CN101166149A

CN101166149A - Method and mobile communication system for obtaining latest content in network

Info

Publication number: CN101166149A
Application number: CNA2006101502994A
Authority: CN
Inventors: 朱进国; 宗在峰
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2006-10-17
Filing date: 2006-10-17
Publication date: 2008-04-23

Abstract

Dual mode terminal (DMT) sets up first tag and second tag. The method includes steps: DMT connects one network from first access network (AN) or second AN; when having detected change on user's context, DMT sets up tag of AN not connected yet currently as 'need to obtain context'; when switching to AN not connected yet currently from AN connected currently, DMT sets up the tag corresponding to AN before switching operation as 'not need to obtain context', and determines whether the tag corresponding to AN after switching operation is need to obtain context'; if yes, then informing AN switched in to obtain up-to-date user context from AN before switching operation. The invention does not modify message in not access layer of UE and SGSN so that the invention possess features: simple management, reducing system burden since network does not need to inform UE each time when context changes.

Description

The method of obtaining latest content in network and mobile communication system

Technical field

The present invention relates to packet domain and evolution territory thereof in the mobile communication system, relate in particular to the method and system that a kind of core network obtains latest content.

Background technology

Since the cellular communication system invention, Radio Transmission Technology has obtained considerablely and has developed, from the artificial antenna technical development of the first generation to the digital radio technology of the second generation, and invented digital mobile communication system GSM (Global system for Mobilecommunications), gsm system mainly provides speech business, wherein, the flank speed of data is 9.6kb/s.

(General Packet Radio Service GPRS) is a kind of mobile pocket data business based on GSM, and its user oriented provides the IP that moves grouping or X.25 connects in GPRS.Gprs system is based on packet-switch technology, and the user can use various high-speed data services by GPRS under mobile status.The speed theoretical value that GPRS provides is 171.2kb/s.At present, still in development, this access technology is called as GERAN (GSM EDGE Radio Access Network) to GPRS.

(Universal Mobile TelecommunicationSystem UMTS) is third generation partner program (3rd Generation PartnershipProject, 3GPP) third generation radio digital communication system of Ti Chuing to universal mobile telecommunications system.Replaced Gb mouth based on the Iu_PS mouth of ATM based on frame relay, air interface is by Wideband Code Division Multiple Access (WCDMA) (the Wideband Code Division Multiple Access based on Frequency Division Duplexing (FDD), WCDMA) technology has replaced the GSM technology, therefore UMTS can provide the speed higher than GPRS, to support multimedia service and internet browsing.UMTS can provide the message transmission rate up to 2Mb/s.Among the UMTS Radio Access Network be called as the global system for mobile communications wireless access network (Universal Terrestrial Radio Access Network, UTRAN).GERAN and UTRAN all can be linked into the core net of UMTS.The framework of UMTS as shown in Figure 1, network element wherein has:

Wireless access network (Radio Access Network, RAN), terminal is by the packet-based core networks (Packet Core) of RAN access UMTS, and RAN comprises UTRAN and GERAN.

(Serving GPRS Support Node SGSN), preserves user's route zone position information to Serving GPRS Support Node, is responsible for safety and access control.SGSN links to each other with UTRAN by the Iu mouth, links to each other with GERAN by the Gb mouth.

(Gateway GPRS Support Node GGSN), is responsible for the IP address of distributing terminals and to the gateway function of external network, links to each other with SGSN inner gateway support node.

(Home Location Register HLR), preserves user's the subscription data and the SGSN address at current place to attaching position register.

Packet data network (Packet Data Network, PDN), for the user provides packet-based service network.

