AT commands for supporting session and service continuity modes of 5G protocol data unitsession operations

1. A method, comprising:

providing a first Attention (AT) command by a modem in a wireless network to an Application Processor (AP), wherein the first AT command indicates a request of Protocal Data Unit (PDU) session anchor relocation;

receiving a second AT command by the modem from the AP, wherein the second AT command comprises an old Context ID (CID) associated with a released or an existing PDU session and a CID associated with a PDU session to be established for the PDU session anchor relocation;

transmitting a PDU session establishment request from the modem to the wireless network, wherein the PDU session establishment request comprises PDU session parameters for the PDU session associated with the old CID; and

receiving a PDU session establishment accept from the wireless network in response to the PDU session establishment request.

2. The method of claim 1 , wherein the providing of the first AT command is performed in response to the modem receiving from the wireless network a session management (SM) message indicating a request of PDU session reactivation.

3. The method of claim 2 , wherein the SM message is a PDU session release command or a PDU session modification command which comprises a 5GSM cause #39 indicating the request of PDU session reactivation.

4. The method of claim 1 , wherein the first AT command is an unsolicited result code +CGEV: NW PDN DEACT which comprises an indicator of a Session and Service Continuity (SSC) mode 2 to indicate the request of PDU session anchor relocation.

5. The method of claim 1 , the first AT command is an unsolicited result code +CGEV: NW MODIFY which comprises a change reason to indicate the request of PDU session anchor relocation or comprises the change reason and an indicator of a PDU session address lifetime.

6. The method of claim 1 , wherein the second AT command is a set command +CGDCONT for configuring the PDU session parameters.

7. The method of claim 1 , further comprising:

providing a third AT command by the modem to the AP in response to the PDU session establishment accept, wherein the third AT command indicates that context of the PDU session associated with the CID has been activated.

8. The method of claim 7 , wherein the third AT command is an unsolicited result code +CGEV: ME PDN ACT which comprises the old CID and an indicator of a Session and Service Continuity (SSC) mode 2 or SSC mode 3 of the established PDU session for the PDU session anchor relocation.

9. The method of claim 1 , wherein the old CID comprises an integer type indicating a context identifier of a quality of service (QoS) flow of a default QoS rule of a Session and Service Continuity (SSC) mode 2 or SSC mode 3 PDU session.

10. The method of claim 1 , wherein the wireless network is a 5G system (5GS).

11. A Mobile Terminal (MT), comprising:

a processor that provides a first Attention (AT) command to an Application Processor (AP) in a wireless network, and receives a second AT command from the AP, wherein the first AT command indicates a request of Protocal Data Unit (PDU) session anchor relocation, and the second AT command comprises an old Context ID (CID) associated with a released or existing PDU session and a CID associated with a PDU session to be established for the PDU session anchor relocation;

a transmitter that transmits a PDU session establishment request to the wireless network, wherein the PDU session establishment request comprises PDU session parameters for the PDU session associated with the old CID; and

a receiver that receives a PDU session establishment accept from the wireless network in response to the PDU session establishment request.

12. The MT of claim 11 , wherein the providing of the first AT command is performed in response to the receiver receiving from the wireless network a session management (SM) message indicating a request of PDU session reactivation.

13. The MT of claim 12 , wherein the SM message is a PDU session release command or a PDU session modification command which comprises a 5GSM cause #39 indicating a request of PDU session reactivation.

14. The MT of claim 11 , wherein the first AT command is an unsolicited result code +CGEV: NW PDN DEACT which comprises an indicator of a Session and Service Continuity (SSC) mode 2 to indicate the request of PDU session anchor relocation.

15. The MT of claim 11 , the first AT command is an unsolicited result code +CGEV: NW MODIFY which comprises an indicator of a PDU session address lifetime and a change reason to indicate the request of PDU session anchor relocation.

16. The MT of claim 11 , wherein the second AT command is a set command +CGDCONT for configuring the PDU session parameters.

17. The MT of claim 11 , wherein the processor further provides a third AT command to the AP in response to the PDU session establishment accept, wherein the third AT command indicates that context of the PDU session associated with the CID has been activated.

18. The MT of claim 17 , wherein the third AT command is an unsolicited result code +CGEV: ME PDN ACT which comprises the old CID and an indicator of a Session and Service Continuity (SSC) mode 2 or SSC mode 3 of the established PDU session for the PDU session anchor relocation.

19. The MT of claim 11 , wherein the old CID comprises an integer type indicating a context identifier of a quality of service (QoS) flow of a default QoS rule of a Session and Service Continuity (SSC) mode 2 or SSC mode 3 PDU session.

20. The MT of claim 11 , wherein the wireless network is a 5G system (5GS).