WO2007140722A1

WO2007140722A1 - A terminal and method for seamless switching among different communication networks

Info

Publication number: WO2007140722A1
Application number: PCT/CN2007/070058
Authority: WO
Inventors: Hui Zhong; Shu Wang; Yuan Liu; Guiming Shu; Yi Zhou; Peiying Dong; Yijun Ren; Tao Kong
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-06-02
Filing date: 2007-05-28
Publication date: 2007-12-13
Also published as: CN101083833A

Abstract

A terminal for switching among different communication networks, comprising: conversation unit, switching unit, detecting unit and network communicating unit. Two methods for switching among different communication networks are also provided, including: detecting the signal states of the CS field network and the IMS field network; then determining the switching moment and implementing the switching operation acording to the detecting results and the prearranged switching policies. The terminal and method can achieve seamless switching between the CS field network and the IMS field network.

Description

Terminal and method for seamlessly switching between different communication networks

The present invention relates to communication network switching techniques, and more particularly to terminals and methods for seamlessly switching between different communication networks. Background of the invention

With the development of communication technologies, the convergence of communication services and the convergence of communication networks through various common protocols have become the development direction, and the purpose is to make user communication more convenient.

The IP Multimedia Subsystem (IMS) for multiple access technologies is the core of the next-generation converged technology. The reason is that IMS IP-based multimedia services and the core control network, and the convergence point "IP" and services of technology convergence. The converged convergence point is "multimedia" and is suitable for fixed-mobile convergence (FMC). IMS is a common platform defined by a number of standards organizations and developed to support a variety of converged services. The public platform does not rely on any access technology and access methods, and supports multiple access technologies using flexible Session Initiation Protocol (SIP) and standardized open interfaces, such as: Global System for Mobile Communications (GSM/GPRS/EDGE) Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA2000), Wireless Fidelity (WiFi) technology, and Worldwide Interoperability for Microwave Access (WiMAX).

In the prior art, Unlicensed Mobile Access (UMA) technology supports seamless handover of voice and data from a mobile network to a wireless local area network or a metropolitan area network, so that mobile voice can be obtained through IP broadband access and unlicensed spectrum technology. data service. UMA provides solutions for accessing GSM and GPRS mobile services through non-certified radio technologies. The supported standards include WiFi (IEEE802.il standard) and Bluetooth (IEEE802.15 standard). With UMA technology, users can use multi-mode mobile terminals to achieve free roaming and switching between mobile networks and public and private WLANs, while achieving a consistent mobile voice and data service experience during network switching. During the connection process, the mobile terminal contacts the UMA network controller (UNC) through the broadband IP access network, and after being authenticated, the mobile terminal accesses the GSM voice and GPRS data service through the non-authenticated wireless network; if it is approved to be stored in the core The current location information of the user of the network is updated, and all voice and data traffic sent to the current point of the mobile terminal through the non-authenticated mobile access network (UMAN) will be routed to the Radio Access Network (RAN).

Existing UMA technologies have the following disadvantages:

1. UMA technology is a technology at the access level. It simply connects a wireless LAN or metropolitan area network system to the 2G core network of GSM/GPRS, so it is only a patch to the existing GSM/GPRS 2G network. Meet the user's future needs and provide enhanced mobile services.

2. The UMA scheme introduces UNC to handle authentication, encryption, and integrity requirements for voice and data transmission. The UNC is similar to the base station subsystem in the GSM system.

(BSS). The above UMA solution brings a large amount of data traffic to the GSM/GPRS core network, resulting in the main entities of the existing GSM/GPRS network, such as the Mobile Switching Center Server (MSC), the Serving GPRS Support Node (SGSN), and the Gateway GPRS Support Node ( GGSN), etc., must be expanded or even replaced to meet additional requirements, thus offsetting the advantage of the UMA solution having less changes to existing GSM/GPRS networks, resulting in higher costs than IMS solutions for large-scale user deployments. A lot.

