Method and user equipment for operation using S and F satellite operation and control plane CIoT optimization

1 . An operation method of user equipment (UE), comprising

when the UE supports control plane cellular internet of things (CIoT) evolved packet system (EPS) optimization with overhead reduction, transmitting a first message including capability information in which a control plane CIoT EPS optimization with overhead reduction bit is set,

wherein the control plane CIoT EPS optimization with overhead reduction bit is ignored when a control plane CIoT EPS optimization bit is set to zero (0);

when the UE supports a store and forward (S&F) operation and the network node is operating in a S&F mode, receiving a service accept message including a S&F wait time duration; and

starting a first timer based on a value of the S&F wait time duration,

wherein while the first timer is running, the UE does not initiate a non-access stratum (NAS) procedure over a S&F satellite cell in a tracking area of a tracking area identity (TAI) list, unless the S&F satellite cell broadcasts a same satellite identity (ID) broadcasted by the S&F satellite cell.

2 . The method of claim 1 , further comprising:

if the service accept message includes a value for a T3448 timer, stopping the timer T3448 and considering a transport of user data via a control plane as successful.

3 . The method of claim 2 , wherein

if the value for the T3448 timer indicates that the T3448 timer is either zero or deactivated, the UE considers this case as an abnormal case and proceeds as if the value for the T3448 timer is not included.

4 . The method of claim 1 , further comprising:

if the service accept message includes an EPS bearer context status information, deactivating all EPS bearer contexts locally which are active in the UE but are indicated by the network node as being inactive.

5 . A user equipment (UE), the UE comprising:

at least one processor; and

at least one computer memory operably connectable to the at least one processor and storing instructions that, when executed by the at least one processor, perform operations comprising:

when the UE supports control plane cellular internet of things (CIoT) evolved packet system (EPS) optimization with overhead reduction, transmitting a first message including capability information in which a control plane CIoT EPS optimization with overhead reduction bit is set,

wherein the control plane CIoT EPS optimization with overhead reduction bit is ignored if when a control plane CIoT EPS optimization bit is set to zero (0);

when the UE supports a store and forward (S&F) operation and the network node is operating in a S&F mode, receiving a service accept message including a S&F wait time duration; and

starting a first timer based on a value of the S&F wait time duration,

wherein while the first timer is running, the UE does not initiate a non-access stratum (NAS) procedure over a S&F satellite cell in a tracking area of a tracking area identity (TAI) list, unless the S&F satellite cell broadcasts a same satellite identity (ID) broadcasted by the S&F satellite cell.

6 . The UE of claim 5 , wherein the operations further comprise:

if the service accept message includes a value for a T3448 timer, stopping the timer T3448 and considering a transport of user data via a control plane as successful.

7 . The UE of claim 5 , wherein

if the value for the T3448 timer indicates that the T3448 timer is either zero or deactivated, the UE considers this case as an abnormal case and proceeds as if the value for the T3448 timer is not included.

8 . The UE of claim 5 , wherein the operations further comprise:

if the service accept message includes an EPS bearer context status information, deactivating all EPS bearer contexts locally which are active in the UE but are indicated by the network node as being inactive.

9 . A semiconductor chipset, comprising:

at least one processor; and

at least one memory capable of storing instructions and being connected electrically to the at least one processor operably, wherein operations, performed when the instructions are executed by the at least one processor, includes:

when the UE supports control plane cellular internet of things (CIoT) evolved packet system (EPS) optimization with overhead reduction, transmitting a first message including capability information in which a control plane CIoT EPS optimization with overhead reduction bit is set,

wherein the control plane CIoT EPS optimization with overhead reduction bit is ignored if when a control plane CIoT EPS optimization bit is set to zero (0);

when the UE supports a store and forward (S&F) operation and the network node is operating in a S&F mode, receiving a service accept message including a S&F wait time duration; and

starting a first timer based on a value of the S&F wait time duration,

wherein while the first timer is running, the UE does not initiate a non-access stratum (NAS) procedure over a S&F satellite cell in a tracking area of a tracking area identity (TAI) list, unless the S&F satellite cell broadcasts a same satellite identity (ID) broadcasted by the S&F satellite cell.

10 . The semiconductor chipset of claim 9 , wherein the operations further comprise:

if the service accept message includes a value for a T3448 timer, stopping the timer T3448 and considering a transport of user data via a control plane as successful.

11 . The semiconductor chipset of claim 9 , wherein

if the value for the T3448 timer indicates that the T3448 timer is either zero or deactivated, the UE considers this case as an abnormal case and proceeds as if the value for the T3448 timer is not included.

12 . The semiconductor chipset of claim 9 , wherein the operations further comprise:

if the service accept message includes an EPS bearer context status information, deactivating all EPS bearer contexts locally which are active in the UE but are indicated by the network node as being inactive.