After IMS (IP Multimedia Subsystem, IP Multimedia System) introduces 3GPP, can provide more multimedia service by the mobile network, these service needed networks provide higher rate and shorter propagation delay time.In addition, non-3GPP wireless access technology (for example, WLAN (wireless local area network) (Wireless Local Area Network, WLAN), global microwave access intercommunication (World Interoperability for Microwave Access, WiMAX) etc.) be a dark horse, these technology can provide higher access bandwidth on the one hand, and cost is more and more lower on the other hand, and so just the access technology (UTRAN/GERAN) to original 3GPP has caused very big threat.Therefore, the 3GPP tissue has begun the research to UTRAN among the UMTS and Packet Core next stage evolution.The problem of this research is called System Architecture Evolution (System Architecture Evolution, SAE), its objective is and make the wireless communication system of evolution that higher transmission rate, shorter transmission delay and lower cost can be provided, and support the mobility between the inner connecting system of 3GPP simultaneously, and the mobility between 3GPP connecting system and the non-3GPP connecting system.

At present the framework of SAE as shown in Figure 2, wherein Xin Zeng network element has:

(Evolved RAN E-RAN), is follow-on wireless access network to the wireless access network of evolution, and higher up-downgoing speed can be provided, lower transmission delay and reliable more wireless transmission.

Chain of command functional entity (Mobility Management Entity, MME), be in charge of and store subscriber equipment (User Equipment, UE) context (for example, UE/ user ID, mobility management states, user security parameters etc.), for the user distributes temporary mark, be to be responsible for this user is carried out authentication when UE quarters at this tracing area or this network.

The user plane functions entity (User Plane Entity, UPE), the user face data route is handled, and termination is in the downlink data of the UE of idle state, when the downlink data that mails to UE arrives, initiates paging.The context of management and storage UE is such as IP bearer service parameter and network internal routing iinformation etc.

(Inter Access System Anchor, IASA), the different IASA of being of it and UPE are responsible for the distribution of the IP address of the overall situation to the anchor point of different access systems.Be different connecting systems, comprise the mobility anchor point of 3GPP and non-3GPP connecting system.

No matter be, with three kinds of states are arranged per family: released state, idle condition and connection status at UMTS or in SAE.Under released state, network is not known user's current position information; Under idle condition, do not have to connect between user and the network, but network is known user's current position information, wherein, in UMTS be the route district (Routing Area, RA), in SAE be tracking area (Tracking Area, TA); Under connection status, exist between user and the network to connect.

The problem that SAE is studying at present is: under idle condition, and the mobility of dual-mode terminal UE between UMTS and two kinds of connecting systems of SAE.The construction of considering SAE is on the basis that UMTS covers, so at first can cover partly.Like this, under idle condition, dual-mode terminal may change between these two access waies back and forth, and UE will ceaselessly register between two kinds of access waies, thereby has greatly taken the on-air radio resource.3GPP is studying corresponding solution, when the user changes access way, can initiate enrollment process, is referred to as no signaling and moves (SignalingFree).Basic thought is to allow UE register in SAE and UMTS simultaneously, when UE when a connecting system is converted to the another one connecting system, if the old RA/TA that preserves among current RA/TA and the UE is consistent, that is to say that customer location does not change, just need not in new system, initiate enrollment process, save Radio Resource like this.

After introducing Signaling free, dual-mode terminal is registered in MME and SGSN simultaneously, but this terminal can only have the signaling contact with a system a moment.When the user resides in the system, preserve the up-to-date context of user in this system, the context has here comprised MM context (Mobile Mobility context, the mobility context) and PDP Context (Packet Data Protocol context, block data protocol context), comprise the encryption of up-to-date use and Integrity Key etc. in the MM context, PDP Context has comprised up-to-date Qos (Quality of Service, the service quality) parameter of carrying and the address information of GGSN etc.When terminal is transferred to the another one system from a system, user's latest content also is kept in the system, when the user initiates signaling in current system, upgrade or the initiation business such as the position, current system need arrive previous system and obtain the up-to-date context of user, can re-authenticate the user like this, authentication originally can continue to use, and simultaneously current system can be according to the current Qos of up-to-date PDP context modification etc.If the user transfers to after this system, do not initiate any signaling, when just turning back to a system then, this time, a last system just need not obtain context from this system, because context does not just change, at this moment if come to get, it is anti-rather than up-to-date to get context in the past.Therefore, the problem of existence is that when current system needs to obtain context in previous system if need knowing, and how to find the user's context in the previous system.

