WO2009024089A1

WO2009024089A1 - A system for implementing back compatibility with network, an attaching method and a detaching method

Info

Publication number: WO2009024089A1
Application number: PCT/CN2008/072067
Authority: WO
Inventors: Xiaoqin Duan; Jian Zhang; Qingyu Li; Xiaobo Wu
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2007-08-20
Filing date: 2008-08-20
Publication date: 2009-02-26
Also published as: CN101374258A; CN101374258B

Abstract

The invention provides a system for implementing back compatibility with network, which includes: an evolved mobile switching center eMSC/VLR, a home subscriber server HSS and a mobility management entity MME; furthermore, the invention provides an attaching method, which includes: attaching a UE to a target MME; obtaining the address information of the target eMSC; according to the obtained address information of the target eMSC, attaching the UE to the target eMSC/VLR. In addition, the invention provides a detaching method. With the invention, the circuit domain service could be employed in the evolved network continuously, the back compatibility could be implemented, the traditional circuit domain entity could be further employed, a smooth migration of the system upgrade could be guaranteed, and the existing investment of the operator could be protected.

Description

System for implementing network backward compatibility and attachment and de-attachment method

The present invention relates to a third generation mobile communication technology, and more particularly to a system for implementing network backward compatibility and an attaching and detaching method. Background technique

At present, with the development of communication technology, the third generation of mobile communication technology has become increasingly mature. The Universal Mobile Telecommunications System (UTMS) is the third generation mobile communication system using Wideband Code Division Multiple Access (WCDMA) air interface technology. A similar structure for a mobile communication system, including a Radio Access Network (RAN) and a Core Network (CN). Among them, the RAN is used to handle all functions related to wireless services, and the CN handles all voice calls and data connections in the UTMS system, and implements exchange and routing functions with external networks. The CN is logically divided into a Circuit Switched Domain (CS Domain) and a Packet Switched Domain (PS Domain). The UMTS Territorial Radio Access Network (UTRAN) and the CN together with User Equipment (UE) constitute the entire UMTS system.

The above network architecture is based on the previous version of 3GPP Re 16 architecture. Considering the competitiveness of the future network, 3GPP is researching a new evolution network architecture to meet the application requirements of mobile networks in the next ten years or longer. Including the Sys tern Architecture Evolution (SAE) and the Long Term Evolution (LTE) of the access network, where the evolved access network is called Evolved-UTRAN (E-UTRAN). The goal of network evolution is to provide a network with low latency, high data rate, high system capacity and coverage, low cost, and full Internet Protocol (IP).

Currently in 3GPP, various vendors are actively studying SAE and LTE. The purpose of LTE is to provide a capability. A low-cost network with reduced latency, improved user data rates, improved system capacity and coverage. Therefore, in the process of UMTS evolution to SAE, there will be a phase in which UMTS and SAE networks coexist. The evolved network architecture specified in TS23.401-vllO in the 3GPP standard is as shown in Figure 1, and the connection relationship between the modules. For details, refer to the relevant chapters in the 3GPP standard. Here, only the functions of the modules related to the present invention are briefly introduced, including:

The serving gateway (S-GW) 101 is an entity that terminates the downlink data by the UE in the idle state, triggers the paging and simultaneously saves the context information of the UE, such as the IP address and routing information of the UE.

The Packet Data Network Gateway (PDN GW) 102 is an anchor point of the user plane and remains unchanged during the session time period of the user. Meanwhile, the Policy and Charging Enforcement Function (PCEF) is also implemented. Located on this entity.

The Policy and Charging Rules Function (PCRF) 103 is used to generate a Policy and Charging Control (PCC) rule and deliver it to the PCEF, and is sent by the PCEF. To implement the rule, in the network architecture shown in FIG. 1, the PCRF 103 sends the rule to the PDN GW 102, and the rule is executed by the PCRF 103.

The Home Subscriber Server (HSS) 105 is configured to support user registration and store user identity, location data, and filtering policy information, as well as management of authentication and authorization control information for network access by users.

The Mobility Management Entity (MME) 104 is configured to save the mobility management context of the UE, such as the identifier of the user, the Tracking Area (TA) information, and the like, and authenticate the user.

The MME 104 is connected to the Serving GPRS Support Node (SGSN) through the S3 interface, and the 2G/3G users can pass the UTRAN/GERAN (GSM/EDGE Radio Access Network, GSM/EDGE Radio Access Network; GSM: Global system for mobile) Communications, Global System for Mobile Communications; EDGE: Enhanced data rates for GSM evolution, GSM Evolution Enhanced Data Rate) Access to SGSN, Evolved Network Architecture is compatible 2G/ 3G, this is mainly for the smooth evolution of the system. Because only the E-UTRAN hotspot coverage can be performed in the initial stage of the evolution network, users will only be able to access the network through UTRAN/GERAN outside the hotspot coverage area.

Therefore, in this case, it is inevitable that the handover problem caused by the UE moving between the evolved network coverage area and the 2G/3G network, and the network in the domain and radio access technology (Radio Acces s Technology, RAT) Ensure continuity of business when changing.

It can be seen from the above that the evolved network is also an important technical indicator for the backward compatibility of existing networks. In order to protect the existing investment and equipment of the operator and make full use of the entities of the traditional circuit domain, 3GPP proposes a scheme for carrying CS domain data and signaling in the PS domain of the evolved network, which is currently called This is specifically discussed in the evolved Mobi le Swi tching Center (eMSC) and in TR23.882 of the 3GPP standard, and it is proposed that: In LTE/SAE, the control entity eMSC is used to control the The services of different access areas simplify the problem of service continuity between the CS domain and the LTE/SAE; at the same time, the interaction between the voice and the parallel IP multimedia subsystem (IP Mul t imedia Sub-system, IMS) session is terminated by the terminal. Implemented, and proposed a new interface, given the principle of advice, but the current standard does not cover the architectural details of the eMSC solution, and for the various related business processes under the architecture, such as: UE attached to eMSC Details, details of mobility management in idle state, and details of detachment are not covered.

It can be seen from the above that the prior art does not solve the backward compatibility problem of the evolved network for the UMTS network, and cannot maintain the continuity of the service when the UE moves between the evolved network and the 2G/3G network, and cannot implement various corresponding The business processes, such as the UE attaching to the eMSC, the mobility management in the idle state, and the detachment, etc., are bound to affect the deployment of the operator network and the use of the user service. Summary of the invention

Embodiments of the present invention provide a system that implements network backward compatibility, enabling a UE to continue to use legacy circuit domain services in an evolved network. Embodiments of the present invention also provide an attaching method and an attaching apparatus, so that the UE can smoothly access the network backward compatible system.

Embodiments of the present invention also provide a method for UE detaching in a network backward compatible system, so that the UE can smoothly log out from the network backward compatible system when not in use.

In order to achieve the above object, the technical solution of the present invention is specifically implemented as follows:

An attachment method comprising:

Attaching the UE to the target mobility management entity MME;

Obtaining the eMSC address information of the target evolved mobile switching center;

The UE is attached to the target eMSC/VLR according to the obtained target eMSC address information.

An attachment device, comprising:

a first attaching module, configured to attach the UE to the target E;

An obtaining module, configured to obtain target eMSC address information;

And a second attaching module, configured to attach the UE to the target eMSC/VLR according to the obtained target eMSC address information.

A system for implementing network backward compatibility, including: eMSC/VLR, HSS, and MME;

HSS for saving user information;

The MME is configured to exchange the user information with the HSS, and interact with the eMSC/VLR through the Gs+ interface to control plane signaling;

The eMSC/VLR is configured to exchange the user information with the HSS, determine the UE according to the user information, and process the control plane signaling.

A method for UE attachment, comprising:

The UE deletes the bearer between the MME and the PDN GW, and then the MME sends an IMS I detach request to the eMSC/VLR, and the eMSC/VLR receives the IMS I detach request, deletes the connection information of the eMSC/VLR to the MME, and sends the connection information to the MME. E sends an IMS I detach attachment message.

It can be seen from the foregoing technical solutions that the present invention implements continuous use in an evolved network by introducing a mobile switching center MSC and a media gateway MGW in an evolved legacy circuit domain in an evolved network. The function of the traditional circuit domain service enables the packet domain users in the evolved network to communicate with the traditional circuit domain users, thus achieving good backward compatibility, and at the same time, by means of attaching and detaching, the user can be in the evolved network and Switching in the traditional network enables a greater use of traditional circuit domain entities, ensuring a smooth transition of system upgrades and protecting the operator's existing investments. DRAWINGS

1 is a schematic structural diagram of an evolution network in the prior art;

2 is a schematic structural diagram of a network structure of a first network architecture when a UE is located in a home network according to a preferred embodiment of the present invention;

3 is a schematic diagram of a network structure of a first network architecture in a preferred embodiment of the present invention when a UE is located in a visited network and a user service Loca l Breakout (local grooming);

4 is a schematic diagram of a network structure of a first network architecture in a preferred embodiment of the present invention when a UE is located in a visited network and a user service Home-Routed (route back to the network);

FIG. 5 is a schematic structural diagram of a network structure of a second network architecture when a UE is located in a home network according to a preferred embodiment of the present invention; FIG.

