HANDOVER METHOD, SYSTEM, AND DEVICE

• US 20140348131A1
• Filed: 07/15/2014
• Published: 11/27/2014
• Est. Priority Date: 06/25/2012
• Status: Active Grant

• Current Assignee: Huawei Device Company Limited (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Device Company Limited (Huawei Investment & Holding Co., Ltd.)
• Inventors: JIN, Hui, YI, Qiang, DUAN, Xiaoyan, GAO, Chenliang
• Granted Patent: US 9,516,569 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0061 of neighbour cell information
• CPC Class Codes: H04W 36/00835 Determination of neighbour cell lists
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Embodiments of the present invention provide a handover method performed by a source access network device, which includes: sending, a handover request or a WLAN offload request to a UE, so that the UE determines information about a target AP according to AP information corresponding to a target RAN and information about a currently accessed AP, and sends a WLAN offload binding request carrying the information about the target AP to a target access network device in the target RAN, so as to complete a RAN handover, where the handover request or the WLAN offload request includes the AP information corresponding to the target RAN, and the AP information corresponding to the target RAN is information about an AP in a WLAN that covers, together with the target RAN, a location of the UE; and receiving a handover response or a WLAN offload response returned by the UE.

Claims

1. A handover method, comprising:

sending, by a source access network device, a handover request or a wireless local area network (WLAN) offload request to a user equipment (UE), so that the UE determines information about a target access point (AP) according to AP information corresponding to a target radio access network (RAN) and information about a currently accessed AP, and sends a WLAN offload binding request carrying the information about the target AP to a target access network device in the target RAN, so as to complete a RAN handover, wherein the handover request or the WLAN offload request comprises the AP information corresponding to the target RAN, and the AP information corresponding to the target RAN is information about an AP in a WLAN that covers, together with the target RAN, a location of the UE; and

receiving, by the source access network device, a handover response or a WLAN offload response returned by the UE.

2. The handover method according to claim 1, before the sending, by a source access network device, a handover request or a wireless local area network WLAN offload request to a user equipment UE, comprising:

sending, by the source access network device, a first WLAN information request to the target access network device; and

receiving, by the source access network device, a first WLAN information response returned by the target access network device, wherein the first WLAN information response comprises the AP information corresponding to the target RAN;

or

sending, by the source access network device, a second WLAN information request to a server, wherein the second WLAN information request comprises an identifier of the target access network device; and

receiving, by the source access network device, a second WLAN information response returned by the server, wherein the second WLAN information response comprises the AP information corresponding to the target RAN, which is acquired by the server by querying according to the identifier of the target access network device.

3. The handover method according to claim 2, wherein the first WLAN information request comprises AP information corresponding to a source RAN and/or instruction information requesting the AP information corresponding to the target RAN, and the source RAN is a RAN to which the source access network device belongs.

4. The handover method according to claim 2, before the sending, by a source access network device, a handover request or a wireless local area network WLAN offload request to a user equipment UE, comprising:

deciding, by the source access network device, to initiate a RAN handover process.

5. A handover method, comprising:

receiving, by a user equipment (UE), a handover request or a wireless local area network (WLAN) offload request sent by a source access network device, wherein the handover request or the WLAN offload request comprises access point (AP) information corresponding to a target radio access network (RAN), the target RAN is a RAN to which a target access network device belongs, and the AP information corresponding to the target RAN is information about an AP in a WLAN that covers, together with the target RAN, a location of the UE;

determining, by the UE, information about a target AP according to the AP information corresponding to the target RAN and information about an AP currently accessed by the UE;

sending, by the UE, a handover response or a WLAN offload response to the source access network device; and

sending, by the UE, a WLAN offload binding request to the target access network device, so as to complete a RAN handover, wherein the WLAN offload binding request comprises the information about the target AP.

6. The handover method according to claim 5, wherein the determining, by the UE, information about a target AP according to the AP information corresponding to the target RAN and information about an AP currently accessed by the UE comprises:

if the AP information corresponding to the target RAN comprises the information about the AP currently accessed by the UE, and a signal strength of the AP currently accessed by the UE is greater than or equal to a preset signal threshold, retaining, by the UE, a connection with the AP currently accessed by the UE, and determining that the information about the AP currently accessed by the UE is the information about the target AP; and

if the AP information corresponding to the target RAN does not comprise the information about the AP currently accessed by the UE, or the AP information corresponding to the target RAN comprises the information about the AP currently accessed by the UE but the signal strength of the AP currently accessed by the UE is smaller than the preset signal threshold, disconnecting, by the UE, from the AP currently accessed by the UE, and selecting, from the AP information corresponding to the target RAN, information about an AP not currently accessed by the UE as the information about the target AP.

7. The handover method according to claim 6, wherein the selecting, by the UE from the AP information corresponding to the target RAN, information about an AP not currently accessed by the UE as the information about the target AP comprises:

performing, by the UE, WLAN scanning, so as to acquire signal strengths of APs that correspond to AP information in the AP information corresponding to the target RAN; and

selecting, by the UE from the AP information corresponding to the target RAN, information about an AP that has a greatest signal strength and that is not currently accessed by the UE as the information about the target AP.

