CN101521871B

CN101521871B - Method, device and system for updating tracking area

Info

Publication number: CN101521871B
Application number: CN2008101009173A
Authority: CN
Inventors: 习建德; 熊春山; 沈宇希; 徐晖; 梁华瑞; 姜怡华
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2008-02-26
Filing date: 2008-02-26
Publication date: 2010-10-27
Anticipated expiration: 2028-02-26
Also published as: CN101521871A

Abstract

The invention provides a method, a device and a system that are used for updating tracking areas; a base station eNodeB updates a TAU requesting message according to the tracking area sent by user equThe invention provides a method, a device and a system that are used for updating tracking areas; a base station eNodeB updates a TAU requesting message according to the tracking area sent by user equipment (UE), and transfers the TAU requesting message to the new MME when judging that a new mobile management entity (MME) needs to be selected for the UE; the new MME obtains context information inipment (UE), and transfers the TAU requesting message to the new MME when judging that a new mobile management entity (MME) needs to be selected for the UE; the new MME obtains context information inthe original MME according to the TAU requesting information and judges whether the UE moves to the new position charging management area; if so, a TAU process for establishing PDN connection with PDNthe original MME according to the TAU requesting information and judges whether the UE moves to the new position charging management area; if so, a TAU process for establishing PDN connection with PDN GW which selects current service network for the UE is executed; if not, the TAU process which does not need to carry out PDN GW optimization selection is executed. The method, the device and the sysGW which selects current service network for the UE is executed; if not, the TAU process which does not need to carry out PDN GW optimization selection is executed. The method, the device and the system can change the PDN GW which visits the PDN which establishes the connection and can realize the optimization of PDN connection.tem can change the PDN GW which visits the PDN which establishes the connection and can realize the optimization of PDN connection.

Description

A kind of methods, devices and systems of tracing section updating

Technical field

The present invention relates to mobile communication technology, particularly relate to a kind of methods, devices and systems that can optimize the tracing section updating (TAU) of packet data network (PDN, Packet Data Network) connection.

Background technology

In present 3GPP EPS (the 3rd Generation Partnership Project Evolved Packet System) system, allow subscriber equipment (UE, grouped data network gateway (PDN GW by visit ground when User Equipment) roaming into the visited network in cross-location accounting management zone, PDN Gateway) be linked into PDN and obtain service, this situation is called local break-out (Local breakout).

When UE enters the signatory PDN of " adhering to " state or desire and another one and connects in the visited network in cross-location accounting management zone, system will be according to the user contracting data of user's subscribed services device (HSS) preservation in the PDN GW choice mechanism, allow the user to set up being connected under the local breakout situation with the PDN that contracts by the PDN GW that visited network distributes, this PDN connects and comprises a default bearing, in addition, can also comprise one or more dedicated bearers.After this, according to existing tracing section updating TAU method, as long as UE does not shut down, be in Evolved Packet System connectivity management idle condition (EPS Connectivity Management-Idle, ECM-IDLE) after UE moves to a new visited network or gets back to home network from current visited network, keep being connected by PDN GW that in former visited network, uses and the PDN network that inserts at former visited network with continuing.This is because existing tracing section updating TAU method can not discharge UE and signatory PDN at the former visited network shared bearing resource that connects in the TAU process, thereby can't discharge PDN GW resource with the employed former visited network that should signatory PDN connects, when this will mean that UE is in new visited network or home network, will utilize the PDN GW of former visited network to insert described signatory PDN.This will produce following problem: when (1) user changes Evolved Packet System connectivity management connection status (ECM-CONNECTED) over to and carries out business, because of the inconsistent user of generation in the accounting management zone, position of the on-site position of the UE accounting management zone and the Internet resources that use irrational problem of chargeing.(2) resource of former visited network can not effectively discharge and cause the local user of visited network to insert difficulty; (3) same business can be by new visited network or home network services but is needed to cause the huge waste of backbone network resource between the operator around obtaining service to former visited network.