In the UMTS system, in order to prevent real user identifier by illegal wiretapping, the message between UE and core net uses TMSI (Temporary Mobile SubscriberIdentity, Temporary Mobile Subscriber Identity) to identify this user.TMSI is distributed by SGSN.Similar temporary mark is also arranged in SAE, be called as S-TMSI, distribute by MME.When the user after SAE and UMTS registration, the UMTS module among the UE has been preserved TMSI and current route district RA, the SAE module has been preserved S-TMSI and current tracking area TA.In order to tell whether current system needs to obtain context in previous system, introduced parameters C RN (Context Reference Number, context reference number), this number unique identification user's context.CRN is distributed by network side, and each user's context change all will be upgraded, and sends among the UE then.UE is with this CRN when inserting new system.If the old CRN that preserves in the CRN that the judgement UE of new system brings up and this system is inconsistent, then judge need arrive in the previous system and obtain context, if consistent, then need not obtain.Simultaneously UE brings simultaneously network with two temporary mark TMSI in two systems and S-TMSI and route district RA and tracking area TA, and tell the network last time in which system, to insert, current like this system finds a last system according to RA or TA, and finds user's context according to TMSI or S-TMSI in a last system.

The problem that this scheme exists is, the non-access layer information that has increased the CRN parameter modification between UE and the SGSN, and SGSN must compare big upgrading, causes so at present and the UE that exists can't insert the situation of the SGSN after the upgrading.Also more complicated of the distribution mechanism of CRN in addition, when each user's context changed, such as after the authentication and after Qos revises, network all needed to notify UE, has increased system burden.

Summary of the invention

Main purpose of the present invention is to provide a kind of dual-mode terminal to obtain contextual method and system, is used for overcoming the existing the problems referred to above of prior art.

To achieve these goals, according to a first aspect of the invention, the invention provides the method that a kind of mobile communications network obtains up-to-date user's context.The method that network obtains user's context may further comprise the steps:

Step S102 corresponds respectively to first mark and second mark of first Access Network and second Access Network in the dual-mode terminal setting;

Step S104, dual-mode terminal insert in first Access Network and second Access Network;

Step S106 when detecting the user's context change in the Access Network of the current access of dual-mode terminal, is set to obtain context corresponding to the current not mark of the Access Network of access;

Step S108, when dual-mode terminal when the Access Network of current access changes the current Access Network that does not insert over to, mark corresponding to the Access Network before changing over to is set to not need to obtain context, and judge corresponding to the Access Network that is changed over to mark whether obtain context for needs, if for need obtain context, then notify the Access Network that is changed over to obtain up-to-date user's context from changing preceding Access Network over to.

Alternatively, first Access Network and second Access Network are respectively UMTS network and SAE network, and perhaps first Access Network and second Access Network are respectively SAE network and UMTS network.

In step S102, the initial value of first mark and second mark is set to not need to obtain context respectively.

Alternatively, in step S106, dual-mode terminal can oneself detect user's context change in the network in the Access Network of current access, such as the authentication request of receiving network, mean that the safe context in the user's context changes in the network.In step S106, network also can be by explicit means, and such as increasing a mark in the message in being dealt into UE, UE receives this mark, can detect user's context change in the network.When dual-mode terminal detects the user's context change, be set to obtain context corresponding to the current not mark of the Access Network of access.

In step S106, if knowing to be provided with in the dual-mode terminal, network need obtain contextual tagging, then when follow-up context changes once more, explicit notification dual-mode terminal change in context again.

In step S108, obtain context if desired, when then dual-mode terminal is initiated signaling for the first time in the Access Network that is changed over to, the Temporary Mobile Subscriber Identity and the Location Area Identification of the Access Network before use changes over to, the Access Network that is changed over to is according to these two signs, find the user data in the Access Network before changing over to, and the up-to-date user's context in this user data is obtained to the Access Network that is changed over to.

