WO2009030162A1 - Method, device and system for implementing mobile handover - Google Patents

Abstract

A method for implementing mobile handover is provided, wherein a mobile node MN establishes a session with an opposite node by initial attachment in the AN domain of the current access network, and when the MN needs to perform the mobile handover to a new AN domain, the method further includes: finding and selecting a target access router N-AR in the new AN domain, pre-establishing a connection with the N-AR, modifying the property of the established service session through the pre-established connection with the N-AR, rebuilding the media stream address binding of the media stream agent function in the boundary gateway function entity to the media stream anchor in the access network domain in accordance with the modified property of the service session, completing the mobile handover, finishing the service session in the AN domain of the current access network, and releasing the attaching point resource in the current AN domain. In addition, a system and device for implementing mobile handover are also provided. With the invention, the seamless handover could be realized in the Inter-AN mode of the NGN architecture.

Description

 Method, device and system for realizing mobile switching The present application claims priority to Chinese patent application filed on August 28, 2007 by the Chinese Patent Office, Application No. 200710148415.3, entitled "Method, Equipment and System for Realizing Mobile Switching" The entire contents of which are incorporated herein by reference. Technical field

 The present invention relates to a mobile handover (Handover) technology, and more particularly to a method, device and system for implementing mobile handover in a Next Generation Network (NGN). Background technique

 The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) specifies the structure of the Next Generation Network (NGN), which is divided into Service Control Floor (SCF), Transport Control Layer and Transport Layer. Three floors.

 The SCF is used to implement the service control of the call session for each application service; and the functions such as registration, session initiation, and session control are performed through the Session Initiation Protocol (SIP). 1 is a schematic diagram of the composition of an SCF in a prior art NGN architecture, which is mainly composed of a Proxy-Call Session Control Functional Entity (P-CSCF) and a S-CSCF. Service-Call Session Control Functional Entity ) and the Home Subscriber Server (HSS). The P-CSCF is an interface point between the service control layer and the transport control layer, and is used to query the transport control layer for the current transport layer location of the mobile node (MN, Mobility Node), and request resources from the transport control layer.

2 is a schematic diagram of a composition of a transmission control layer in a prior art NGN architecture. The transmission control layer mainly includes a Network Attatchment Control Function (NACF) and a Resource Admission Control Function (RACF). Among them, the main functions of NACF include network access authentication, IP address and mobile subscriber (CPE, Customer Premises Equipment). The configuration of the access parameters, the binding update of the mobile location, and the generation and delivery of the user policy.

 The main functional entities included in NACF are as follows:

 The Access Management Functional Entity (AM-FE) is used to implement the Dynamic Host Configuration Protocol Layer 3 Delay (DHCP L3 Relay) and the Authentication, Authentication, and Accounting Client (AAA Client) functions.

 The Transport Authentication and Authorization Functional Entity (TAA-FE) is used to implement the AAA server function. It can also act as an AAA proxy (Proxy) server when roaming.

 The Transport Layer User Configuration Library Functional Entity (TUP-FE) is a database that stores information such as user-customized configuration files. The user profiles mentioned here include: Username, Password, User Initial Gating Information, and User Service. Quality of Service (QoS) configuration, etc.

 The Network Address Configuration Function Entity (NAC-FE) is used to implement the configuration of IP addresses and access parameters.

 The transport layer location management function entity (TLM-FE) is used to implement the address binding update function of the mobile user; the TLM-FE is the core point of the NACF: downward, the current address information of the user is obtained from the TAA-FE and the NAC-FE. The user-related information is bound; upward, the current location query information is reported to the SCF; to the right, the bound user location and the user-customized QoS configuration are pushed to the RACF.

 The RACF is mainly used for resource admission and policy generation. The service quality request is obtained from the SCF, and the location and user subscription information is obtained from the NACF, and the control policy is sent to the transport layer for resource control. The functional entities mainly included in the RACF are included. A policy decision function entity (PD-FE).

 The transport layer is the transport device of the L2/L3 layer, which is embodied as an access point (AP, Access Point), an access router (AR, Access Router), etc., and is also an implementation of the access and resource policy.

In practical applications, the mobile switching problem of the MN is often involved, that is, the location where the MN changes its location in the session, and the problem of switching the session is required. Before introducing the mobile switching method in the prior art, first introduce some terms that will be used in the following process: (1) Domain and Access Domain The domain is a management scope concept. Each administrative domain has a unique domain name, which is used to identify the administrative domain to which a user belongs. + Manage domain ID" format, such as "user@home.com".

 A management domain further includes a core domain (Access Domain) and a access network domain (Access Network Domain), and one core domain may correspond to multiple access domains; in each access domain, multiple The access subnet of the heterogeneous access technology may include multiple access attachment points in one access domain, and each access attachment point may correspond to one access subnet and one access router AR. An access domain is controlled by a local attachment control subsystem.

 (2) Current Access Router (P-AR)

 P-AR refers to the router (AR) where the MN is currently attached, sometimes referred to as 0-AR (Old-AR) or Serving AR.

 (3) Target Access Router (N-AR)

 The router selected or designated by the MN to be moved to switch, also referred to as the target AR (Target AR )

 ( 4 ) Anchor-GW

 In the range of an AN domain, the Anchor-GW has a local media stream anchor function with respect to the MN: The data media stream sent to the MN in the AN domain needs to pass through the Anchor-GW to reach the MN, and the data media sent by the MN The stream needs to be sent through the Anchor-GW. The Anchor-GW is the media stream forwarding point of the transport layer in the entire AN domain.

 (5) Local home address (L-HoA) in the AN domain

 The L-HoA in the AN domain is a HoA with local characteristics. When the MN moves in the same AN domain, the L-HoA is unchanged. Only after the MN moves out of the current AN domain, the L-HoA is replaced. When the layer establishes a service session, the L-HoA will be used as the SIP session address of the MN, that is, the IP address in the SIP session.

 (6) Security Alliance (SA)

SA refers only to security associations established between functional entities, such as MN and DHCP. A mutually trustworthy relationship established between Server, AR or AAA Proxy entities; usually generated by the initial key of both parties; with SA, both parties can effectively confirm whether the signaling or data comes from the other party that has been authenticated by security. Entity, thus preventing the occurrence of such phenomena as theft or attack.

 Three types of mobile switching modes are proposed in the existing multi-protocol and IP-based interworking (ITU-T SG13), as shown in Figure 3, where the MM1 mobile switching mode refers to mobile across the core network and across carriers; MM2 The mobile switching mode refers to the mobility between different AN domains in the same core network, also known as the Inter-AN switching mode. The MM3 mobile switching mode refers to the mobility in the same AN domain, also known as the Intra-AN switching mode. . For both MM2 and MM3 switching modes, it is required to support the implementation of the handover without interrupting the ongoing service, and reduce the delay of the mobile handover during the handover process, and keep the data loss to be minimal. Switch. In Figure 3, CN is the core domain, AN1-1, and AN1-2 are two different AN domains. Within each AN domain, multiple access subnets of the same or different access technologies may be included.

 For the above three modes of mobile handover, there are two main mobile handover protocols currently used, one is a SIP-based handover protocol, and the other is a handover protocol based on the Mobile Internet Protocol (MIP), where the SIP-based protocol is an application layer. The session establishment protocol implements the relevant signaling process of the mobile handover through SIP message exchange; the MIP protocol is the L2/L3 layer handover protocol, and the mobile handover process is implemented by the Mobile IP technology.

 Taking the SIP-based handover protocol as an example, there are currently two mobile handover technologies.

 First, under the Internet (Internet) architecture, the MN establishes a call session with the peer node (CN) participating in the session through SIP signaling. When the MN needs to move and attach to a new location, the mobile handover procedure includes: moving at the MN Obtain a new IP address in a pre-configured manner before attaching to a new location; SIP registration with the SIP server in the MN home network using the newly obtained IP address; Send to the CN using the re-INVITE message specified in RFC3261 SIP message, modify session attributes.