6 is a schematic diagram of a network structure of a second network architecture in a preferred embodiment of the present invention when a UE is located in a visited network and a user service Loca l Breakout;

FIG. 7 is a schematic structural diagram of a network structure of a second network architecture when a UE is located in a visited network and a user service Home-Routed according to a preferred embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a network structure of a third network architecture when a UE is located in a home network according to a preferred embodiment of the present invention; FIG.

FIG. 9 is a schematic structural diagram of a network structure of a fourth network architecture when a UE is located in a home network according to a preferred embodiment of the present invention; FIG.

10 is a schematic flowchart of attaching a UE to an evolved network in the prior art;

FIG. 11 is a schematic flowchart of a UE carrying a default bearer as a signaling bearer and attaching to an eMSC through connectivity at an IP level according to a preferred embodiment of the present invention; FIG. 12 is a schematic flowchart of a UE carrying a dedicated bearer as a signaling bearer and attaching to an eMSC through connectivity at an IP level according to a preferred embodiment of the present invention; FIG.

FIG. 13 is a schematic flowchart of reporting, by the UE, the capability of the CSoPS and attaching to the eMSC in the joint attach mode according to the preferred embodiment of the present invention;

14 is a schematic flowchart of reporting the capability of the CSoPS by the network and attaching to the eMSC in the joint attach mode according to the preferred embodiment of the present invention;

15 is a schematic flowchart of attaching to an eMSC by means of a PCC according to a preferred embodiment of the present invention; FIG. 16 is a schematic diagram of a process of reattaching to a new eMSC by joint location update according to a preferred embodiment of the present invention;

17 is a schematic diagram of a process of reattaching to a new eMSC through IP layer connectivity according to a preferred embodiment of the present invention;

FIG. 18 is a schematic flowchart of a joint detachment manner initiated by a UE according to a preferred embodiment of the present invention;

20 is a schematic structural diagram of a control plane protocol stack including an IP Sec layer when a CS service is run in a PS domain and signaling interaction is performed through IP connectivity according to a preferred embodiment of the present invention;

FIG. 21 is a schematic structural diagram of a control plane protocol stack without an IP Sec layer when a CS service is run in a PS domain and signaling interaction is performed through IP connectivity according to a preferred embodiment of the present invention;

FIG. 22 is a schematic structural diagram of a user plane protocol stack including an IP Sec layer when a CS service is run in a PS domain according to a preferred embodiment of the present invention; FIG.

FIG. 23 is a schematic structural diagram of a user plane protocol stack without an IP Sec layer when a CS service is run in a PS domain according to a preferred embodiment of the present invention. detailed description

The embodiment of the present invention provides a specific eMSC architecture solution, so that the UE is in an evolved network and

Business continuity can be maintained when moving between 2G/ 3G networks, so that various industries can be implemented The process, and ensure that the CS domain service (CS over PS, CSoPS for short) can be carried through the PS domain. After the UE is added to the network to support the CSoPS upgrade, the UE and the network side can support the CSoPS capability, thereby ensuring that the UE moves between the evolved network and the 2G/3G network. Business continuity.

The evolved network after the eMSC entity is introduced may use the following network architectures: Embodiment 1

2 shows a network structure of a first network architecture when a UE is located in a home network, including: PDN GW 202, PCRF 203, EMSC 204, EMGW 205 (evolved Media GateWay, evolved media gateway), HSS 206, S-GW 207, MME 209, and The SGSN 208, wherein the EMSC 204 further includes an eMGCF2041 module and an eMSC/VLR2042 module, the EMGW 205 further includes an eIM-MGW2051 module and an eMGW2052 module.

The UE 201 is connected to the eMSC/VLR 2042 in the EMSC 204 through the interface L1, and the interface is used for interaction of CS control plane signaling such as registration of the simulated CS domain, location update, mobility management, and voice call control signaling.

The EMSC 204 is connected to the HSS 206 through the interface C, and is configured to request CS domain related information such as user identity, location data, and filtering policy information from the HSS 206, and according to the received voice call control signaling sent by the UE 201 through the interface L1, through the Mn interface. The eIM-MGW2051 sends a control message, which includes the Codec service type, the media plane parameter of the UE, the bearer bit rate, and the like. According to the bearer service request of the UE, the PCRF 203 is triggered by the interface Rx+ to establish a Guaranteed Bit Rate (GBR). Carrying, to realize the QoS guarantee of the media plane data of the voice call from the UE to the PDN GW, and further providing other application layer session information for the PCRF 203 to formulate the policy and charging control rules through the Rx+ interface; if the call is an outgoing call, the EMSC 204 The call signaling is exchanged with the peer entity through the ISUP/BICC interface. Otherwise, if the call is an intra-office call, the EMSC 204 exchanges call signaling with the access network entity through the Iu-CS/A interface (this case is not shown in the figure). . The EMSC 204 further includes an eMGCF2041 module and an eMSC/VLR2042 module, where the eMGCF 2041 is configured to control the eIM-MGW2051 module and the eMGW2052 module in the EMGW 205 entity to perform codec format conversion of the media stream. The eMSC/VLR 2042 controls the eMGW 2052 to perform related operations on the media plane according to the received voice call control signaling sent by the UE 201 through the interface L1.

The EMGW 205 is an evolved media gateway, and can be divided into an e IM-MGW2051 module and an eMGW2052 module according to functions, and the two are respectively a PS domain logic module and a CS domain logic module, and the entity is externally connected to the PS domain entity and the CS domain entity respectively, Within, two logic modules are connected by an internal interface Nb. e IM-MGW2051 interacts with the PDN GW 202 via the SG i interface. If the call is an outgoing call, the eMGW2052 interacts with the peer entity through the Nb interface. Otherwise, if the call is an intra-office call, the eMGW2052 passes the Iu-CS/ The A interface interacts with the access network entity to exchange media plane data (this is not shown in the figure). When the IM-MGW2051 and the eMGW2052 interact with the media plane data through the internal interface Nb, the media plane data needs to be in the PS domain media. A conversion is made between the face data and the CS domain media surface data, that is, el M-MGW2051 is converted to CS domain media plane data when transmitting media plane data to eMGW2052, and conversely, eMGW2052 is converted to PS when transmitting media plane data to e IM_MGW2051. Domain media surface data.

The PCRF 203 is connected to the EMSC 204 through the Rx+ interface, and is configured to receive various application layer session information delivered by the EMSC 204, thereby obtaining restrictions on the user accessing the network, application services currently being performed by the user, and user subscription information, and then formulating corresponding policies and The charging rule is executed, and the established rule is sent to the PDN GW 202 through the S7 interface.

The PDN GW 202 is connected to the PCRF 203 through the S7 interface, receives the rules and is executed by the PCRF 203, and establishes the required media plane bearer. The SG i interface is connected to the e IM-MGW2051 for filtering the user data stream in the PS domain. And send to e IM-MGW2051; through S5 interface

The S-GW 207 is connected.

The S-GW 207 is a serving gateway of the evolved network, the MME 209 is a core network control plane entity of the evolved network, and the SGSN 208 is a core network control plane entity of the 2G/3G network and has the function of a user plane entity, and the three entity functions and their phases The interfaces of neighboring entities are described in the existing standards, and will not be described here.

Figure 3 shows the first network architecture. When the UE is on the visited network and the user service Loca l The network structure of the breakout network. In this scenario, the HSS 306 is located in the home network, and all other modules are functional entities located in the visited network, and the connection relationships and functions of the parts are the same as those described in FIG. 2, where No longer.

Figure 4 shows the network structure of the first network architecture when the UE is located in the visited network and the user service is Home-Routed. In this scenario, the HSS 406 and the PDN GW 402 are located in the home network, and the network also includes the H in the home network. - PCRF4031, H-PCRF4031 and V-PCRF4032 in the visited network communicate through interface S9, all other entities are functional entities located in the visited network, and the connection relationships and functions of each part are the same as described in Figure 2, where No longer.