3. UMA has less consideration for the needs of enterprise users. Intra-enterprise and public WiFi hotspots and other places usually use wireless LAN or metropolitan area network gateways and AAA models for access, which is quite different from UMA access methods, so users cannot use local wireless access nodes (APs) for access. And the UMA solution provides a switch between GSM/GPRS and WiFi, However, switching between multiple APs is not supported, and there are serious problems for large enterprise applications. In addition, the UMA switching scheme is based on the UMA architecture of both the terminal and the network. The terminal side and the network side guarantee the reliability and continuity of the handover process. However, the UMA solution has higher requirements on the terminal. The CS part and the WiFi part of the terminal are relatively tight, and it is generally required to develop a new terminal supporting the UMA protocol. Summary of the invention

An embodiment of the present invention provides a terminal for seamlessly switching between different communication networks, and another method for implementing seamless handover between different communication networks, which can implement a CS domain network and an IMS domain network. Switch between.

The technical solutions provided by the embodiments of the present invention are specifically as follows:

A terminal for implementing switching between different communication networks, comprising:

a call unit, configured to provide a human-computer interaction interface between the CS and the IMS phone, complete a call function of the CS and the IMS phone; perform information exchange with the network side by the network communication unit, and implement the terminal according to the control of the switching unit In standby or in a call state, switching between the IMS domain network and the CS domain network, and transmitting handover signaling to the network side;

a switching unit, configured to notify the detecting unit of status information of the control switching, receive a switching notification from the detecting unit, and control the calling unit to perform a switching operation according to the switching notification;

a detecting unit, configured to receive status information of the control switching from the switching unit, adjust a detection policy, detect the acquired communication network information, determine a switching timing according to the detection result and the set switching policy, and notify the switching Unit

The network communication unit is configured to process the signaling and the voice data according to the CS domain and the IMS domain network communication protocol, and collect the communication network information for the detection unit to acquire.

A method for implementing communication switching between different communication networks, applicable to a CS domain network Switching to and from the IMS domain network, the method includes the following steps:

Detecting signal conditions of the CS domain network and the IMS domain network;

If the detection result is that the IMS domain network is in good condition, determining a handover timing according to the detection result and the set handover policy;

At the determined switching opportunity, the terminal side initiates and completes the process of registering the IMS domain to the network side, determines the special service call number, and initiates and completes the process of activating the CS domain forwarding service.

Another method for implementing communication switching between different communication networks is applicable to handover between a CS domain network and an IMS domain network, and is characterized by the following steps:

If the detection result is that the IMS domain network is not in good condition, determining a handover timing according to the detection result and the set handover policy;

At the determined switching opportunity, the terminal side initiates and completes the IMS domain logout process to the network side; initiates and completes the process of deactivating the CS domain forwarding service. The method performs real-time detection on the communication network signal of the IMS domain and the circuit switched (CS) domain, determines the switching timing according to the obtained detection result and the set switching policy, and implements seamless handover between different communication networks to ensure the switching period. The continuity of the conversation. The IMS-based terminal and method can support mobility in a SIP session for multiple access technologies from the service layer, and implement seamless handover between the IMS domain network and the CS domain network. BRIEF DESCRIPTION OF THE DRAWINGS

1 is a schematic structural diagram of a multimode terminal according to an embodiment of the present invention;

2 is a schematic diagram of a signal flow of an embodiment for performing registration according to the handover method of the present invention; FIG. 3 is a schematic diagram of a signal flow of a first embodiment for deregistering according to the handover method of the present invention; 4 is a schematic diagram of a signal flow of a second embodiment for performing logout according to the handover method of the present invention;

5 is a schematic diagram of a signal flow of an embodiment for switching from a GSM network to a WiFi network during a session according to the handover method of the present invention;

6 is a schematic diagram of a signal flow of a first embodiment for switching from a WiFi network to a GSM network during a tongue transition according to the present invention;

7 is a schematic diagram of a signal flow of a second embodiment for switching from a WiFi network to a GSM network during a session in accordance with the handover method of the present invention. Mode for carrying out the invention

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

FIG. 1 is a schematic structural diagram of a multimode terminal according to an embodiment of the present invention. As shown in FIG. 1, the terminal includes: a configuration management unit 100, a call unit 110, a switching unit 120, a detecting unit 130, and a network communication unit 140.