In the above mobile switching process, the re-INVITE is bundled in the existing session, so the call ID of the session does not change, only the IP address and the port number are changed, so that the CN participating in the session can understand the mobile switching. Just to change an existing session Instead of establishing a new session, after the CN receives the re-INVITE, it will send a 200 OK response to accept the change, so during the above mobile handover process, the session established before the mobile handover does not need to be interrupted. However, the mobile switching mode is only suitable for the Internet architecture, and cannot be transferred to the NGN architecture. In this method, the CN participating in the session can obtain the current location information of the MN through the IP address of the SIP message and the media stream. Not conducive to privacy protection. And there is still room for improvement in switching delays.

 Second, in the NGN architecture, establishing a SIP-based call session typically includes: SIP registration of the call session, SIP initiation of the call session, and Core Border Gateway Function (C-BGF) selection and IP address translation.

 The SIP registration of the call session includes: the MN initiates a registration message to the S-CSCF through the P-SCSF, and binds the currently assigned IP address of the user to the user identifier; the S-CSCF downloads the authentication data of the application layer of the user from the HSS. User configuration, establishing an SA between the P-CSCF and the MN.

 The SIP of the call session initiated by the MN side to the CN side includes: The MN generates a SIP INVITE request message, where the CN identity identifier is included, and the identity identifier includes a CN user name and a home domain name; determining the CN home network by using the CN identity identifier The S-CSCF sends the SIP INVITE to the CN through the P-CSCF of the current region of the CN according to the registration information of the current IP address registered by the CN; the MN and the CN interact through the subsequent series of SIP information. Conversation.

 In carrying out the process of the present invention, the inventors have found that the prior art has at least the following problems:

According to the above SIP-based call session, the existing ITU-T NGN standard can support a Nomadism scenario for mobile handover, that is, when the MN moves from the original location to a new location, the original interrupt is interrupted. The established session, and then to the new location to establish a new session in accordance with the steps of establishing a call session as described above. For example, the MN establishes a session with the CN after accessing the initial attachment of an AN domain. If the MN needs to move to another AN domain, the session established after the initial attachment needs to be interrupted, after the MN moves to the new location. , re-establish a session with the CN. Based on the above description of the existing mobile switching solution, it can be seen that in the prior art NGN architecture, seamless handover without interruption, reduced delay, and less packet loss cannot be achieved. Summary of the invention

 Embodiments of the present invention provide a method for implementing mobile handover, which can implement seamless handover in an Inter-AN mode under an NGN architecture.

 Embodiments of the present invention provide a system for implementing mobile switching, which can implement seamless handover in an Inter-AN mode under an NGN architecture;

 The embodiment of the invention provides an L-NACF, and the L-NACF can implement the seamless handover process in the Inter-AN mode under the NGN architecture.

 The embodiment of the invention provides an H-NACF, and the H-NACF can implement the seamless handover process in the Inter-AN mode under the NGN architecture.

 The embodiment of the present invention provides an RACF, which can implement resource admission and QoS control for seamless handover in the Inter-AN mode under the NGN architecture.

 The embodiment of the invention provides an AM-FE, and the AM-FE can implement the seamless handover access management function in the Inter-AN mode under the NGN architecture.

 An embodiment of the present invention provides a method for implementing mobile handover, where a mobile node MN completes an initial attachment in a current access network AN domain and establishes a service session with the opposite node CN, when the MN needs to be from the current AN domain. When the mobile switch to the new AN domain, the method further includes:

 Discovering and selecting a target access router N-AR in the new AN domain, and performing connection pre-establishment on the N-AR;

 Modifying, by the pre-established connection to the N-AR, an attribute of the established service session, and re-establishing a media stream proxy function in the border gateway function entity and a media stream address of the access network domain media stream anchor point according to the modified attribute Binding

 The mobile switching is completed, and the service session in the current AN domain is ended, and the current AN domain attachment point resource is released.

An embodiment of the present invention provides a system for implementing mobile switching, where the system includes: a MN and a next-generation network NGN; the NGN includes a core network domain and a transport layer control management unit and a service layer control management unit, which are composed of entities in the access network AN domain; the service layer control management unit includes a service control layer function entity SCF; the MN is used to access the NGN, and Performing a mobile handover in the NGN; the transport layer control management unit is configured to complete initial MN attachment in the current AN domain; and discover and select the new AN domain when the MN needs to switch to a new AN domain N-AR, pre-establishing the connection of the N-AR;

 The SCF in the service layer control management unit is configured to establish a session between the MN and the CN; modify the attribute of the established service session by using the pre-established connection to the N-AR; and reconstruct the boundary gateway function entity according to the modified attribute The media data stream proxy function is bound to the media stream address of the access domain media stream anchor; the mobile handover is completed, and the current AN domain attachment point session and resources are released.

 A local network attachment control function entity L-NACF, wherein the L-NACF includes an L-MMF, an authentication, an authentication, an accounting server/proxy, and a network address configuration function entity NAC-FE; Further included in the L-MMF are: L-HMF and L-LMF;

 The L-HMF is configured to query the candidate AR information of the current attachment point in the H-NACF and the neighboring access point L2 detected by the MN when the MN needs to switch to the new AN domain, according to the configured selection. a policy, selecting an N-AR in the new AN domain;

 The L-LMF is configured to perform location binding update according to the L-HoA address configured by the NAC-FE under the binding request of the AM-FE, and push binding information to the L-RACF; and to the H-NACF Forward the binding request;

 The charging, authenticating, and accounting server/proxy is configured to receive an access authentication request from the MN, implement access authentication of the MN, and forward the access authentication request from the MN to the H-NACF, and pass the authentication in the MN. After receiving the SA and user configuration information from the H-NACF;

 The NAC-FE is configured to configure an L-HoA address for the MN.

The embodiment of the present invention provides a home network attachment control function entity H-NACF, and the H-NACF includes an H-MMF and an authentication, authentication, and accounting server; One step includes: H-HMF and H-LMF;

 The authentication, authentication, and accounting server is configured to perform full authentication on the MN in the initial attach of the MN, and send the SA and user configuration information generated in the initial attach process to the L-NACF;

 The H-HMF is configured to query the candidate AR information of the current attachment point according to the physical identification information of the neighboring AR of the current attachment point obtained from the L-NACF, and send the candidate AR information to the L-NACF;

 The H-LMF is configured to receive the location binding request forwarded by the L-NACF and the reported location index information, perform location binding update, and push the binding information to the H-RACF.

 An embodiment of the present invention provides a resource admission control function entity RACF, where the RACF includes: H-RACF and L-RACF;

 The L-RACF is configured to receive the binding information pushed by the L-NACF after the location binding update, determine whether the service resource requested by the H-RACF can be accepted and reserved, and if not, reject the resource request of the H-RACF. Otherwise, the control policy is generated and delivered to the resource control node; the resource of the original attachment point is released according to the indication of the L-NACF or the request from the H-RACF;

 The H-RACF is configured to receive the binding information pushed by the H-NACF after the location binding update, determine the L-RACF in the new AN domain to which the MN is to be handed over, and send a resource request to the L-RACF; When the service session is established, it receives the resource request from the P-CSCF and forwards it to the L-RACF to save the resource requirements of the service session.

 The embodiment of the present invention provides an access management function entity AM-FE, where the AM-FE includes an access attachment point mobility management function entity A-MMF; the A-MMF specifically includes an access attachment point control function entity A-ACF;

 The A-ACF is used to report the physical identification information of the neighboring access point obtained by the MN during the L2 detection process to the L-HMF in the process of selecting the N-AR; checking and reporting the current access point and the MN. L2 link status or event.

Compared with the prior art, the method, device and system for implementing mobile handover provided by the embodiments of the present invention, before the MN needs to perform mobile handover, but before the mobile handover has started, the N-AR discovery in the new AN domain Select, and connect through the N-AR in the new AN domain Pre-established, initiates a SIP session modification through a pre-established connection, so that the existing SIP session does not need to be interrupted during the mobile handover, that is, the existing session and the peer communication can still be used when the MN moves to the new AN domain, and is implemented under the NGN architecture. Seamless switching in Inter-AN mode. DRAWINGS

 1 is a schematic diagram of the composition of an SCF in a prior art NGN architecture;

 2 is a schematic diagram of a structure of a transmission control layer in a prior art NGN architecture; FIG. 3 is a schematic diagram of three mobile switching modes proposed in the prior art ITU-T SG13; FIG. 4 is a method for implementing mobile switching according to an embodiment of the present invention; FIG. 5 is a schematic diagram of an extended NGN architecture according to an embodiment of the present invention; FIG.