To achieve these goals, according to a second aspect of the invention, the invention provides a kind of mobile communication system that is used to obtain latest content.Mobile communication system comprises: first Access Network; Second Access Network; Dual-mode terminal is provided with first mark and second mark, and first mark is corresponding to first Access Network, and second mark is corresponding to second Access Network, and dual-mode terminal inserts in first Access Network and second Access Network; Mark is provided with module, be used for when the Access Network in the current access of dual-mode terminal detects the user's context change, mark corresponding to the current Access Network that does not insert is set to obtain context, and be used for when dual-mode terminal when the Access Network of current access changes the current Access Network that does not insert over to, be set to not need to obtain context corresponding to the mark of the Access Network before changing over to; Judging module, be used for when dual-mode terminal when the Access Network of current access changes the current Access Network that does not insert over to, judgement corresponding to the Access Network that is changed over to mark whether obtain context for needs, if for need obtain context, then the notice network that changes over to obtains up-to-date user's context from changing preceding network over to.

The initial value of first mark and second mark is set to not need to obtain context respectively.

Alternatively, in the Access Network of current access, can oneself detect user's context change in the network,, mean that the safe context in the user's context changes in the network such as the authentication request of receiving network by dual-mode terminal.Network also can be by explicit means, and such as increasing a mark in the message in being dealt into UE, UE receives this mark, can detect user's context change in the network.When dual-mode terminal detects the user's context change, be set to obtain context corresponding to the current not mark of the Access Network of access.

If knowing to be provided with in the dual-mode terminal, network need obtain contextual tagging, when follow-up context changes once more, and explicit notification dual-mode terminal change in context again.

If in dual-mode terminal, need obtain context corresponding to being labeled as of the Access Network that is changed over to, when then in the Access Network that is changed over to, initiating signaling for the first time, the Temporary Mobile Subscriber Identity and the Location Area Identification of the Access Network before use changes over to, the Access Network that is changed over to is according to these two signs, find the user data in the Access Network before changing over to, and user's context up-to-date in this user data is obtained to the Access Network that is changed over to.

By technique scheme, the present invention does not make amendment to the non-access layer information of UE and SGSN, and therefore the UMTS UE before still can insert SGSN.UE only uses two marks to indicate whether to obtain context in this scheme, and is therefore very simple, when mark be made as need obtain context after, need not all notify UE in the time of the each change in context of network, reduced system burden.

Description of drawings

Accompanying drawing described herein is used to provide further understanding of the present invention, constitutes the application's a part, and illustrative examples of the present invention and explanation thereof are used to explain the present invention, do not constitute improper qualification of the present invention.In the accompanying drawings:

Fig. 1 is the schematic diagram of the system architecture of UMTS;

Fig. 2 is the schematic diagram of the system framework of SAE;

Fig. 3 is the flow chart that dual-mode terminal according to the present invention obtains contextual method;

Fig. 4 is the block diagram that dual-mode terminal according to the present invention obtains contextual mobile communication system; And

Fig. 5 is according to the contextual schematic diagram of obtaining of the embodiment of the invention.

Embodiment

Describe the present invention below with reference to the accompanying drawings in detail.

With reference to Fig. 3, obtain contextual method according to dual-mode terminal in the mobile communication system of the present invention and may further comprise the steps:

Step S102 corresponds respectively to first mark and second mark of first Access Network and second Access Network in the dual-mode terminal setting.

Step S104, dual-mode terminal insert in first Access Network and second Access Network.

Step S106 when detecting the user's context change in the Access Network of the current access of dual-mode terminal, is set to obtain context corresponding to the current not mark of the Access Network of access.

Dual-mode terminal can oneself detect user's context change in the network in the Access Network of current access, such as the authentication request of receiving network, mean that the safe context in the user's context changes in the network.

Network also can tell the dual-mode terminal user's context to change by explicit means, and such as increasing a mark in the message in being dealt into dual-mode terminal, dual-mode terminal is received this mark, can detect user's context change in the network.

Obtain context if desired, when then dual-mode terminal is initiated signaling for the first time in the Access Network that is changed over to, the Temporary Mobile Subscriber Identity and the Location Area Identification of the Access Network before use changes over to, the Access Network that is changed over to is according to these two signs, find the user data in the Access Network before changing over to, and the up-to-date user's context in this user data is obtained to the Access Network that is changed over to.

