Methods and apparatus for link handover

Patent metadata

Field	Value
Publication number	US-12082064-B2
Application number	US-201917280870-A
Country	US
Kind code	B2
Filing date	Sep 27, 2019
Priority date	Sep 28, 2018
Publication date	Sep 3, 2024
Grant date	Sep 3, 2024

Abstract

A link handover method, a network entity, and a terminal are provided. The method includes: sending a first link handover instruction to a second network entity, and maintaining a first data transmission link with a terminal; receiving a link handover response fed back by the second network entity according to the first link handover instruction; sending a second link handover instruction to the terminal according to the link handover response; wherein the second link handover instruction carries radio resource control (RRC) reconfiguration information for establishing a second data transmission link between the terminal and the second network entity.

First claim

What is claimed is:

1. A link handover method applied to a first network entity, comprising steps of:
sending a first link handover instruction to a second network entity, and maintaining a first data transmission link with a terminal;
receiving a link handover response fed back by the second network entity according to the first link handover instruction;
sending a second link handover instruction to the terminal according to the link handover response; wherein the second link handover instruction carries radio resource control (RRC) reconfiguration information for establishing a second data transmission link between the terminal and the second network entity;
wherein when the first network entity and the second network entity are both primary network entities, the first link handover instruction carries 0 ms handover indication information for notifying a network; the link handover response carries 0 ms handover indication information for notifying the terminal and a first radio resource configuration parameter generated after the second network entity performs radio resource configuration for the terminal; the RRC reconfiguration information includes the 0 ms handover indication information for notifying the terminal and the first radio resource configuration parameter.

2. The method according to claim 1 , further comprising:
receiving a link release instruction sent by the second network entity after the second data transmission link is established;
releasing the first data transmission link and radio resource configuration on the first network entity side according to the link release instruction.

3. The method according to claim 2 , wherein when the first network entity and the second network entity are both primary network entities each including a distribution unit and a centralized unit, the step of receiving a link release instruction sent by the second network entity after the second data transmission link has been established includes:
receiving, by a centralized unit of the first network entity, the link release instruction sent by a centralized unit of the second network entity after the second data transmission link has been established.

4. The method according to claim 2 , wherein when the first network entity and the second network entity are both secondary network entities, the step of receiving the link release instruction sent by the second network entity after the second data transmission link has been established comprises:
receiving the link release instruction sent by the primary network entity corresponding to the first network entity after the second data transmission link has been established.

5. The method according to claim 2 , wherein before or after the step of receiving the link release indication sent by the second network entity after the second data transmission link has been established, the method further comprises:
sending a packet data convergence protocol serial number (SN) state report to the second network entity,
wherein the SN state report includes information about data that is not successfully sent to the terminal.

6. The method according to claim 5 , wherein when the first network entity and the second network entity are both primary network entities each including a distribution unit and a centralized unit, the step of sending an SN state report to the second network entity comprises:
when data transmission between a distribution unit of the first network entity and the terminal stops, sending, by the distribution unit of the first network entity, uplink data transmission state information to a centralized unit of the first network entity;
sending, by the centralized unit of the first network entity, the SN state report to a centralized unit of the second network entity according to the uplink data transmission state information.

7. The method according to claim 5 , wherein when the first network entity and the second network entity are secondary network entities, the step of sending an SN state report to the second network entity comprises:
when data transmission between the first network entity and the terminal is stopped, sending, by the first network entity, the SN state report to the primary network entity corresponding to the first network entity, and forwarding, by the primary entity corresponding to the first network entity, the SN state report to the second network entity.

8. The method according to claim 1 , wherein the link handover response further includes a first data relay address; after the step of receiving the link handover response fed back by the second network entity according to the first link handover instruction, the method further includes:
sending part of data that needs to be sent to the terminal to the second network entity through the first data relay address.

9. The method according to claim 1 , wherein when the first network entity and the second network entity are both primary network entities each including a distribution unit and a centralized unit, the step of sending a first link handover instruction to the second network entity comprises:
sending, by a centralized unit of the first network entity, the first link handover instruction to a centralized unit of the second network entity, and the first link handover instruction carries 0 ms handover instruction information for notifying a network.

10. The method according to claim 9 , wherein the step of receiving a link handover response fed back by the second network entity according to the first link handover instruction comprises:
receiving, by the centralized unit of the first network entity, the link handover response fed back by the centralized unit of the second network entity according to the first link handover instruction, wherein the link handover response carries the 0 ms handover indication information for notifying the terminal and a second radio resource configuration parameter;
wherein the second radio resource configuration parameter is generated after the distribution unit of the second network entity receives a first user context modification message sent by the centralized unit of the second network entity and configures a radio resource for the terminal, after the distribution unit of the second network entity generates the second radio resource configuration parameter, the distribution unit of the second network entity forwards the second radio resource configuration parameter to the centralized unit of the second network entity, and the first user context modification message carries the 0 ms handover indication information for notifying the network.

11. The method according to claim 10 , wherein the step of sending a second link handover instruction to the terminal according to the link handover response comprises:
sending, by the centralized unit of the first network entity, a second user equipment context modification message to the distribution unit of the first network entity, wherein the second user equipment context modification message carries the second radio resource configuration parameter and the 0 ms handover instruction information for notifying the terminal;
sending, by the distribution unit of the first network entity, a second link handover instruction to the terminal, wherein RRC reconfiguration information carried in the second link handover instruction includes the second radio resource configuration parameter and the 0 ms handover instruction information for notifying the terminal;
wherein the link handover response also carries a second data relay address, and after receiving, by the centralized unit of the first network entity, the link handover response fed back by the centralized unit of the second netwo

Assignees

• Datang mobile communications equipment co ltd

Inventors

• Zhang Dajun

Classifications

• H04W36/142

  over the same radio air interface technology · CPC title

• H04W36/00698

  using different RATs · CPC title

• H04W36/087

  between radio units of access points · CPC title

• H04W12/04

  Key management, e.g. using generic bootstrapping architecture [GBA] · CPC title

• H04W36/18

  for allowing seamless reselection, e.g. soft reselection · CPC title