It can be concluded from the above description that the first network architecture has the following characteristics:

1. The architecture introduces a new functional entity eMSC, which has the functions of a traditional MSC-Server in the circuit domain and also has an interface with the PCC system, so its function is similar to the proxy call server control function in the IMS domain (Proxy Ca ll Server) Cont ro l Func t ion , P-CSCF ) , can trigger the establishment of a proprietary GBR bearer (packet domain bearer of analog circuit domain service) through the Rx+ interface to transmit the voice call media stream, so that the voice stream from the UE to the PDN GW The transmission between the two is guaranteed by QoS;

1. The media plane data of the voice call is directly sent by the eMGW to the UE, and the media plane data in the PS domain will be carried on the GBR bearer (the packet domain bearer of the analog circuit domain service) triggered by the eMSC;

3. The UE may send registration signaling, location update message, handover message, and voice call signaling of the analog CS domain through the interface L1 to the eMSC.

As you can see, the architecture has the following advantages:

It is only necessary to establish a signaling plane and a data plane logical path for carrying a voice call, the EMSC is similar to the IMS domain P-CSCF entity, and the EMGW is a communication peer entity, and the IMS domain call architecture can be reused;

1) The changes to the existing evolved network equipment are small, so the impact on the existing LTE/SAE system is minimal; 2) The PCC system can be reused, and the changes to each interface are small;

3) By means of solid E, the eMSC is shielded from the mobility management of the UE, ie: the eMSC does not need to know Location information of the UE. Of course, we do not exclude the connection between the UE and the eMSC through the IP plane. Although the IP address of the UE does not change, due to the change of the location area of the UE, the eMSC reselection process is triggered, that is, the eMSC needs to know the UE. Physical location information.

Embodiment 2

FIG. 5 shows a network structure of a second network architecture when the UE is located in the home network, including:

PDN GW 502, PCRF 503, EMSC 504, EMGW 505, HSS 506, MME 507, S-GW 508 and SGSN 509, wherein EMSC 504 further includes eMGCF 5041 and eMSC/VLR 5042, and EMGW 505 further includes e I M-MGW 5051 and eMGW 5052. The functions of the parts and the connection relationship between them are similar to those in the first embodiment. The difference is that the EMSC 504 and the MME 507 are connected through a Gs+ interface (the interface is similar to the Gs interface in 2G/3G), and the interface is used in the EMSC 504 and The MME 507 exchanges signaling, such as: handover message, reporting UE location message or attached message, location update, mobility management, etc., and can also perform voice call control signaling through the interface. When the call control signaling is performed between the UE 501 and the EMSC 504, the voice call control signaling may pass through a non-access stratum message between the UE 501 and the MME 507 (Non-Acce ss Node, NAS) and a Gs+ interface between the MME 507 and the EMSC 504. Bridge.

The EMSC 504 is connected to the HSS 506 through the interface C, and is configured to request CS domain related information such as user identity, location data, and filtering policy information from the HSS 506, and according to the received control signaling sent through the Gs+ interface between the MN and the EMSC 504. The Mn interface controls the e IM-MGW 5051 to establish a media stream association between the UE and the e lM - MGW. The Gs+ interface can also be used only as a handover signaling for forwarding UEs from the PS domain to the CS domain.

The S-GW is the service gateway of the evolved network, the MN is the core network control plane entity of the evolved network, and the SGSN is the core network control plane entity of the 2G/3G network and has the function of the user plane entity. The interfaces of adjacent entities are described in the existing standards, and will not be described here.

Figure 6 shows the network structure of the second network architecture when the UE is located on the visited network and the user service Loca l Breakout. Figure 7 shows the second network architecture. When the UE is located on the visited network and the user service is Home-Routed. Network composition, similar to the first embodiment, these two situations The relationship between the network architecture and the network architecture in FIG. 5 is the same as that in the first embodiment. Those skilled in the art can reasonably derive the description according to the description in the first embodiment, and therefore no further details are provided herein.

As can be seen from the above description, the second network architecture has the following characteristics:

1) Introducing a new functional entity eMSC, which has the function of the traditional MSC-Server in the circuit domain, and also has an interface with the PCC system, so it is similar to the P-CSCF functional entity in the IMS domain, and can be triggered by the Rx+ interface. There is a GBR bearer (the packet domain bearer of the analog circuit domain service) for transmitting the voice call media stream, so that the voice stream is guaranteed by the QoS between the UE and the PDN GW;

2) The media plane data of the voice call is directly sent by the eMGW to the UE, and the data in the PS domain media plane is carried on the GBR bearer triggered by the eMSC;

3) The UE may establish a logical channel/interface between the eMSCs for performing the registration of the analog CS domain and transmitting voice call signaling, for example: the logic may be implemented by establishing a dedicated signaling plane bearer between the UE and the eMSC. Channel/interface, CS control plane signaling can be sent through IP connectivity; at this time, the Gs+ interface between MN and eMSC is only used for forwarding switching messages.

4) Introduce the interface G s+ between the solid E and the eMSC to deliver the attached message, the location update message, the switch message, and the like.

This architecture has the following advantages:

1) When the Gs+ interface is only used in the handover process, only the signaling plane and the data plane logical path carrying the voice call need to be established, the eMSC is similar to the IMS domain P-CSCF entity, the MGW is the communication peer entity, and the IMS domain can be reused. Call architecture

2) Reusable PCC system, with minor changes to each interface;

3) When the Gs+ interface is only used during the handover process, the mobility management of the eMSC can be blocked by the EMSC;

4) When the Gs+ interface is also used as the mobility management interface, there is no need to establish a signaling plane channel for the CS domain call between the UE and the eMSC (for example, the interface is used to transmit the UE simulated CS domain attachment, call, etc. Signaling of domain services, and can be used when delivering handover messages); 5) When the Gs+ interface is also used as a mobility management interface, the current process of joint attachment and joint location update in TS23.060 can be reused.

Embodiment 3

Figure 8 shows the network structure of the UE when the UE is located in the home network in the third network architecture, including:

PCRF803, EMSC804, EMGW805, HSS806, MME807, S-GW808 and SGSN809, which further comprises eMGCF8041 EMSC804 and eMSC / VLR8042, EMGW805 further comprising eIM-MGW805 eMGW8052 and PDN GW802 _o

The eMGW8052 includes a PDN GW 802 entity, which is connected to the S-GW 808 and the PCRF 803 respectively. Within the EMGW 805, the PDN GW 802 is also connected to the eIM-MGW8051 through the SGi interface, so as to ensure connectivity of the media plane bearer path. The PDN GW 802 is the same as the PDN GW in the first embodiment and the second embodiment, except that the PDN GW is integrated into the EMGW 805, and the PDN GW 802 is connected to the PCRF 803 through the S7+ interface, and receives the policy issued by the PCRF 803. Execute, establish the required media plane bearer, connect to the eIM-MGW8051 through the SG i interface, filter the user data stream in the PS domain and send it to the e IM-MGW8051.

In addition, the connection structure, the working mode, and the functions of all the modules are the same as those of the second embodiment when the UE is located in the home network, and details are not described herein.

As can be seen from the above analysis, the third network architecture has the following characteristics:

A new functional entity eMSC is introduced, which has the function of the traditional MSC-Server in the circuit domain, and also has an interface with the PCC system. Therefore, its role is similar to the P-CSCF functional entity in the IMS domain, and can be triggered to be established through the Rx+ interface. The GBR bearer is used to transmit the voice call media stream, so that the voice stream is secured by the QoS between the UE and the PDN GW;

The new functional entity eMGW is introduced as an anchor for the user's voice call, similar to the PS domain PDN GW, having an S5+ interface with the S-GW;

The media plane data of the voice call is directly sent by the eMGW to the UE, and the data in the PS domain media plane is carried on the GBR bearer triggered by the eMSC. Introducing an interface Gs+ between the MN and the eMSC to deliver an attach message, a location update message, a handover message, and the like;

At the time of handover, the eMSC has the role of the MME in the PS domain, and at this time, the EI needs to register its own address to the eMSC;

The eMSC can learn the location information of the UE through the Gs+ interface.

The UE simulates the registration of the CS domain through the established logical channel, sends voice call signaling or sends registration and call information through the signaling plane;

The PDN-GW function is integrated in the EMGW. When the UE is attached, the MME needs to directly select the PDN GW according to the subscription data (for example, the default APN). When there are multiple APNs, the MME needs to pass a special identifier (which may be similar to the APN). Special identification) to select PDN GW;

The above mentioned case of selecting a PDN-GW entity is not only considered to be usable under this architecture, but also applicable under other architectures of this patent. In this way, the MME can select a more suitable PDN-GW to meet better bearer service requirements. The selected conditions can refer to the user's subscription data, the operator's preference, the device load, the network topology, etc., but not limited to these. the way.