 6 is a schematic diagram of an extended AM-FE composition in an embodiment of the present invention;

 FIG. 7 is a schematic diagram of an H-MMF acquiring peripheral AR information according to an embodiment of the present invention; FIG. 8 is a flowchart of an initial attach process in a method for implementing mobile handover according to an embodiment of the present invention;

 FIG. 9 is a flowchart of initial establishment of full authentication and SA establishment in the process shown in FIG. 8; FIG. 10 is a schematic diagram of a system structure based on establishing an application layer service session in the process shown in FIG. 8;

 FIG. 11 is a flowchart of discovering and selecting an N-AR in a new AN domain in a method for implementing mobile handover according to an embodiment of the present invention;

 FIG. 12 is a flowchart of pre-establishing a connection to an N-AR in a method for implementing mobile handover according to an embodiment of the present invention;

 13 is a schematic diagram of attach pre-authentication in the process shown in FIG. 12;

 14 is a flowchart of location binding and resource reservation in the process shown in FIG. 12; FIG. 15 is a schematic diagram of a hierarchical structure of a RACF according to an embodiment of the present invention;

 FIG. 16 is a flowchart of a P-CSCF not changing when a SIP session re-registration and session modification are initiated in a method for implementing mobile handover according to an embodiment of the present invention;

 FIG. 17 is a flowchart of a change based on a P-CSCF when initiating a SIP session re-registration and session modification in a method for implementing mobile handover according to an embodiment of the present invention;

FIG. 18 is a schematic diagram of a handover completion in a method for implementing mobile handover according to an embodiment of the present invention; a flow chart for placing initial resources;

 FIG. 19 is a schematic structural diagram of a system for implementing mobile switching according to an embodiment of the present invention; FIG. 20 is a schematic structural diagram of an L-NACF according to an embodiment of the present invention;

 FIG. 21 is a schematic structural diagram of an H-NACF according to an embodiment of the present invention. detailed description

 In order to make the objects and advantages of the embodiments of the present invention more comprehensible, the embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

 4 is a flowchart of a method for implementing mobile handover according to an embodiment of the present invention. When a MN needs to move to a new AN domain, the MN further includes:

 Step S401: Discover and select an N-AR in the new AN domain, and perform pre-establishment on the N-AR connection.

 Step S402: Modify the attribute of the established service session by pre-establishing the connection to the N-AR, and re-establish the media stream address function of the media data stream proxy function in the border gateway function entity to the Anchor-GW of the new access domain according to the modified attribute. Binding

 Step S403: Complete the mobile handover, end the service session in the current AN domain, and release the current AN domain attachment point resource.

 The method for implementing mobile handover provided by the embodiment of the present invention, in the MN, needs to perform mobile handover, but before the mobile handover has started, the N-AR in the new AN domain is discovered and selected, and the N-AR is in the new AN domain. Performing connection pre-establishment, and initiating SIP session modification through the pre-established connection, so that the existing SIP session can be used without interruption when the mobile switching is performed, that is, the existing session and the peer communication can still be used when the MN mobile switches to the new AN domain. Seamless switching in Inter-AN mode.

 In the above method, it is known whether the MN currently needs to perform mobile handover through the L2 link state information of the MN and the access point.

The initial attaching process and the process described in steps S401 to S403 are methods for the first time that the MN first enters the AN domain to complete initial attachment and perform the first mobile switching. After the MN completes the above first mobile handover, it is also possible to perform continuous mobile handover. In each subsequent movement, the description is performed in accordance with the description of steps S401 to S403. In order to implement the foregoing solution provided by the embodiment of the present invention, it is necessary to first add or extend some functional entities in the existing NGN architecture, and a specific extension architecture is proposed as follows:

(1) Home Network Attachment Control Function Entity (H-NACF) 1 and Local Network Attachment Control Function Entity (L-NACF) 3:

 FIG. 5 is a schematic diagram of an extended NGN architecture in an embodiment of the present invention. As shown in Figure 5, two levels of NGN attach control function entities, Home NACF 1 and Local NACF3, referred to as H-NACF1 and L-NACF3, are introduced in the core domain and the AN domain respectively.

 The H-NACF1 is located in the core network domain and is a subscription point for the service. The original authentication data and the user profile information of the transport layer are stored in the user network transport layer. The user initially accesses the AN domain. When the user is fully authenticated (Full Authentication), and then the generated SA and the saved transport layer user profile (User Profile) are sent to L-NACF3; In addition, H-NACF1 can also be based on L-NACF 3 The physical identification information of the neighboring access point of the current attachment point is reported, and the related information of the candidate AR that can be used for the mobile handover around the current attachment point is queried and delivered.

 The L-NACF3 is used to manage the access attachment process of an AN domain, implement the mobility management control of the MN in the same AN domain, configure the L-HoA address for the attached MN in the AN domain, and perform fast pre-authentication for the attached MN in the AN domain. The user's transport layer User Profile information is temporarily stored in the local cache (Cache).

 In addition to the above functions, H-NACF1 and L-NACF3 also each have a hierarchical structure, and the current location binding information of the MN is saved. The current detailed location information of the MN stored and bound by the L-NACF3 in the AN domain includes L3 logical location information (L3-CoA), L2 physical location ID (L2 Physical Access ID), and L2 logical location information (L2 Logic). Access ID), optionally including geographic location information of the MN. H-NACF1 saves and binds the AN domain address where the MN is currently located, that is, the L-NACF location index.

In this way, when the SCF2 needs to query the location information of the MN, it only needs to send a query request to the H-NACF1, and the H-NACF1 further queries the corresponding L-NACF and obtains the MN in the AN domain according to the L-NACF3 location index of the MN. Detailed location information. (2) Hierarchical media stream forwarding points Anchor-GW and C-BGF/I-BGF:

 In the embodiment of the present invention, a hierarchical media data stream forwarding point is introduced: an Anchor-GW located in the AN domain and a C-BGF/I-BGF located in the core network domain.

 The Anchor-GW has a local anchor function. When the MN moves within the AN domain, both the outgoing and received media streams need to pass through the Anchor-GW of the AN domain.

 After the initial attachment is completed, the MN establishes a service session through the SIP message, and the SCF2 selects a C-BGF as the L3 core boundary point of the media data stream between the AN domain and the core domain. Correspondingly, the forwarding path of the media data stream is:

 CN ~> C-BGF ~> Anchor-GW ~> P-AR -> MN ;

 The I-BGF is an upper-layer border gateway function entity that is higher than the above-mentioned C-BGF, and is used to forward the media data stream when the MN switches between the AN domains and the P-CSCF changes.

 (3) Hierarchical resource management functional entity RACF4

 Hierarchical Home Network Resource Management Functional Entity (H-RACF) 1 and Local Network Resource Management Functional Entity (L-RACF) 3:

 The H-RACF 1 receives the MN first binding related information pushed by the H-LMF 112; the L-RACF accepts the MN second binding related information pushed by the L-LMF.

 The MN first binding related information that the H-LMF 111 pushes to the H-RACF 1 contains at least the AN domain information in which the MN is currently located. According to this information, the H-RACF1 can determine the L-RACF3 location of the current AN domain of the MN, and The resource request issued by the SCF is sent to L-RACF3 for resource admission control.

 The L-LMF 312 pushes the MN second binding related information of the L-RACF3, including the detailed user location information of the MN, and the transport layer user profile. L-RACF performs resource admission control based on this information and the resources available to the network.

 The SCF sends a resource request for the application layer session to the transport layer, which is sent to the H-RACF and then forwarded to the L-RACF.