The configuration management unit 100 is configured to save configuration information of each unit in the terminal, and connect with all other units in the terminal to perform information interaction;

The call unit 110 is configured to provide a human-computer interaction interface between the CS and the IMS phone, complete the call function of the CS and the IMS phone, and perform information interaction with the network side, according to the control of the switching unit 120, to implement the terminal in standby or in a call state. Switching between the IMS domain network and the CS domain network, and transmitting handover signaling to the network side;

The switching unit 120 is configured to notify the detecting unit 130 of the status information of the control switching, and receive the switching notification from the detecting unit 130, before controlling the calling unit 110 to perform the switching operation according to the switching notification;

The detecting unit 130 is configured to receive status information of the control switching from the switching unit 120, Adjusting the detection policy, determining the switching opportunity according to the obtained communication network information and the set switching policy, and notifying the switching unit 120;

The network communication unit 140 is configured to process the signaling and the voice data according to the CS domain and the IMS domain network communication protocol, and collect the communication network information for the detection unit 130 to acquire.

The call unit 110 includes: a CS phone module 111 and an IMS phone module 112, and each module is respectively connected to the configuration management unit.

The CS phone module 111 is configured to provide a human-machine interaction interface of the CS phone, complete the call function of the CS phone, and perform information interaction with the CS domain network through the network communication unit 140, and implement the terminal in standby or call state according to the control of the switching unit 120. Switching between the IMS domain network and the CS domain network; transmitting handover signaling to the CS domain network side;

The IMS phone module 112 is configured to provide a human-computer interaction interface of the IMS phone, complete the call function of the IMS phone, perform information interaction with the IMS domain network through the network communication unit 140, and implement the terminal in standby or according to the control of the switching unit 120. In the call state, the handover between the IMS domain network and the CS domain network sends handover signaling to the IMS domain network side.

The CS telephone module 111 can initiate calls and calls through the CS network such as GSM/GPRS/EDGE, WCDMA, CDMA2000, etc., and can exchange information with the switching unit 120 through the program call interface.

The IMS telephone module 112 can access the IMS network through WiFi, WiMAX, Bluetooth, etc., and initiate and make calls, and can also make calls and answer calls through fixed IP access. The IMS telephony module 112 can interact with the switching unit 120 via a program call interface.

The CS telephony module 111 can also be coupled to the IMS telephony module 112 to share and interact with portions of the communication information.

The switching unit 113 is configured to implement a specific handover process between the CS communication network and the IMS communication network. The switching unit 113 is configured to notify the network communication unit 120 of the handover control state to control The detection policy receives the switching notification from the detecting unit 130, and controls the CS telephone module 111 and the IMS telephone module 112 to perform communication and switching operations according to the current self-maintained switching control state, such as deciding which telephone module to use to initiate the call and answer the incoming call. The module can also control session switching between the CS telephony module 111 and the IMS telephony module 112 during a call. The switching unit 113 can also notify its own switching control status information to the detecting unit 130 to control the detection policy of the detecting unit 130. In addition, the switching unit 113 can also perform control operations on the communication protocol module 141 when needed, such as shutting down the network interface or entering a sleep state.

The network communication unit 140 includes: a communication protocol module 141 and a hardware module 142, each of which is connected to a configuration management unit. among them

The communication protocol module 141 is configured to process the received signaling and voice data according to the CS domain and the IMS domain network communication protocol; obtain the communication network information from the hardware module 142 for the detection unit 130 to periodically acquire; and receive the message from the call unit 110. The signaling is switched, and the handover signaling is sent to the hardware module 142; here, the detecting unit 130 can periodically obtain the communication network information from the communication protocol module 141 through the operating system call interface.

The hardware module 142 is connected to and driven by the communication protocol module 141 through a driving interface for providing basic hardware driving functions, supporting multiple CS domain networks and IMS domain networks, and is responsible for information interaction with the terminal externally, and collecting communication network information. The handover signaling from the communication protocol module 141 is sent to the network side.