For example Beijing contracted user UE roams into Xi'an, PDN GW by Shaanxi behind the start-up logging of Xi'an has set up with a signatory PDN and has been connected, when after this under the situation of not shutting down, getting back to Beijing, UE will utilize Shaanxi PDN GW to insert this signatory PDN, this will cause the problem of but being used the Internet resources in Shaanxi by Beijing charging, and, the Internet resources in Shaanxi influence local user's access network under it owing to can not discharging, simultaneously also make Pekinese's Internet resources can not get effective utilization, that is to say the optimization utilization that is unfavorable for the whole system Internet resources.

This shows, existing tracing section updating method can not change and is used to visit the employed PDN GW of the PDN that has connected, this will cause the position of UE stride message area when changing system can't connect this PDN and be optimized, the problems such as unreasonable that are unfavorable for the optimization utilization of grid resource and cause that customer service after this charges.

Summary of the invention

In view of this, main purpose of the present invention is to provide a kind of tracing section updating method, and this method can change the employed PDN GW of PDN that visit has connected, realizes the optimization that PDN is connected.

In order to achieve the above object, the technical scheme of the present invention's proposition is:

A kind of method of tracing section updating, this method may further comprise the steps:

A, base station (eNodeB) when judgement need be selected new MME for UE, are transmitted to new MME with the TAU request message according to the tracing section updating TAU request message that user equipment (UE) sends;

B, new MME obtain contextual information according to the TAU request message from former MME, judge that whether UE has moved to new accounting management zone, position, if then change step c over to, otherwise changes steps d over to;

C, new MME send PDN GW to former MME and optimize indication, and carry the TAU refuse information of adhering to indication again according to described contextual information to the UE transmission; Former MME optimizes indication according to PDN GW and starts implicit expression attachment removal process; UE starts attaching process again according to adhering to the new MME of indication triggering again, connects for UE selects the PDN GW of current service network to set up PDN, and the TAU process finishes;

D, new MME trigger gateway starting update load bearing process, send TAU to UE and accept message.

Aforesaid method further comprises between described step b and the step c:

New MME changes PDN GW indication according to the permission in the described contextual information, judges whether UE allows to change PDN GW, if allow, then changes step c over to, otherwise, change steps d over to.

Aforesaid method further comprises between described step b and the step c:

New MME judges according to the indication of the local break-out in the described contextual information whether UE has used the PDN GW in the former visited network to set up the PDN connection, if, then change step c over to, otherwise, change steps d over to;

The indication of described local break-out is that UE is at visited network but not home network adheres to or when setting up PDN and connecting, be provided with and be stored in the contextual information by the MME in the visited network.

Aforesaid method, the TAU refuse information comprises default bearing sign deletion indication among the described step c, and UE is according to default bearing sign deletion indication deletion and the relevant contextual information of former default bearing sign.

The embodiment of the invention also provides a kind of system that realizes tracing section updating, can change the employed PDN GW of PDN that visit has connected, realizes the optimization that PDN is connected.

In order to achieve the above object, the technical scheme of embodiment of the invention proposition is:

A kind of system that realizes tracing section updating, this system comprises:

UE is used for sending the TAU request message to eNodeB; Reception is accepted message from TAU refuse information and the TAU of eNodeB; Initiate initial attaching process according to adhering to indication again to new MME;

ENodeB is used to receive the TAU request message of UE, and in the time need selecting new MME for UE, the TAU request message is transmitted to the new MME that selects; The TAU refuse information and the TAU that receive MME accept message and are transmitted to UE;

New MME is used for judging according to the TAU request message whether UE has moved to new accounting management zone, position, if then carry out the optimized choice of PDN GW, sends PDN GW to former MME and optimizes indication, sends to UE and carries the TAU refuse information of adhering to indication again; Be used at attaching process again, connect for UE selects PDN GW in the current service network to set up PDN; Be used for sending the establishment bearing request message to gateway;

Former MME is used for optimizing indication according to PDN GW and starts implicit expression attachment removal process;

Gateway is used for establishment bearing request message starting update load bearing process or establishment load bearing process according to MME.

