WO2008052466A1

WO2008052466A1 - Method, system and equipment for switching among different networks

Info

Publication number: WO2008052466A1
Application number: PCT/CN2007/070958
Authority: WO
Inventors: Shuiping Long
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-10-25
Filing date: 2007-10-25
Publication date: 2008-05-08
Also published as: CN101170758B; CN101170758A

Abstract

A method for switching the user equipment among different IP networks, the method includes that: the user equipment to be switched, carrying the session renegotiation for switching to the object IP network with the opposite end, bases on the dialog which has been established at the IP network to be switched, and via the voice call continuity application server, switching to the object IP network after the session renegotiation with the opposite end. A corresponding voice call continuity application server, a proxy call session controlling function entity and a user equipment.

Description

Method, system and device for switching between different IP networks

The present invention relates to the field of IP Multimedia Subsystem (IMS) technology, and more particularly to a method, system and device for switching between different IP networks. Background of the invention

IMS is the third Generation Partnership meter Ge ^{1 j (The 3rd Generation Partnership Project} , 3GPP) in version 5 (Release 5, R5) to support IP multimedia subsystem services proposed, its central feature is the use of the Session Initiation Protocol (Session Initial Protocol (SIP) protocol and its independence from access, IMS provides a common service platform for future multimedia applications, and it is an important step towards providing an all-IP network service system.

The IMS standard has evolved R5 and R6 versions with the 3GPP standard system. Following the basic stabilization of the R6 version in March 2005, 3GPP introduced the R7 version, which adds some new features while enhancing the original system functions.

Since the IMS voice service and the circuit domain voice service will exist at the same time for a period of time, the switching between voice services is an urgent problem to be solved. The VCC function is a new function proposed by the R7 version to solve the problem.

According to the above standard definition, VCC refers to the continuity of voice calls, that is, when users move between various access technologies, their calls remain contiguous. For example, users from traditional 2G networks (such as GSM, CDMA, CDMA) When moving to a 3G network (for example, Universal Mobile Telecommunications System UMTS, High Rate Packet Data Network HRPD), its call continues, and other 3G services, such as high-speed Internet access, can be initiated. Referring to FIG. 1, in order to support VCC, when a user initiates/receives a call through a Circuit Switched (CS) network (ie, a 2G network), signaling must enter the IMS network, and one of the IMS networks, VCC AS, It can be used to control the VCC handover. In addition, the network element that the user enters into the CS network through the IMS network is the Media Gateway Control Function (MGCF), and the MGCF also controls the media gateway (MGGW) to carry the route. At present, the industry proposes a VCC network handover scheme between a CS network and an IP network of a user equipment, and has not proposed a scheme for the user equipment to switch between IP networks. However, when the quality of the IP network of the user equipment is deteriorated, When switching to a new IP network, the user equipment may also drop calls, affecting the quality of the user's call. Summary of the invention

The technical problem to be solved by the embodiments of the present invention is to provide a method for switching between different IP networks, a device, and a user equipment to switch between different IP networks, so as to support user equipment to switch between different IP networks, and to prevent user equipment from falling. To improve the quality of user calls.

To solve the above problem, the embodiment of the present invention provides a method for a user equipment to switch between different IP networks, including:

The user equipment to be switched is renegotiated based on the established conversation of the IP network to be switched and the session is switched to the target IP network through the voice call continuity application server, and is switched to the target after the renegotiation with the peer session is completed. IP network.

Correspondingly, the embodiment of the present invention further discloses a user equipment, including a call processing unit, where the call processing unit includes an IP network inter-network voice call continuity switching processing unit, and the IP network inter-network voice call continuity switching process. The unit includes:

An inter-IP network voice call continuity switching initiation unit is configured to initiate an inter-IP network voice call continuity switch according to a predetermined policy; The session negotiation processing unit initiates session re-negotiation of the voice call continuity handover to the target IP network based on the established session of the IP network to be handed over.

Correspondingly, a system for switching between different IP networks is also disclosed in the embodiment of the present invention. The system includes: a user equipment to be switched, a peer user equipment, and a network session unit;

The user equipment to be switched is located in an IP network to be switched, and is used to perform a session to the target IP network based on the established session of the IP network to be switched and through the network session unit and the peer user equipment. Re-negotiation, switching to the target IP network after the renegotiation with the peer user equipment session is completed;

The peer user equipment communicates with the user equipment to be switched over the IP network; the network session unit is configured to forward a session re-negotiation message between the user equipment to be switched and the peer user equipment .

