:
a) a data packet acknowledgement (ACK) or Non-acknowledgement (NACK); and
b) an area update response.
6. The RRC connection resume method of claim 1 , further comprising:
transmitting, by the UE, an area update request to the second base station;
performing, by the second base station, an area update procedure with other network entities when the area update request is received;
receiving, by the UE, an area update response from the second base station.
7. The RRC connection resume method of claim 1 , wherein the RRC suspend message further comprises an RRC resume validity timer, and the RRC connection resume method further comprises:
starting, by the UE, the RRC resume validity timer when the RRC resume validity timer in the RRC suspend message is received; and
removing, by the UE, at least a part of UE context when the RRC resume validity timer expires.
8. A user equipment (UE), comprising:
a processor configured to:
receive an RRC suspend message from a first base station;
perform an RRC resume procedure with a second base station in response to the RRC suspend message; and
receive an RRC resume response from the second base station,
wherein the RRC suspend message comprises:
a) target cell information, and
b) target radio access technology information comprising numerology information.
9. The UE of claim 8 , wherein the processor is further configured to transmit an RRC resume request to the second base station, and the RRC resume request comprises at least one of:
a) an RRC resume request cause; and
b) source cell information.
10. The UE of claim 8 , wherein the RRC resume response comprises at least one of:
a) a data packet acknowledgement (ACK) or Non-acknowledgement (NACK); and
b) an area update response.
11. The UE of claim 8 , wherein the processor is further configured to:
transmit an area update request to the second base station; and
receive an area update response from the second base station.
12. The UE of claim 8 , wherein the RRC suspend message further comprises an RRC resume validity timer, and the processor is further configured to:
start the RRC resume validity timer when the RRC resume validity timer in the RRC suspend message is received; and
remove at least a part of UE context when the RRC resume validity timer expires.
13. A base station, comprising:
a processor configured to:
transmit an RRC suspend message to a user equipment (UE);
receive a UE context fetch request from a second base station; and
transmit a UE context fetch response to the second base station in response to the UE context fetch request,
wherein the RRC suspend message comprises:
a) target cell information, and
b) target radio access technology information comprising numerology information.
14. The base station of claim 13 , wherein the base station and the second base station is realized by different radio access numerologies, one of the base station and the second base station is a wide-band numerology and another one is a narrow-band-Internet-of-Things numerology.
15. The base station of claim 13 , wherein the base station and the second base station is realized by different radio access technologies, and one of the base station and the second base station is a narrow-band-Internet-of-Things numerology.
16. The base station of claim 13 , wherein the processor is further configured to:
receive an area update request from the second base station; and
transmit an area update response to the second base station in response to the area update request.
17. The base station of claim 13 , wherein the RRC suspend message further comprises an RRC resume validity timer, and the processor is further configured to:
start the RRC resume validity timer when the RRC resume validity timer in the RRC suspend message is transmitted; and
remove at least a part of UE context when the RRC resume validity timer expires.