Aforesaid system, described new MME is further used for obtaining from the contextual information of former MME and allows to change PDN GW indication, and judge according to allow changing PDN GW indication whether UE allows to change PDN GW, if not, then do not carry out the optimized choice of PDN GW.

Aforesaid system, described new MME is further used for obtaining the local break-out indication from the contextual information of former MME, and judge according to local break-out indication whether UE has used the PDN GW in the former visited network to set up the PDN connection, if not, then do not carry out the optimized choice of PDN GW.

Aforesaid system, described new MME are further used for sending default bearing sign deletion indication to UE, and described default bearing sign deletion indication is contained in the TAU refuse information; Described UE is further used for according to default bearing sign deletion indication deletion and the relevant contextual information of former default bearing sign.

The embodiment of the invention also proposes a kind of device that is used for tracing section updating, and its technical scheme is:

A kind of device that is used for tracing section updating, this device comprises:

Transmit-Receive Unit is used to receive the TAU request message of UE and be sent to judging unit; Receive the Attach Request message of UE and be sent to adhesion unit; The PDN connection request information and sending that receives UE is to PDN connection management unit; PDN GW is optimized indication be sent to the MME that UE moves preceding position, and will carry the TAU refuse information of adhering to indication again and be sent to UE; To create bearing request message and be sent to gateway, and TAU be accepted message be sent to UE;

Judging unit is used for judging according to the TAU request message of Transmit-Receive Unit whether UE has moved to new accounting management zone, position, if, then send PDN GW optimize indication and carry adhere to indication again the TAU refuse information to Transmit-Receive Unit; Otherwise, send TAU and accept message and create bearing request message to Transmit-Receive Unit;

Adhesion unit is used for the Attach Request message according to UE, realizes that the network of UE initially adheres to, and is included as the PDN connection that UE sets up acquiescence;

PDN connection management unit is used for the PDN connection request message according to UE, connects for UE sets up PDN.

Aforesaid device, described judging unit comprises:

Cross-location accounting management region decision unit is used for judging according to the TAU request message whether UE has moved to new accounting management zone, position; If not, then do not carry out the optimized choice of PDN GW.

Aforesaid device, this device further comprises:

The contextual information unit is used to deposit the contextual information of UE;

Described Transmit-Receive Unit is further used for receiving the contextual information that MME that UE moves preceding position sends, and the permission that will wherein comprise changes PDN GW indication and local break-out and indicates and be sent to judging unit;

Described judging unit further comprises:

Allow to change PDN GW judging unit, be used for judging according to allowing to change PDN GW indication whether UE allows to change PDN GW,, then do not carry out the optimized choice of PDN GW if do not allow;

The local break-out judging unit is used for judging according to local break-out indication whether UE has used the PDN GW in the former visited network to set up the PDN connection, if not, then do not carry out the optimized choice of PDN GW;

Described adhesion unit is further used for when the PDN GW that uses visited network to distribute sets up the PDN connection, local break-out is set indicates and deposit in the contextual information unit;

Described PDN connection management unit is further used for when the PDN GW that uses visited network to distribute sets up the PDN connection, local break-out is set indicates and deposit in the contextual information unit.

Aforesaid device, described judging unit contain default bearing sign deletion indication in the TAU refuse information that Transmit-Receive Unit sends;

Described Transmit-Receive Unit is further used for sending default bearing sign deletion indication to UE.

