Device and method for handling a feature

1. A network for handling a feature, comprising:

at least one storage device; and

at least one processing circuit, coupled to the at least one storage device, wherein the at least one storage device stores, and the at least one processing circuit is configured to execute instructions of:

receiving a first non-access stratum (NAS) message comprising a first information element (IE) and a second IE, from a communication device, wherein the first IE identifies a first network slice, and the second IE identifies a second network slice; and

transmitting a second NAS message comprising a third IE, a fourth IE and a fifth IE, to the communication device, wherein the third IE indicates that the communication device is attached to the first network slice successfully, the fourth IE indicates that the communication device is not attached to the second network slice, and the fifth IE comprises a first timer value indicating a first time period for which the second network slice is not available to be attached, in response to the first NAS message.

2. The network of claim 1 , wherein the first IE comprises a single network slice selection assistance information (S-NSSAI) identifying the first network slice.

3. The network of claim 1 , wherein the second IE comprises a S-NSSAI identifying the second network slice.

4. The network of claim 1 , wherein the third IE comprises a S-NSSAI identifying the first network slice and a first value indicating that the communication device is attached to the first network slice successfully.

5. The network of claim 1 , wherein the fourth IE comprises a S-NSSAI identifying the second network slice and a second value indicating that the communication device is not attached to the second network slice.

6. The network of claim 1 , wherein the second NAS message comprises a sixth IE comprising a second timer value indicating a second time period for which the communication device is available to attach to the first network slice.

7. The network of claim 6 , wherein the instructions further comprise:

accepting any service for the first network slice for the second time period indicated in the sixth IE.

8. The network of claim 1 , wherein the instructions further comprise:

rejecting the communication device for attaching to the second network slice in the first time period indicated in the fifth IE.

9. A communication device for handling a feature, comprising:

at least one storage device; and

at least one processing circuit, coupled to the at least one storage device, wherein the at least one storage device stores, and the at least one processing circuit is configured to execute instructions of:

transmitting a first non-access stratum (NAS) message comprising a first information element (IE) and a second IE, to a network, wherein the first IE identifies a first network slice, and the second IE identifies a second network slice;

receiving a second NAS message comprising a third IE, a fourth IE and a fifth IE, from the network, wherein the third IE indicates that the communication device is attached to the first network slice successfully, the fourth IE indicates that the communication device is not attached to the second network slice, and the fifth IE comprises a first timer value indicating a first time period for which the second network slice is not available to be attached, in response to the first NAS message;

not transmitting a third NAS message to the network for a second time period, wherein the third NAS message is related to the second network slice; and

transmitting the third NAS message to the network after the second time period.

10. The communication device of claim 9 , wherein the first IE comprises a single network slice selection assistance information (S-NSSAI) identifying the first network slice.

11. The communication device of claim 9 , wherein the second IE comprises a S-NSSAI identifying the second network slice.

12. The communication device of claim 9 , wherein the third IE comprises a S-NSSAI identifying the first network slice and a first value indicating that the communication device is attached to the first network slice successfully.

13. The communication device of claim 9 , wherein the fourth IE comprises a S-NSSAI identifying the second network slice and a second value indicating that the communication device is not attached to the second network slice.

14. The communication device of claim 9 , wherein the second NAS message comprises a sixth IE comprising a second timer value indicating a third time period for which the communication device is available to attach to the first network slice.

15. The communication device of claim 14 , wherein the instructions further comprise:

transmitting user data to use a service related to the first network slice for the third time period indicated in the sixth IE, to the network; and

stopping transmitting the user data to the network and transmitting the third NAS message, after the third time period.

16. The communication device of claim 9 , wherein the instructions further comprise:

receiving a fourth NAS message from the network, wherein the fourth NAS message indicates that the communication device is attached to the second network slice successfully.