8. The handover method according to claim 6, further comprising:

if the information about the target AP is the information that is selected by the UE from the AP information corresponding to the target RAN and is the information about an AP not currently accessed by the UE, executing, by the UE, according to the information about the target AP when being handed over to the target access network device, a process of accessing the target AP.

9. The handover method according to claim 5, further comprising:

receiving, by the UE, a WLAN offload policy command sent by the target access network device, wherein the WLAN offload policy command comprises a WLAN offload policy;

sending, by the UE, a WLAN offload policy acknowledgement to the target access network device; and

sending, by the UE, service data to the target AP and/or receiving service data sent by the target AP according to the WLAN offload policy.

10. An access network device, comprising:

a first transmitter, configured to send a handover request or a wireless local area network (WLAN) offload request to a user equipment (UE), so that the UE determines information about a target access point (AP) according to AP information corresponding to a target radio access network (RAN) and information about a currently accessed AP, and sends a WLAN offload binding request carrying the information about the target AP to a target access network device in the target RAN, so as to complete a RAN handover, wherein the handover request or the WLAN offload request comprises the AP information corresponding to the target RAN, and the AP information corresponding to the target RAN is information about an AP in a WLAN that covers, together with the target RAN, a location of the UE; and

a first receiver, configured to, after the first transmitter sends the handover request or the WLAN offload request, receive a handover response or a WLAN offload response returned by the UE.

11. The access network device according to claim 10, wherein the first transmitter is further configured to sent a first WLAN information request to the target access network device before sending the handover request or the WLAN offload request;

and

the first receiver is further configured to, after the first transmitter sends the first WLAN information request, receive a first WLAN information response returned by the target access network device, wherein the first WLAN information response comprises the AP information corresponding to the target RAN;

or

the first transmitter is further configured to send a second WLAN information request to a server before sending the handover request or the WLAN offload request, wherein the second WLAN information request comprises an identifier of the target access network device; and

the first receiver is further configured to, after the first transmitter sends the second WLAN information request, receive a second WLAN information response returned by the server, wherein the second WLAN information response comprises the AP information corresponding to the target RAN, which is acquired by the server by querying according to the identifier of the target access network device.

12. The access network device according to claim 11, wherein the first WLAN information request comprises AP information corresponding to a source RAN and/or instruction information requesting the AP information corresponding to the target RAN, and the source RAN is a RAN to which the access network device belongs.

13. The access network device according to claim 11, further comprising:

a deciding module, configured to decide to initiate a RAN handover process before the first transmitter sends the handover request or the WLAN offload request.

14. A user equipment (UE), comprising:

a second receiver, configured to receive a handover request or a wireless local area network (WLAN) offload request sent by a source access network device, wherein the handover request or the WLAN offload request comprises access point (AP) information corresponding to a target radio access network (RAN), the target RAN is a RAN to which a target access network device belongs, and the AP information corresponding to the target RAN is information about an AP in a WLAN that covers, together with the target RAN, a location of the UE;

a processor, configured to receive the handover request or the WLAN offload request from the second receiver, and determine information about a target AP according to the AP information corresponding to the target RAN in the handover request or the WLAN offload request and information about an AP currently accessed by the UE; and

a second transmitter, configured to, after the second receiver receives the handover request or the WLAN offload request, send a handover response or a WLAN offload response to the source access network device, and after the processor determines the information about the target AP, send a WLAN offload binding request to the target access network device, so as to complete a RAN handover, wherein the WLAN offload binding request comprises the information about the target AP.

15. The UE according to claim 14, wherein the processor is specifically configured to:

if the AP information corresponding to the target RAN comprises the information about the AP currently accessed by the UE, and a signal strength of the AP currently accessed by the UE is greater than or equal to a preset signal threshold, retain a connection between the UE and the AP currently accessed by the UE, and determine that the information about the AP currently accessed by the UE is the information about the target AP; and

if the AP information corresponding to the target RAN does not comprise the information about the AP currently accessed by the UE, or the AP information corresponding to the target RAN comprises the information about the AP currently accessed by the UE but the signal strength of the AP currently accessed by the UE is smaller than the preset signal threshold, disconnect the connection between the UE and the AP currently accessed by the UE, and select, from the AP information corresponding to the target RAN, information about an AP not currently accessed by the UE as the information about the target AP.

16. The UE according to claim 15, wherein the processor is more specifically configured to perform WLAN scanning, so as to acquire signal strengths of APs that correspond to AP information in the AP information corresponding to the target RAN;

and select, from the AP information corresponding to the target RAN, information about an AP that has a greatest signal strength and is not currently accessed by the UE as the information about the target AP.

17. The UE according to claim 15, wherein the processor is further configured to, when the information about the target AP is the information that is selected by the processor from the AP information corresponding to the target RAN and is the information about an AP not currently accessed by the UE, execute, according to the information about the AP when being handed over to the target access network device, a process of accessing the target AP.

18. The UE according to claim 14, wherein the second receiver is further configured to receive a WLAN offload policy command sent by the target access network device, and receive, according to a WLAN offload policy, service data sent by the target AP, wherein the WLAN offload policy command comprises the WLAN offload policy;

and

the second transmitter is further configured to, after the second receiver receives the WLAN offload policy command, send a WLAN offload policy acknowledgement to the target access network device, and send, according to the WLAN offload policy, service data to the target AP.