A kind of device that is used for tracing section updating, this device moves the Mobility Management Entity at preceding place for UE, and this device comprises:

The contextual information unit is used to store contextual information;

Transmit-Receive Unit is used for obtaining contextual information from described contextual information unit, and is sent to the MME of UE current location; Be used to receive PDN GW optimization indication from the MME of UE current location, and be sent to implicit expression attachment removal unit, wherein, described PDN GW optimizes the MME that is designated as the UE current location and judges according to described contextual information and send when UE moves to new accounting management zone, position;

Implicit expression attachment removal unit is used for optimizing indication according to PDN GW and starts implicit expression attachment removal process.

Aforesaid device, described contextual information unit are further used for storing the contextual information that comprises the local break-out indication and allow to change PDN GW indication.

In sum, the tracing section updating method that the present invention proposes, Apparatus and system send PDN GW by new MME to former MME and optimize the former MME startup implicit expression attachment removal process that triggers of indicating, and carry the TAU refuse information triggering UE that adheres to indication again according to described contextual information to the UE transmission and initiate attaching process again to new MME, thereby can change the employed PDN GW of PDN that visit has connected, realize the optimization that PDN is connected.

Description of drawings

Fig. 1 is the flow chart of the inventive method.

Fig. 2 is the flow chart of the embodiment one of the inventive method.

Fig. 3 is the structural representation of system of the present invention.

The structural representation of embodiment when Fig. 4 is in the current position of UE for apparatus of the present invention.

The structural representation of another embodiment when Fig. 5 is in the current position of UE for apparatus of the present invention.

Example structure schematic diagram when Fig. 6 moves the position at preceding place for apparatus of the present invention are in UE.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, the present invention is described in further detail below in conjunction with the accompanying drawings and the specific embodiments.

Basic thought of the present invention is: in existing TAU process, increase is to the judgement of the optimized choice of PDN GW, judge need carry out the optimized choice of PDN GW after, by new Mobility Management Entity (MME, Mobility Management Entity) triggers former MME to former MME transmission PDN GW optimization indication information this UE is carried out implicit expression attachment removal process, and send to UE and to adhere to indication again and trigger UE and initiate initial attaching process again, thereby realize that UE is carrying out the optimization that cross-location accounting management zone connects optimized choice and the acquiescence PDN of PDN GW when mobile.

Fig. 1 is a method flow diagram of the present invention.As shown in Figure 1, tracing section updating method of the present invention mainly may further comprise the steps:

Step 101, base station eNodeB when judgement need be selected new MME for UE, are transmitted to the TAU request message the new MME that selects according to the TAU request message that UE sends;

Here, user's global unique temporary identity (GUTI that eNodeB carries from the TAU request message that UE sends, Globally Unique Temporary Identity) and in the selected network indication (Selected Network indicator) obtain MME, if the MME that gets access to does not link to each other with this eNodeB, then use among the 3GPP TS23.401 (GPRS enhancements for E-UTRAN access (Release 8)) " MME selection function " to select new MME as UE, then the TAU request message is transmitted to selected new MME, foregoing is a prior art, repeats no more herein.

Step 102, new MME obtain contextual information according to the TAU request message from former MME, judge whether UE has moved to new accounting management zone, position, if, then change step 103 over to, otherwise, change step 104 over to;

Here, judge that the method whether UE has moved to new accounting management zone, position is: obtain former MME sign in new user's global unique temporary identity of MME from the TAU request message, and obtain position accounting management area information under it according to former MME sign, position accounting management area information under position accounting management area information under the former MME and the new MME is compared, if it is different, then judge UE and moved to a new accounting management zone, position, if it is identical, then judging UE only is to move in same position accounting management zone, do not need to carry out again the optimized choice of PDN GW, this method belongs to the prior art content, repeats no more herein.

Here, accounting management territory, position can be diverse location charging zone in the same public land mobile network (PLMN, Public Land Mobility Network), also can be the diverse location accounting management zone of different PLMN.

Step 103, new MME send grouped data network gateway PDN GW to former MME and optimize indication, and carry the TAU refuse information of adhering to indication again according to described contextual information to the UE transmission; Former MME optimizes indication according to PDN GW and starts implicit expression attachment removal process; UE starts attaching process again according to adhering to the new MME of indication triggering again, connects for UE selects the PDN GW of current service network to set up PDN; The TAU process finishes.

