WO2009089777A1

WO2009089777A1 - Method, apparatus for updating location area during network switch

Info

Publication number: WO2009089777A1
Application number: PCT/CN2009/070052
Authority: WO
Inventors: Zhili Zeng
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2008-01-14
Filing date: 2009-01-07
Publication date: 2009-07-23
Also published as: CN101489216B; CN101489216A

Abstract

A method and an apparatus for updating location area during network switch include the following features : UE receives a location area list sent by the source network area, and the list includes at least one location area of the destination network corresponding to the source network area; after UE switches to the destination network, it will be registered to the real location area in the destination network; if the real location area is in the list, the location area to which UE is registered will be maintained. The present invention can avoid unnecessary location update in the existing scheme, and also save system signaling expense.

Description

Method and device for updating location area in network switching

This application claims priority to Chinese Patent Application No. 200810000704.3, entitled "Network Switching Location Area Update Method and Apparatus," filed on January 14, 2008, the entire contents of which are incorporated by reference. In this application.

Technical field

The present invention relates to the field of mobile communication technologies, and in particular, to a location area updating method and apparatus for network switching.

Background technique

Due to the huge network data of IP Multimedia System (IMS), it is very difficult to construct, and the IMS standard is not perfect. Therefore, the 3rd Generation Partner Project (3GPP) System architecture evolution (System

Architecture Evolution, SAE) The goal of using IMS's Circuit Service (CS) domain is still a matter of time. Therefore, IMS Long Term Evolution (LTE) applications are still not used. Or use the LTE application solution that does not use IMS as a transition.

Among the many LTE transition schemes that do not use IMS, there is a LTE fallback to CS (LTE).

The Fallback to CS scheme is currently concerned with the standard. The scheme has the following characteristics: 1 LTE is only responsible for high-speed data access, does not support Voice over IP (VoIP), and returns voice services from LTE. CS domain; 2 User Equipment (UE) preferentially resides in the LTE access network, and the UE completes the Global System for Mobile communication (GSM)/Universal Mobile Phone (Yueliang) through the LTE access network ( Universal Mobile Telephone Service (UMTS) location update of the network; 3 When the UE is camped on the LTE access network, if there is a GSM/UMTS voice call, the Evolved Mobile Switching Center (eMSC) will page ( The PAGE message is sent to the LTE access network, and the paging message is sent to the UE through the LTE access network. 4 After receiving the voice paging from the LTE access network, the UE searches and transfers to the GSM/UMTS network. Then return a paging response (PAGE Response) from the GSM/UMTS network to the LTE access network, and complete voice service access in the GSM/UMTS network. .

Referring to FIG. 1 , it is a schematic diagram of an LTE Fallback to CS solution, where Net2 mainly completes PS service access and is an LTE access network. When there is voice service demand, the UE will switch to Netl. It is a voice service access, and Netl is a network such as GSM/UMTS. During the UE camping on Net2, if Net2 receives the voice paging message of Net1, Net2 will send the paging message to the UE through the base station (Base Station, BS); after receiving the paging message, the UE will search and switch. Go to Netl and return the paging response from Netl and complete the voice service access. After the voice service ends, return to Net2.

The LTE Fallback to CS scheme requires that when the UE camps on the LTE access network, it must be able to correctly perform location registration and location update on the GSM/UMTS core network so that the paging process can be completed correctly when there is voice paging.

In order to complete the above-mentioned cross-network location registration and location update, the existing solution is to configure a location area (LA) information of a GSM/UMTS network on the cell of the LTE access network, and access the network through the LTE access network. The system control information message of the cell is broadcasted so that the UE can detect the change of the LA, complete the location registration and update.

However, since the LTE access network and the GSM/UMTS network belong to two different networks, the tracking area (Tracing Area, TA) under the LTE access network is caused by different frequencies and the like.

The LA of the GSM/UMTS network is difficult—correspondingly, in fact, TA and LA may be overlapping and spanning.