A voice call continuity application server, including:

a detection indication processing unit, configured to: after detecting that the user equipment to be switched has been switched to the target IP network, indicating that the proxy call session control function entity of the IP network to be switched has completed the user equipment to be switched to the target IP network Switch.

A proxy call session control function entity, including:

The release processing unit is configured to: after detecting that the user equipment to be switched has been switched to the target IP network, release the bearer resource of the user equipment to be switched under the IP network to be switched.

Compared with the prior art, one or more embodiments of the present invention have the following beneficial effects: The user equipment to be switched is based on the established conversation on the IP network to be switched and through the voice call continuity application server (VCC AS) and The peer performs the session re-negotiation to switch to the target IP network, and switches to the target IP network after the renegotiation with the peer session is completed. In the handover mode of the embodiment of the present invention, the VCC does not need to allocate the E.164 number and SIP associated with the VCC AS to the user equipment to be switched, compared with the existing VCC network handover scheme between the CS network and the IP network. The URI address resource; and the user equipment to be switched does not need to create a new session, but negotiates the session through the established session. Therefore, the VCC AS does not need to perform operations such as release of the session, and the implementation scheme is simpler. In addition, the embodiment of the present invention implements direct handover between IP networks. When the IP network coverage of the user equipment is degraded, the user equipment can also switch to another new better coverage IP through the embodiment of the present invention. The network avoids the dropped calls of user equipment and improves the quality of the user's call. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a prior art VCC structure reference model;

2 is a flow chart of a first preferred embodiment of a method for switching user equipments between different IP networks according to the present invention; FIG. 3 is a flow chart of a second preferred embodiment of a method for switching user equipments between different IP networks according to the present invention; FIG. 5 is a flowchart of a fourth preferred embodiment of a method for switching user equipments between different IP networks according to the present invention; FIG. 5 is a flowchart of a fourth preferred embodiment of a method for switching user equipments between different IP networks according to the present invention; FIG. 7 is a flow chart of a sixth preferred embodiment of a method for switching user equipments between different IP networks; FIG. 7 is a flowchart of a sixth preferred embodiment of a method for user equipment switching between different IP networks according to the present invention; A schematic diagram of a functional module for implementing VCC switching between different IP networks; 9 is a schematic diagram showing the overall structure of a system embodiment for switching between different IP networks in the present invention;

10 is a schematic diagram of functional modules for implementing VCC switching between user equipments in different IP networks by a VCC application server according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of functional modules of a P-CSCF for performing VCC switching between different IP networks in a P-CSCF according to an embodiment of the present invention. Mode for Carrying Out the Invention The solution provided by the embodiment of the present invention is that the user equipment to be switched is based on the established conversation of the IP network to be switched and the session is switched to the target IP network through the voice call continuity application server and the peer end. Re-negotiation, switching to the target IP network after the renegotiation with the peer session is completed, wherein the IP network in the embodiment of the present invention may include a Wireless Local Access Network (WLAN) and high-rate packet data (High Rate Packet Data, HRPD, network, etc., and the details are not described here. Since the user equipment can be switched between different IP networks, the embodiment of the present invention avoids dropped calls of the user equipment and greatly improves the quality of the user's call. In the implementation of the present invention, the session negotiation between the user equipment and the VCC AS may be completed by the proxy session control function entity (P-CSCF) of the target IP network, or may be completed by the P-CSCF of the IP network to be switched.

Specific embodiments of the present invention will be described below by way of specific embodiments for session negotiation through different P-CSCFs.

2 to 5 are main flowcharts of first to fourth preferred embodiments of a method for switching user equipments between different IP networks according to the present invention. In the four embodiments, the session negotiation between the user equipment and the VCC AS is performed by the P-CSCF of the target IP network; the IP network to be switched uses the WLAN network as an example, and accesses the core network through the P-CSCF1. Target network The HRPD network is used as an example, and the core network is accessed through the P-CSCF2. In the fourth preferred embodiment shown in FIG. 5, the IP network to be switched and the P-CSCF of the target IP network are the same entity, and both are utilized. The P-CSCF indicates that the P-CSCF in FIG. 5 is equivalent to the P-CSCF1 and the P-CSCF2 in FIG. 2 to FIG. 4; the pktl in the user equipment UE1 to be switched indicates the radio interface accessing the WLAN network, and pkt2 indicates Accessing the wireless interface of the HRPD network, the UE1 establishes a call and makes a call with the remote end through the IP network of the WLAN, and the user equipment UE 1 and the VCC AS to be switched establish a dialog 2, and the dialog ID is local tag = pkoDL far End tag = juio and Call ID = afjo8ijfsjfuf56wewi8. When the IP network that should be switched to the HRPD is decided according to some policies (such as changes in radio conditions), the network switching process is performed, which mainly includes the following steps:

First, in step slO1, if the user equipment UE1 to be switched does not perform IMS registration through the HRPD network, first register with pkt2, and then perform step sl02; if UE1 is already registered in the HRPD network, step sl02 is directly executed;

In step sl02 ~ step sl04, the user equipment UE 1 to be switched sends a re-INVITE message or an update message through dialog 2, and the carrying information is as follows:

From: UE1 URI; tag=pkoDI, To: OEP; tag=juio, Call ID: afjo8ijfsjfuf56wewi8, Contact: IP address assigned by the HRPD network, UE 1 SDP

The re-INVITE message or the update message is a message defined in the IMS, and the message is sent by the pkt2 of the UE1, and passes through the P-CSCF2 (P-CSCF in FIG. 5) and the service of the HRPD network. The Serving Call Session Control Function (S-CSCF) and the VCC AS are sent to the peer end, and the re-INVITE message or the update message contains the new SDP information of the UE 1 (the new service stream is transmitted and received by the HRPD network). IP address and port, media type and encoding mode change, etc.), the Contact header contains the IP address assigned by the HRPD network. It should be noted that the IP address may be different from the service flow IP address. In step s05, the remote end answers the final response message (200 OK message in this embodiment) to the UE 1, and the final response message (ie, the 200 OK message) contains the SDP information of the far-end response; the returned response message still passes the HRPD. The P-CSCF2 of the network (P-CSCF in Figure 5) returns to pkt2 of UE1.

Through the above steps sl02~s sl05 UE1 completes the renegotiation with the peer end, so that the service flow is switched to the new IP address and port, and the signaling flow (SIP message) is switched to the new IP address (contact header indication);

In step sl06, as the three-way handshake mechanism of the SIP protocol, UE 1 may return an ACK message to the opposite end. The ACK message is also sent by pkt2 of UE1 and sent to the peer through P-CSCF2 (P-CSCF in Figure 5) and S-CSCF, VCC AS of the HRPD network.

In addition, for the specific implementation of the foregoing four embodiments, the P-CSCF of the IP network to be switched may further perform the release of the bearer resources of the UE1, and may adopt various manners. Referring to FIG. 2, FIG. 3, FIG. 4 and FIG. 5, are all preferred embodiments employed in the present invention.

With reference to FIG. 2, according to the first preferred embodiment of the present invention, the P-CSCF1 of the IP network to be switched learns that the user equipment to be switched releases the bearer resources when the network connection under the IP network to be switched is lost. That is, step 107a). Specifically, the method for obtaining the loss of the network connection may be: When the P-CSCF1 does not detect the maintenance connection signal sent by the UE1 within a certain period of time, it determines that the network connection is lost. After the P-CSCF1 releases the bearer resource, it also sends a BYE message to the VCC AS instead of the user equipment to be handed over (ie, step s108a), indicating that the UE1 related session is released; and the VCC AS goes to the P-IP of the IP network to be switched. The CSCF returns a 200 OK message response (ie, step sl09a).

Referring to FIG. 3, according to a second preferred embodiment of the present invention, after the VCC AS recognizes that the user equipment to be switched is handed over to the target IP network, the P-CSCF user equipment of the IP network to be switched has been switched to the target IP network. ; releasing the P-CSCF of the IP network to be switched The user equipment is in the IP network to be switched, and the VCC AS can instruct the UE to complete the IP access network handover by sending a NOTIFY message to the P-CSCF of the IP network to be switched (step sl07b). The P-CSCF of the IP network to be switched sends a 200 message response to the VCC AS (step s108b), and then releases the bearer resources of the user equipment under the IP network to be switched (step s109b).

