Network-instructed handover from WLAN to another radio access network

Patent metadata

Field	Value
Publication number	US-9756533-B2
Application number	US-201414246841-A
Country	US
Kind code	B2
Filing date	Apr 7, 2014
Priority date	Apr 13, 2013
Publication date	Sep 5, 2017
Grant date	Sep 5, 2017

Abstract

Systems and methods are disclosed for providing a network-instructed handover of a wireless device from a Wireless Local Area Network (WLAN) to a Radio Access Network (RAN) of another Radio Access Technology (RAT), e.g., a 3 rd Generation Partnership Project (3GPP) or 3 rd Generation Partnership Project 2 (3GPP2) RAT. In one embodiment, a WLAN access node determines that a handover of a wireless device from the WLAN to another RAN of a different RAT is to be performed and transmits a handover instruction to the wireless device that instructs the wireless device to perform a handover from the WLAN to a RAN of a different RAT. In this manner, the WLAN access node is able to steer the wireless device from the WLAN to a RAN of a different RAT.

First claim

What is claimed is:

1. A method of operation of a Wireless Local Access Network, WLAN, access node, comprising:
deciding that a handover of a wireless device from a WLAN to another radio access network of a different radio access technology is to be performed; and
transmitting a handover instruction to the wireless device that instructs the wireless device to perform a handover from the WLAN to a radio access network of a different radio access technology, wherein the different radio access technology is a 3rd Generation Partnership Project, 3GPP, radio access technology, wherein the handover instruction comprises information that indicates whether the handover is a full handover of all communication sessions or a selective handover of one or more but less than all communication sessions, and wherein the WLAN can perform both full handovers and selective handovers.

2. The method of claim 1 wherein the handover is a selective handover.

3. The method of claim 1 wherein the handover is a full handover.

4. The method of claim 1 wherein the handover instruction is a general instruction to perform a handover to a radio access network of a different radio access technology.

5. The method of claim 1 wherein the handover instruction comprises information that identifies the different radio access technology for the handover.

6. The method of claim 1 wherein the handover instruction comprises information that identifies a target cell in the radio access network of the different radio access technology.

7. The method of claim 6 wherein the handover instruction further comprises information that identifies the different radio access technology and the radio access network of the different radio access technology.

8. The method of claim 6 wherein the handover instruction further comprises assistance information that assists the wireless device when performing the handover.

9. The method of claim 8 wherein the assistance information comprises at least some system information of the target cell.

10. The method of claim 1 wherein the handover instruction comprises one or more parameters that enable the wireless device to connect to the radio access network of the 3GPP radio access technology.

11. The method of claim 1 wherein the handover instruction comprises a retry timer value that defines an amount of time that the wireless device should attempt to access the radio access network of the different radio access technology when performing the handover.

12. The method of claim 1 wherein the WLAN is an IEEE 802.11 wireless network.

13. The method of claim 12 wherein the different radio access technology is a cellular network radio access technology.

14. The method of claim 13 wherein the 3GPP cellular network radio access technology is a 3 rd Generation Partnership Project 2, 3GPP2, radio access technology.

15. The method of claim 14 wherein transmitting the handover instruction to the wireless device comprises transmitting, to the wireless device, a management frame selected from a group consisting of:
a Deauthentication Management frame comprising a reason code that corresponds to the handover instruction; and
a Disassociation Management frame comprising a reason code that corresponds to the handover instruction.

16. The method of claim 15 wherein transmitting the management frame further comprises transmitting information regarding the handover instruction in one or more vendor-specific elements within the management frame.

17. The method of claim 16 wherein the information regarding the handover instruction comprises at least one of a group consisting of:
a target set of networks for the handover;
a target radio access technology for the handover;
a target cell;
assistance information that assists the wireless device when performing the handover;
a 3GPP handover command; and
a Non-Access Stratum, NAS, parameter.

18. The method of claim 16 wherein the information regarding the handover instruction comprises a retry timer value that defines an amount of time that the wireless device should attempt to access the radio access network of the 3GPP or 3GPP2 radio access technology when performing the handover.

19. The method of claim 14 wherein transmitting the handover instruction to the wireless device comprises transmitting, to the wireless device, an Association Response Management frame comprising the handover instruction.

20. The method of claim 14 wherein transmitting the handover instruction to the wireless device comprises transmitting, to the wireless device, a Basic Service Set, BSS, Transition Management frame with zero neighbor report elements.

21. The method of claim 20 wherein transmitting the BSS Transition Management frame further comprises transmitting information regarding the handover instruction in one or more vendor-specific elements within the BSS Transition Management frame.

22. The method of claim 21 wherein the information regarding the handover instruction comprises at least one of a group consisting of:
a target set of networks for the handover;
a target radio access technology for the handover;
a target cell;
assistance information that assists the wireless device when performing the handover;
a 3GPP handover command; and
a Non-Access Stratum, NAS, parameter.

23. The method of claim 21 wherein the information regarding the handover instruction comprises a retry timer value that defines an amount of time that the wireless device should attempt to access the radio access network of the 3GPP or 3GPP2 radio access technology when performing the handover.

24. The method of claim 14 wherein transmitting the handover instruction to the wireless device comprises transmitting, to the wireless device, a Wireless Network Management Notification, WNM-Notification, Request frame comprising the handover instruction within one or more optional subelements formatted as one or more vendor-specific elements.

25. The method of claim 24 wherein the handover instruction comprises at least one of a group consisting of:
information indicative of the 3GPP or 3GPP2 radio access technology for the handover;
a cell identifier of a target cell in the radio access network of the 3GPP or 3GPP2 radio access technology to which the wireless device is to be handed over; and
one or more attachment parameters that indicate which communication sessions of the wireless device are to be handed over.

26. The method of claim 14 wherein transmitting the handover instruction to the wireless device comprises transmitting, to the wireless device, a Wireless Network Management Notification, WNM-Notification, Request frame comprising the handover instruction.

27. The method of claim 1 wherein:
deciding that a handover of the wireless device from the WLAN to another radio access network of a different radio access technology is to be performed comprises:
deciding to initiate a handover to the 3 rd Generation Partnership Project, 3GPP, radio access technology;
sending a handover preparation request to a radio access node in a radio access network of the 3GPP radio access technology; and
receiving a handover preparation response from the radio access node comprising a 3GPP handover command; and

transmitting the handover instruction comprises transmitting the 3GPP handover command to the wireless device.

28. The method of claim 27 where

Assignees

• Ericsson Telefon Ab L M

Inventors

• Mestanov Filip
• Hedberg Tomas
• Rayment Stephen
• Roeland Dinand
• Stattin Magnus
• Vikberg Jari

Classifications

• H04W36/0061

  of neighbour cell information · CPC title

• H04W36/38

  by fixed network equipment · CPC title

• H04W36/0066 Primary

  of control information between different types of networks in order to establish a new radio link in the target network · CPC title

• H04W36/14

  Reselecting a network or an air interface · CPC title

• H04W36/0022

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