Radio terminal, radio communication system, and radio communication method

1. A radio terminal that performs radio communication with a base station, comprising:

a communicator configured to perform radio measurement and monitoring of a paging signal; and

a controller configured to control the communicator to receive information related to first duration, the information being sent by Non-Access Stratum (NAS) message from the base station,

wherein the controller does not perform the radio measurement and the monitoring during the first duration and performs the radio measurement and the monitoring during second duration following the first duration, and

wherein uplink data transmission from the radio terminal is performed during the first duration and the controller controls the radio measurement and the monitoring after the end of the first duration.

2. The radio terminal according to claim 1 , wherein

the controller controls the communicator to configure the second duration following the first duration.

3. The radio terminal according to claim 1 , wherein

the information related to the first duration is information relating to length of the first duration.

4. The radio terminal according to claim 1 , wherein

the controller is further configured to control the radio measurement and the monitoring by ending the first duration for transmitting uplink data of the radio terminal to a suitable base station.

5. The radio terminal according to claim 1 , wherein

the controller receives the information related to the first duration by Non-Access Stratum (NAS) Attach Accept that is the NAS message to be exchanged during NAS Attach procedure.

6. A base station that performs radio communication with a radio terminal, the base station comprising:

a memory; and

a processor coupled to the memory; the processor configured to:

control to transmit information related to first duration to be set in the radio terminal, the information being sent by Non-Access Stratum (NAS) message to the radio terminal,

wherein the first duration is duration in which the radio terminal controls communication not to perform radio measurement and monitoring of a paging signal, and second duration following the first duration is duration in which the radio terminal controls the communication to perform the radio measurement and the monitoring, and

wherein uplink data transmission from the radio terminal is performed during the first duration and the radio terminal controls the radio measurement and the monitoring after the end of the first duration.

7. The base station according to claim 6 , wherein

the information related to the first duration is information relating to length of the first duration.

8. The radio terminal according to claim 6 , wherein

the processor controls to transmit the information related to the first duration by Non-Access Stratum (NAS) Attach Accept that is the NAS message to be exchanged during NAS Attach procedure.

9. A radio communication method for a radio terminal and a base station that performs radio communication with the radio terminal, the radio communication method comprising:

configuring, by the radio terminal, first duration based on information related to the first duration received by Non-Access Stratum (NAS) message from the base station, the information being sent by the Non-Access Stratum (NAS) message from the base station,

wherein the radio terminal does not perform radio measurement and monitoring of a paging signal of the base station during the first duration and performs the radio measurement and the monitoring during second duration following the first duration,

further performing, by the radio terminal, uplink data transmission during the first duration, and

controlling, by the radio terminal, the radio measurement and the monitoring after the end of the first duration.