Alternatively, first Access Network and second Access Network are respectively UMTS network and SAE network, and perhaps first Access Network and second Access Network are respectively SAE network and UMTS network.Dual-mode terminal moving between first Access Network and second Access Network moved for no signaling.

With reference to Fig. 4, the dual-mode terminal that is used for according to the present invention obtains contextual mobile communication system 10 and comprises: first Access Network 20; Second Access Network 30; Dual-mode terminal 40, be provided with first mark 70 and second mark, 80, the first marks 70 corresponding to first Access Network, 20, the second marks 80 corresponding to second Access Network 30, dual-mode terminal 40 inserts in first Access Networks 20 and second Access Network 30; Mark is provided with module 50, be used for when the Access Network in dual-mode terminal 40 current accesses detects the user's context change, mark corresponding to the current Access Network that does not insert is set to obtain context, and be used for when dual-mode terminal 40 when the Access Network of current access changes the current Access Network that does not insert over to, be set to not need to obtain context corresponding to the mark of the Access Network before changing over to; Judging module 60, be used for when dual-mode terminal 40 when the Access Network of current access changes the current Access Network that does not insert over to, judgement marks whether to needs obtain context corresponding to the Access Network that is changed over to, if for need obtain context, then upgrades user's context.

Alternatively, first Access Network 20 and second Access Network 30 are respectively UMTS network and SAE network, and perhaps first Access Network 20 and second Access Network 30 are respectively SAE network and UMTS network.Dual-mode terminal 40 moving between first Access Network 20 and second Access Network 30 moved for no signaling.

The initial value of first mark 70 and second mark 80 is set to not need to obtain context respectively.

Alternatively, can in the Access Network of current access, detect user's context automatically by dual-mode terminal 40 and change, also can change to dual-mode terminal 40 by network explicit notification user's context.When dual-mode terminal 40 detects the user's context change, be set to obtain context corresponding to the current not mark of the Access Network of access.

Need obtain contextual tagging if network is known to be provided with in the dual-mode terminal 40, when follow-up context changes once more, no longer the user's context change is notified to dual-mode terminal 40.

If need obtain context corresponding to being labeled as of the Access Network that is changed over to, the Access Network that is then changed over to is according to the Temporary Mobile Subscriber Identity and the Location Area Identification of the Access Network before changing over to, find the user data in the Access Network before changing over to, and user's context up-to-date in this user data is obtained to the Access Network that is changed over to.

The total thought of the present invention is: by dual-mode terminal UE decision and tell network, whether need to obtain up-to-date context.Detailed process is as follows:

In each module of dual-mode terminal UE, all design a mark, such as mark of design in the UMTS module, mark of design in the SAE module.Whether this mark indication UE needs to obtain up-to-date context from network, this mark only forwards the another one system the user to from a system, usefulness just in the time of the network signaling for the first time, the user resides in same this mark that do not need to consider intrasystem the time.

When dual-mode terminal when a system forwards the another one system to, initiate contact with network if desired, upgrade or the initiation business such as the position, UE obtains up-to-date context according to these marker for judgment needs in the purpose system, is so just inserted the TMSI of place system or S-TMSI and RA or TA the last time and brings the core net that will insert.After the core net that will insert is received like this, to can not find user data according to TMSI that brings up or S-TMSI, must find the last core net that inserts the place according to RA that brings up or TA, find user data according to TMSI or S-TMSI last once the access in the core net of place then, and up-to-date context is taken in the current system.

The administrative mechanism of this mark is as follows:

This mark is present among the UE, and initial value is not for obtaining context.

When UE after a system forwards the another one system to, the mark in the last system of UE is set to not obtain context.

When UE detected the user's context change in current system when, just mark described in another system was set to obtain context.UE can detect context changes automatically, receives authentication request such as UE, and the authentication parameter in the user's context has just changed like this; Perhaps by network when detecting context changes for the first time, initiatively require the UE setting to be labeled as and need obtain context.Because this mark has only two values, if therefore network judges that UE has been provided with this mark, change for user's context afterwards, network need not be notified UE once more.