The communication protocol module 141 is further connectable to the switching unit 120 for operating the network interface in accordance with the control of the switching unit 120.

The communication network information described in this embodiment includes information such as network identifier, carrier information, and signal strength.

The configuration management unit 100 in the embodiment shown in FIG. 1 is an optional unit, and the configuration management unit 100 may not be separately set in the terminal, and the configuration information of each unit is determined by each unit itself. Save, and each unit is connected to each other for information interaction, including interaction of configuration information. As shown in FIG. 1 , in the terminal solution provided by the embodiment of the present invention, the CS phone module 111 and

The IMS telephony module 112 is two relatively separate portions that are joined together by a common switching unit 120 and detection unit 130. The handover process is initiated by the terminal side and supported by the network side. The continuity of the handover is ensured by the switching unit 120 and the network side of the terminal side, and the existing services, such as forwarding services, are switched, and the implementation is simple, and the terminal and the terminal are Changes to the network are relatively small.

The terminal finally interacts with the outside through the hardware module 142. The communication protocol module 141 periodically transmits the communication network information from the hardware module 142 to the detecting unit 130. If the detecting unit 130 finds that the network condition needs to be switched, the switching message is notified to the switching unit 120, and the switching unit 120 sends a corresponding command to the CS telephone module 111 and the IMS telephone module 112 according to the actual situation, and then sends the handover related signaling to The communication protocol module 141 connected thereto is forwarded through the hardware module 142 to implement information interaction with the network side. When needed, the switching unit 120 also sends commands to the communication protocol module 141 to control its operation of shutting down or entering a sleep state for certain interfaces.

The two methods for seamlessly switching between different communication networks provided by the embodiments of the present invention are mainly for seamless handover between the CS domain network and the IMS domain network. One method consists of the following steps:

The method for determining the special service call number may be: when the terminal side initiates the IMS registration process to the network side, the network side determines the special service call number, and returns the special service call to the terminal side. Call the number; or

The network side and the terminal side determine the special service call number according to the pre-configuration.

Another method includes the following steps:

At the determined switching opportunity, the terminal side initiates and completes the IMS domain logout process to the network side; initiates and completes the process of deactivating the CS domain forwarding service.

Among them, the IMS domain network is not good enough to be divided into two cases: one is that the IMS domain network signal is gradually weakened; the other is that the IMS domain network signal suddenly disappears.

Here, the CS domain network may be a GSM/GPRS/EDGE network, a WCDMA network or a CDMA2000 network; the IMS domain network may be a WiFi network, a Bluetooth network, a WiMAX network or a fixed IP access network, such as an IP-based voice (VoIP) telephone network. .

The method provided by the embodiment of the present invention mainly includes several parts of a registration process, a logout process, and a handover process. The registration process and the logout process are all for the IMS domain. When the user switches from the CS domain network to the IMS domain network, the registration process is required, including the IMS domain registration and the activation of the CS domain unconditional forwarding service. When the user switches from the IMS domain network to the CS domain network, the logout needs to be performed. The process includes two parts: IMS domain logout and deactivation of the CS domain unconditional forwarding service.

The following takes the CS domain network as the GSM network and the IMS domain network as the WiFi network as an example to illustrate the handover process between the CS domain network and the IMS domain network, that is, taking the communication switching process between the GSM network and the WiFi network as an example. For analysis and explanation.

2 is a schematic diagram of a signal flow of an embodiment for registering according to the handover method of the present invention. In this embodiment, the registration process is described by taking a handover from a GSM network to a WiFi network. The IMS telephone module is an IMS SIP user agent (UA), and the CS telephone module is a GSM module. As shown As shown in Figure 2, when the GSM user enters the WiFi network, it needs to perform IMS domain registration and CS domain forwarding activation to switch to the WiFi network. The first registration method shown by steps 201 - 208A in Figure 2, the specific steps are as follows:

Step 201: The detecting unit detects the WiFi signals of all the APs at the bottom layer timing, selects a most suitable AP that meets the handover to WiFi condition according to the switching policy, and connects to the AP, and then notifies the switching unit;

Step 202: The switching unit initiates an IMS domain registration process to the IMS SIP UA.