The L1 interface between the UE and the eMSC is introduced to transmit the call signaling of the simulated CS domain, but the interface can be omitted in the framework, and the CS domain call signaling between the UE and the eMSC can pass through the NAS between the UE and the solid E. The message is bridged by the MME to the eMSC.

This architecture has the following advantages:

The EMGW is integrated with the PDN GW and directly acts as a user-side voice data anchor to achieve better QoS guarantee.

Embodiment 4

Figure 9 shows the network structure of the fourth network architecture when the UE is located in the home network, including: PDN GW902, PCRF903, EMSC904, EMGW905, HSS906, MME907, S-GW908 and SGSN909. In addition, the Gs+ interface in the architecture is not Required interface. The functions of the various parts and the connection relationship between them are similar to those of the first or second embodiment. The difference is that: the Iu-CP-C s + interface is introduced between the EMSC and the PDN GW, and the Iu- is introduced between the eMGW and the PDN GW. UP-C s + interface, so PDN The GW plays an RNC-like role, and the QoS guarantee between the PDN-GW and the eMGW can be implemented using the existing Iu-CS interface mechanism. There is no requirement for deploying the PCC architecture. Under this architecture, the GBR bearer can be established through the PCC system, or the bearer can be established through the current Iu-CS interface. Here we do not limit the only I u - CS interface between EMSC and PDN-GW. Under the framework, the EMSC can directly control the bearer establishment of the CsoverPS service initiated by the PDN-GW according to the received circuit domain call instruction. In addition, the architecture makes minor changes to existing evolution networks.

In the foregoing four network architectures, when the UE and the EMSC perform the signaling interaction through the IP connectivity, the IP Sec layer can be classified into two types according to the control plane protocol stack, including:

20 is a schematic structural diagram of a control plane protocol stack with an IP Sec layer. The control plane protocol stack of the interface L1 in the protocol stack structure is an IP Sec layer to a CC/SS/SMS layer shown in FIG. 20, which is carried in an IP layer. on.

21 is a schematic diagram of a control plane protocol stack structure without an IP Sec layer. The control plane protocol stack of the interface L1 in the protocol stack structure is a UDP layer to CC/SS/SMS layer shown in FIG. 21, which is carried on the IP layer. .

It should be noted that, since the control plane protocol stack under the protocol stack architecture is carried on the IP layer, and the interface L1 is used to transmit circuit domain signaling, the control plane protocol stack structure, whether or not it has an IP Sec layer, Both can only be used for the network architecture transmitted by IP connectivity bearer signaling as described above.

When the L1 interface is available, the CC, SS, SM/MM/RANAP protocol stack can be directly encapsulated into a tunneling protocol (for example, GRE: GRE: Gener ic Routing Encapsulation), and then The encapsulated packet is encapsulated into a packet at the IP level.

Similarly, in the above four network architectures, media plane data is carried on the IP layer. According to whether the user plane protocol stack has an IP Sec layer, it can also be divided into two types, including:

FIG. 11 is a schematic structural diagram of a user plane protocol stack with an IP Sec layer. The media surface data of the protocol stack structure is carried on the IP layer through RTP, UDP, and IP Sec protocols.

FIG. 23 is a schematic structural diagram of a user plane protocol stack without an IP Sec layer. The media plane data of the protocol stack structure is carried on the IP layer by using RTP and UDP protocols. It should be noted that, since the media plane data of the circuit domain is carried on the IP layer, the user plane protocol stack architecture, whether or not having the IP Sec layer, is applicable to all network architectures described above.

In addition, it should be noted that the EMSC and the EMGW described in all the foregoing embodiments of the present invention are names that are uniformly set and used in the embodiments of the present invention, and are not limited to the literal understanding. The EMSC and the EMGW may be two entities that are independently configured. The EMSC and the EMGW may be connected through the Mn and Mc interfaces in the above architecture, or may be connected through an enhanced interface such as H.248. The EMSC and EMGW may also be a single entity that is functionally differentiated and not physically separated. Similarly, for the eMGCF and the eMSC/VLR in the EMSC, they may be two entities that are independently configured to perform the functions of the EMSC in combination, or may be functionally distinguished and physically separated from each other. At the same time, for the elM-MGW and the eMGW in the EMGW, they may be two entities that are independently set, and the functions of the EMSC are combined to complete, or may be functionally distinguished and physically separated from each other. And the EMSC has no physical correspondence with the EMGW, that is, when the EMSC is a single entity, the EMGW may be two entities that are independently set. Therefore, it should be understood that any equivalent and alternative constructions of the architecture are considered to be included within the scope of the present invention.

In the mobile communication system, the user must use the service provided by the network, and must first attach to the network, that is, the process of the user registering to the network, and the attaching process performed when the UE is powered on is called initial attachment. 3GPP TS23. 401-vl l O 5. 3. 2 gives the UE attachment process in the evolved network, as shown in Figure 10, including:

Step 1001: The UE initiates an attach request to the evolved base station eNodeB, where the request will carry its own network capability information and PDN address information, if the UE does not have a valid system architecture evolution temporary mobile subscriber identity (SAE Temporary Mobi le Subscr iber Ident i ty , S-TMSI), Bei' J carries the International Mobile Subscriber Identity (IMSI), otherwise carries the S-TMSI and the tracking area identifier associated with this S-TMSI (Tracking Area) Ident if ica t ion, TAI ). Step 1002: The eNodeB selects an MME according to a predetermined mechanism, and forwards an attach request message to the MME.

Step 1003: If the UE uses the S-TMSI for the identity, and the MME that is attached to the previous MME is the source MME, the MME that is attached last time is the target MME, and the target MME is the source MME. E sends an identification request message including S-TMS I and its associated TA I to request the IMS I of the UE, and the source E includes the IMSI of the UE and the authentication quintuple in the identification response message to return the target 8. If the UE is not known in the source solid E, then the source E returns an appropriate error cause.

Step 1004: If the UE is unknown in both the target MME and the source MME, the target MME sends an identifier request message to the UE to request IMSI, and the UE will return the IMSI.

Step 1005: If there is no context information of any UE in the network, the authentication process must be performed, otherwise the process is optional.

Step 1006: If there is a bearer context activated by the UE in the target, the target E will send a delete bearer message to the gateway (including the S-GW and the PDN GW) to delete the bearer context, and the gateway will return a delete bearer response message.

Step 1007: If the MN has changed since the last detachment, or the attachment is the first time that the UE is attached to the network, the target EI sends an update location message to the HSS.

Step 1008: The HSS deletes the user context on the source MME.

Step 1009: If there is a bearer context of the active state of the UE on the source MME, the source E sends a delete bearer request message to the gateway to delete the bearer context. The gateway returns to delete the bearer response message to the source MME.

Step 1010: The HSS sends an insert user subscription data message to the target MN. The MN will confirm the presence of the UE under the new tracking area (TA). If the confirmation is successful, the target MN will construct the user context and Returns the Insert User Contract Data Confirmation message to the HSS.

Step 1011: The HS S sends an update location confirmation message to the target solid E.

Step 1012: The target E selects an S-GW according to the S-GW selection function, and sends a default bearer request message to the selected S-GW, where the request message includes: IMSI, MME context ID, RAT type, default bearer QoS, and PDN address information, where the RAT type will be used in subsequent PCC decisions.

Step 101: The S-GW creates a new entry in the EPS bearer table and sends a default bearer request message to the PDN GW. The request message includes: an S-GW address of the user plane, an S-GW user plane TEID, S-GW control plane TEID, RAT type, default bearer QoS, PDN address information. From this step to step 1021, the S-GW will buffer any downstream packet data from the PDN GW.

Step 1014: Depending on the situation, for example: Whether the PCC system is deployed, the PDN GW may need to interact with the PCRF to obtain a default PCC rule, which may result in the establishment of multiple dedicated bearers.

Step 1015: The PDN GW returns a default bearer response message to the S-GW, where the response message includes: a PDN GW user plane address, a PDN GW user plane TEID, and a PDN GW control plane TEID, if the PDN address information is reassigned The address information will also be included in the response message.

Step 1016: The S-GW returns to establish a default bearer response message to the target MN, the response message includes: S-GW user plane address, S-GW user plane TEID, S-GW context ID, if the PDN address information is reallocated The address information will also be included in the response message.

Step 1017: The target E sends an attach accept message to the eNodeB, and the message includes: S-TMS I,

The TA list, if the PDN address information is reassigned, will also include the address information in the response message.

Step 1018: The eNodeB sends a radio bearer setup request message to the UE, and the attach accept message is also sent to the UE.

Step 1019: The UE sends a radio bearer setup response message including attach completion information to the eNodeB.