 (4) AM-FE, Local Mobile Management Function Entity (L-MMF) 32 of AN domain and Mobile Management Function Entity (H-MMF) of Core Domain 11 :

 1 AM-FE:

The AM-FE is usually physically located on a physical device with the P-AR/N-AR. AM-FE is mainly used to implement DHCP Relay and PAA functions in the existing NGN architecture. The PAA function refers to the AAA Client function, that is, to block specific access authentication, to remotely authenticate dial-up user services (Radius) or extend Radius ( The protocol is forwarded to the AAA Server/Proxy in the L-NACF3 to implement the attach authentication process. The function of the embodiment is extended in the embodiment of the present invention, including: in the attach authentication, the SA required by the MN and the related entity is generated;

 In order to support the mobility management, a sub-function entity, that is, an access mobility management function entity (A-MMF), is also introduced in the existing AM-FE32. As shown in FIG. 6, FIG. 6 is an extended embodiment of the present invention. Schematic diagram of the composition of AM-FE32. The A-MMF further includes an Access Point Control Function Entity (A-ACF).

 The A-ACF is located between the L2 and the L3 of the access point; the L2 link state parameter and the trigger message of the MN are reported through the interface with the local handover management function entity (L-HMF) 311 of the AN domain, and - The interface of HMF311 receives the L-HMF control command and controls the L2 switch.

 The A-ACF can partially implement the MIH function specified in IEEE 802.12. For example, it is known from the link state of the MN and the access router that the MN is about to be removed from the current attachment point range. Similarly, according to the link information, the MN can Automatically attached to a new attachment point.

 2 L-MMF31 :

 L-MMF31 in the AN domain is a functional entity that is extended to support intra-domain mobility switching, including L-HMF311 and TLM-FE in the original NGN NACF with extended performance, now called L-LMF312.

L-HMF311 is the management and decision point of MN mobile handover in the AN domain; L-HMF311 is responsible for managing the current connection status and mobility mode of all MNs in the AN domain; L-HMF311 is based on the current query from the core domain or from the AN domain. The periphery of the attachment point can be detected by the AR information and the L2 link scanning detection information reported by the MN, combined with the local mobility management policy to determine the new attachment point N-AR of the MN, and subsequently, the L-HMF can also pass the L-RACF. The interface performs QoS resource query, reservation, etc. of the new attachment point. Added location binding update information in L-LMF312. The L-LMF is hierarchical with the home location management function entity (H-LMF) of the core domain.

 The user related information of L-LMF binding is shown in Table 1:

 3 H-MMF11 :

 The H-MMF11 includes the original H-LMF 112 and a newly added core domain handover management entity (H-HMF) 111.

 The H-HMF 111 is a decision maker, a policy and a command issuer of the mobile switching transaction in the core network domain, and has the AR information query function of the current attachment point, as shown in FIG. 7, FIG. 7 is an embodiment of the present invention. The MMF11 obtains the surrounding AR information: obtains the current P-AR identifier through the interface with the L-HMF 312, and obtains the neighboring adjacent AR by querying the Topologic Location Database and the Geography Location Database. Then, the information server (Information Server) is queried for information about these peripheral ARs and sent to the L-HMF.

If the network Topologic Location Database, Geography Location Database and Information Server are configured in L-NACF3, then the above process can also be done in L-HMF311.

As a hierarchical user location management function, H-LMF112 provides the attachment information shown in Table 2 by L-LMF to bind:

 Among them, L-LMF Addr can be used as an index to query further detailed location.

 When SCF2 needs to query the current location of the MN, use the L-HoA address or MN.

The Identifier looks up to the H-LMF 112; the H-LMF 112 according to the bound information, to the corresponding

L-LMF 312 queries and obtains more detailed L2 physical/logical position information of MN, and

/ or L3 logical location information.

 Based on the above-mentioned extension to the NGN architecture of the embodiment of the present invention, the detailed process of each phase in the method for implementing mobile handover in the NGN in the embodiment of the present invention is described in detail below:

 First, the method for implementing mobile switching provided by the embodiment of the present invention, the initial attaching process of the MN in an AN domain, that is, the initial attaching process performed before the mobile switching process shown in FIG. 4 is started, FIG. 8 shows The process of the initial attachment process, the process includes:

 Step S801: The MN performs an initial attach full authentication process and SA related information generation. In this step, the initial attachment full authentication process and SA related information generation may be performed by

The process shown in Figure 9 is implemented. The process shown in Figure 9 includes:

 Step S901: The MN sends an authentication request to the PAA in the AM-FE (Authentication)

Request ) Message.

 Step S902 to step S903: The PAA sends an AAA request message to the H-NACF through the L-NACF.

Step S904: The H-NACF performs authentication, and sends an AAA response message to the L-NACF. In this step, the AAA Server of the H-NACF itself performs authentication according to the AAA-Key (MK) of the saved MN, and after the authentication is completed, sends an AAA response message to the L-NACF, which carries the primary session generated during the authentication process. The key (MSK, Master Session Key), the random number Nonce of the MSK, and the User Profile file of the MN.

 Step S905: The L-NACF saves the User Profile file and the MSK carried in the AAA response message in a cache, and sends an AAA response message to the PAA in the AM-FE, which carries the MSK and Nonce, PAA. Get MSK.

 Step S906: The PAA in the AM-FE sends an authentication response message to the MN, which carries Nonce„

 In this step, the MN generates an MSK according to the obtained Nonce and the pre-saved MK.

 Step S907: An MSK-based authentication relationship is established between the PAA and the MN in the AM-FE.

 MSK can be used to establish bootstrap for subsequent mobile switching

SA.

 The above steps S901 to S907 describe the initial attach full authentication process and the SA establishment process in step S801.

 Step S802: The L-NACF configures the initially attached L-HoA address for the MN.

 After the authentication in step S801 is passed, the L-NACF configures the address configuration mode supported by the current AN domain for the MN, such as IPv4, IPv6 stateless, or IPv6 statefull.

 If the IPv4 configuration mode is adopted, the MN completes the address configuration through the DHCP v4 configuration process, and can insert the configuration option (Option) by the access physical device with the L2 DPCH Relay to carry the L2 Logic/Physical Access ID and other information.

 If the IPv6 Statefull configuration mode is used, the MN obtains the address configuration from the DHCP v6 of the L-NACF by using the DHCP v6 protocol.

The specific implementations of the foregoing two configurations are: The MN sends an address request to the L-NACF; and the L-NACF provides the address configuration provided by the MN. If the IPv6 Stateless configuration mode is used, the MN can generate the L-HoA according to the AN-Homework-Home Index (A-Homework-Prefix) issued by the AR and the Media Access Control (MAC) address of the MN.

 Step S803: Select an Anchor-GW for the MN.

 Step S804: Perform initial position binding in the L-LMF and the H-LMF.

 层次 Hierarchical location binding registration, location binding in L-LMF and H-LMF respectively

 The location binding registration message received by the L-LMF may be a location binding request or a location binding update message, and the L-LMF further sends a location binding or update message to the H-LMF, where the information carried includes The content shown; the location binding or update message may further include a Lifetime value of the binding or update message, when the time specified by the value is reached, if the binding has not been updated, then L-LMF and H-LMF The corresponding binding entry will be deleted. Accordingly, the H-LMF and L-LMF loopback binding registration response messages.

 Step S805: The MN establishes an application layer service session by using the SIP message, and requests the RACF to apply for the resource required by the service during the establishment of the service session, and the RACF saves the resource requirement of the application.

 The implementation of this step is based on the system shown in Figure 10, and mainly includes the following steps:

The MN carries the MN-Identifier and the L-HoA in the SIP registration (Register) message, and registers with the SCF2, during which the service layer session authentication of the MN can be completed, and the registration message is stored in the HSS;

 The MN sends a SIP Invite message to the SCF2, initiates a session, and negotiates RTP/RCTP media stream parameters, including the transport address and port.

 The SIP session uses L-HoA as the session address. When the MN performs mobile handover in the same AN domain, the SIP session address does not change. If SCF2 needs to know the exact information of the MN in the AN domain, it can query H-LMF 112 and L-LMF 312 to know the detailed location of the MN.

 During the session establishment process, the P-CSCF in the SCF2 requests the RACF for the resources required by the service according to the service information carried by the SIP, and the RACF performs resource admission control.