Referring to FIG. 4, according to a third preferred embodiment of the present invention, the user equipment to be switched indicates that the P-CSCF has completed the handover of the user equipment to be switched to the target IP network, and the P-CSCF of the IP network to be switched is released. In the embodiment, the UE may send a REFER message to the P-CSCF of the IP network to be switched to indicate that the P-CSCF has completed the IP network handover (step s1077); The P-CSCF of the switched IP network sends a 200 message response to the UE (step s1082); and then releases the bearer resource of the user equipment under the IP network to be switched (step s109).

Referring to FIG. 5, according to a fourth preferred embodiment of the present invention, if the P-CSCF of the target IP network and the P-CSCF of the IP network to be switched are the same entity, the P-CSCF sends the user equipment according to the to-be-switched user equipment. The re-invitation message or the update message identifies that the user equipment to be switched initiates the handover to the target IP network (step s107d). After the handover is completed, the P-CSCF releases the bearer resource of the user equipment to be switched under the IP network to be switched. (Step sl08d).

In the above four preferred embodiments, the session negotiation between the user equipment and the VCC AS is completed using the P-CSCF of the target IP network. In the process of switching the IP network, the specific implementation manner is described in detail by taking the session of the WLAN network to the HRPD network as an example. In fact, for the handover between different IP networks, if the P-CSCF of the target IP network is used to implement session negotiation between the user equipment and the VCC AS, and finally to implement the handover between the IP networks, the above implementation manner may be adopted, for example, Switching the session from the HRPD network to the WLAN network is not mentioned here. Referring to FIG. 6 and FIG. 7, respectively, are main flowcharts of the fifth and sixth preferred embodiments of the method for the user equipment of the present invention to switch between different IP networks. In the two embodiments, the session negotiation between the user equipment and the VCC AS is completed by the P-CSCF of the IP network to be switched; the IP network to be switched takes the WLAN network as an example, and accesses the core network through the P-CSCF1. The target network is exemplified by the HRPD network, and accesses the core network through the P-CSCF2. In the sixth preferred embodiment shown in FIG. 7, the IP network to be switched and the P-CSCF of the target IP network are the same entity. The P-CSCF in FIG. 7 is equivalent to the P-CSCF1 and the P-CSCF2 in FIG. 6; the pktl in the user equipment UE 1 to be switched indicates the radio interface accessing the WLAN network, pkt2 Indicates a wireless interface that accesses the HRPD network. The UE1 establishes a call and makes a call with the remote end through the IP network of the WLAN. The user equipment UE 1 and the VCC AS to be switched establish a dialog 2, and the dialog ID is local tag = pkoDL. Remote tag = juio and Call ID = afjo8ijfsjfuf56wewi8. When the IP network that should be switched to the HRPD is decided according to some policies (such as changes in radio conditions), the network switching process is performed, which mainly includes the following steps:

Step s201, if the user equipment UE1 to be switched does not perform IMS registration through the HRPD network, first register by pktl, and then perform step s202; if UE1 is already registered in the HRPD network, step s202 is directly performed;

In step s202 to step s204, the user equipment UE 1 to be switched sends a re-INVITE message or an update message through dialog 2, and the carrying information is as follows:

From: UE1 URI; tag=pkoDI, To: OEP; tag=juio, Call ID: afjo8ijfsjfuf56wewi8, Contact: IP address assigned by the WLAN network, UE 1 SDP

The re-invitation re-INVITE message or the update message is sent by the pktl of the UE1, and is sent to the peer end through the P-CSCF1 and the S-CSCF of the WLAN network, and the VCC AS, which includes the new SDP information of the UE 1 (the HRPD network) Assigned new traffic stream to send and receive IP addresses and ends The interface includes the IP address assigned by the WLAN network. The IP address and the service stream IP address may be different.

Since the Contact header in the re-invitation re-INVITE message or the update message contains the IP address allocated by the WLAN network, in the handover process, only the service bearer is switched to the HRPD network, and the service control is still performed on the WLAN network. ;

In step s205, the remote end answers the final response message (200 OK message in this embodiment) to the UE 1, and the final response message (ie, the 200 OK message) contains the SDP information of the far-end response; the returned message is through the WLAN. The P-CSCF1 of the network returns to the pktl of the UE1; through the above steps s202 to s205, the UE 1 completes the renegotiation with the peer end, so that the service flow is switched to the new IP address and port;

In step s206, as a three-way handshake mechanism of the SIP protocol, UE 1 may return an ACK message to the opposite end. The ACK message is also sent by the pktl of the UE1, and is sent to the peer end through the P-CSCF1, the S-CSCF, and the VCC AS of the WLAN network.