Step 1020: The eNodeB forwards the attach complete message to the target MN. The SI control plane message will contain the TE ID of the eNodeB and the address of the eNodeB for downlink data transmission on the S1 interface. After attaching the accept message, once the UE obtains the PDN address information, the UE may send the uplink packet data to the eNodeB and tunnel to the S-GW and the PDN gateway.

Step 1021: The target MME sends an update bearer request message to the S-GW ₀ Step 1022: The S-GW returns an update bearer response message to the target MN. The S-GW will then send the downstream packet data buffered thereon.

Step 1023: After receiving the update bearer response message, if the EPS bearer has been established, the target E can send an update location request message including the PDN GW address to the HSS to prepare for non-3GPP access.

Step 1024: The HSS stores the PDN GW address and sends an update location response to the target MN6.

After the system introduces the eMSC entity, the UE also needs to attach to the eMSC in order to continue to use the CS domain service in the PS domain. In the attaching process, the network side needs to know whether the UE supports the CSoPS capability, and further determines whether the UE supports the CSoPS capability according to whether the UE supports the CSoPS capability, and further attaches to the eMSC while attaching to the MME. The CSoPS service can be initiated in the PS domain. On the other hand, if the request attached to the eMSC is initiated by the UE, the UE also needs to know whether the network side supports CSoPS. The ability of the network to learn whether the UE supports CSoPS may be carried by the UE in the attach request message, or may be saved by the network side, such as: saving in the HSS; for the UE to know whether the network side supports CSoPS, The system broadcast message sent by the UE to the UE in its coverage may carry the capability, for example: by broadcasting a broadcast block in the system broadcast message MIB (Master information block) broadcast block to broadcast the network network side, wireless The ability of the side can also carry the ability of the network side to support CSoPS in the Attach Accept message sent to the UE after the UE is attached to the MN. In addition, if the UE is an intelligent terminal like a SIP terminal, the UE knows that it is currently located in the LTE. It is necessary to initiate registration with the eMSC, thereby actively initiating an attach procedure to the eMSC.

For the initial attachment of the UE to the eMSC, different initial architectures and processes will be used in different network architectures and application scenarios. The timing relationship of each message in the process will also be adjusted according to the situation. According to the way of attaching to the eMSC, the attaching process is roughly divided into the following types: 1. Attachment through connectivity at the IP level; 2. Joint attachment; 3. Attachment through the PCC system. The following is a detailed description of the above situations:

method one: When there is no Gs+ interface in the evolved network, the UE may be initially attached to the eMSC through the connectivity of the IP layer. Specifically, the UE may be configured to carry the CS control plane signaling by using the default bearer or the dedicated bearer to attach to the eMSC.

Embodiment 5

Figure 11 is a flow chart showing the UE attaching to the eMSC by default bearer in the manner of attaching through the connectivity of the IP layer, including the following steps:

Steps 1101 to 1117 are the same as steps 1001 to 1024 in FIG. 10. If the discovery of the eMSC is performed by the network side, the address of the eMSC is included in the attach accept message and sent to the UE in step 1112 and step 1113. In addition, the discovery of the eMSC can also be performed by the UE, and the specific eMSC discovery mechanism will be further explained below.

Step 1118: After receiving the message carried in step 1113, the UE determines that the attachment to the eMSC needs to be initiated. If the control plane protocol stack contains the IP Sec layer, the UE needs to establish a security association between the UE and the eMSC according to the received eMSC address.

Step 1119: The UE sends an IMSI attach request message to the target eMSC/VLR through the IP connectivity, where the UE to the PDN GW is the default bearer.

Step 1120: The target eMSC/VLR sends an update location message to the HSS.

Step 1121: If the eMSC/VLR changes, the HSS deletes the user context on the source eMSC/VLR.

Step 1122: The HSS inserts user subscription data to the target eMSC/VLR.

Step 1123: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1124: The target eMSC/VLR sends an IMSI Attach Accept message to the UE.

Step 1125: If the TMSI of the UE is reassigned, the UE sends an IMSI Attach Complete message to the target eMSC/VLR.

Among them, the eMSC discovery mechanism mainly has the following methods:

1. In the attach request message or in the setup bearer request message for initiating the setup bearer, the protocol protocol configuration option of the request message (Protocol Cong ionic input configuration, PC0 option) The information carrying the eMSC address is requested, and the PDN GW or the MN E queries the eMSC address by parsing the parameters in the PC0 option, for example, configuring the address of the eMSC or the PDN GW through the Dynamic Hosting Protocol (DHCP). The query mechanism obtains the eMSC address.

2. The eMSC address information is configured or saved for the user in the HSS, and the information is provided by the HSS to the MN 8. For example, the HSS directly provides the address of the eMSC, that is, in the network planning, the corresponding eMSC and its address information are configured in a Li E pool. When the UE is attached to the network, the E E obtains the eMSC address from the HSS. After the update, if the E is changed, the HSS will provide the updated address information of the updated target eMSC.

3. The MME selects an eMSC for the UE according to a preset mechanism, for example, according to the location information, the operator policy, the network topology, or the correspondence between the E and eMSCs configured on the network side, and saves the MSC in the MM context. In order, the EMSC can be found when switching. The two possible methods are as follows: A. The HSS indicates an indication of an Access Point Name (APN), which carries whether to allow roaming or location area identification, and the E E discovers the eMSC according to the information; In order to implement the association between the MME and the mobility of the eMSC, the MN can perform the query to the control entity eMSC according to the target side ID information. For example, the MME will carry an identifier of the location when requesting the eMSC address, for example, in the DNS query process. Add a location area identifier after the domain name so that a more reasonable eMSC can be queried.

4. The UE initiates a process similar to a DHCP or Name Server (DNS) to obtain the address of the eMSC. For example, the DHCP request message is extended to indicate the address of the eMSC, or the mobile station's international ISDN number (MS I SDN) is allocated to the UE, and is used for a telephone call. The format of Te lephone Uniform Resource Loca tor (Te l -URL ) is requested in DHCP.

5. The network sends a broadcast to the UE located within its coverage, including whether the network supports CSoPS capability and eMSC address.

6. When the Gs+ interface is used for relocation, the MME needs to relocate to a correct eMSC, and can determine a correct eMSC according to parameters such as the target cell identifier (Target Ce ll ID), but The eMSC that guarantees this selection is the same entity as the eMSC registered by the UE. Therefore, in this case, the content of the eMSC can be stored in the MN as the content of the mobility management context (Mobility Management Context), so that the MME can find the correct eMSC when relocating the eMSC.

7. The MME instructs the packet data network gateway (PDN GW, Packet Data Network GateWay) to discover the eMSC according to the discovery mechanism of the P-CSCF in the prior art. In order to realize the mobility association between the solid E and the eMSC, the MN will carry a location. The indication, such as TA, requests the PDN GW to discover the eMSC, and returns the result to the MME.

Embodiment 6

The default bearer is used to carry the CS control plane signaling, and the QoS cannot be guaranteed. For example, the delay is relatively large, and the bandwidth is difficult to guarantee. Therefore, the method of carrying the CS control plane signaling by using the dedicated bearer may be used to complete the UE attaching to the UE. The process of the eMSC, FIG. 12 shows a flow chart of the UE attaching to the eMSC through a dedicated bearer in the manner of attaching through the connectivity of the IP layer, which includes the following steps:

Steps 1201 to 1211: The same as steps 1001 to 1016 in Fig. 10.

Step 1212: Establish a dedicated bearer for carrying eMSC signaling, this step will establish a dedicated bearer wired link portion.

Step 1213: The target MME sends an attach accept message to the eNodeB, where the message includes: S-TMS I, TA list, if the PDN address information is re-allocated, the address information is also included in the response message, and further, the message further Includes eMSC address and dedicated bearer parameters.

Step 1214: The eNodeB sends a radio bearer setup request message to the UE, and the attach accept message is also sent to the UE. The radio bearer setup request message will contain the eMSC address and the dedicated bearer parameters.

Steps 1215 to 1218: The same as steps 1019 to 1024 in FIG. 10, and the establishment of a dedicated bearer radio link will also be performed.

Step 1219: After receiving the message of step 1114, the UE determines that the attach to the eMSC needs to be initiated. If the control plane protocol stack contains the IP Sec layer, the UE needs to establish the UE according to the received eMSC address. The security association of the eMSC.

Step 1220: The UE sends an IMS I attach request message to the target eMSC/VLR through the IP connectivity, where the UE to the PDN GW is a dedicated bearer established in the foregoing step.

Step 1221: The target eMSC/VLR sends an update location message to the HSS.