If you follow the hierarchical structure of the RACF that will be introduced later, SCF will first ask The request is sent to the H-RACF, and the H-RACF sends the request to the L-RACF according to the MN binding related information pushed by the H-LMF to complete the resource admission control. This part is described in detail later.

 Step S806: The C-BGF performs address translation binding of the media data stream.

 After receiving the SIP Invite message, the P-CSCF in the SCF initiates an address translation binding to the C-BGF through the RACF, obtains RTP/RCTP address translation data from the C-BGF, and implements the L-HoA address of the MN and its core network. Conversion of domain addresses. .

 The C-BGF acts as a media stream forwarding proxy. For the MN, the C-BGF represents the CN, and for the CN side, the C-BGF represents the MN; the media stream path that the C-BGF sends to the MN is:

CN ~> C-BGF ~> Anchor- GW ~> P-AR ~> MN„

The C-BGF is a media stream RTP/RTCP proxy, which performs IP address translation of the media stream; the P-CSCF modifies the SDP address information of the SIP according to the address translation binding information provided by the C-BGF, thus shielding the MN address from the CN. The location information, what CN can see is only the address information of a core domain, thus satisfying the privacy requirement, and also avoids the situation that the changed L-HoA needs to notify the CN when the L-HoA of the MN changes.

 Second, the N-AR discovery and selection process for implementing the mobile handover method and the N-AR provided in the embodiment of the present invention is introduced. That is, the step S401 in the process shown in FIG. 4 finds and selects the N-AR in the new AN domain, and FIG. 11 is the above N. -AR's discovery and selection process, including:

 Step S1101: The MN performs an L2 scan, and sends an L2 detection 4 probe (Probe) to the neighboring AR.

 Step S1102: Each neighboring AR sends an L2 link Beacon message to the MN, where the physical identification information of the access point, such as the SSID and the BSID, is carried.

 Step S1103: The MN reports the information about the current attachment point of the MN to the L-HMF by using the RtSolPr message through the A-ACF in the A-MMF of the current attachment point P-AR. The RtSolPr message carries the information obtained from the Beacon information. The physical identifiers of the surrounding ARs, such as SSID and BSID.

 Step S1104: The L-HMF queries the H-MMF or locally obtains the surrounding available AR of the current attachment point of the MN and related information as an alternative AR.

Step S1105: The L-HMF reports the A-ACF according to the current attachment point P-AR of the MN. Information, alternative AR information, and configured policies to make decisions, select N-AR. Step S1106: The L-HMF sends the relevant information of the selected N-AR to the MN through the A-ACF of the current attachment point P-AR of the MN by using the PrRtAdv message. The information about the selected N-AR includes the IP address of the N-AR, the MAC address, and whether the mobile point will cross.

AN domain mobile information.

 Since the AM-FE and the AR coexist in one device, the MN is equal to the PAA address of the N-AR.

 The third embodiment describes the method for implementing the mobile handover provided by the embodiment of the present invention. The pre-connection establishment process of the N-AR across the AN domain, that is, the process pre-establishment of the N-AR in the process step S401 shown in FIG. 4, FIG. 12 is The pre-connection establishment process of the N-AR across the AN domain, including:

 Step S1201: Perform an attach pre-authentication process.

 In this step, the attach pre-authentication can be described by using FIG. 13 . FIG. 13 is a schematic diagram of attach pre-authentication according to an embodiment of the present invention. The MN uses a link with the N-AR to pass the PAA of the N-AR to the new AN domain. The new NACF initiates a pre-authentication request; the PAA of the N-AR authenticates the transport layer to the H-NACF through the L-NACF in the new NACF, and obtains and saves the MSK key. Or the new NACF obtains the MSK through a secure channel established with the NACF in the current AN domain to establish a security association.

 During the pre-authentication process, the N-AR also obtains configuration options from the L-NACF of the new AN domain, such as the IP address configuration mode. If it is the IPv6 Stateless configuration mode, the N-AR obtains the Home-Network-Prefix.

 Step S1202: Perform pre-configuration of addresses and parameters.

 In this step, the MN implements the address and parameter configuration of the inter-domain inter-domain handover. In the IPv4 or IPv6 Statefull configuration mode, the DHCP server in the L-NACF configures the L-HoA address for the MN; if it is the IPv6 Stateless configuration mode, the MN uses the transmission. The Home-Network-Prefix option and its own MAC address generate L-HoA.

 Step S1203: Perform location binding update and resource reservation.

In this step, FIG. 14 is a flowchart of implementing location binding update and resource reservation in an embodiment of the present invention. As shown in Figure 14, when the L-LMF receives the location binding or update message First, the first temporary binding entry is established; the resource configuration parameter of the user or service in the transport-layer user profile User-Profile item in the first temporary binding entry is selected according to the access technology corresponding to the N-AR. Or adjust.

 For the mobile switching between the AN domains, the L-LMF needs to further send the second binding request and the reporting binding information to the H-LMF. The H-LMF first queries whether the binding entry with the same name already exists according to the MN-Identifier. Then, a second temporary binding entry is pre-established in the H-LMF, where the existing binding entry corresponds to the attachment location of the P-AR, and the second temporary binding entry corresponds to the pre-attached location of the N-AR, including the new AN domain. Information such as the address of L-HoA, MN-Identifier and L-LMF.

 The pre-established temporary binding entry described above will be converted to a formal binding entry after the MN completes the move.

 When the L-LMF and the H-LMF establish a temporary binding entry, the MN related information of the first temporary binding entry and the second temporary binding entry are respectively pushed to the L-RACF and the H-RACF. In the embodiment of the present invention, the RACF may be the same as the structure in the prior art, but may also be based on a hierarchical structure, that is, an L-RACF of an AN domain and an H-RACF of a core domain, and the specific structure is as shown in FIG. Show.

 Based on the hierarchical structure of the RACF, the process of implementing the mobile handover resource reservation between the AN domains may include the following steps:

 The L-LMF 312 and the H-LMF 112 in the new AN domain respectively establish the MN first temporary binding entry and the MN second temporary binding entry;

 The L-LMF 312 and the H-LMF 112 in the new AN domain push the MN related temporary binding entry information to the corresponding L-RACF and H-RACF, respectively.

 In the subsequent process, when the MN updates the SIP session: The P-SCSF sends a resource request of the MN to the H-RACF in the core domain according to the L-HoA of the MN or the identity of the MN in the SIP message.

Based on the information of the MN pushed by the H-LMF, the H-RACF knows the new AN domain in which the MN is located, thereby knowing the L-RACF in the AN domain, and forwards the resource request to the L-RACF. When the service session of the initial attachment point is established, the resource request sent by the P-CSCF is received and forwarded to the L-RACF to save the resource requirements of the service session. The L-RACF receives the binding information pushed by the L-NACF after the location binding update, determines whether the service resource requested by the H-RACF can be accepted and reserved, and if not, rejects the resource request of the H-RACF, otherwise generates control. The policy is delivered to the resource control node; the resource of the original attachment point is released according to the indication of the L-NACF or the request from the H-RACF.

 Subsequently, when the L-LMF 312 and the H-LMF 112 receive the unbinding message to the original binding entry, the original binding entry is deleted, and the temporary binding entry replaces the original entry to become a formal location binding entry; when L-LMF 312 When the original binding entry is deleted by the H-LMF 112, the L-RACF and the H-RACF are notified to release the resources corresponding to the original binding.

 Fourth, the method for implementing the mobile handover provided by the embodiment of the present invention is initiated, and the process of modifying the session established in the initial attachment is initiated, that is, the content of the process step S402 shown in FIG. 4, and FIG. 16 is the initiation of the SIP session re-registration and session. Modified flow chart, the process includes:

 Step S1601: Update the SIP registration relationship by using the L-HoA obtained by the pre-establishment process. In this step, the MN sends a new L-HoA and MN identity update registration request to the P-CSCF by using the P-CSCF address obtained from the attach procedure;

 The MN sends a new or old L-HoA by using a SIP message in the process of updating the SIP registration relationship. The specific format of the SIP message may be:

 The L-HoA is placed as an IP address in the Via header of the registration request message; the identity of the MN is placed in the To header, which may be the domain name of the MN; the binding of the IP address and the identity of the MN is specified. It can be placed in the Contact header at a sustained time. In addition, the message may also include the session ID to be used in the subsequent process, that is, the session ID that has been established in the initial attachment is placed in the Call-ID message header. An example of a SIP registration message is given below, as shown in Table 3.