In addition, for the specific implementation of the foregoing two embodiments, the P-CSCF of the IP network to be switched may further perform the release of the bearer resources of the UE1, and may adopt various manners. Referring to FIG. 6 and FIG. 7, the present invention is A preferred embodiment employed.

Referring to FIG. 6, according to a fifth preferred embodiment of the present invention, the user equipment to be switched indicates that the P-CSCF has completed the handover of the user equipment to be switched to the target IP network, and the P-CSCF of the IP network to be switched is released. In the embodiment, the UE may send a REFER message to the P-CSCF of the IP network to be switched to indicate that the P-CSCF has completed the IP network handover (step s207a); The P-CSCF of the switched IP network sends a 200 message response to the UE (step s208a); and then releases the bearer resource of the user equipment under the IP network to be handed over (step s209a).

Referring to FIG. 7, according to a sixth preferred embodiment of the present invention, if the P-CSCF of the target IP network The P-CSCF is the same entity as the P-CSCF of the IP network to be switched, and the P-CSCF identifies that the user equipment to be switched initiates handover to the target IP network according to the re-invitation message or the update message sent by the user equipment to be switched ( Step s207b), after the handover is completed, the P-CSCF releases the bearer resource of the user equipment to be switched under the IP network to be switched (step s208b).

In the above two preferred embodiments, the negotiation between the user equipment and the VCC AS is completed by using the P-CSCF of the IP network to be switched. In the handover process of the IP network, the specific implementation manner is described in detail by taking the session of the WLAN network to the HRPD network as an example. In fact, for the handover between other different IP networks, if the P-CSCF of the IP network to be switched is used to implement the session negotiation between the user equipment and the VCC AS, and finally to implement the handover between the IP networks, the above implementation manner may be adopted, for example, , Switch the session from the HRPD network to the WLAN network, and will not go into details here.

The foregoing is a specific implementation manner of a method for switching user equipments between different IP networks provided by the present invention.

Referring to FIG. 8 , which is a schematic diagram of a functional module for implementing a VCC handover between different IP networks in a user equipment according to an embodiment of the present invention, where the user equipment includes a call processing unit, and the call processing unit is improved in the embodiment of the present invention. , that is, in the call processing unit, there are:

The inter-IP network voice call continuity switching processing unit 11 is configured to control network switching of voice call continuity between different IP networks.

According to the logical function of the implementation, the inter-IP network voice call continuity switching processing unit 11 specifically includes two logical functional units, that is, an inter-IP network voice call continuity switching initiation unit 111 and a session negotiation processing unit 112, where

IP network inter-network voice call continuity switching initiation unit 111, voice call between the IP networks The continuity switching initiation unit 111 is mainly configured to initiate an inter-IP network voice call continuity switching according to a predetermined policy.

The session negotiation processing unit 112 is mainly configured to initiate session re-negotiation of the voice call continuity handover to the target IP network based on the established session of the IP network to be handed over. In the embodiment of the present invention, the call to the VCC application server is initiated based on the established session of the IP network to be switched, and the session is re-negotiated with the peer end. For details, refer to the foregoing process description.

The switching unit 113, after the session re-negotiation is completed, switches the user equipment from the IP network to be switched to the target IP network.

Further, the user equipment provided by the embodiment of the present invention may further include an indication unit 10, after the user equipment switches to the target IP network, and indicates that the IP network to be switched releases the bearer resource of the user equipment in the network to be switched.

In addition, referring to FIG. 9, in order to implement the VCC network switching between the different IP networks of the user equipment, the embodiment of the present invention further provides a system for switching between different IP networks, where the system includes: user equipment to be switched 1, and opposite user Device 2, network session unit 3. The network conference unit 3 includes a P-CSCF 31 and a VCC application server 32.

The user equipment 1 to be switched is used for re-negotiating the session to the target IP network based on the established conversation in the IP network to be switched and the peer user equipment 2 through the network session unit 3, in the pair After the end user equipment 2 completes the session renegotiation, it switches to the target IP network. The network session unit 3 is configured to forward a message of the session re-negotiation between the user equipment 1 to be switched and the opposite user equipment 2. The P-CSCF 31 in the network session unit 3 is configured to forward a session re-negotiation message between the user equipment 1 to be switched and the VCC application server 32, and the VCC application server 32 is configured to be used at the P-CSCF 31 and the peer end. The user equipment 2 forwards the message of the session re-negotiation; the P-CSCF 31 includes the P-CSCF and the target of the IP network to be switched. P-CSCF for IP networks. Specifically, the P-CSCF of the IP network to be switched and the P-CSCF of the target IP network may be different physical entities, or may be integrated into the same physical entity.