Referring to Figure 2, the location area between the two networks (Netl and Net2) (the location area of Netl is named LA, and the location area of Net2 is named TA). The boundaries are interlaced. In Figure 2:

Netl and Net2 represent two networks, for example, Netl is a UMTS network, and Net2 is an LTE access network;

Netl-LAll, Netl-LAI 2 and Netl-LA21 (square in the figure) represent three location areas under Netl, Net2-TA11 (circular in the figure) represents the location area under Net2, visible, Net2 location area Net2-TA11 Crossed Netl's three location areas Netl-LAll, Netl-LAI 2 and Netl-LA21;

Net2-CELL1, Net2-CELL2 ~ Net2-CELL6 represent the cell coverage of Net2, and the coverage of each cell of Netl is omitted in the figure;

Net2-CELL1 [Netl-LAll] indicates that the Netl location area Netl-LAl 1 is configured on the Net2-CELL1 cell of Net2; Net2-CELL2[] ~ Net2-CELL6[] is similar;

As can be seen from Figure 2, the coverage of the Net2-CELL6 cell spans Netl-LAll and Netl-LA12 of Netl's two location areas, but according to the current LTE Fallback to CS scheme, only one location of Netl-LA12 is configured on the Net2-CELL6 base station. District information. At this time, UEs within the coverage of the Net2-CELL6 cell may actually be in Netl-LAll or may be in Netl-LA12.

Referring to FIG. 3, it is a schematic diagram of the UE in the coverage of the Net2-CELL6 cell in FIG. 2 switching to Netl.

As described above, the UE preferentially resides in the LTE access network Net2. When the UE is located in the Net2-CELL6 coverage area, it will receive the location information Netl-LA12 of the Net1 configured on the Net2-CELL6 base station, so that the UE will The location registration is performed by Net2-CELL6 access to the Netl core network B to which the location area Netl-LA12 belongs.

Thereafter, if Netl has a voice page to the UE, the incoming call will terminate at Netl Core Network B, and the Netl Core Network B initiates paging to the UE. However, at this time, the UE may be located in the coverage area of Netl-LAI 1. Considering the foregoing situation, after the UE switches to the network Netl, it finds that its current location area is Netl-LAll instead of the originally registered Netl. -LAI 2 , so the UE will initiate a location update process to update the location to Netl-LAll, and then complete the access processing of the call through the cooperation of the core network.

However, after the voice call processing is completed, the UE needs to preferentially camp on Net2. After the UE re-switches to Net2, it is found that the cross-network location area information of the Net2-CELL6 broadcast of the Net2 cell is

Netl-LA12, then the UE will have to perform a Netl location area re-update through Net2 access, so that the location area is updated to Netl-LA12.

Obviously, the location area update from Netl-LAll update to Netl-LA12 performed by the above UE after returning to Net2 is redundant, because both Netl-LAll and Netl-LA12 are Net2-CELL6. There is no need to update at all. However, in the current solution, the UE cannot know that Net2-CELL6 corresponds to both Netl-LAll and Netl-LA12, which is the reason for the above unnecessary update. Such redundant updates may cause problems such as wasted signaling resources and even service access delays.

Summary of the invention

In view of this, the embodiments of the present invention provide a method and a device for updating a location area in a network handover, so as to solve the problem of waste of signaling resources and impact on service access caused by unnecessary location area update in the existing solution.

To this end, the following technical solutions are used in the embodiments of the present invention: A method for updating a location area in a network handover, comprising: receiving, by a UE, a location area list sent by a source network cell, where the location area list includes at least one location area of a target network corresponding to the source network cell; and switching to a target network in the UE Thereafter, the UE is registered to a location area of the target network that is actually located; when the location area registered by the UE belongs to the location area list, the location area registered by the UE is maintained.

A location update UE in a network handover, comprising: a list receiving unit, configured to receive a location area list sent by a source network cell, where the location area list includes at least one location area of a target network corresponding to the cell; a unit, configured to register, after the UE switches to the target network, the UE to the location area where the UE is actually located; the location area update control unit, where the location area for registration in the location area registration unit belongs to the location When the area list is selected, the registered location area is kept unchanged.

A network switching location update device, the device is located in a source network, and includes: a location area list configuration unit, configured to configure a location area list for the source network cell, where the location area list includes at least one target network corresponding to the cell a location area; a list sending unit, configured to send the location area list to a UE camping on the cell.