Network need not to distribute the mark among the UE among the present invention, has therefore reduced the complexity of managing this mark.In addition, to the not influence of Non-Access Stratum interface of UE and SGSN, existing UMTS terminal still can be linked among the SGSN.

Describe the execution mode of this programme below in detail, referring to Fig. 5.Consider the dual-mode terminal of SAE and UMTS, two marks are arranged in this terminal, when a mark SAE-Flag record inserts from SAE for the first time, whether need to obtain context from UMTS, when another mark UMTS-Flag record inserts from UMTS for the first time, whether need to obtain context from SAE.

The user starts shooting from off-mode, and UE detects and need be linked among the UMTS, so initiate register flow path in UMTS, this register flow path is the same with existing register flow path.In registration process, SGSN will distribute the route district RA at P-TMSI and user place to bring UE preservation.In registration for the first time, network must carry out authentication, generates new safe key, so UE SAE-Flag is set to obtain context.Passed through authentication because network is known, judged that UE has been provided with SAE-Flag for need obtain context, therefore follow-up user's context change will not reinform UE and reset this mark.When UE was in the UMTS always, if initiate routing update, service request or return page response, UE need not to judge this mark, and the P-TMSI and the RA that directly use SGSN to distribute identify this user.

UE detects and need be linked among the SAE, and UE at first is made as UMTS-Flag does not need to obtain context, and judging then needs to initiate the TA renewal process, and is inconsistent such as the TA that preserves among current tracking area TA and the UE.UE judges that SAE-Flag for need obtain context, comes identifying user in the P-TMSI and the RA that are to use SGSN to distribute.After the MME of SAE receives the TA update request, will find the SGSN and the user data of last registration according to P-TMSI and RA, and obtain up-to-date user's context in MME.In the TA renewal process, MME distributes S-TMSI and TA and passes to UE.Similar with the front, if detecting user's context in SAE, UE changed, such as in SAE, having carried out authentication again, UMTS-Flag then is set for need obtain context.

When UE detects when need turn back to UMTS, UE at first is made as SAE-Flag does not need to obtain context, and when inserting the UMTS network for the first time, if judge that UMTS-Flag is for need obtain context, then use the S-TMSI/TA of MME to identify this user, if judge UMTS-Flag for not needing to obtain context, the P-TMSI/RA that then uses original SGSN to distribute identifies this user.

In this programme, whether a system obtains the fail safe that contextual method can not reduce system to the front by the UE decision, although because the UE indication need not remove to obtain context, system will judge whether UE is re-authenticated according to CKSN/KSI and other criterions.

In sum, the method among the present invention provides a kind of decision whether to obtain the mechanism of latest content to previous system; This method need not to revise the non-access layer information of UE and network, does not therefore influence existing UE and inserts core net; Core net need not to distribute and the managing context reference number, and therefore influence reduces greatly than existing program to core net.

The above is the preferred embodiments of the present invention only, is not limited to the present invention, and for a person skilled in the art, the present invention can have various changes and variation.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. a mobile communications network obtains the method for latest content, it is characterized in that, may further comprise the steps:

Step S102 corresponds respectively to first mark and second mark of first Access Network and second Access Network in described dual-mode terminal setting;

Step S104, described dual-mode terminal insert in described first Access Network and described second Access Network;

Step S106 when detecting the user's context change in the Access Network of the current access of described dual-mode terminal, is set to obtain context corresponding to the current not mark of the Access Network of access;

Step S108, when described dual-mode terminal when the Access Network of described current access changes the described current Access Network that does not insert over to, mark corresponding to the Access Network before changing over to is set to not need to obtain context, and judge corresponding to the Access Network that is changed over to mark whether obtain context for needs, if for need obtain context, then notify the Access Network that is changed over to obtain up-to-date user's context from changing preceding Access Network over to.

2. method according to claim 1 is characterized in that, described first Access Network and described second Access Network are respectively UMTS network and SAE network, and perhaps described first Access Network and described second Access Network are respectively SAE network and UMTS network.