Here, new MME is by triggering the implicit expression attachment removal process that former MME initiates, discharged original position accounting management zone corresponding bearer resource, and will from contextual information, obtain the PDN that has set up and connect pairing access point name (Access Point Name, APN) tell to UE by the TAU refuse information, UE initiates attaching process again according to the indication of adhering to again in the TAU refuse information then, the PDN GW of new MME selection current location accounting management Local Area Network is the connection that UE sets up the PDN network of described APN indication in this process, thereby realize that UE is in the interregional optimization that optimized choice and the PDN of PDN GW is connected when mobile of cross-location accounting management, concrete implicit expression attachment removal process and initial attaching process are prior art, repeat no more herein.

Step 104, new MME trigger gateway and start the renewal load bearing process, send TAU to UE and accept message.

This step is the renewal load bearing process of carrying out when not needing to carry out PDN GW optimized choice, belongs to prior art, repeats no more herein.

For tracing section updating method of the present invention is described better, be described in detail with preferred embodiment below.

Fig. 2 is the flow chart of the embodiment one of the inventive method.As shown in Figure 2, embodiment one may further comprise the steps:

Step 201, the UE that is in Evolved Packet System connectivity management idle condition (ECM-IDLE) detect and self enter into a new tracking area, send the TAU request message to eNodeB and start the TAU process.

UE finds that in moving process current tracking area identification (TAI) not in the UE TAI tabulation of registered network, then detects it and enters into a new tracking area;

Step 202, eNodeB when judgement need be selected new MME for UE, are transmitted to the TAU request message the new MME that selects according to the TAU request message that UE sends.

Step 203, new MME obtain the contextual information of relevant this UE from former MME.

Here, described contextual information has comprised user signing contract information and the local break-out indication of this UE, includes in the user signing contract information to allow to change PDN GW indication, and concrete new MME is a prior art to the method that former MME obtains contextual information, repeats no more herein

Step 204, new MME and HSS authenticate UE.

Concrete verification process carries out according to the definition of the safety function in the 3GPP TS23.401 standard (Security Function) chapters and sections, belongs to the prior art content, repeats no more herein.In addition, this step is in order to strengthen the fail safe of TAU process, can to accept or reject according to actual needs in actual applications.

Step 205, new MME judge whether UE has moved to new accounting management zone, position, if then change step 206 over to, otherwise change step 210 over to according to the TAU request message.

Here, new MME is by judging whether UE has moved to new accounting management zone, position and determined whether to carry out the optimization of PDN GW, if UE only is mobile then need not to carry out the optimization of PDN GW in same position accounting management zone.

Local break-out indication in step 206, the new MME based on contextual information judges whether UE has used the PDN GW in the former visited network to set up the PDN connection, if then change step 207 over to, otherwise change step 210 over to.

In actual applications, Virtual network operator can be according to charging policy, only require UE when moving to another visited network or its home network, just to carry out the optimized choice of PDN GW from a visited network, when moving to other visited network, then do not need to carry out the optimization of PDN GW from home network, purpose is in order to discharge the resource of visited network, to make things convenient for operator to unify charging policy.In these cases, correspondingly need in setting up initial attaching process that PDN connects and UE request PDN connection procedure, existing triggering MME increase following content: when the MME of visited network utilizes local PDN GW to be connected for the UE in other possessions sets up PDN, local break-out is set indicates and is stored in the contextual information, connect to indicate this UE to utilize the PDN GW of visited network to set up PDN, indication discharges this PDN GW resource according to local break-out when being convenient to after this UE and getting back to home network or other visits, therefore, in the present embodiment, whether increased according to the local break-out indication has used the PDN GW in the former visited network to set up the judgement that PDN connects to UE, if not, then need not carry out the optimized choice of PDN GW.