A computer readable storage medium comprising computer program code, the computer program code being executed by a computer unit, such that the computer unit: initiates a user equipment to receive a list of location areas sent by a source network cell, the location area list including the source At least one location area of the target network corresponding to the network cell; after the user equipment switches to the target network, registering the user equipment to a location area of the target network actually located; the location area registered by the user equipment belongs to the location When the zone list is maintained, the location area registered by the user equipment is maintained.

It can be seen that as long as the location area registered by the UE in the target network belongs to the location area list, when the UE returns to the LTE access network, the second location area update is not needed, thereby avoiding unnecessary in the existing solution. The location area is updated, which saves system signaling overhead and does not affect the normal processing of other services of the UE.

DRAWINGS

1 is a schematic diagram of a prior art LTE Fallback to CS solution;

2 is a schematic diagram of overlapping two network location areas in the prior art;

3 is a schematic diagram of UE handover in the Net2-CELL6 in FIG. 2;

4 is a flowchart of Embodiment 1 of a method for updating a location area in a network handover according to the present invention; FIG. 5 is a schematic diagram of Embodiment 1 of a method for updating a location area in a network handover according to the present invention; FIG.

6 is a flowchart of Embodiment 2 of a method for updating a location area in a network handover according to the present invention;

7 is a schematic diagram of Embodiment 2 of a method for updating a location area in a network handover according to the present invention;

8 is a schematic structural diagram of a UE according to the present invention;

FIG. 9 is a schematic structural diagram of a source network BS according to the present invention.

detailed description

The embodiment of the present invention is derived from the LTE access network to the GSM/UMTS network, but is not limited to the handover mode, for example, the CDMA 2000 IX access network can be switched to the CDMA 2000 lx-EV DO access. Network, or, from GSM/UMTS network to LTE access network, etc.

The method for updating a location area in network switching according to an embodiment of the present invention includes the following steps:

1. The UE receives a location area list sent by the source network cell, where the location area list includes at least one location area of the target network corresponding to the source network cell.

2. After the UE switches to the target network, register the UE to a location area of the target network that is actually located;

3. When the location area registered by the UE belongs to the location area list, the location area registered by the UE is maintained.

In order to describe the embodiment of the present invention in more detail, the following uses the LTE access network as the source network and the GSM/UMTS network as the target network as an example.

First, the first embodiment of the method of the present invention will be described.

For a cell whose coverage area spans multiple location areas of another network, when configuring the inter-network location area, it will configure a list of all the inter-network location areas it spans instead of configuring only one of the location areas. . The configured list of inter-network location areas is also broadcast in system broadcast messages.

Still taking Figure 2 as an example, the coverage area of Net2-CELL5 spans Netl-LAl l and Netl-LA21, so the inter-network location area on Net2-CELL5 will be configured as LA-List5: ( Netl-LAl l , Netl- a list of LA21) and broadcast it;

Similarly, the coverage area of Net2-CELL6 spans Netl-LAl l and Netl-LA12, so the inter-network location area on Net2-CELL6 will be configured as LA-List6: (Netl-LAl l , Netl-LA12) The list is broadcast and broadcast.

Location update processing under the cross-network location area list configuration:

1. When the UE camps on LTE, if the UE does not perform location registration in the CS network, a location area is selected from the list of inter-network location areas of the currently received LTE cell broadcast as the initial registration location area for location registration. The above selection rules may be selected by priority or randomly;

2. When the UE camps on the LTE, if the location area LA currently registered by the UE is one of the currently received LTE cell broadcast inter-network location area lists, the location update of the CS domain is not performed;

3. When the UE camps on the LTE, if the location area LA currently registered by the UE is not one of the currently received LTE cell-area cross-network location area lists, the inter-network location area list from the currently received LTE cell broadcast A location area is selected as the registration location area for location registration. The above selection rules may be selected by priority or randomly.

Referring to FIG. 4, a flowchart of Embodiment 1 includes:

Step 401: The BS of the LTE access network as the source network configures the LA list LA[] of the cell where the UE is located, where the LA[] includes multiple LAs of the target cell GSM/UMTS network corresponding to the cell;

For how the LTE access network knows which LAs of the GSM/UMTS network the UE is located, it can be implemented in the network planning phase or through the interaction between the networks.

