Method for interaction between layers in wireless communication system and apparatus therefor

Patent metadata

Field	Value
Publication number	US-11452163-B2
Application number	US-202016818331-A
Country	US
Kind code	B2
Filing date	Mar 13, 2020
Priority date	Mar 20, 2017
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A method for forwarding a non-access stratum (NAS) message of a user equipment (UE) in a wireless communication system is disclosed. The method includes sending an uplink (UL) NAS message including a session management (SM) message to an access and mobility management function (AMF), and receiving, from the AMF, an indication message indicating that the SM message is unroutable, wherein indication information indicating that the SM message is unroutable is delivered to a SM sublayer of the UE.

First claim

The invention claimed is:

1. A method performed by an access and mobility function (AMF) operating in a wireless communication system, the method comprising:
receiving, from a user equipment (UE), an uplink (UL) non-access stratum (NAS) message that comprises a session management (SM) message; and
transmitting, to the UE, a downlink (DL) NAS message that comprises a cause value indicating that the SM message was not forwarded due to routing failure,
wherein an indication that the SM message was not forwarded due to routing failure is transferred, from a lower sublayer of the UE to an upper sublayer of the UE, based on the cause value,
wherein the SM message is generated in the upper sublayer of the UE and is provided to the lower sublayer of the UE, and
wherein the UL NAS message comprising the SM message is sent to the AMF by the lower sublayer of the UE.

2. The method of claim 1 , wherein the upper sublayer of the UE is a Session Management (SM) sublayer that performs protocol data unit (PDU) session control, and
wherein the lower sublayer of the UE is a Mobility Management (MM) sublayer that performs mobility control of the UE.

3. The method of claim 1 , wherein a pre-configured timer is started by the UE, based on the upper sublayer of the UE providing the SM message to the lower sublayer of the UE; and
wherein the pre-configured timer is stopped by the UE, and a procedure related to the SM message is stopped, based on the upper sublayer receiving, from the lower sublayer, the indication that the SM message was not forwarded due to routing failure.

4. The method of claim 3 , wherein at least one re-transmission of the SM message is performed by the UE, based on the pre-configured timer expiring, and
a procedure related to the SM message is stopped by the UE, based on failure of the at least one re-transmission of the SM message.

5. The method of claim 1 , wherein the UL NAS message further comprises a data network name (DNN) or single network slice selection assistance information (S-NSSAI) for the selection of a session management function (SMF) to forward the SM message.

6. The method of claim 2 , wherein based on the SM message being a message requesting an establishment of a PDU session, the UL NAS message further comprises a PDU session identifier (ID) for the PDU session to which the establishment is requested.

7. The method of claim 1 , wherein the lower sublayer forwards, to the upper sublayer, information about whether the SM message not being forwarded due to routing failure is permanent or temporary, together with the indication.

8. The method of claim 7 , wherein based on the SM message not being forwarded due to routing failure being permanent, the upper sublayer performs a release procedure for a PDU session or a data network (DN) related to the SM message.

9. The method of claim 8 , wherein the upper sublayer includes the PDU session or the DN in a procedure forbidden list and manages the PDU session or the DN.

10. The method of claim 8 , wherein based on services related to the PDU session or the DN being required, the upper sublayer requests a deregistration to the lower sublayer.

11. An access and mobility function (AMF) configured to operate in a wireless communication system, the AMF comprising:
a transceiver;
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:
receiving, via the transceiver from a user equipment (UE), an uplink (UL) non-access stratum (NAS) message that comprises a session management (SM) message; and
transmitting, via the transceiver to the UE, a downlink (DL) NAS message that comprises a cause value indicating that the SM message was not forwarded due to routing failure; and
wherein an indication that the SM message was not forwarded due to routing failure is transferred, from a lower sublayer of the UE to an upper sublayer of the UE, based on the cause value,
wherein the SM message is generated in the upper sublayer of the UE and is provided to the lower sublayer of the UE, and
wherein the UL NAS message comprising the SM message is sent to the AMF by the lower sublayer of the UE.

12. The AMF of claim 11 , wherein the upper sublayer of the UE is a Session Management (SM) sublayer that performs protocol data unit (PDU) session control, and
wherein the lower sublayer of the UE is a Mobility Management (MM) sublayer that performs mobility control of the UE.

13. The AMF of claim 11 , wherein a pre-configured timer is started by the UE, based on the upper sublayer of the UE providing the SM message to the lower sublayer of the UE; and
wherein the pre-configured timer is stopped by the UE, and a procedure related to the SM message is stopped, based on the upper sublayer receiving, from the lower sublayer, the indication that the SM message was not forwarded due to routing failure.

14. The AMF of claim 13 , wherein at least one retransmission of the SM message is performed by the UE, based on the pre-configured timer expiring, and
a procedure related to the SM message is stopped by the UE, based on failure of the at least one re-transmission of the SM message.

15. The AMF of claim 11 , wherein the UL NAS message further comprises a data network name (DNN) or single network slice selection assistance information (S-NSSAI) for the selection of a session management function (SMF) to forward the SM message.

16. The AMF of claim 12 , wherein based on the SM message being a message requesting an establishment of a PDU session, the UL NAS message further comprises a PDU session identifier (ID) for the PDU session to which the establishment is requested.

17. The AMF of claim 11 , wherein the lower sublayer forwards, to the upper sublayer, information about whether the SM message not being forwarded due to routing failure is permanent or temporary, together with the indication.

18. The AMF of claim 17 , wherein based on the SM message not being forwarded due to routing failure being permanent, the upper sublayer performs a release procedure for a PDU session or a data network (DN) related to the SM message.

19. The AMF of claim 18 , wherein the upper sublayer includes the PDU session or the DN in a procedure forbidden list and manages the PDU session or the DN.

20. The AMF of claim 18 , wherein based on services related to the PDU session or the DN being required, the upper sublayer requests a deregistration to the lower sublayer.

Assignees

• Lg Electronics Inc

Inventors

• Park Sangmin
• Kim Hyunsook
• Ryu Jinsook
• Kim Dongsoo
• Youn Myungjune

Classifications

• H04W76/25 Primary

  Maintenance of established connections · CPC title

• H04W80/10

  adapted for {application} session management, e.g. SIP [Session Initiation Protocol] {(connection management H04W76/00; arrangements for session management H04L67/14)} · CPC title

• H04W80/02 Primary

  Data link layer protocols · CPC title

• Y02D30/70

  in wireless communication networks · CPC title

• H04W76/30

  Connection release · CPC title