Specifically, referring to FIG. 10 and FIG. 11, in order to implement VCC network switching between different IP networks of the user equipment, the VCC application server and the P-CSCF of the IP network to be switched further enhance corresponding functional units. Referring to FIG. 10, the present invention In the embodiment, the VCC application server enhancement includes a detection indication processing unit 12, and the detection indication processing unit 12 is mainly used to indicate the IP network to be switched after detecting that the user equipment to be switched has been switched to the target IP network. The P-CSCF has completed the handover of the user equipment to be switched to the target IP network.

Referring to FIG. 11 , the P-CSCF enhancement of the IP network to be switched in the embodiment of the present invention includes a release processing unit 13 , and the release processing unit 13 is mainly configured to detect that the user equipment to be switched has been switched to the target IP network, and then released. The bearer resource of the user equipment to be switched under the IP network to be switched.

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

Claims

Claim

A method for a user equipment to switch between different IP networks, the method comprising: the user equipment to be switched is switched based on the established conversation of the IP network to be switched, and the server and the peer are switched by the voice call continuity application server. The session renegotiation to the target IP network is switched to the target IP network after the renegotiation with the peer session is completed.

2. The method for switching user equipments between different IP networks according to claim 1, wherein the user equipment to be switched is based on a conversation established on an IP network to be switched and through a voice call continuity application server. The renegotiation of the session with the peer to the target IP network specifically includes:

The user equipment to be switched initiates a network wireless connection on the target IP network, and the P-CSCF of the target IP network sends a re-invitation message or an update message to the voice call continuity application server based on the established conversation of the IP network to be switched, The re-invitation message or the update message carries the session description information of the user equipment to be switched;

The voice call continuity application server sends a re-invitation message or an update message to the peer end based on the conversation that has been established with the peer end, and the re-invitation message or the update message carries the session description information of the user equipment to be switched;

After the peer end negotiation, the session re-negotiation is completed by the voice call continuity application server sending back a final response message to the user equipment to be switched, and the final response message carries the session description information of the peer end.

3. The method according to claim 1, wherein the user equipment to be handed over re-negotiates the session to the target IP network by the voice call continuity application server and the peer end based on the established session of the IP network to be handed over. Specifically include:

The user equipment to be switched sends a re-invitation message or an update message to the voice call continuity application server based on the P-CSCF of the IP network to be switched, based on the established session of the IP network to be switched, and the re-invitation message or the update message carries The session of the user equipment to be switched Description;

The method for the user equipment to switch between different IP networks according to claim 2, wherein after the negotiation between the user equipment to be switched and the peer session is completed, the method further includes: a proxy call session of the IP network to be switched The control function entity learns that the user equipment to be switched releases the resource of the user equipment under the IP network to be switched when the network connection under the IP network to be switched is lost.

The method for the user equipment to switch between different IP networks according to claim 4, wherein after releasing the bearer resource, the method further includes:

The proxy call session control function entity instructs the voice call continuity application server to release the user equipment related conversation to be switched.

The method for switching user equipments between different IP networks according to claim 5, wherein the voice call continuity application server receives the indication according to the proxy call session control function entity, and then switches to the to-be-switched The proxy call session control function entity of the IP network returns a reply message.

The method for the user equipment to switch between different IP networks according to claim 2, wherein after the renegotiation of the user equipment to be switched and the peer session is completed, the method further includes: the voice call continuity application server recognizes After the user equipment to be switched is switched to the target IP network, the proxy call session control function entity user equipment of the IP network to be switched has been switched to the target IP network; The proxy call session control function entity of the IP network to be switched releases the bearer resource of the user equipment under the IP network to be switched.

The method for switching user equipments between different IP networks according to claim 7, wherein the voice call continuity application server indicates that the proxy call session control function entity user equipment of the IP network to be switched has been switched to The target IP network is:

The voice call continuity application server sends a notification message to the proxy call session control function entity of the IP network to be switched, indicating that the proxy call session control function entity of the IP network to be switched completes the IP network handover by the user equipment to be switched. .