Step 402: The LTE access network sends the configured LA list to the UE by using a broadcast message. Step 403: The UE selects an LA from the LA list randomly or according to the priority as the initial registration LA, and records it as LA-initial;

Step 404: The UE switches from the LTE access network to an LA in the GSM/UMTS network, denoted as LA-real; the UE completes the required service in the GSM/UMTS network;

Step 405: The UE determines whether LA-real is LA-initial, and if so, does not perform LA update processing, and then performs step 407; otherwise, step 406 is performed;

Step 406: The UE updates the location area to LA-real;

Step 407: The UE re-switches back to the LTE access network.

Step 408: The UE determines whether the currently registered LA-real belongs to LA[]. If it belongs, it does not need to perform location area update, and ends the process; otherwise, step 409 is performed;

Step 409: The UE selects one LA from LA[] randomly or according to priority to register. It can be seen that although the UE handover to the LA in the GSM/UMTS network is not the initially registered LA, the location area update is also performed on the GSM/UMTS network, but as long as the re-registered LA belongs to LA[], the UE is back again. When the LTE accesses the network, the second location area update is not required, thereby avoiding unnecessary location area update in the existing solution, saving signaling overhead, and not affecting normal processing of other services of the UE.

The following is still explained by way of example. Referring to FIG. 5, the UE in FIG. 2 is switched to Netl in the coverage range of the Net2-CELL6 cell.

The coverage area of Net2-CELL6 spans Netl-LAI 1 and Netl -LAI 2, so

A cross-network location area list (Netl-LAl l, Netl -LAI 2) is configured on Net2-CELL6 and broadcast.

The UE preferentially resides on Net2 after booting. The UE receives the list of inter-network location areas of the Net2 broadcast.

[Netl-LAl 1 , Netl -LAI 2] , and select Netl-LA12 to register with Netl.

When Netl has a voice paging to the UE, the paging will be routed to the Netl core network B, and the Netl core network B initiates paging through the Net2 access network.

After the UE switches to Netl, it finds that its actual location is Netl-LAl l, and then initiates a location update process and accesses the service. At this time, the UE registers to the location area Netl-LAl 1.

After the voice service ends, the UE switches to Net2 for priority camping. At this time, the UE finds that its registered location area Netl-LAl 1 belongs to the cross-network location area list [Netl-LAl 1 , Netl-LA12] of the Net2-CELL6 broadcast, so there is no need to perform location area registration of the CS domain.

The second embodiment of the method of the present invention is described below.

As described above, it is necessary to configure a location area list of the target network on the cell of the source network. However, the source network and the target network are two independent networks after all. If the list of inter-network location areas configured on the cell of the source network is incomplete, such as missing a corresponding location area of the target network, then when the UE is actually in the missing area, When the area is overwritten, frequent location updates will still occur during network switching.

Referring to FIG. 6, FIG. 6 is a flowchart of the second embodiment, where the steps 601 to 608 are similar to the steps 401 to 408 of FIG. 4, and the difference is that the steps 609 to 611 include:

Step 601: The BS of the LTE access network that is the source network configures the LA list of the cell where the UE is located, where the location area list includes multiple LAs of the target cell GSM/UMTS network corresponding to the cell; Step 602: The LTE access network sends the configured LA list to the UE by using a broadcast message, and the LA list is recorded as LA[];

Step 603: The UE selects an LA from the LA list randomly or according to the priority as the initial registration LA, which is LA-initial;

Step 604: The UE switches from the LTE access network to an LA in the GSM/UMTS network, which is denoted as LA-real;

Step 605: The UE determines whether LA-real is LA-initial, and if so, does not perform LA update processing, otherwise, step 606 is performed;

Step 606: The UE updates the location area to LA-real;

Step 607: The UE re-switches back to the LTE access network.

Step 608: The UE determines whether the currently registered LA-real belongs to LA[]. If it belongs, it does not need to perform location area update. Otherwise, step 609 is performed;

Step 609: The UE sends an inter-network location area missing report to the LTE access network, and requests the BS of the LTE access network to add LA-real to the LA[].

Step 610: After receiving the missed report of the inter-network location area, the LTE access network may automatically update the corresponding LA[], or configure the maintenance personnel to assist in improving the inter-network location area configuration of the network;

Step 611: The UE may directly select an LA registration from the original unupdated LA[], or after the LTE access network updates 1^[] (ie, LA[] has added LA-real), the UE does not need to Update LA.

