CELL HANDOVER METHOD AND DEVICE

• US 20160037398A1
• Filed: 10/15/2015
• Published: 02/04/2016
• Est. Priority Date: 04/16/2013
• 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: LI, Mingchao, XIONG, Xin, CAO, Zhenzhen
• Granted Patent: US 9,749,913 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/0069 in case of dual connectivity, e.g. decoupled uplink/downlink
• CPC Class Codes: H04W 36/0072 of resource information of target access point
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Embodiments of the present invention provide a cell handover method and a device. so that the target eNB uses a current serving small node as a user plane serving node after UE is handed over and uses the target eNB as a control plane serving node after the UE is handed over; receiving a handover request acknowledgment sent by the target eNB; and sending offloading configuration information of the current serving small node to the current serving small node, and sending RRC reconfiguration information of the UE to the UE, so that offloading configuration is performed separately by the current serving small node and the UE. This avoids a problem that in a cell handover process, a transmission resource required for transmission increases and a delay is relatively great because the current serving small node forwards a large amount of data to the target eNB.

Claims

1. A cell handover method, comprising:

sending a handover request to a target eNB, wherein the handover request comprises a context of a current serving small node, a context of user equipment UE, and an offloading indication, so that the target eNB uses the current serving small node as a user plane serving node after the UE is handed over, and uses the target eNB as a control plane serving node after the UE is handed over;

receiving a handover request acknowledgment sent by the target eNB, wherein the handover request acknowledgment comprises radio resource control RRC reconfiguration information of the UE and offloading configuration information of the current serving small node, and the handover request acknowledgment is sent after the target eNB determines that the UE can be handed over, that the current serving small node can serve as the user plane serving node after the UE is handed over, and that the target eNB can serve as the control plane serving node after the UE is handed over; and

sending the offloading configuration information of the current serving small node to the current serving small node, and sending the RRC reconfiguration information of the UE to the UE, so that offloading configuration is performed separately by the current serving small node and the UE.

2. The method according to claim 1, before the sending a handover request to a target eNB eNB, comprising:

determining, according to a measurement report of the UE and radio resource management RRM information, one eNB from a pre-obtained small node sharing list as the target eNB to which the UE is to be handed over, wherein the small node sharing list comprises identities IDs of multiple eNBs that share the current serving small node;

or

determining, according to the measurement report of the UE and the RRM information, one eNB as the target eNB to which the UE is to be handed over.

3. The method according to claim 1, wherein the context of the current serving small node comprises:

an identity of the current serving small node.

4. The method according to claim 3, wherein the context of the current serving small node further comprises:

a use frequency and system information that are of the current serving small node, and a security algorithm supported by the current serving small node.

5. A cell handover method, comprising:

receiving a handover request sent by a source eNB eNB, wherein the handover request comprises a context of a current serving small node, a context of user equipment UE, and an offloading indication;

determining, according to the handover request, whether the UE can be handed over, whether the current serving small node can serve as a user plane serving node after the UE is handed over, and whether a target eNB can serve as a control plane serving node after the UE is handed over, and if the UE can be handed over, the current serving small node can serve as the user plane serving node after the UE is handed over, and the target eNB can serve as the control plane serving node after the UE is handed over, generating radio resource control RRC reconfiguration information of the UE and offloading configuration information of the current serving small node; and

sending, to the source eNB, a handover request acknowledgment that carries the RRC reconfiguration information of the UE and the offloading configuration information of the current serving small node, so that the source eNB sends the RRC reconfiguration information of the UE to the UE and sends the offloading configuration information of the current serving small node to the current serving small node.

6. The method according to claim 5, after the sending, to the source eNB, a handover request acknowledgment that carries the RRC reconfiguration information of the UE and the offloading configuration information of the current serving small node, further comprising:

receiving an uplink synchronization message that is sent by the UE after the UE completes offloading configuration according to the RRC reconfiguration information of the UE, and delivering a timing advance TA and an uplink grant to the UE; and

receiving an offloading configuration success message sent by the UE based on the TA and the uplink grant.

7. The method according to claim 6, after the receiving an offloading configuration success message sent by the UE based on the TA and the uplink grant, further comprising:

sending the UE offloading configuration success indication to the current serving small node, so that the current serving small node confirms that the UE completes the offloading configuration.

8. A cell handover method, comprising:

receiving offloading configuration information sent by a source eNB eNB, wherein the offloading configuration information is sent after the source eNB receives a handover request acknowledgment sent by a target eNB to which user equipment UE is to be handed over, and the offloading configuration information comprises configuration information required for establishing a bearer with the target eNB and configuration information required for establishing a user plane connection to the UE;

performing offloading configuration according to the offloading configuration information, buffering user plane data of the UE, and recording a sending status of the user plane data of the UE; and

after confirming that the UE completes the offloading configuration, sending the buffered user plane data of the UE according to configuration information obtained after offloading configuration of a small node and the sending status of the user plane data of the UE.

9. The method according to claim 8, wherein the confirming that the UE completes the offloading configuration comprises:

receiving a UE offloading configuration success indication sent by the target eNB; and

confirming, according to the UE offloading configuration success indication, that the UE completes the offloading configuration.

10. The method according to claim 8, wherein the confirming that the UE completes the offloading configuration comprises:

receiving an uplink synchronization message sent by the UE, and delivering a timing advance TA and an uplink grant to the UE;

receiving an offloading configuration success message sent by the UE based on the TA and the uplink grant; and

confirming, according to the offloading configuration success message, that the UE completes the offloading configuration.