Step 203A: Perform IMS domain registration with the IMS SIP UA to the IMS domain.

Step 204A: After the IMS domain is successfully registered, the IMS domain returns a set of special service numbers to the terminal, including: an unconditional forwarding number (ForwardNo), a cancellation number (DeregisterNo), and a switching number (HOServiceNo);

Step 205A: The flow of the activation forwarding service is initiated by the switching unit to the GSM module. Step 206A: Query the forwarding service to the CS domain. If the user does not activate the unconditional forwarding number, activate the unconditional forwarding service and the unconditional forwarding number. Otherwise, end;

Step 207A: The CS domain returns a message to the GSM module to complete the activation forwarding service.

Step 208A: The IMS domain returns a message to complete registration of the IMS SIP UA.

In the foregoing first registration mode, the steps 205A-207A indicate the process of initiating and completing the activation of the CS domain forwarding service by the terminal side; and the process may also be initiated by the network side IMS domain, as shown in step 204B-205B of FIG. Shown. Therefore, in this embodiment, the second registration mode is further provided. After steps 201-202 shown in FIG. 2, steps 203B, 204B, 205B, and 206B are performed, and the CS is initiated and completed through the network side IMS domain. The domain forwards the business process and completes the registration. Wherein, steps 203B, 204B, 205B and 206B are as follows:

Step 203B: The IMS SIP UA performs IMS domain registration with the IMS domain.

Step 204B: The process of initiating a forwarding service from the IMS domain to the CS domain on the network side; Step 205B: The CS domain returns a message for completing the activation forwarding service to the IMS domain. Step 206B, after the registration is successful, the IMS domain returns a set of special service numbers to the terminal IMS SIP UA, including: an unconditional forwarding number (ForwardNo), The logout number (DeregisterNo) and the switch number (HOServiceNo); and return the message to complete the registration.

The following describes the logout process by switching from a WiFi network to a GSM network. When a GSM user roams out of the WiFi network, there will be two cases where the WiFi signal is gradually weakened and the WiFi signal suddenly disappears.

FIG. 3 is a schematic diagram of a signal flow of a first embodiment for deregistering according to the handover method of the present invention, illustrating a case where a WiFi signal is gradually attenuated and switched to a GSM network for logout, wherein the IMS telephone module is an IMS SIP UA, a CS telephone module. For the GSM module. The first logout method shown in steps 301 - 306A in Figure 3, the specific steps are as follows:

Step 301: The detecting unit detects that the WiFi signal is gradually attenuated, and notifies the switching unit. Step 302: The switching unit initiates an IMS domain deregistration process to the IMS SIP UA. Step 303: The IMS SIP UA performs the IMS domain deregistration to the IMS domain.

Step 304A: The process of deactivating the forwarding service is initiated by the switching unit to the GSM module. Step 305A: The GSM module queries the CS domain for forwarding service. If the user has activated the unconditional forwarding number, the unconditional forwarding service is deactivated and deleted. Unconditional forwarding number; Step 306A, the CS domain returns a message to the GSM module to complete the deactivation of the forwarding service and complete the logout message.

In the foregoing first deregistration mode, the steps 304A-306A indicate that the process of deactivating the CS domain forwarding service is initiated and completed by the terminal side; and the process may also be initiated by the network side IMS domain, as shown in step 304B of FIG. Shown in 305B. Therefore, in this embodiment, the second deregistration mode is further provided. After steps 301-303 shown in FIG. 3, steps 304B, 305B, and 306B are performed, and the deactivated CS domain is initiated and completed through the network side IMS domain. Forward the business process and complete the cancellation. Wherein steps 304B, 305B and 306B are as follows: Next:

Step 304B: The process of deactivating the forwarding service is initiated by the IMS domain to the CS domain on the network side. Step 305B: The CS domain returns a message to complete the deactivation of the forwarding service to the IMS domain.

Step 306B, the CS domain returns a message to complete completion of the logout to the GSM module.

