System and methods for session management

• US 10,849,186 B2
• Filed: 01/04/2018
• Issued: 11/24/2020
• 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): Pham, Chi H
• Assistant Examiner(s): Rivas, Raul
• Application Number:
  US15/862,111
• Publication Number:
  US 20180199240A1
• Time in Patent Office: 1,055 Days
• Field of Search: None
• 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 comprising:

sending, by a radio access network (RAN) node to an access and mobility management function (AMF) over an N2 interface, a path switch request message to inform that a UE has moved to a target cell served by the RAN node, the path switch request message including a list of packet data unit (PDU) sessions to be switched and a list of accepted QoS flows for a PDU session in the list, wherein the accepted QoS flows are QoS flows which are accepted and not rejected by the RAN node;

receiving, by the AMF, the path switch request message;

sending, by the AMF to the RAN node, an acknowledgement associated with the path switch request message; and

receiving, by the RAN node from the AMF, the acknowledgement.

2. The method according to claim 1, further comprising:

prior to sending the path switch request message, receiving, by the RAN node, data from a source RAN node of a user equipment (UE) associated with the PDU sessions in a handover procedure used to handover the UE from the source RAN node of the UE to the RAN node.

3. The method according to claim 1 further comprising:

prior to sending the acknowledgement, sending, by the AMF to a session management function (SMF), the received list of PDU sessions to trigger the SMF to determine whether an existing UP function (UPF) can continue to serve a UE associated with a PDU session in the list; and

after receiving the list of PDU sessions, determining, by the SMF, whether the existing UPF can continue to serve the UE associated with the PDU session in the list.

4. The method according to claim 3, further comprising:

sending, by the SMF, a response acknowledging PDU sessions which have been switched successfully, wherein the acknowledgement associated with the path switch request message is sent from the AMF to the RAN node after the AMF receives the response from the SMF; and

receiving, by the AMF from the SMF, the response.

14. The method of claim 3, wherein if the existing UPF can continue to serve the UE, the method further comprises:

for the PDU sessions to be switched, sending, by the SMF, an N4 session modification request message to the existing UPF; and

returning, by the existing UPF, an N4 session modification response message to the SMF after the PDU sessions are switched.

15. The method of claim 2, wherein after receiving the acknowledgement, the method further comprises:

sending, by the RAN node, a release resources message to the source RAN node of the UE to confirm success of a handover of the UE from the source RAN node of the UE to the RAN node and trigger a release of resource with the source RAN node of the UE.

5. A network system comprising:

a radio access network (RAN) node configured to;

send, to an access and mobility management function (AMF) over an N2 interface, a path switch request message to inform that a UE has moved to a target cell served by the RAN node, the path switch request message including a list of packet data unit (PDU) sessions to be switched and a list of accepted QoS flows for a PDU session in the list, wherein the accepted QoS flows are QoS flows which are accepted and not rejected by the RAN node; and

an access and mobility function (AM F) configured to;

receive the path switch request message and send an acknowledgement associated with the path switch request message to the RAN node;

wherein the RAN node is further configured to receive the acknowledgement from the AMF.

6. The system according to claim 5, wherein the RAN node is further configured to:

before sending the path switch request message, receive data from a source RAN node of a user equipment (UE) associated with the PDU sessions in a handover procedure used to handover the UE from the source RAN node of the UE to the RAN node.

7. The system according to claim 5, further comprising a session management function (SMF), wherein

the AMF is further configured to:

before sending the acknowledgement, send to the SMF the received list of PDU sessions to trigger the SMF to determine whether an existing UP function (UPF) can continue to serve a UE associated with a PDU session in the list; and

the SMF is configured to;

receive the list of PDU sessions, and determine whether the existing UPF can continue to serve the UE associated with the PDU session in the list.

8. The system according to claim 7, wherein

the SMF is further configured to:

send a response acknowledging PDU sessions which have been switched successfully, wherein the acknowledgement associated with the path switch request message is sent from the AMF to the RAN node after the AMF receives the response from the SMF; and

the AMF is configured to;

receive the response from the SMF.

16. The system of claim 7, wherein the SMF is further configured to:

after determining that the existing UPF can continue to serve the UE;

for the PDU sessions to be switched, send an N4 session modification request message to the existing UPF; and

receive, from the existing UPF, an N4 session modification response message after the PDU sessions are switched.

17. The system of claim 16, wherein the system further comprises the UPF which is configured to:

receive the N4 session modification request message from the SMF and return the N4 session modification response to the SMF.

18. The system of claim 6, wherein the RAN node is further configured to:

after receiving the acknowledgement, send a release resources message to the source RAN node of the UE to confirm success of a handover of the UE from the source RAN node of the UE to the RAN node and trigger a release of resource with the source RAN node of the UE.

9. An apparatus comprising a processor coupled with a memory, the processor being configured to execute steps of:

sending, to an access and mobility management function (AMF) over an N2 interface, a path switch request message to inform that a UE has moved to a target cell served by the apparatus, the path switch request message including a list of packet data unit (PDU) sessions to be switched and a list of accepted QoS flows, wherein the accepted QoS flows are QoS flows which are accepted and not rejected by the RAN node; and

receiving, from the AMF, an acknowledgement associated with the path switch request message.

10. The apparatus according to claim 9, the processor being further configured to execute steps of:

before sending the path switch request message, receiving data from a source RAN node of a user equipment (UE) associated with the PDU sessions in a handover procedure used to handover the UE from the source RAN node of the UE to the RAN node.

19. The apparatus according to claim 10, the processor being further configured to execute steps of:

sending a release resources message to the source RAN node of the UE to confirm success of a handover of the UE from the source RAN node of the UE to the RAN node and trigger a release of resource with the source RAN node of the UE.

11. An apparatus comprising a processor coupled with a memory, the processor being configured to execute steps of:

receiving, from a radio access network (RAN) node over an N2 interface, a path switch request message to inform that a user equipment (UE) has moved to a target cell served by the RAN node, the path switch request message including a list of packet data unit (PDU) sessions to be switched and a list of accepted QoS flows for a PDU session in the list, wherein the accepted QoS flows are QoS flows which are accepted and not rejected by the RAN node; and

sending, to the RAN node, an acknowledgement associated with the path switch request message.

12. The apparatus according to claim 11, the processor being further configured to execute steps of:

before sending the acknowledgement, sending, to a session management function (SMF), the received list of PDU sessions to trigger the SMF to determine whether an existing UP function (UPF) can continue to serve a UE associated with a PDU session in the list.

13. The apparatus according to claim 12, the processor being further configured to execute steps of:

receiving, from the SMF, a response acknowledging PDU sessions which have been switched successfully, wherein the acknowledgement associated with the path switch request message is sent to the RAN node after the apparatus receives the response from the SMF.