To: <sip:MN@homel .com>

To: <sip:MN@homel .com>

 Call-ID: 398174293@MN.homel.com

 CSeq: 25 REGISTER

 Contact: <sip: MN. new-L-Ho A>; expires=600000

 Content-Length: 0

 Table 3 During the re-registration process between the MN and the P-CSCF, the P-CSCF and the MN re-establish the SA to implement secure SIP port protection, and the original IP address and SA will be deregistered. The format of the above registration request message can still be used when registering, but the binding time of the original IP address and the identity of the MN in the Contact message header can be set to 0.

 Step S1602: The MN sends a re-INVITE message in the SIP protocol to the P-CSCF by using the established session Call ID and the new IP address in the initial attachment, and the P-CSCF requests the C-BGF to perform location conversion binding.

 In this step, the MN sends a re-INVITE message to the P-CSCF by using the Call ID of the established session in the initial attachment and the IP address of the new L-HoA. After the S-CSCF determines that this is an existing session, the P-CSCF requests the C-BGF to perform the NAPT conversion of the new address according to the indicated IP address, implements the RTP/RTCP proxy function, and returns 200 messages to the MN. - The RTP/RTCP address of the BGF proxy is sent back. The P-CSCF simultaneously requests resource reservation, and the C-BGF sends the media stream to the MN with the new IP address and the new IP route.

 Step S1603: The P-CSCF requests a resource update from the RACF, and receives a resource update response of the RACF.

 The above steps S1601 to S1603 are the same when the MN moves between the AN domains, and the corresponding P-CSCF is the same. That is, when the P-CSCF finds that the re-initiated session is the same as the original session, the C-BGF requests a new IP address. NAPT conversion.

 If the P-CSCF changes when the MN switches between the AN domains, the execution steps of the process will change, as shown in Figure 17.

 Step S1701: The MN sends a SIP registration request to the S-CSCF through the new P-CSCF by using the new L-HoA, and receives the 200 acknowledgement message returned by the S-CSCF.

 Step S1702: The MN initiates deregistration to the old P-CSCF by using the old L-HoA, and receives the 200 acknowledgement message returned by the old P-CSCF.

Step S1703: The MN uses the established session Call ID and the new one in the initial attachment. The IP address sends a re-INVITE message in the SIP protocol to the new P-CSCF, and the new P-CSCF requests binding from the I-BGF.

 In this step, the MN sends a re-INVITE message to the new P-CSCF by using the Call ID and the new IP address of the established session in the initial attach. It is determined by the S-CSCF that this is an existing session. The new P-CSCF requests the I-BGF to perform the NAPT conversion of the new address according to the indicated IP address, implements the RTP/RTCP proxy function, and returns 200 messages to the MN. The RTP/RTCP address of the I-BGF proxy is sent back. The P-CSCF requests resource reservation at the same time, and the I-BGF sends the media stream to the MN with the new IP address and the new IP route.

 Step S1704: The new P-CSCF requests resource reservation from the RACF.

 In the flow shown in Figure 17, since the corresponding P-CSCF changes when the MN switches between AN domains, the SIP message will be terminated at the S-CSCF, that is, the new P-CSCF needs to use the new IP address to S- The CSCF performs SIP registration and then requests the C-BGF to bind the NAPT of the new IP address.

 The fifth embodiment introduces the method for implementing mobile handover provided by the embodiment of the present invention, and the process of releasing the initial resource after the handover is completed, that is, the content of step S403 in the flow shown in FIG. 4, and FIG. 18 is the process of releasing the initial resource after the handover is completed. , including:

 Step S1801: The MN sends the old L-HoA to the P-CSCF, deregisters the location before the mobile handover, and sends a SIP Bye message to terminate the old L-HoA session. The MN disconnects the L2 link with the P-AR.

 Step S 1802: The L-LMF in the current AN domain receives the location binding or update, and the L-LMF in the current AN domain forwards to the H-LMF, and the L-LMF and the H-LMF in the current AN domain delete the current AN. A location binding entry for the domain that instructs H-RACF and L-RACF to release the corresponding resource.

 Step S1803: The H-LMF converts the temporary binding entry of the new AN domain location into a formal binding entry, and issues an LBU to the L-LMF in the new AN domain, and the L-LMF in the new AN domain receives the LBU. The binding entry is updated to a formal binding entry.

 The above method of resource reservation can also be completed as follows:

The P-CSCF receives the SIP re-INVITE message initiated by the MN, according to the SIP The information carried by the re-INVITE initiates a resource reservation request to the H-RACF;

 The H-RACF determines the L-RACF in the new AN domain to which the MN is to be handed over according to the information of the user of the second temporary binding entry of the MN pushed by the H-LMF in the new AN domain, and according to the resources of the currently saved service session. Demand, send a resource request to L-RACF;

 The L-RACF determines whether the service resource requested by the H-RACF can be reserved according to the user information of the first temporary binding entry of the MN pushed by the L-LMF, and rejects the resource request of the H-RACF if not, otherwise generates The control policy is delivered to the resource control node, and the resource reservation to the H-RACF is successfully reserved.

 In this case, after completing the mobile switchover, include:

 After the H-RACF and L-RACF have successfully reserved the N-AR attachment point resources in the new AN domain, the resources of the current AN-domain P-AR attachment point are released.

 In the method for implementing mobile handover in the NGN provided by the embodiment of the present invention, in order to reduce the data loss of the mobile handover, after the MN completes the establishment of the new L-HoA address SIP session, the L-HoA address of the current AN domain is terminated before the SIP session is terminated. The C-BGF/I-BGF can forward the media stream to the two access domains AN at the same time. At this time, the MN can receive the media data stream through the P-AR or the media data stream through the N-AR. All the same. After the MN sends a SIP Bye message to terminate the session of the current AN domain L-HoA address, it can be considered that the MN has switched to the new AN domain and uses the N-AR to receive the media data stream.

 Next, a system for implementing mobile handover according to an embodiment of the present invention is introduced. FIG. 19 is a schematic structural diagram of a system for implementing mobile handover according to an embodiment of the present invention. The system includes: a MN and a next-generation network NGN, where the NGN network includes a core. A transport layer control management unit and a business layer control management unit composed of entities in the domain and the access network AN domain. The above business layer control management unit includes an SCF.

 MN, used to access the NGN and perform mobile switching in the NGN.

 a transport layer control management unit, configured to complete initial MN attachment in the current AN domain; and when the MN needs to switch to the new AN domain, discover and select an N-AR in the new AN domain, and perform pre-establishment on the N-AR connection;

a service layer control management unit for establishing a session between the MN and the CN; Pre-established connection, modifying the attribute of the established service session; reconstructing the media stream proxy function of the border gateway function entity to the media stream address binding of the Anchor-GW of the new access domain according to the modified attribute; completing the mobile switching, releasing the current AN domain attachment point resource.

 The system for implementing mobile handover provided by the embodiment of the present invention needs to perform mobile handover after the MN needs to perform mobile handover, but before the mobile handover has started, the N-AR discovery and selection in the new AN domain, and the connection pre-establishment of the N-AR is performed. Initiating a SIP session modification through a pre-established connection, so that the existing SIP session does not need to be interrupted during the mobile handover, and only the pre-established connection to the N-AR is used to modify the attributes of the existing SIP session, that is, the MN moves to the new AN. The existing session and peer communication can still be used in the domain, which enables seamless switching in Inter-AN mode.

 In the foregoing system, the core network domain may further include an H-NACF, and the AN domain may further include an L-NACF, and the transport layer control management unit may further include an H-RACF distributed in the core network domain and distributed in the AN domain. L-RACF.