It can be seen that after the UE is switched back to the source network from the target network, the configuration of the inter-network location area list is assisted or automatically improved by detecting and reporting the missing inter-network location area configuration.

Still illustrated by an example. Referring to FIG. 7, when the UE switches back from Net1 to Net2 (the UE preferentially camps on Net2), if the UE finds that its reserved Netl location registration is not included in the received inter-network location area list of the Net2 broadcast, the UE generates A cross-network location area legacy report is sent to the BS of Net2 to assist in the configuration modification of the BS's cross-network location area list.

Specific steps are as follows:

1. After the UE terminates the service in Netl (such as GSM and other CS domain networks), it needs to preferentially camp on Net2 (such as LTE), so it switches from Netl to Net2. During the handover, the value of the location registration area stored in the Net1 is unchanged, and the value of the location registration area is recorded as LA-Reg. 2. The UE search detects Net2; if the UE is switched from Net1 to Net2, the UE compares whether the currently saved LA-Reg is in the list of received inter-network location areas of the Net2 broadcast; if not, generates an inter-network location The missing area is reported to the BS of Net2 to assist in the configuration modification of the inter-network location area.

3. The UE registers with Net2 and completes the necessary Netl location update via Net2.

In the above step 2, the UE may report to the BS of Net2 through a new message, such as an "cross-network location area missing report" message (including the legacy LA-Reg in the message); or by extending other messages, through the newly established The "cross-network location area missing report field" (including the legacy LA-Reg in the field) is reported to the BS of Net2. In the second step, the BS of the Net2 can automatically update to the inter-network location area configuration of the corresponding cell after receiving the legacy LA-Reg included in the "cross-network location area omission report", or maintain the background report maintenance by configuring the background report. Personnel, to assist in the improvement of the network's cross-network location area configuration.

Corresponding to the foregoing method, the embodiment of the present invention further provides a UE for location update in network handover. Referring to FIG. 8, the UE includes a list receiving unit 801, a location area registration unit 802, and a location area update control unit 803. The list receiving unit 801 is configured to receive a location area list that is sent by the source network cell, where the location area list includes multiple location areas of the target network corresponding to the cell, and the location area registration unit 802 is configured to switch to the UE. After the target network, the UE is registered to the location area where the location is actually located; the location area update control unit 803 is configured to maintain the registration when the location area registered by the location area registration unit 802 belongs to the location area list The location area is unchanged.

Preferably, the UE further includes a missing notification sending unit 804, configured to: when the location area update control unit 803 determines that the registered location area does not belong to the location area list, to the source The network cell sends a cross-network location area missing report, and requests the registered location area to be added to the location area list.

Preferably, the location area update control unit 803 controls the location area registration unit 802 to register the UE in the list when the location area registered by the location area registration unit 802 does not belong to the location area list. a location area.

Preferably, the UE further includes an initial registration location area configuration unit 805 and a location area registration control unit 806, wherein the initial registration location area configuration unit 805 is configured to select one location area from the location area list as an initial of the UE The location area registration control unit 806 is configured to determine whether the initial registration location area is the same as the actual location area of the UE. If not, the location area registration unit 802 is activated to register the UE to the actual location. The location area. In addition, the embodiment of the present invention further provides a location update device in a network handover, that is, a BS located in a source network, or a functional entity of a BS, or a functional entity independent of a BS. Referring to FIG. 9, the apparatus includes a location area list configuration unit 901 and a list sending unit 902, where the location area list configuration unit 901 is configured to configure a location area list for a source network cell, where the location area list includes a target corresponding to the cell. A plurality of location areas of the network; the list sending unit 902 is configured to send the location area list to the UE residing in the cell.

Preferably, the apparatus further includes a missing report receiving unit 903 and a list update list, wherein the missing report receiving unit 903 is configured to receive an inter-network location area missing report sent by the UE, where the inter-network location area missing report includes the UE The currently registered location area; the list update unit 904 is configured to add a location area currently registered by the UE in the report to the list.

The source network includes, but is not limited to, various LTE access networks, and the target network includes but is not limited to a CS domain network, such as a GSM network or a UMTS network. The basic functional units of the UE and the BS provided by the embodiments of the present invention are the same as the basic functional units of the UE and the BS in the prior art, and are not described or limited herein.