Permission in step 207, the new MME based on contextual information changes PDN GW indication and judges whether UE allows the GW at the interregional change of diverse location accounting management PDN, if allow, then changes step 208 over to, otherwise changes step 210 over to.

In actual applications, can allow to change PDN GW indication parameter by in user signing contract information, being provided with, whether allow the change of the interregional PDN GW of diverse location accounting management by the UE decision, it is corresponding when new MME judges whether to carry out the optimized choice of PDN GW, need carry out the judgement of this step, that is to say if UE does not allow the change of the interregional PDN GW of diverse location accounting management, then need not to carry out the optimized choice of PDN Gateway.

Above-mentioned steps 205,206 and 207 all is used to judge whether to carry out the optimized choice of PDN GW, and wherein step 206 and 207 can be accepted or rejected according to the practical application needs.In addition, in actual applications step 205,206 and 207 is not had strict sequence requirement, only selected preferable built-up sequence to describe in the present embodiment.

Step 208, new MME send PDN GW to former MME and optimize indication, and carry the TAU refuse information of adhering to indication and default bearing sign deletion indication again to the UE transmission;

In the present embodiment, described PDN GW optimizes indication and is carried by context acknowledge message.

Step 209, former MME optimize indication according to PDN GW and start implicit expression attachment removal process; UE identifies relevant contextual information according to default bearing sign deletion indication deletion and former default bearing, and initiates attaching process again according to adhering to indication again to new MME, and the TAU process finishes.

Here, former MME initiates implicit expression attachment removal process to former gateway (Serving GW) and former PDN GW, and concrete implicit expression attachment removal process is referring to 3GPP TS23.401 section 5.3.8.3 " MME-initiated Detach procedure ".

The attaching process that UE initiates to new MME is referring to 3GPP TS23.401 section 5.3.2.1 " E-UTRAN Initial Attach ", in order to cooperate the enforcement of present embodiment, need improve this process according to the method in the step 206: increase the setting of local break-out indication parameter so that when after this UE roams into other visited network to the release of this PDN GW resource.By initiating initial attaching process again, UE can select new PDN GW to utilize new default bearing to set up the PDN connection, and the PDN GW that this new PDN GW may be new visited network also may be the PDN GW of home network.

Step 210, new MME send to Serving GW and create bearing request message, trigger ServingGW starting update load bearing process, send tracking area by eNodeB to UE afterwards and accept (TAUAccept) message.

Here, new MME by to this process of Serving GW according to 3GPP TS23.401 standard in the E-UTRAN Tracking Area Update procedure chapters and sections flow process carry out, belong to prior art, repeat no more herein.

In the method flow of the foregoing description one, step 201 and 202 has realized the step 101 of the inventive method, step 203 and step 205 have realized the step 102 of the inventive method, and step 208 and 209 has realized the step 103 of the inventive method, and step 210 has realized the step 104 of the inventive method.

At said method, the present invention also proposes a kind of system that realizes tracing section updating, and as shown in Figure 3, this system mainly comprises:

New MME is the MME of UE current location, is used for judging according to the TAU request message whether UE has moved to new accounting management zone, position, if, then carry out the optimized choice of PDN GW, send PDN GW to former MME and optimize indication, send to UE and carry the TAU refuse information of adhering to indication again; Be used at attaching process again, connect for UE selects PDN GW in the current service network to set up PDN; Be used for sending the establishment bearing request message to gateway;

Former MME for UE moves the MME of preceding position, is used for optimizing indication according to PDN GW and starts implicit expression attachment removal process;

Gateway is used for the establishment bearing request message starting update load bearing process according to MME.

In actual applications, in order to cooperate the user to select whether to allow in cross-location accounting management zone the demand that changes PDN GW when mobile, new MME also is used for obtaining permission from the contextual information of former MME and changes PDN GW indication, judge according to allowing to change PDN GW indication whether UE allows to change PDNGW, if do not allow, then do not carry out the optimized choice of PDN GW.