 The H-NACF is configured to perform full authentication on the MN in the initial attach, and send the SA and user configuration information generated in the initial attach to the L-NACF in the current AN domain; according to the current attachment of the MN obtained from the L-NACF Pointing the physical identification information of the neighboring AR to query the candidate AR information around the current attachment point of the MN; receiving the location binding request forwarded by the L-NACF and the reported location index information, performing the second location binding update, and pushing the binding to the H-RACF Information.

 The L-NACF is used to select the candidate AR information of the current attachment point in the H-NACF and the L2 detection information of the neighboring AR reported by the MN when the MN needs to switch to the new AN domain, and select according to the pre-configured selection policy. N-AR; receives the SA and user configuration information from the H-NACF, configures the L-HoA address for the MN, performs the first location binding update, pushes the binding information to the L-RACF, and forwards the location binding to the H-NACF. Request and report its own location index information.

The L-RACF is configured to receive the binding information pushed by the L-NACF after the first location binding update, determine whether the service resource requested by the H-RACF can be accepted and reserved, and if not, reject the resource of the H-RACF. Request, otherwise generate a control policy and deliver it to the resource control node; release the resources of the original attachment point according to the indication of the L-NACF or the request from the H-RACF during the handover process. The H-RACF is configured to receive the binding information pushed by the second location binding update performed by the H-NACF, determine the L-RACF in the new AN domain to which the MN is to be handed over, and send a resource request to the L-RACF. When the service session of the initial attachment point is established, the resource request from the P-CSCF is received and forwarded to the L-RACF to save the resource requirements of the service session.

 The foregoing L-NACF may include: an L-MMF, an authentication, an authentication, an accounting server/proxy, and a network address configuration function entity NAC-FE; the L-MMF further includes: an L-HMF 311 and an L-LMF 312, Figure 20 is a schematic view showing the structure of the L-NACF3.

 The L-HMF 311 is configured to: when the MN needs to switch to the new AN domain, query the candidate AR information in the current attachment point in the H-NACF, and the neighboring access point L2 detected by the MN, according to the configured selection policy. Select the N-AR in the new AN domain.

 The L-LMF 312 is configured to perform a first location binding update according to the configured L-HoA address, and forward the binding request to the H-NACF.

 The authentication, authentication, and accounting server/proxy 34 is configured to receive an access authentication request from the MN to implement access authentication of the MN, and to forward the access authentication request from the MN to the H-NACF1, and pass the authentication request at the MN. After that, it receives SA and user configuration information from H-NACF1.

 The above-mentioned H-NACF1 may include: H-MMF11 and an authentication, authentication, and accounting server; H-MMF11 further includes: H-HMF111 and H-LMF112, and FIG. 21 is a schematic structural diagram of the H-NACF1.

 The authentication, authentication, and accounting server is configured to perform full authentication on the MN in the initial attachment of the MN, and deliver the SA and user configuration information generated in the initial attachment to the L-NACF3.

 The H-HMF 111 is configured to query the candidate AR information around the current attachment point according to the physical identification information of the neighboring AR of the current attachment point obtained from the L-NACF3, and send the candidate AR information to the L-NACF3.

 The H-LMF 112 is configured to receive the location binding request forwarded by the L-NACF3 and the reported location index information, and perform the second location binding update.

 The SCF in the system of the embodiment of the present invention includes: a P-CSCF, an S-CSCF, and an HSS.

The P-CSCF is configured to send the SIP request message of the MN to the S-CSCF. SIP request message; after the S-CSCF authenticates the MN, sends a SIP request message to the CN, establishes a session between the MN and the CN; requests the S-CSCF to modify the established session attribute, and modifies according to the response returned by the S-CSCF Attribute, re-establish the media stream address binding function of the media data stream proxy function in the border gateway function entity to the Anchor-GW of the new access domain; query the location information of the MN to the H-NACF1, and receive the L-NACF3 in the saved H-NACF1 The result of the query in the L-NACF corresponding to the location index; requesting resources from the RACF for the resources required for the established service session.

 The S-CSCF is configured to perform service session authentication on the MN, and send the SA to the P-CSCF after the authentication; return a response to the established session attribute modification to the P-CSCF; save the session state of the service session; and request the authentication data from the HSS. .

 HSS, used to store authentication data and registration information.

 In the above system, the transmitting unit may further include: A-AR, C-BGF and/or I-BGF.

 The anchor-GW is used to forward the media stream to the MN in the current AN domain. The Anchor-GW may be a pre-assigned AR or an AR of the attachment point when the MN first attaches in the AN domain.

 The C-BGF, when the MN mobile handover uses the same P-CSCF as the original session, is the core boundary point of the L3 media stream between the core network domain and the AN domain as the MN media data stream.

 The I-BGF, when the MN mobile handover uses a P-CSCF that is different from the original session, acts as the L3 interconnection boundary point between the core network domain and the AN domain as the MN media data stream.

 The device for implementing mobile switching provided by the embodiment of the present invention includes an L-NACF, an H-NACF, and an AM-FE.

The L-NACF provided in the embodiment of the present invention may use the L-NACF introduced in the system for implementing the mobile switching provided by the embodiment of the present invention as a preferred embodiment. The H-NACF provided in the embodiment of the present invention may use the foregoing. The H-NACF introduced in the system for implementing mobile handover provided by the embodiment of the present invention is a preferred embodiment; the AM-FE can use the structure shown in FIG. 6 as a preferred embodiment; and the RACF includes L-RACF and H- For the RACF, the structure shown in Fig. 15 can be used as a preferred embodiment. The structure of the above three devices will not be described here. The method, the device and the system for implementing the mobile switching provided by the embodiment of the present invention are respectively introduced by using the specific network architecture as the application scenario, and in actual applications, other networks similar to the specific network architecture. The architecture can also be used as an application scenario of the embodiment of the present invention.