Step 1222: If the eMSC/VLR changes, the HSS deletes the user context on the source eMSC/VLR.

Step 1223: The HSS inserts user subscription data into the target eMSC/VLR.

Step 1224: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1225: The target eMSC/VLR sends an IMS I Attach Accept message to the UE.

Step 1226: If the TMS I of the UE is reassigned, the UE sends an IMS I Attach Complete message to the target eMSC/VLR.

It should be noted that, in this process, the discovery mechanism of the eMSC is the same as that described in the fifth embodiment. In addition, in this process, a dedicated bearer carrying CS control plane signaling is to be established, and step 1212 is to establish a part of the dedicated bearer wired link. In addition to the establishment of the default bearer radio link part in steps 121 3 to 1218, It is also necessary to establish a proprietary bearer wireless link portion.

The establishment of the CS bearer-specific bearer is triggered by the E-E, similar to the default bearer establishment method in the evolved network. In addition, the CS bearer-specific bearer establishment trigger mechanism includes the following:

1. During the attach process, the PDN GW triggers the top-down setup of the dedicated bearer to carry CS control plane signaling.

After the UE is attached to the MME, the eMSC address is carried in the attach accept message and the UE initiates the process of attaching to the eMSC. First, the default bearer is used to carry the CS control plane signaling to initiate the attach request to the eMSC, and then the eMSC passes the PCRF. The dedicated bearer is triggered to be established. After the dedicated bearer is established, the CS control plane bearer is transferred from the default bearer to the dedicated bearer.

3. The UE is triggered to establish the dedicated bearer, which is similar to the proprietary bearer setup procedure triggered by the UE in the evolved network. Method 2:

When there is a Gs+ interface in the evolved network, the UE initially attaches to the EMSC and is initially attached to the eMSC, which is also called joint attachment, and further divided into two cases according to whether the UE actively reports the CSoPS capability or the network sinks the CSoPS capability. .

Example 7

If the UE indicates whether the UE has the CSoPS capability by using the parameter Attach Type in the attach request message, if yes, the network side determines whether to initiate the attach procedure to the eMSC according to whether the UE supports the CSoPS, and the corresponding process is as shown in FIG. The method includes the following steps: Step 1301: The UE initiates an attach request to the eNodeB, and the eNodeB selects a solid E entity for the UE, and forwards the attach request to the corresponding MN. The attach request message includes: the network capability and the PDN address of the UE. The Attach Type parameter, the S-TMSI, and the TAI or IMSL Attach Type parameter associated with the S-TMSI are used to indicate to the network side which type of attachment, for example: only attached to the evolved network, which has been attached to the IMSI before. In this case, the UE attaches to the evolved network and the joint network to the evolved network and the CS network. In this embodiment, the UE will instruct the network to perform joint attach, and the parameter also indicates that the UE has the capability of CSoPS.

Steps 1302 to 1310: The same as steps 1002 to 1011 in Fig. 10.

Step 1311: The network side determines whether it supports CSoPS capability. If supported, the target MME sends a location update request to the target eMSC/VLR for joint attach.

Step 1312: The target eMSC/VLR sends an update location message to the HSS.

Step 1313: If the eMSC/VLR changes, the HSS deletes the user context of the source eMSC/VLR.

Step 1314: The HSS inserts user subscription data into the target eMSC/VLR.

Step 1315: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1316: The target eMSC/VLR sends a location update accept message to the target.

Steps 1317 to 1319: The default bearer is established, and the related steps are the same as steps 1012 to 1016 in FIG. Step 1 320 to Step 1 321: The procedure is the same as Step 1 017 to Step 1018 of FIG. 10, except that in these two steps, information about whether the UE has successfully joined to the eMSC is carried.

Step 1 322 to Step 1 325: The flow is the same as that of FIG. 10, Step 1019 to Step 1 024.

Step 1 326: If the UE's TMS I is reassigned, the target MME will send a TMS I Reallocation Complete message to the target eMSC/VLR.

It should be noted that the UE attachment mode of the process is a joint attachment mode, so the address of the target eMSC needs to be known, and the discovery mechanism of the eMSC is the same as described above. In addition, step 1 311 to step 1 316 are processes for jointly attaching to the eMSC, and steps 1 317 to 1 319 are procedures for establishing a default bearer, and the two processes do not have strict timing sequence. In this embodiment, What is described is that the joint bearer is first established and then the default bearer is established, but the default bearer may be established first and then the joint attach is performed.

Example eight

If the UE does not carry the CSoPS-capable identifier in the attach request message, but the UE notifies the UE whether the network supports the CSoPS capability after the UE attaches to the MME, and then the UE determines whether to initiate according to whether the UE has the CSoPS capability. To the initial attachment process of the eMSC, the corresponding flowchart is as shown in FIG. 14, and includes the following steps:

Steps 1401 to 141 3: The flow is the same as steps 1001 to 1016 in FIG.

Step 1414: The target MME sends an attach accept message to the eNodeB, where the message includes: S-TMS I, TA list, if the PDN address information is re-allocated, the address information is also included in the message, and if the network side supports CSoPS The capability will include the information in the message. Further, if the eMSC address is discovered by the network side, the message will also include the eMSC address.

Step 1415: The eNodeB sends a radio bearer setup request message to the UE, and the attach accept message is also sent to the UE. If the attach accept message includes the CSoPS-capable identifier and/or the eMSC address of the network, In this step, the corresponding information is also included in the attach accept message.

Step 1416~Step 1419: The flow is the same as the step 1 0 019~step 1024 in Figure 10.

After receiving the message shown in step 1415, the UE determines that the network side supports the CSoPS capability, and the UE If the CSoPS capability is also available, the request information of the IMSI attached to the designated eMSC is carried in steps 1416 to 1417.

Step 1420: The target MME sends an IMSI attach request message to the target eMSC/VLR.

Step 1421: The target eMSC/VLR sends an update location message to the HSS.

Step 1422: If the eMSC/VLR changes, the HSS deletes the user context on the source eMSC/VLR.

Step 1423: The HSS inserts user subscription data to the target eMSC/VLR.

Step 1424: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1425: The target eMSC/VLR sends an IMSI Attach Accept message to the target MN, and forwards it to the UE by MN.

Step 1426: If the TMSI of the UE is reassigned, the UE sends an IMSI Attach Complete message to the target eMSC/VLR via the target MME.

It should be noted that the eMSC discovery mechanism in this process is the same as described above.

Method three:

There is no G s + interface in the network, and the UE can also attach to the eMSC through the PCC system.

Example nine

In this embodiment, the UE sends a request to the EMSC to send information to the eMSC through the NAS message, and the E further sends the request to the PDN GW through a GPRS Tunneling Protocol for Control Plane (GTP-C) message. The request is sent to the eMSC through the PCC system. In the attaching process, the UE carries the CSoPS-capable identifier of the UE by using the Attach Type parameter in the attach request message, and then the network side determines whether to initiate the initial attach process to the eMSC according to whether the UE has the capability of CSoPS, and correspondingly The process shown in Figure 15 includes the following steps:

Step 1501: The UE initiates an attach request to the eNodeB, and the eNodeB selects a solid E entity for the UE, and forwards the attach request to the corresponding MN. The attach request message includes: the network capability, the PDN address, the Attach Type parameter, and the S of the UE. -TMSI and the TAI associated with this S-TMSI or IMSI. The At tach Type parameter is used to indicate to the network side which type of attachment is to be performed, for example: attaching only to the evolved network, attaching to the evolved network if the IMSI is attached before, and jointly attaching to the evolved network and the CS network, in this implementation In the example, the UE will instruct the network to perform joint attachment, and the parameter also indicates that the UE has the capability of CSoPS.

Step 1502 to Step 1510: The flow is the same as that of FIG. 10, step 1003 to step 1011.

Step 1511: In this step, the IMS I attach request message is carried in the setup default bearer request message sent by the target E to the S-GW and further sent to the PDN GW.

Step 1512: In this step, the IMSI attach request message is carried in the PCRF interaction message sent by the PDN GW to the PCRF.

Step 1513: The PCRF sends an IMSI attach request message to the target eMSC/VLR.

Step 1514: The target eMSC/VLR sends an update location message to the HSS.

Step 1515: If the eMSC/VLR changes, the HSS deletes the user context on the source eMSC/VLR.

Step 1516: The HSS inserts user subscription data into the target eMSC/VLR.

Step 1517: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1518: The target eMSC/VLR sends an IMSI Attach Accept message to the PCRF.

Step 1519: The PCRF sends a PCRF interaction confirmation message to the PDN GW, and carries an IMSI attach accept message.