3. method according to claim 1 is characterized in that, under the idle condition, described dual-mode terminal moving between described first Access Network and described second Access Network moved for no signaling.

4. according to each described method in the claim 1 to 3, it is characterized in that, in step S102, the initial value of described first mark and described second mark is set to not need to obtain context respectively.

5. method according to claim 1 is characterized in that, in step S106, described dual-mode terminal active detecting user's context changes, and is set to obtain context corresponding to the mark of the described current Access Network that does not insert.

6. method according to claim 1, it is characterized in that, in step S106, the described dual-mode terminal user's context of the Access Network proactive notification of described current access changes, and is set to obtain context corresponding to the mark of the described current Access Network that does not insert.

7. method according to claim 6, it is characterized in that, in step S106, if knowing to be provided with in the described dual-mode terminal, the Access Network of described current access need obtain contextual tagging, then when the subsequent user context changes once more, the described dual-mode terminal change in context of proactive notification no longer.

8. according to each described method in the claim 1 to 3, it is characterized in that, in step S108, obtain context if desired, when then described dual-mode terminal is initiated signaling for the first time in the Access Network that is changed over to, use the Temporary Mobile Subscriber Identity and the Location Area Identification of the Access Network before changing over to, the Access Network that is changed over to is according to these two signs, find the user data in the Access Network before changing over to, and the up-to-date user's context in the described user data is obtained to the Access Network that is changed over to.

9. a mobile communication system that is used to obtain latest content is characterized in that, comprising:

First Access Network;

Second Access Network;

Described dual-mode terminal is provided with first mark and second mark, and described first mark is corresponding to described first Access Network, and described second mark is corresponding to described second Access Network, and described dual-mode terminal inserts in first Access Network and second Access Network;

Mark is provided with module, be used for when the Access Network in the current access of described dual-mode terminal detects the user's context change, mark corresponding to the current Access Network that does not insert is set to obtain context, and be used for when described dual-mode terminal when the Access Network of described current access changes the described current Access Network that does not insert over to, be set to not need to obtain context corresponding to the mark of the Access Network before changing over to;

Judging module, be used for when described dual-mode terminal when the Access Network of described current access changes the described current Access Network that does not insert over to, judgement corresponding to the Access Network that is changed over to mark whether obtain context for needs, if for need obtain context, then notify the Access Network that is changed over to obtain up-to-date user's context from changing preceding Access Network over to.

10. mobile communication system according to claim 9 is characterized in that, described first Access Network and described second Access Network are respectively UMTS network and SAE network, and perhaps described first Access Network and described second Access Network are respectively SAE network and UMTS network.

11. mobile communication system according to claim 9 is characterized in that, under the idle condition, described dual-mode terminal moving between described first Access Network and described second Access Network moved for no signaling.

12., it is characterized in that the initial value of described first mark and described second mark is set to not need to obtain context respectively according to each described mobile communication system in the claim 9 to 11.

13. mobile communication system according to claim 9 is characterized in that, described dual-mode terminal active detecting user's context changes, and is set to obtain context corresponding to the mark of the described current Access Network that does not insert.

14. mobile communication system according to claim 9, it is characterized in that, the described dual-mode terminal user's context of the Access Network proactive notification of described current access changes, and is set to obtain context corresponding to the mark of the described current Access Network that does not insert.

15. according to the mobile communication system described in the claim 14, it is characterized in that, if knowing to be provided with in the described dual-mode terminal, the Access Network of described current access need obtain contextual tagging, then when the subsequent user context changes once more, the described dual-mode terminal change in context of proactive notification no longer.

16. according to each described mobile communication system in the claim 9 to 11, it is characterized in that, if need obtain context corresponding to being labeled as of the Access Network that is changed over to, when then described dual-mode terminal is initiated signaling for the first time in the Access Network that is changed over to, the Temporary Mobile Subscriber Identity and the Location Area Identification of the Access Network before use changes over to, the Access Network that is changed over to is according to these two signs, find the user data in the Access Network before changing over to, and the up-to-date user's context in the described user data is obtained to the Access Network that is changed over to.