11. The method according to claim 8, wherein the buffered user plane data of the UE comprises buffered uplink user plane data and buffered downlink user plane data;

and

the sending the buffered user plane data of the UE according to configuration information obtained after offloading configuration of a small node and the sending status of the user plane data of the UE comprises;

sending the buffered downlink user plane data to the UE and the buffered uplink user plane data to the target eNB according to the configuration information obtained after the offloading configuration of the small node and the sending status of the user plane data of the UE.

12. An eNB, comprising:

a sending module, configured to send a handover request to a target eNB eNB, wherein the handover request comprises a context of a current serving small node, a context of user equipment UE, and an offloading indication, so that the target eNB uses the current serving small node as a user plane serving node after the UE is handed over, and uses the target eNB as a control plane serving node after the UE is handed over; and

a receiving module, configured to receive a handover request acknowledgment sent by the target eNB, wherein the handover request acknowledgment comprises radio resource control RRC reconfiguration information of the UE and offloading configuration information of the current serving small node, and the handover request acknowledgment is sent after the target eNB determines that the UE can be handed over, that the current serving small node can serve as the user plane serving node after the UE is handed over, and that the target eNB can serve as the control plane serving node after the UE is handed over;

wherein

the sending module is further configured to;

send the offloading configuration information of the current serving small node to the current serving small node, and send the RRC reconfiguration information of the UE to the UE, so that offloading configuration is performed separately by the current serving small node and the UE.

13. The eNB according to claim 12, further comprising:

a determining module, configured to;

determine, according to a measurement report of the UE and radio resource management RRM information, one eNB from a pre-obtained small node sharing list as the target eNB to which the UE is to be handed over, wherein the small node sharing list comprises identities IDs of multiple eNBs that share the current serving small node;

or configured to determine, according to the measurement report of the UE and the RRM information, one eNB as the target eNB to which the UE is to be handed over.

14. The eNB according to claim 12, wherein the context of the current serving small node comprises:

an identity of the current serving small node.

15. An eNB, comprising:

a receiving module, configured to receive a handover request sent by a source eNB eNB, wherein the handover request comprises a context of a current serving small node, a context of user equipment UE, and an offloading indication;

a judging module, configured to;

determine, according to the handover request, whether the UE can be handed over, whether the current serving small node can serve as a user plane serving node after the UE is handed over, and whether a target eNB can serve as a control plane serving node after the UE is handed over, and if the UE can be handed over, the current serving small node can serve as the user plane serving node after the UE is handed over, and the target eNB can serve as the control plane serving node after the UE is handed over, generate radio resource control RRC reconfiguration information of the UE and offloading configuration information of the current serving small node; and

a sending module, configured to send, to the source eNB, a handover request acknowledgment that carries the RRC reconfiguration information of the UE and the offloading configuration information of the current serving small node, so that the source eNB sends the RRC reconfiguration information of the UE to the UE and sends the offloading configuration information of the current serving small node to the current serving small node.

16. The eNB according to claim 15, wherein the receiving module is further configured to receive an uplink synchronization message that is sent by the UE after the UE completes offloading configuration according to the RRC reconfiguration information of the UE;

and the sending module is further configured to deliver a timing advance TA and an uplink grant to the UE; and

the receiving module is further configured to receive an offloading configuration success message sent by the UE based on the TA and the uplink grant.

17. A small node, comprising:

a receiving module, configured to receive offloading configuration information sent by a source eNB eNB, wherein the offloading configuration information is sent after the source eNB receives a handover request acknowledgment sent by a target eNB to which user equipment UE is to be handed over, and the offloading configuration information comprises configuration information required for establishing a bearer with the target eNB and configuration information required for establishing a user plane connection to the UE;

a buffering module, configured to;

perform offloading configuration according to the offloading configuration information, buffer user plane data of the UE, and record a sending status of the user plane data of the UE; and

a sending module, configured to;

after it is confirmed that the UE completes the offloading configuration, send, according to configuration information obtained after offloading configuration of the small node and the sending status of the user plane data of the UE, the user plane data of the UE buffered by the buffering module.

18. The small node according to claim 17, wherein:

the receiving module is further configured to receive a UE offloading configuration success indication sent by the target eNB; and

the small node further comprises;

a first confirming module, configured to confirm, according to the UE offloading configuration success indication, that the UE completes the offloading configuration.

19. The small node according to claim 17, wherein:

the receiving module is further configured to receive an uplink synchronization message sent by the UE, and the sending module is further configured to deliver a timing advance TA and an uplink grant to the UE;

the receiving module is further configured to receive an offloading configuration success message sent by the UE based on the TA and the uplink grant; and

the small node further comprises;

a second confirming module, configured to confirm, according to the offloading configuration success message, that the UE completes the offloading configuration.

20. The small node according to claim 17, wherein the user plane data of the UE buffered by the buffering module comprises buffered uplink user plane data and buffered downlink user plane data;

and

the sending module is specifically configured to;

after it is confirmed that the UE completes the offloading configuration, according to the configuration information obtained after the offloading configuration of the small node and the sending status that is of the user plane data of the UE and is recorded by the buffering module, send, to the UE, the downlink user plane data buffered by the buffering module, and send, to the target eNB, the uplink user plane data buffered by the buffering module.