In actual applications, if only require UE when moving to another visited network or its home network, just to carry out the optimized choice of PDN GW from a visited network, then new MME also is used for obtaining the local break-out indication from the contextual information of former MME, and judge according to local break-out indication whether UE has used the PDN GW in the former visited network to set up the PDN connection, if not, then do not carry out the optimized choice of PDN GW.

In addition, for the user profile that UE is preserved is upgraded in time after former default bearing resource obtains discharging, new MME also is used for sending the TAU refuse information of carrying default bearing sign deletion indication to UE; Described UE then is used for according to default bearing sign deletion indication deletion and the relevant contextual information of former default bearing sign.

In realizing the system of tracing section updating, the enforcement of each parts can be carried out by certain equipment or device, for the device of MME correspondence, when its during as the MME of UE current location, its internal structure schematic diagram can mainly comprise as shown in Figure 4:

Transmit-Receive Unit 401 is used for the TAU request message of UE41 and is sent to judging unit 402; Receive the Attach Request message of UE41 and be sent to adhesion unit 403; The PDN connection request information and sending that receives UE41 is to PDN connection management unit 404; PDN GW is optimized indication be sent to the MME42 that UE moves preceding position, and will carry the TAU refuse information of adhering to indication again and be sent to UE41; To create bearing request message and be sent to gateway 43, and TAU be accepted message be sent to UE41;

Judging unit 402 is used for judging whether to carry out according to the TAU request message of Transmit-Receive Unit 401 optimized choice of PDNGW, if, then send PDN GW optimize indication and carry adhere to indication again the TAU refuse information to Transmit-Receive Unit 401; Otherwise, send TAU and accept message and create bearing request message to Transmit-Receive Unit 401;

Adhesion unit 403 is used for the Attach Request message according to UE, realizes that the network of UE initially adheres to, and is included as the PDN connection that UE sets up acquiescence;

PDN connection management unit 404 is used for the PDN connection request message according to UE, connects for UE sets up PDN.

In the said apparatus, described judging unit 402 comprises at least:

Cross-location accounting management region decision unit 4021 is used for judging according to the TAU request message whether UE41 has moved to new accounting management zone, position; If not, then do not carry out the optimized choice of PDN GW.

In actual applications, if only require UE when moving to another visited network or its home network, just to carry out the optimized choice of PDN GW from a visited network, and whether allow to change PDN GW when allowing UE to cross-location accounting management zone and select, then as shown in Figure 5, said apparatus also comprises:

Contextual information unit 405 is used to deposit the contextual information of UE;

Accordingly, described Transmit-Receive Unit 401 is further used for receiving the contextual information that MME42 that UE moves preceding position sends, and the permission that will wherein comprise changes PDN GW indication and local break-out and indicates and be sent to judging unit 402;

Described judging unit 402 further comprises:

Allow to change PDN GW judging unit 4022, be used for judging according to allowing to change PDN GW indication whether UE allows to change PDN GW,, then do not carry out the optimized choice of PDN GW if do not allow;

Local break-out judging unit 4023 is used for judging according to local break-out indication whether UE41 has used the PDN GW in the former visited network to set up the PDN connection, if not, then do not carry out the optimized choice of PDN GW;

Described adhesion unit 403 is further used for when the PDN GW that uses visited network to distribute sets up the PDN connection, local break-out is set indicates and deposit in the contextual information unit 405;

Described PDN connection management unit 404 is further used for when the PDN GW that uses visited network to distribute sets up the PDN connection, local break-out is set indicates and deposit in the contextual information unit 405.

In actual applications, for the ease of UE upgrading in time to its user profile, described judging unit 402 contains default bearing sign deletion indication in the TAU refuse information that Transmit-Receive Unit 401 sends, so that trigger UE according to this indication deletion and the relevant contextual information of former default bearing sign; Described Transmit-Receive Unit 401 is further used for sending default bearing sign deletion indication to UE.