 In conclusion, the above is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Rights request A method for implementing mobile handover, characterized in that: the mobile node MN completes initial attachment in the current access network AN domain and establishes a service session with the opposite node CN, when the MN needs to switch from the current AN domain to In the new AN domain, the method further includes: discovering and selecting a target access router N-AR in the new AN domain, and performing pre-establishment on the N-AR;  Modifying, by the pre-established connection to the N-AR, an attribute of the established service session, and re-establishing a media stream proxy function in the border gateway function entity and a media stream address of the access network domain media stream anchor point according to the modified attribute Binding  The mobile switching is completed, and the service session in the current AN domain is ended, and the current AN domain attachment point resource is released.  2. The method according to claim 1, wherein the process in which the MN completes initial connection and establishes a service session in the current AN domain includes:  The MN performs full authentication of the initial attachment, and establishes a security association SA;  Configuring a local home address L-HoA in the current AN domain to which the MN is initially attached;  Selecting a local anchor router Anchor-GW for the MN;  Performing initial location binding in the local location management function entity L-LMF of the current AN domain and the home location management function entity H-LMF of the core domain;  The MN establishes an application layer-based service session by using a SIP message; and, in the process of establishing the service session, requests the network resource admission control function entity RACF to apply for a resource required by the service, and the RACF saves the resource requirement of the application;  The border gateway function entity performs address translation binding of the media data stream.  3. The method according to claim 2, wherein the initial location binding in the L-LMF and the H-LMF of the current AN domain is: Performing, in the L-LMF, an initial location binding of the MN identifier and the location of the MN in the current AN domain; and the L-LMF binding information further includes a user profile of the MN; An initial location binding of the MN identity to the L-LMF location where the MN is currently located is performed in the H-LMF.  4. The method of claim 1 wherein said discovering and selecting N-AR is:  After the MN initiates the L2 detection packet, the MN receives the L2 detection response containing the physical information of the peripheral AR from the plurality of neighboring ARs;  The MN reports the current attachment point related information of the MN including the neighboring AR physical identification information to the local handover management function entity L-HMF of the current AN domain;  The L-HMF queries the handover management function entity H-HMF of the core domain or obtains the neighboring AR information of the current attachment point as the candidate AR according to the information about the current attachment point reported by the MN;  The L-HMF selects one of the ARs as an N-AR according to the information reported by the MN, the candidate AR information, and a pre-configured policy.  5. The method according to claim 4, wherein after the L-HMF selects the N-AR, the method further comprises:  The L-HMF sends a message including the IP address of the selected N-AR, the MAC address, and whether the message is transmitted to the MN.  The method according to any one of claims 1 to 5, wherein the pre-establishing the connection to the N-AR comprises:  Attachment pre-authentication, address pre-configuration, location binding update, and resource reservation are performed on the MN via the N-AR.  The method according to claim 6, wherein the attach pre-authentication is: the MN initiates access authentication to the new AN domain by the attachment point where the N-AR is located; or, the new AN domain directly from the current AN The domain obtains authentication information for the MN.  The method according to claim 6, wherein the method for resource reservation comprises:  The P-CSCF receives the SIP re-INVITE message initiated by the MN, and initiates a resource reservation request to the H-RACF according to the information carried by the SIP re-INVITE; The H-RACF pushes the second temporary binding of the MN in the new AN domain according to the H-LMF Information of the user of the entry, determining the L-RACF in the new AN domain to which the MN is to switch, and transmitting a resource request to the L-RACF according to the resource requirement of the currently saved service session;  Determining, by the L-RACF, whether the service resource requested by the H-RACF can be reserved according to the user information of the first temporary binding entry of the MN pushed by the L-LMF, and rejecting the resource of the H-RACF if not Request, otherwise generate a control policy and deliver it to the resource control node, and return the resource reservation to the H-RACF successfully;  The mobile switching is completed, and the current AN domain attachment point resource is released:  After the H-RACF and the L-RACF are successfully reserved in the new AN domain N-AR attachment point, the resources of the current AN domain P-AR attachment point are released.  A system for implementing mobile switching, the system comprising: a MN and a next-generation network NGN; the NGN includes a transport layer control management unit consisting of an entity of a core network domain and an access network AN domain; a service layer control management unit; the service layer control management unit includes a service control layer function entity SCF;  The MN is configured to access the NGN and perform mobile handover in the NGN; the transport layer control management unit is configured to complete initial MN attachment in the current AN domain; and the MN needs to switch to the new In the AN domain, the N-AR in the new AN domain is found and selected, and the N-AR is pre-established;  The SCF in the service layer control management unit is configured to establish a session between the MN and the CN; modify the attribute of the established service session by using the pre-established connection to the N-AR; and reconstruct the boundary gateway function entity according to the modified attribute The media data stream proxy function is bound to the media stream address of the access domain media stream anchor; the mobile handover is completed, and the current AN domain attachment point session and resources are released.  The system according to claim 9, wherein the core network domain includes a home network attachment control function entity H-NACF, and the AN domain includes a local network attachment control function entity L-NACF;  The transport layer control management unit further includes an L-RACF distributed in the H-RACF of the core domain and an AN domain in the AN domain; The H-NACF is configured to perform full authentication of the MN in the initial attach, and the The SA and the user configuration information generated in the initial attachment are sent to the L-NACF in the current AN domain; and the current attachment point of the MN is queried according to the physical identification information of the AR of the current attachment point of the MN obtained from the L-NACF. The neighboring candidate AR information; receiving the location binding request forwarded by the L-NACF and the reported location index information, performing location binding update, and pushing the binding information to the H-RACF;  The L-NACF is configured to query the current attachment point candidate AR information in the H-NACF and the L2 detection information of the neighboring AR reported by the MN according to the pre-configured when the MN needs to switch to the new AN domain. Selecting a policy, selecting an N-AR; receiving SA and user configuration information from the H-NACF, configuring an L-HoA address for the MN, performing location binding update, and pushing binding information to the L-RACF; The H-NACF forwards the location binding request and reports the own location index information;  The L-RACF is configured to receive binding information that is sent after the location binding update is performed by the L-NACF, determine whether the service resource requested by the H-RACF can be accepted and reserved, and if not, reject the H - the resource request of the RACF, otherwise the control policy is generated and delivered to the resource control node; the resource of the original attachment point is released according to the indication of the L-NACF or the request from the H-RACF;  The H-RACF is configured to receive binding information that is sent after the location binding update is performed by the H-NACF, determine the L-RACF in a new AN domain to which the MN is to be handed over, and send the L-RACF to the L-RACF. Resource request; When the service session of the initial attachment point is established, the resource request sent by the P-CSCF is received and forwarded to the L-RACF, and the resource requirement of the service session is saved.  The system according to claim 10, wherein the L-NACF includes: an L-MMF, an authentication, an authentication, an accounting server/proxy, and a network address configuration function entity NAC-FE; The L-MMF further includes: an L-HMF and an L-LMF, where the L-HMF is used to query the candidate AR information of the current attachment point in the H-NACF, and the MN report when the MN needs to switch to the new AN domain. The neighboring access point L2 detects information, and selects the N-AR in the new AN domain according to the configured selection policy; The L-LMF is configured to be used according to the configuration request of the AM-FE The L-HoA address performs a location binding update, and pushes the binding information to the L-RACF; and forwards the binding request and the reported location index information to the H-NACF;  The authentication, authentication, and accounting server/proxy is configured to receive an access authentication request from the MN to implement access authentication of the MN, and to forward the access authentication request from the MN to the H-NACF, and authenticate the MN. After passing, the SA and user configuration information from the H-NACF are received.  A local network attachment control function entity L-NACF, wherein the L-NACF includes an L-MMF, an authentication, an authentication, an accounting server/proxy, and a network address configuration function entity NAC-FE; The L-MMF further includes: L-HMF and L-LMF;  The L-HMF is configured to query the candidate AR information of the current attachment point in the H-NACF and the neighboring access point L2 detected by the MN when the MN needs to switch to the new AN domain, according to the configured selection. a policy, selecting an N-AR in the new AN domain;  The L-LMF is configured to perform location binding update according to the L-HoA address configured by the NAC-FE under the binding request of the AM-FE, and push binding information to the L-RACF; and to the H-NACF Forward the binding request;  The charging, authenticating, and accounting server/proxy is configured to receive an access authentication request from the MN, implement access authentication of the MN, and forward the access authentication request from the MN to the H-NACF, and pass the authentication in the MN. After receiving the SA and user configuration information from the H-NACF;  The NAC-FE is configured to configure an L-HoA address for the MN.  A home network attachment control function entity H-NACF, wherein the H-NACF includes an H-MMF and an authentication, authentication, and accounting server; and the H-MMF further includes: H-HMF And H-LMF;  The authentication, authentication, and accounting server is configured to perform complete authentication on the MN in the initial attach of the MN, and send the SA and user configuration information generated in the initial attach process to the L-NACF. ; The H-HMF is used according to the current attachment point surrounding AR obtained from the L-NACF Physical identification information, querying candidate AR information around the current attachment point, and sending the candidate AR information to the L-NACF;  The H-LMF is configured to receive the location binding request forwarded by the L-NACF and the reported location index information, perform location binding update, and push binding information to the H-RACF.  14. A resource admission control function entity RACF, wherein the RACF includes: H-RACF and L-RACF;  The L-RACF is configured to receive the binding information pushed by the L-NACF after the location binding update, determine whether the service resource requested by the H-RACF can be accepted and reserved, and if not, reject the H-RACF. Resource request, otherwise generate a control policy and deliver it to the resource control node; release the resources of the original attachment point according to the indication of the L-NACF or the request from the H-RACF;  The H-RACF is configured to receive binding information that is pushed by the H-NACF after the location binding update, determine the L-RACF in the new AN domain to which the MN is to be handed over, and send a resource request to the L-RACF. When the service session of the initial attachment point is established, the resource request sent by the P-CSCF is received, and forwarded to the L-RACF, and the resource requirement of the service session is saved.  An access management function entity AM-FE, wherein the AM-FE includes an access attachment point mobility management function entity A-MMF; and the A-MMF specifically includes an access attachment point control function. Entity A-ACF;  The A-ACF is used to report the physical identification information of the neighboring access point obtained by the MN during the L2 detection process to the L-HMF in the process of selecting the N-AR; Point to the L2 link state or event of the MN.