For the above-mentioned case where the WiFi signal is gradually weakened, since the terminal is not disconnected from the WiFi network at this time, the above two deregistration methods are that the terminal actively initiates the IMS domain deregistration process through the WiFi network, and deactivates the CS domain. After forwarding the service, switch to the GSM network. The difference between the two deregistration methods is as follows: The first deregistration method is to initiate and complete the deactivation forwarding service through the terminal side, and the second deregistration mode is initiated and completed through the network side. Deactivate the forward business.

For the case where the WiFi signal is cancelled when the WiFi signal suddenly disappears, since the terminal loses contact with the WiFi network at this time, the terminal cannot directly perform the IMS domain logout through the IMS domain. Although the terminal is no longer under WiFi network coverage, the user state saved by the network is still registered. If another IMS user calls the user at this time, the network side cannot route the call to the terminal. In this case, the direct deregistration cannot be performed by the method shown in FIG. 3 above. At this time, the terminal can retrieve the special registration method to transfer the information to the IMS domain to complete the special IMS domain deregistration, including the following special IMS. Domain logout method:

Mode A: The terminal initiates a special service number (DeregisterNo) call from the CS domain. After the call is routed to the IMS network, the user status is changed to unregistered by the IMS domain.

Mode B: The terminal sends a short message through the Short Message Service (SMS) service, and forwards the required information to the IMS domain through a specific gateway interface, and the IMS domain changes the user status to unregistered.

Mode C: The terminal notifies the IMS domain through the General Packet Radio Service (GPRS) service, and then the IMS changes the user status to unregistered.

In this way, the CS domain can be deactivated after the special IMS domain is deregistered in the above manner. Forward the service, switch to the GSM network. At this time, when other users initiate a call within the IMS network, they will be processed by the unregistered server and correctly routed to the CS domain to find the terminal.

For the above situation when the WiFi signal suddenly disappears, the special IMS domain logout mode A can be used, that is, the special IMS domain logout mode is completed by initiating a special service number (DeregisterNo) call from the CS domain to complete the special IMS domain logout mode, thereby completing the special Logout. The processing flow is shown in Figure 4.

4 is a schematic diagram of a signal flow of a second embodiment of the handover method of the present invention, illustrating a case where a WiFi signal is suddenly lost and is switched to a GSM network for special deregistration, wherein the IMS telephone module is an IMS SIP UA, and the CS telephone module is GSM module. The first special deregistration method shown by steps 401 - 407A in Figure 4 is as follows:

Step 401: The detecting unit detects that the WiFi signal suddenly disappears and is unavailable, and notifies the switching unit;

Step 401: The switching unit initiates a CS domain logout process to the GSM module.

Step 403: The GSM module sends a special service number (DeregisterNo) call to the CS domain. Step 404, the CS domain notifies the IMS domain, and the IMS domain changes the user state to the unregistered state. Step 405A: Before the deactivation is initiated by the switching unit to the GSM module Step 406A: The GSM module queries the CS domain for forwarding services. If the user has activated the unconditional forwarding number, the unconditional forwarding service is deactivated and the unconditional forwarding number is deleted. Step 407A, the CS domain to the GSM module Returns a message to complete the deactivation of the forwarded service and a message to complete the special logout.

In the foregoing first special deregistration mode, the steps 402-404 are performed by using the special IMS domain deregistration mode A to complete the special IMS domain deregistration, wherein the special service number (DeregisterNo) is already on the network side when performing IMS domain registration. Send to the terminal; steps

405A - 407A indicate the process of initiating and completing the deactivation of the CS domain forwarding service by the terminal side; and the process may also be initiated by the network side, as shown in step 405B of FIG. Therefore, phase The present embodiment further provides a second special deregistration mode, which is shown in step 401 shown in FIG.

After the 404, the steps 405B and 406B are performed, and the process of deactivating the CS domain forwarding service is initiated and completed by the network side CS domain, and the logout is completed. Wherein, steps 405B and 406B are as follows:

Step 405B: The process of deactivating the forwarding service is initiated and completed by the CS domain on the network side; Step 406B, the CS domain returns a message for completing the special deregistration to the GSM module.