Step 1520: In this step, the IMS I attach accept message is carried in the setup default bearer acknowledgement message sent by the PDN GW to the S-GW and further sent to the target MN.

Step 1521: In this step, the attach accept message includes: indicating that not only the UE is attached to the MME, but also the IMS I is attached to the eMSC.

Step 1522: In this step, the radio bearer setup request message includes: indicating that not only the UE is attached to the implicit, but the IMSI is also attached to the eMSC.

Step 1523 to step 1526: The same as steps 1019 to 1024 in FIG.

Step 1527: If the TMSI of the UE is reassigned, the target MME to the target eMSC/VLR Send a TMS I Reassign Complete message.

In the above attach procedure, there is a problem of how to find an optimal PDN GW to carry CS voice calls. In practical applications, the following options are available for the selection of the PDN GW:

1) When the eMSC is completely an upper layer entity, it has nothing to do with the PDN GW, and only needs to maintain the IP layer connectivity between the UE and the eMSC;

2) When attached, 丽 E can query a specific PDN according to the contract data or the APN indication.

GW, the PDN GW and each eMSC have a better physical area configuration, or based on the user's subscription data HSS directly provides an appropriate PDN GW address to the MME;

3) When mu l t i - APN exists, the UE directly selects a new PDN GW (different from the default bearer PDN GW) when the UE initiates the call, and according to the PDN GW, establishes a dedicated bearer to carry the CS control plane signaling.

In the above attach procedure, when there is an interface between the MME and the eMSC, there is also a problem of how to select a correct MN to complete the subsequent handover process. Possible selection methods are:

1) All Li E's functions are consistent, ensuring uniform functions are performed;

2) After the eNodeB selects an MME, it is determined whether the MME supports the CSoPS capability, and if it does not support re-rout e according to its own configuration parameter, it can be used to support a CSoPS capable E.

3) Configure the relevant parameters on the eNB to select a correct MME, that is, the MME supporting CSoPS capability.

In the process of attaching to the eMSC, the eMSC may authenticate the UE (the operation is not shown in the above-mentioned attachment embodiment). For example, when the UE registers with the eMSC through IP connectivity, the eMSC will initiate and inter-UE. The secure authentication to negotiate the security parameters, the eMSC can inform the UE that there is no need to establish a security association between the UE and the eMSC.

The above attaching process is an initial attaching process, that is, a process of attaching to the network when the UE is powered on. In the following, a description will be given of a scenario in which a UE that has been attached to a network needs to reattach to a new eMSC due to mobility. After the UE is attached to the eMSC, if the user moves in the Idle state, the MME whose service is currently serving the UE may be changed, which may cause the eMSC to change. In order to cope with this situation, the idle state is required. The mobility management, that is, the process of reattaching to the new target E and the target eMSC. According to the possible differences in the network architecture, the partitioning method similar to the initial attaching process can be divided into two cases: mobility management in the Idle state with the Gs+ interface and mobility management in the Idle state without the Gs+ interface. .

Example ten

When there is a Gs+ interface in the network architecture, the joint location update will be performed. In this embodiment, the case where the E and S-GW are simultaneously changed is taken as an example. The reattachment process is as shown in FIG. 16, and includes the following steps:

1601: The UE initiates a tracking area update request to the target MME via the eNodeB.

1602: The target MME requests a user context from the source MME.

1603: The network authenticates the user.

Step 3:1? 1604: The target MME sends a context confirmation message to the source MME.

Step 3⁄4 .1? 1605: The target MME sends a create bearer request message to the target S-GW due to the change of the S-GW.

1606: Update the bearer information between the target S-GW and the PDN GW.

Step 3⁄4 .1? 1607: The target S-GW sends a Create Bearer Response message to the target.

Step 3⁄4 .1? 1608: The target MME sends an update location message to the HSS.

1609: The HSS deletes the user context on the source MME.

1610: The source MME sends a delete bearer request message to the S-GW to delete the bearer context. The S-GW returns a delete bearer response message to the source 6.

Step 1611: The HSS inserts user subscription data into the target MME.

Step 1612: The HS S sends an update location confirmation message to the target solid E.

Step 161 3: The target MME sends a location update request to the target eMSC/VLR for joint location update. Step 1614: The target eMSC/VLR sends an update location message to the HSS.

Step 1615: If the eMSC/VLR changes, the HSS deletes the user context on the source eMSC/VLR.

Step 1616: The HSS inserts user subscription data into the target eMSC/VLR.

Step 1617: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1618: The target eMSC/VLR sends a location update accept message to the target.

Step 1619: The target MME sends a tracking area update accept message to the UE.

Step 1620: The UE sends a tracking area update complete message to the target MME.

Step 1621: If the TMS I of the UE is reassigned, the target MME sends a TMS I Reallocation Complete message to the target eMSC/VLR.

It should be noted that the method uses joint location update, and needs to determine the address of the target eMSC in the process, and the discovery mechanism of the eMSC is the same as that described above.

In addition, this embodiment assumes that Li E and S-GW are simultaneously changed, and may be used in practical applications.

The S-GW does not change. The corresponding process should be: Step 1605 and Step 1 607 are changed to target E. The S-GW notifies the UE that the service E entity has changed, and the change is recorded by the S-GW. The response message is sent for subsequent paging of the UE in the I dle state. Accordingly, the operations of step 1606 and step 1610 need not be performed, and the rest are the same as described above.

Embodiment 11

If the Gs+ interface does not exist in the network architecture, the re-attachment process needs to be performed through IP connectivity. In this embodiment, the case where the MME and the S-GW are simultaneously changed is taken as an example. The re-attachment process in this case is as shown in the figure. 17, including the following steps:

Steps 1701 to 1712: The same as steps 1601 to 1612 of Fig. 16, in which it is judged whether the eMSC has changed and its address is obtained.

Step 1 71 3: The target MME sends a tracking area update accept message to the UE, and feeds back the new eMSC address to the UE.

Step 1714: The UE sends a tracking area update complete message to the target MME. Step 1715: If the IP Sec layer is included in the control plane protocol stack, the UE needs to establish a security association between the UE and the target eMSC according to the received eMSC address.

Step 1716: The UE sends a location area update request message to the target eMSC/VLR through the IP connectivity, where the UE to the PDN GW is a bearer previously established for bearer CS control plane signaling, and the bearer may be a default bearer or may be Dedicated bearer.

Step 1717: The target eMSC/VLR sends an update location message to the HSS.

Step 1718: If the eMSC/VLR changes, the HSS deletes the user context on the source eMSC/VLR.

Step 1719: The HSS inserts user subscription data to the target eMSC/VLR.

Step 1720: The HSS sends an update location confirmation message to the target eMSC/VLR.

Step 1721: The target eMSC/VLR sends a location area update accept message to the UE.

Step 1722: The UE sends a location area update complete message to the target eMSC/VLR.

It should be noted that the address of the eMSC needs to be determined during the processing of the method, and the discovery mechanism is the same as described above. In addition, it should be additionally noted that there is no concept of a location area (LA) in the SAE. When the TA changes, the UE may trigger a logical LAU process, or the network side entity notifies the UE to go. Perform location update of the associated analog CS domain to implement eMSC migration. The information of the TA where the UE is located is saved on the eMSC, or the information of the LA where the UE is located is saved, and LA can be derived from the TA. The eMSC determines whether to send the simulated TMS I to the UE according to the policy of the operator, the configuration of the data, and the like. The new eMSC determines o ld eMSC according to the location relationship, identity, and the like of the UE. Even the UE itself advertises the ID of the eMSC in the location update message.

In addition, this embodiment assumes that the MN and S-GW are changed at the same time. In actual application, the S-GW may not be changed. In this case, the corresponding process should be: Step 1705 and Step 1707 are changed to target E-direction. The S-GW informs the UE that the service E entity has changed, and the S-GW records the change and replies with a response message, which is used for subsequent paging of the UE in the Idle state, and accordingly, no further steps are required. The operations of 1706 and step 171 0 are the same as described above.

In the above mobility management process in the I dle state, similar to the attach process, there is also how to go The problem of finding an optimal PDN GW to carry CS voice calls, discovering an optimal CSoPS-capable problem, and eMSC may need to authenticate the UE, the method is similar to the attach procedure, here is not Let me repeat.

When the user no longer uses the network service, such as shutdown or the battery is exhausted, or the network notifies the user that the network cannot continue to be connected, the detach process will be initiated by the user or the network.

According to different entities that trigger the detachment service, the detachment process can be divided into two situations, namely, the detachment process initiated by the UE and the detachment process initiated by the network side.