The method for the user equipment to switch between different IP networks according to claim 2 or 3, wherein, after the negotiation between the user equipment to be switched and the peer session is completed, the method further includes: The proxy call session control function entity has completed the handover of the user equipment to be switched to the target IP network, and the proxy call session control function entity of the IP network to be switched releases the bearer resources of the user equipment to be switched under the IP network to be switched.

The method for the user equipment to switch between different IP networks according to claim 9, wherein the user equipment to be switched indicates a proxy call session control function entity, and the user equipment completes the IP network handover.

The method for the user equipment to switch between different IP networks according to claim 10, wherein the user equipment to be switched instructs the proxy call session control function entity user equipment to complete the IP network handover to: The user equipment that is to be switched sends a REFER message to the proxy call session control function entity, where the refer-to header of the REFER message is set to the universal resource identifier value of the user equipment to be switched.

The method for switching user equipments between different IP networks according to claim 2 or 3, wherein the proxy call session control function entity of the target IP network and the proxy call session control function entity of the IP network to be switched are The same entity, the user to be switched After the device negotiates with the peer session, it also includes:

The proxy call session control function entity identifies that the user equipment to be switched is to be handed over to the target IP network according to the re-invitation message or the update message sent by the user equipment to be switched, and the proxy call session control function entity releases the switch after the handover is completed. The bearer resource of the user equipment to be switched under the IP network to be switched.

The method for switching user equipments between different IP networks according to any one of claims 1 to 8, wherein the IP network to be switched is a high-rate packet data network, and the target IP network is Wireless local access to the network.

The method for the user equipment to switch between different IP networks according to any one of claims 1 to 8, wherein the IP network to be switched is a wireless local access network, and the target IP network is Wireless local access to the network.

A user equipment, comprising a call processing unit, wherein the call processing unit switches to a target IP network based on a conversation established on an IP network to be switched and through a voice call continuity application server and a peer end Session re-negotiation, switching to the target IP network after renegotiation with the peer session is completed.

The user equipment according to claim 15, wherein the call processing unit further comprises:

An inter-IP network voice call continuity switching initiation unit is configured to initiate an inter-IP network voice call continuity switch according to a predetermined policy;

The session negotiation processing unit initiates session re-negotiation of the voice call continuity handover to the target IP network based on the established conversation of the IP network to be handed over.

The switching unit switches the user equipment from the IP network to be switched to the target IP network after the session re-negotiation is completed.

The user equipment according to claim 15 or 16, wherein the user equipment further comprises an indication unit, after the user equipment switches to the target IP network, indicating that the user equipment is to be cut The switched IP network releases the bearer resources of the user equipment under the network to be switched.

A system for switching between different IP networks, the system comprising: a user equipment to be switched, a peer user equipment, and a network session unit;

The user equipment to be switched is located in an IP network to be switched, and is used to perform a session based on the established IP network to be switched and to switch to the target IP network through the network session unit and the peer user equipment. Re-negotiation, switching to the target IP network after the renegotiation with the peer user equipment session is completed;

The system according to claim 18, wherein the network session unit comprises a proxy call session control function entity and the voice call continuity application server; the proxy call session control function entity is used in a message for re-negotiating a forwarding session between the user equipment that is to be handed over and the voice call continuity application server;

The voice call continuity application server is configured to forward a message of the session re-negotiation between the proxy call session control function entity and the peer user equipment.

The system according to claim 19, wherein the voice call continuity application server comprises:

The system according to claim 19, wherein the proxy call session control function entity in the IP network to be switched comprises:

The release processing unit is configured to release the bearer resource of the user equipment to be switched under the IP network to be switched after the user equipment to be switched has been switched to the target IP network.

22. The system according to claim 19, wherein the proxy call session control function entity in the IP network to be switched and the proxy call session control function entity in the target IP network are the same physical entity.

A voice call continuity application server, comprising: a detection indication processing unit, configured to: after detecting that the user equipment to be switched has been switched to a target IP network, indicating an IP network to be switched The proxy call session control function entity has completed the handover of the user equipment to be switched to the target IP network.

A proxy call session control function entity, comprising: a release processing unit, configured to: after detecting that the user equipment to be switched has been switched to the target IP network, releasing the user equipment to be switched at the to-be-switched Hosting resources under the IP network.