When the device of MME correspondence was in UE and moves the position at preceding place, its internal structure schematic diagram can mainly comprise as shown in Figure 6:

Transmit-Receive Unit 421 is used for obtaining contextual information from the contextual information unit, and is sent to the MME 40 of UE current location; Be used to receive PDN GW optimization indication, and be sent to implicit expression attachment removal unit 422 from the MME 40 of UE current location;

Implicit expression attachment removal unit 422 is used for optimizing indication according to PDN GW and starts implicit expression attachment removal process.

In actual applications, said apparatus can also comprise:

Contextual information unit 423 is used to store the contextual information that comprises the local break-out indication and allow to change PDN GW indication.

It should be noted that, above-mentioned Fig. 4 and two kinds of MME shown in Figure 5 distinguish the structure of MME from view of function, its objective is the not same-action that MME rose that is in diverse location in the tracing section updating process in order to clearly demonstrate, and in actual applications, each MME in the system all might be former MME be again new MME, therefore, the MME in the practical application is the integration of above-mentioned two kinds of structures.

In sum, more than be preferred embodiment of the present invention only, be not to be used to limit protection scope of the present invention.Within the spirit and principles in the present invention all, any modification of being done, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims

1. the method for a tracing section updating is characterized in that, this method may further comprise the steps:

A, base station eNodeB when judgement need be selected new Mobility Management Entity MME for UE, are transmitted to new MME with the TAU request message according to the tracing section updating TAU request message that user equipment (UE) sends;

C, new MME send grouped data network gateway PDN GW to former MME and optimize indication, and carry the TAU refuse information of adhering to indication again according to described contextual information to the UE transmission; Former MME optimizes indication according to PDN GW and starts implicit expression attachment removal process; UE starts attaching process again according to adhering to the new MME of indication triggering again, connects for UE selects the PDN GW of current service network to set up PDN, and the TAU process finishes;

2. method according to claim 1 is characterized in that, further comprises between described step b and the step c:

3. method according to claim 1 and 2 is characterized in that, further comprises between described step b and the step c:

4. method according to claim 1 is characterized in that, the TAU refuse information comprises default bearing sign deletion indication among the described step c, and UE is according to default bearing sign deletion indication deletion and the relevant contextual information of former default bearing sign.

5. a system that realizes tracing section updating is characterized in that, this system comprises:

6. system according to claim 5, it is characterized in that, described new MME is further used for obtaining from the contextual information of former MME and allows to change PDN GW indication, and according to allowing change PDNGW indication to judge whether UE allows to change PDN GW, if not, then do not carry out the optimized choice of PDN GW.

7. according to claim 5 or 6 described systems, it is characterized in that, described new MME is further used for obtaining the local break-out indication from the contextual information of former MME, and judge according to local break-out indication whether UE has used the PDN GW in the former visited network to set up the PDN connection, if not, then do not carry out the optimized choice of PDNGW.

8. system according to claim 5 is characterized in that, described new MME is further used for sending default bearing sign deletion indication to UE, and described default bearing sign deletion indication is contained in the TAU refuse information; Described UE is further used for according to default bearing sign deletion indication deletion and the relevant contextual information of former default bearing sign.

9. a device that is used for tracing section updating is characterized in that, this device comprises:

10. device according to claim 9 is characterized in that, described judging unit comprises:

11. device according to claim 10 is characterized in that, this device further comprises:

Described judging unit further comprises:

12. device according to claim 9 is characterized in that, described judging unit contains default bearing sign deletion indication in the TAU refuse information that Transmit-Receive Unit sends;

13. a device that is used for tracing section updating, this device is characterized in that for UE moves the Mobility Management Entity at preceding place this device comprises:

The contextual information unit is used to store contextual information;

14. device according to claim 13 is characterized in that, described contextual information unit is further used for storing the contextual information that comprises the local break-out indication and allow to change PDN GW indication.