System and methods for session management

• US 10,462,840 B2
• Filed: 01/04/2018
• Issued: 10/29/2019
• Est. Priority Date: 01/09/2017
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Dao, Ngoc Dung, Zhang, Hang, Li, Xu
• Primary Examiner(s): Anwar, Mohammad S
• Application Number:
  US15/862,287
• Publication Number:
  US 20180199398A1
• Time in Patent Office: 663 Days
• CPC Class Codes: H04L 41/0806 for initial configuration or provisioning, e.g. plug-and-play
• CPC Class Codes: H04L 41/0894 Policy-based network configuration management
• CPC Class Codes: H04L 41/0895 Configuration of virtualised networks or elements, e.g. virtualised network function or OpenFlow elements
• CPC Class Codes: H04L 41/342 between virtual entities, e.g. orchestrators, SDN or NFV entities
• CPC Class Codes: H04L 41/40 using virtualisation of network functions or resources, e.g. SDN or NFV entities
• CPC Class Codes: H04L 41/5019 Ensuring fulfilment of SLA
• CPC Class Codes: H04L 41/5041 characterised by the time relationship between creation and deployment of a service
• CPC Class Codes: H04L 65/1069 Session establishment or de-establishment
• CPC Class Codes: H04L 65/1089 by adding media; by removing media
• CPC Class Codes: H04L 65/80 Responding to QoS
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066
• CPC Class Codes: H04L 67/142 Managing session states for stateless protocols; Signalling session states; State transitions; Keeping-state mechanisms
• CPC Class Codes: H04L 67/143 Termination or inactivation of sessions, e.g. event-controlled end of session
• CPC Class Codes: H04L 67/148 Migration or transfer of sessions
• CPC Class Codes: H04L 69/327 in the session layer [OSI layer 5]
• CPC Class Codes: H04W 12/08 Access security
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/24 Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 36/0011 for data sessions of end-to-end connection
• CPC Class Codes: H04W 36/0016 Hand-off preparation specially adapted for end-to-end data sessions
• CPC Class Codes: H04W 36/0022 : for transferring data sessions between adjacent core network technologies
• CPC Class Codes: H04W 36/0033 : with transfer of context information
• CPC Class Codes: H04W 36/14 : Reselecting a network or an air interface
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 76/27 : Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 76/30 : Connection release
• CPC Class Codes: H04W 76/34 : Selective release of ongoing connections
• CPC Class Codes: H04W 80/10 : adapted for application session management, e.g. SIP [Session Initiation Protocol] connection management H04W76/00; arrangements for session management H04L67/14
• CPC Class Codes: H04W 88/14 : Backbone network devices

Abstract

A network architecture and methods of managing packet data unit (PDU) sessions in a network are provided. The methods include PDU session establishment procedures, PDU session modification procedures, PDU session state transfer procedures, PDU session release procedures, and user equipment (UE) handover procedures.

Claims

1. A method of managing a mobile network, the method comprising:

obtaining, by a session management function (SMF), a trigger to release a packet data unit (PDU) session;

sending, by the SMF, a session release request to a user plane function (UPF), the session release request including an identifier of the PDU session to be released and requesting the UPF to drop all remaining packets of the PDU session and release contexts associated with the PDU session;

receiving, by the UPF from the SMF, the session release request;

dropping, by the UPF, all remaining packets of the PDU session and releasing said contexts associated with the PDU session; and

sending to the SMF by the UPF a response indicating an acknowledgement of the session release request.

2. The method as claimed in claim 1, wherein when the PDU session is associated with multiple UPFs, the SMF sends the session release request to the multiple UPFs, and each of the multiple UPFs returns a different respective response associated with the session release request.

3. The method according to claim 1, wherein the UPF releases all tunnel resource associated with the PDU session when releasing the contexts associated with the PDU session.

4. The method as claimed in claim 3, the session release request further requesting the UPF to release all tunnel resource associated with the PDU session.

5. The method as claimed in claim 1, wherein the method further comprises:

determining, by the SMF, to release the PDU session;

if a user equipment (UE) associated with the PDU session is unreachable, notifying, by the SMF, an access and mobility management function (AMF) that the PDU session is released; and

removing, by the SMF, a context associated with the PDU session.

6. The method as claimed in claim 5, wherein the SMF notifies the AMF that the PDU session is released by invoking an operation including an identifier of the PDU session.

7. The method as claimed in claim 5, wherein a communication associated with a release of a resource between the AMF and the UE is skipped before the SMF removes the context.

8. The method as claimed in claim 1, further comprising:

sending, by the SMF to an access and mobility management function (AMF), a request including a N1 session management (SM) message to release the PDU session and an indication indicating the AMF not to transfer the N1 SM message; and

receiving, by the AMF from the SMF, the request and sending, by the AMF to the SMF, a response indicating that the N1 SM message is not transferred to the UE.

9. The method as claimed in claim 8, wherein the method further comprises:

sending, by the AMF, the response indicating that the N1 SM message is not transferred to the UE, when a user equipment (UE) associated with the PDU session is in a connection management idle (CM-IDLE) state.

10. The method as claimed in claim 8, wherein the N1 SM message includes a PDU session release command.

11. A communication system comprising a session management function (SMF) and a user plane function (UPF), wherein:

the SMF is configured to;

obtain a trigger to release a packet data unit (PDU) session;

send a session release request to the UPF, the session release request including an identifier of the PDU session to be released and requesting the UPF to drop all remaining packets of the PDU session and release contexts associated with the PDU session; and

the UPF is configured to;

receive from the SMF the session release request;

drop all remaining packets of the PDU session and release contexts associated with the PDU session; and

send to the SMF a response indicating an acknowledgement of the session release request.

12. The communication system as claimed in claim 11, wherein the communication system comprises multiple UPFs, and wherein when the PDU session is associated with multiple UPFs, the SMF is configured to send the session release request to the multiple UPFs, and each of the multiple UPFs is configured to return a different respective response associated with the session release request.

13. The communication system according to claim 11, wherein the UPF is further configured to release all tunnel resource associated with the PDU session.

14. The communication system as claimed in claim 13, the session release request further requesting the UPF to release all tunnel resource associated with the PDU session, and wherein the UPF is configured to release all tunnel resource as requested.

15. The communication system as claimed in claim 11, wherein the SMF is further configured to:

determine to release the PDU session;

if a user equipment (UE) associated with the PDU session is unreachable, notify an access and mobility management function (AM F) that the PDU session is released; and

remove a context associated with the PDU session.

16. The communication system as claimed in claim 15, wherein the SMF is further configured to notify the AMF that the PDU session is released by invoking an operation including an identifier of the PDU session.

17. The communication system as claimed in claim 15, wherein a communication associated with a release of a resource between the AMF and the UE is skipped before the SMF removes the context.

18. The communication system as claimed in claim 11, wherein:

the SMF is further configured to send, to an access and mobility management function (AMF), a request including a N1 session management (SM) message to release the PDU session and an indication indicating the AMF not to transfer the N1 SM message; and

the communication system further comprises the AMF, the AMF configured to receive the request from the SMF and send to the SMF a response indicating that the N1 SM message is not transferred to the UE.

19. The communication system as claimed in claim 18, wherein the AMF is further configured to send the response indicating that the N1 SM message is not transferred to the UE, when a user equipment (UE) associated with the PDU session is in a connection management idle (CM-IDLE) state.

20. The communication system as claimed in claim 18, wherein the N1 SM message includes a PDU session release command.