Network handover method and related device

Patent metadata

Field	Value
Publication number	US-10911990-B2
Application number	US-201916503890-A
Country	US
Kind code	B2
Filing date	Jul 5, 2019
Priority date	Jan 6, 2017
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

A network handover method and a related device, where the method includes: when receiving a user terminal handover request that is sent by a source radio access network node and that carries a target base station identifier, determining, by a source mobility management function entity based on the target base station identifier, to trigger an inter-Radio Access Technology (RAT) network handover; sending a first message to a source session management function entity; receiving a second message sent by the source session management function entity, where the second message includes a session management context; and sending a relocation request to a target mobility management function entity, where the relocation request is used to instruct the target mobility management function entity to perform inter-RAT network handover on the user terminal.

First claim

What is claimed is:

1. A network handover method, comprising:
receiving, by a source mobility management function entity in a source system from a source radio access network node in the source system, a user terminal handover required message that carries a target base station identifier in a target system;
determining, by the source mobility management function entity based on the target base station identifier, to trigger a handover of a user terminal from the source system to the target system;
sending, by the source mobility management function entity, a first message for requesting a session management context to a source session management function entity in the source system;
receiving, by the source mobility management function entity, a second message from the source session management function entity, wherein the second message comprises a session management context of the user terminal in the target system; and
sending, by the source mobility management function entity, a relocation request to a target mobility management function entity in the target system, wherein the relocation request is used to instruct to perform the handover on the user terminal, wherein the relocation request carries the target base station identifier, the session management context of the user terminal in the target system, and a mobility management context of the user terminal in the target system, wherein the source system is a 5 th generation (5G) network, and wherein the target system is a 4 th generation (4G) network.

2. The network handover method according to claim 1 , wherein the first message comprises a 5G-to-4G network handover indication, and the 5G-to-4G network handover indication is for determining that an operation is a 5G-to-4G network handover.

3. The network handover method according to claim 1 , wherein before sending, by the source mobility management function entity, the relocation request to the target mobility management function entity, the method further comprises:
obtaining, by the source mobility management function entity, a mobility management context of the user terminal in the source system; and
mapping, by the source mobility management function entity, the mobility management context of the user terminal in the source system to the mobility management context of the user terminal in the target system.

4. A network handover device, comprising:
a memory; and
a processor coupled to the memory and configured to execute instructions stored on the memory such that when executed by the processor, cause the network handover device to:
receive, from a source radio access network node in a source system, a user terminal handover required message that carries a target base station identifier in a target system;
determine, based on the target base station identifier, to trigger a handover of a user terminal from the source system to the target system;
send a first message for requesting a session management context to a source session management function entity in the source system;
receive a second message from the source session management function entity, wherein the second message comprises a session management context of the user terminal in the target system; and
send a relocation request to a target mobility management function entity in the target system, wherein the relocation request is used to instruct to perform the handover on the user terminal,

wherein the relocation request carries the target base station identifier, the session management context of the user terminal in the target system, and a mobility management context of the user terminal in the target system, wherein the source system is a 5 th generation (5G) network, and wherein the target system is a 4 th generation (4G) network.

5. The network handover device according to claim 4 , wherein the first message comprises a 5G-to-4G network handover indication, and the 5G-to-4G network handover indication is for determining that an operation is a 5G-to-4G network handover.

6. The network handover device according to claim 4 , wherein before sending the relocation request to the target mobility management function entity, the network handover device is configured to:
obtain a mobility management context of the user terminal in the source system; and
map the mobility management context of the user terminal in the source system to the mobility management context of the user terminal in the target system.

7. A method, comprising:
receiving, by a source mobility management function entity in a source system from a source radio access network node in the source system, a user terminal handover required message that carries a target base station identifier in a target system;
determining, by the source mobility management function entity based on the target base station identifier, to trigger a handover of a user terminal from the source system to the target system;
sending, by the source mobility management function entity, a first message for requesting a session management context to a source session management function entity in the source system;
sending, by the source session management function entity, a second message to the source mobility management function entity, wherein the second message comprises a session management context of the user terminal in the target system; and
sending, by the source mobility management function entity, a relocation request to a target mobility management function entity in the target system, wherein the relocation request is used to instruct to perform the handover on the user terminal, wherein the relocation request carries the target base station identifier, the session management context of the user terminal in the target system, and a mobility management context of the user terminal in the target system, wherein the source system is a 5 th generation (5G) network, and wherein the target system is a 4 th generation (4G) network.

8. The method according to claim 7 , wherein the first message comprises a 5G-to-4G network handover indication.

9. The method according to claim 8 , further comprising determining, by the source session management function entity, that the handover is a 5G-to-4G network handover based on the 5G-to-4G network handover indication.

10. The method according to claim 9 , further comprising:
obtaining, by the source session management function entity, a session management context of the user terminal in the source system; and
mapping, by the source session management function entity, the session management context of the user terminal in the source system to the session management context of the user terminal in the target system.

11. The method according to claim 10 , further comprising:
obtaining, by the source mobility management function entity, a mobility management context of the user terminal in the source system; and
mapping, by the source mobility management function entity, the mobility management context of the user terminal in the source system to the mobility management context of the user terminal in the target system.

12. A system, comprising:
a source mobility management function entity in a source system, wherein the source mobility management function entity is configured to:
receive, from a source radio access network node in the source system, a user terminal handover required message that carries a target base station identifier in a target system;
determine based on the target base station identifier to trigger a handover of a user terminal from the source system to the target system; and
send a first message for requesting a session management context; and
a source session man

Assignees

• Huawei Tech Co Ltd

Inventors

• Ying Jiangwei
• Yang Yanmei
• Huang Zhenglei

Classifications

• H04W36/144 Primary

  over a different radio air interface technology · CPC title

• H04W36/0011

  for data sessions of end-to-end connection · CPC title

• H04W36/00222

  between different packet switched [PS] network technologies, e.g. transferring data sessions between LTE and WLAN or LTE and 5G · CPC title

• H04W36/10

  Reselecting an access point controller · CPC title

• H04W36/0022 Primary

  for transferring data sessions between adjacent core network technologies · CPC title