For some implementation details of the UE and the BS provided by the embodiment of the present invention, refer to the method embodiment, and details are not described herein again.

A person skilled in the art can understand that all or part of the steps carried by the method of the foregoing embodiment can be completed by a program to instruct related hardware, and the program can be stored in a computer readable storage medium. , including the following steps:

(1) The UE receives a location area list sent by the source network cell, where the location area list includes at least one location area of the target network corresponding to the source network cell;

(2) after the UE switches to the target network, registering the UE to a location area of the target network actually located;

(3) When the location area registered by the UE belongs to the location area list, the location area registered by the UE is maintained.

The above is only a preferred embodiment of the present invention, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present invention. It should be considered as the scope of protection of the present invention.

Claims

Rights request

A method for updating a location area in a network handover, comprising:

Receiving, by the user equipment, a location area list sent by the source network cell, where the location area list includes at least one location area of the target network corresponding to the source network cell;

After the user equipment switches to the target network, registering the user equipment to a location area of the target network actually located;

When the location area registered by the user equipment belongs to the location area list, the location area registered by the user equipment is maintained.

The method according to claim 1, wherein when the location area registered by the user equipment does not belong to the location area list, the method further includes:

Sending an inter-network location area omission to the source network cell, requesting the source network cell to add a location area registered by the user equipment in the location area list.

3. The method of claim 2, wherein

Before transmitting the cross-network location area missing report to the source cell, registering the user equipment to the location area included in the location area list;

Or,

After the source network cell feeds back to the user equipment that the location area of the user equipment registration has been added, the location area where the user equipment is registered is maintained.

The user device is registered to the location area included in the location area list.

The method according to claim 1, 2, 3 or 4, wherein after the user equipment switches to the target network, it is determined whether the actual location area of the user equipment and the preset initial registration location area are Similarly, if different, the step of registering the user equipment to a location area of the target network actually located is performed.

6. The method according to claim 5, wherein the manner of presetting the initial registration location area is:

Randomly selecting a location area from the location area list as an initial registration location area; or According to the priority of each location area in the location area list, the location area with the highest priority is selected as the initial registration location area.

7. A user equipment for location update in network switching, which is characterized in that:

a list receiving unit, configured to receive a location area list sent by the source network cell, where the location area list includes at least one location area of the target network corresponding to the cell;

a location area registration unit, configured to register the user equipment to a location area where the user equipment is located after the user equipment switches to the target network;

The location area update control unit is configured to keep the registered location area unchanged when the location area registered by the location area registration unit belongs to the location area list.

8. The user equipment according to claim 7, further comprising:

And a missing report sending unit, configured to: when the location area update control unit determines that the registered location area does not belong to the location area list, send an inter-network location area missing report to the source network cell, requesting the location area The registered location area is added to the list.

The user equipment according to claim 8, wherein the location area update control unit controls the location area registration unit when the location area registered by the location area registration unit does not belong to the location area list The user device is registered to a location area in the list.

10. The user equipment according to claim 7, 8 or 9, further comprising: an initial registration location area configuration unit, configured to select a location area from the location area list as an initial registration of the user equipment Location area

a location area registration control unit, configured to determine whether the initial registration location area is the same as the actual location area of the user equipment, and if not, initiate the location area registration unit to register the user equipment to the actual Location area.

A location switching device for network switching, the device is located in a source network, and is characterized by:

a location area list configuration unit, configured to configure a location area list for the source network cell, where the location area list includes at least one location area of the target network corresponding to the cell;

And a list sending unit, configured to send the location area list to a user equipment residing in the cell.

12. The device according to claim 11, further comprising: And a missing report receiving unit, configured to receive a cross-network location area missing report sent by the user equipment, where the cross-network location area missing report includes a location area currently registered by the user equipment;

And a list updating unit, configured to add a location area currently registered by the user equipment in the report to the list.

The device according to claim 11 or 12, wherein the device is a base station device or a functional entity located inside the base station device or a functional entity independent of the base station device.

A computer readable storage medium, comprising computer program code, the computer program code being executed by a computer unit such that the computer unit:

Initiating the user equipment to receive a location area list sent by the source network cell, where the location area list includes at least one location area of the target network corresponding to the source network cell;