Firstly, the detachment process initiated by the UE is discussed. According to the network architecture, similar to the previous classification criteria, the detachment process can be further divided into two cases according to whether there is a Gs+ interface in the network: When there is a Gs+ interface, the association is used. The way to attach; when there is no Gs+ interface, the IP connectivity is first removed from the eMSC and then detached from the evolved network.

Example twelve

If there is a Gs+ interface on the network, the joint de-attach method is used. The specific detach process is as shown in Figure 18. The following steps are included:

Step 1801: The UE sends a detach request message to the MME.

Step 1802: The MN sends a delete bearer request message to the S-GW, and the S-GW further sends a delete bearer request message to the PDN GW.

Step 1803: If the PCC architecture is configured in the network, the PDN GW interacts with the PCRF to notify the PCRF that the bearer has been released. Otherwise, step 1804 is directly performed.

Step 1804: The PDN GW sends a delete bearer response message to the S-GW, and the S-GW further sends a delete bearer response message to the MME.

Step 1805: The MN sends an IMS I detach request message to the eMSC/VLR.

Step 1806: The eMSC/VLR sends an IMS I detach accept message to the MME.

Step 1807: If the shutdown is not caused by the exhaustion of the UE, the MME sends a detach accept message to the UE, otherwise step 1808 is directly performed.

Step 1 808: The MME initiates a signaling connection release procedure. It should be noted that the steps 1802 to 1804 are the process of deleting the bearer, and the steps 1805 to 1806 are the IMSI detachment process. The two processes have no strict sequence in sequence, and there is no order correlation. The bearer process may be deleted as described in the embodiment, the IMSI detach process may be followed, or the IMSI detach process may be preceded, the bearer process may be deleted, or the two processes may be performed simultaneously.

Example thirteen

If the Gs+ interface does not exist in the network, the process of de-attaching the eMSC is performed through the IP connectivity, and then the process of detaching the evolved network is performed. The process is as shown in FIG. 19, and the following steps are included: Step 1901: If the control plane protocol stack If the IP Sec layer is included, and there is no security association between the UE and its serving eMSC/VLR, the security association between the UE and the target eMSC is triggered by the UE. Otherwise, step 1902 is directly performed.

Step 1902: The UE initiates an IMSI detachment request message to the eMSC/VLR through the IP connectivity, where the bearer between the UE and the PDN GW is a bearer that carries the CS control plane signaling established for the UE.

Step 1903: The eMSC/VLR sends an IMSI detach accept message to the UE by using IP connectivity. Step 1904: The UE initiates a detach request message to the MME.

Step 1905: The MN sends a delete bearer request message to the S-GW, and the S-GW further sends a delete bearer request message to the PDN GW.

Step 1906: If the PCC architecture is deployed in the network, the PDN GW interacts with the PCRF to notify the PCRF that the bearer has been released.

Step 1907: The PDN GW sends a delete bearer response message to the S-GW, and the S-GW further sends a delete bearer response message to the MME.

Step 1908: If the shutdown is not caused by the exhaustion of the UE, the MME sends a detach accept message to the UE, otherwise step 1909 is directly performed.

Step 1909: The MME initiates a signaling connection release process.

It should be noted that the method is to attach the eMSC through the IP connectivity IMSI, so it must first The IMSI is attached to the eMSC to further attach the evolved network. Otherwise, if the evolved network is first attached, the bearer between the UE and the PDN GW is released, so that the process of the IMSI detaching the eMSC cannot be completed through the IP connectivity.

For the detachment process initiated by the network side, that is, the detachment process initiated by MN E or the detach process initiated by the HSS is similar to the detach process initiated by the UE, and is also classified into a joint detachment with a Gs+ interface. The two processes are detached by IP connectivity without a Gs+ interface. For the de-attachment of the eMSC through the IP connectivity, the IMSI must first be attached to the eMSC to detach the egress network. In this case, the UE may notify the UE to initiate the process of attaching the eMSC to the eMSC, or may initiate the process from the E-E to the S-GW. The IMSI de-attach request, which in turn is sent to the eMSC through the PDN GW. The specific process is similar to that in the twelfth and thirteenth embodiments, except that the detach request is initiated by the network side, and details are not described herein again.

It should be understood that the above description is only a preferred embodiment of the invention and is not intended to illustrate all of the technical features of the invention. Therefore, the above description is not intended to limit the spirit and scope of the invention, and any equivalent changes or substitutions made by those skilled in the art are considered to be within the scope of the present invention.

Claims

What is claimed is: 1. An attachment method, comprising:

Attaching the UE to the target mobility management entity MME;

The UE is attached to the target eMSC/visit location register VLR according to the acquired target eMSC address information.

The method according to claim 1, wherein the acquiring the target eMSC address information specifically includes:

When the target MN interacts with the home subscriber server HSS to perform location update, the target MN sends the tracking area identifier TAI in the location update request information sent to the HSS;

The target E receives the returned update location confirmation message, and the update location confirmation message includes the target eMSC address information queried by the HSS according to the TAI.

The PC0 option of the establishment of the bearer request message initiated by the UE in the cell protocol configuration PC0 option of the attach request message initiated by the UE to the target MN E or the target MME E to the packet data network gateway PDN GW carries the message requesting the eMSC address information, the target The MME or the PDN GW queries the eMSC address information by parsing the PC0 option.

When the target MME interacts with the HSS for location update, the target MME obtains pre-saved eMSC address information from the HSS.

The indication of obtaining the target eMSC address information is extended in the dynamic host configuration protocol DHCP request message initiated by the UE. The method according to claim 1, wherein the acquiring the target eMSC address information specifically includes:

The network side transmits a broadcast message including the target eMSC address information to the UE to obtain the target eMSC address information.

When the target E is relocated to the target eMSC/VLR, the target eMSC/VLR address information can be determined according to the target cell identity.

The target E selects the target eMSC address information for the UE according to the location information, the operator policy, the network topology, or the correspondence between the target MME and the target eMSC/VLR configured on the network side.

The method according to claim 8, wherein the location information is information of an access point name APN, and the target MME is configured according to location information, an operator policy, a network topology, or a target MME configured on the network side. The correspondence between the target eMSC/VLRs for the UE to select the target eMSC address information specifically includes:

The target solid E obtains the target eMSC address information from the information of the APN indicated by the HSS that carries the roaming or location area identification.

The method according to claim 8, wherein the location information is target side ID information, and the target MME is configured according to location information, a carrier policy, a network topology, or a target MME configured on a network side. The correspondence between the eMSC/VLRs for the UE to select the target eMSC address information includes:

The target MN obtains the target eMSC address information through the configuration query according to the target side ID information.

The method according to claim 10, wherein the target side ID information includes a location identifier, and the target MN obtains the target eMSC address information by using the configuration query according to the target side ID information, and specifically includes: The target MME carries a location identifier when requesting the target eMSC address, and queries the target eMSC address information by using the location identifier.

12. The method according to claim 1, further comprising:

The target solid E derives the position area LA from the tracking area TA.

The method according to any one of claims 1 to 2, wherein the attaching the UE to the target MN specifically comprises: initially attaching to the target MN by initiating an attach request message to the target MME And the attaching the UE to the target eMSC/VLR according to the obtained target eMSC address information includes:

The target MN E initiates a location update request to the target eMSC/VLR according to the obtained target eMSC address information;

The target eMSC/VLR interacts with the HSS to perform location update;

The target MME receives the location update accept message returned by the target eMSC/VLR;

The target MME returns an attach accept message to the UE.

The method according to any one of claims 1 to 2, wherein the attaching the UE to the target MN specifically comprises: by initiating a tracking area update request message to the target MME, the UE reattaching to the target MN E: The attaching the UE to the target eMSC/VLR according to the obtained target eMSC address information specifically includes:

The target eMSC/VLR interacts with the HSS to perform location update;

The target MN returns a tracking area update accept message to the UE.

15. An attachment device, comprising:

a first attaching module, configured to attach the UE to the target MN;

An obtaining module, configured to obtain target eMSC address information;

a second attaching module, configured to attach the UE to the target according to the acquired target eMSC address information eMSC/VLR.

The apparatus according to claim 15, wherein the obtaining module comprises: a requesting module, configured to send, to the target HSS, location update request information carrying a TAI; and a receiving module, configured to receive an update returned by the HSS a location confirmation message, where the update location confirmation message carries the target eMSC address information that the HSS queries according to the TAI.

17. The attachment device of claim 15, further comprising:

The derivation module is configured to derive the location area LA according to the tracking area TA.

18. A system for implementing network backward compatibility, comprising: eMSC/VLR, HSS, and MME;

HSS for saving user information;

The system according to claim 18, wherein the control plane signaling comprises a handover message, an attach message, a location update message, a mobility management message, location information of the UE, and/or call control signaling.