For the above-mentioned manner B, which can be used for special deregistration when the WiFi signal suddenly disappears, that is, the manner in which the terminal logs off to the IMS domain through the SMS service, the implementation steps are similar to those used in the above manner A, The difference is: In the flow shown in FIG. 4, step 403 becomes: Sending a logout short message containing DeregisterNo to the network side CS domain, after which the CS domain can go to the IMS domain to complete the special logout process.

For the above-mentioned way of performing special deregistration when the WiFi signal suddenly disappears, that is, the manner in which the terminal notifies the IMS domain to log out through the GPRS service, the implementation steps are similar to those adopted in the above manner A, the only The difference is: In the flow shown in FIG. 4, if a GPRS connection is available, step 403 becomes: sending a deregistration signaling message including DeregisterNo to the network side CS domain through GPRS, after which the CS domain can be transferred to the IMS domain to complete the special Logout process.

In the following analysis of the handover between different communication networks, the handover between the GSM network and the WiFi network is taken as an example. Whether switching from GSM to WiFi or from WiFi to GSM, the handover process is divided into two situations, namely idle period switching and session switching.

During the idle period, the implementation process is relatively simple. For the handover from GSM to WiFi during idle period, the implementation process is the registration process as shown in FIG. 2: No matter which registration mode is adopted, after the registration in the IMS domain is successful and the activation forwarding service is completed, the handover is completed. For the switching from WiFi to GSM during idle period, the implementation process is the foregoing deregistration process as shown in FIG. 3 or FIG. 4: If the WiFi signal is gradually weakened, the implementation is as shown in FIG. 3. The deregistration method shown in the IMS domain deregisters and deactivates the forwarding service, that is, the handover is completed; if the WiFi signal suddenly disappears, the special deregistration method is used to perform the special IMS domain logout and deactivate the forwarding service, that is, the handover is completed. The special IMS domain is logged off, that is, the IMS domain is changed to the unregistered state, and the process can be performed by calling the special number (DeregisterNo) to the CS domain as shown in FIG. A can be implemented by means of an SMS message or a GPRS message, that is, mode B or mode C as described above.

Switching during the session, because the continuity of the user session needs to be guaranteed, the implementation process is complicated and needs to be implemented by means of a special service switching number (HOServiceNo).

FIG. 5 is a schematic diagram of a signal flow of an embodiment for switching from a GSM network to a WiFi network during a session according to the present invention. The IMS telephone module is an IMS SIP UA, and the CS telephone module is a GSM module. As shown in FIG. 5, the detecting unit periodically detects the current WiFi network status. When detecting an AP that meets the condition, the detecting unit connects to the AP and sends a notification to the switching unit, and the switching unit initiates switching from GSM to WiFi. Specific steps are as follows:

Step 501: During the session, the detecting unit detects that the signal satisfies the condition of switching to WiFi, and notifies the switching unit of the detection result;

Step 502: The switching unit initiates an IMS domain registration process to the IMS SIP UA.

Step 503: Perform IMS domain registration by the IMS SIP UA to the IMS domain.

Step 504: After the IMS domain is successfully registered, the IMS domain returns a set of special service numbers to the IMS SIP UA.

Step 505: The switching unit initiates an IMS domain special service handover call to the IMS SIP UA. Step 506: The IMS SIP UA performs a special service handover call (HOServiceNo) to the IMS domain. Step 507: The IMS domain requests the IMS SIP UA to establish a WiFi session. Step 508: The IMS SIP UA returns a message for completing the establishment of the WiFi session to the IMS domain. Step 509: The CS domain requests the GSM module to delete the GSM session.

Step 510: The GSM module returns a message for deleting the GSM session to the CS domain. Step 511A, the switching unit initiates a supplementary registration process, and initiates a process of activating the forwarding service to the GSM module.

Step 512A: The GSM module queries the CS domain for forwarding service. If the user does not activate the unconditional forwarding number, the unconditional forwarding service and the unconditional forwarding number are activated; otherwise, the end;

Step 513A: The CS domain returns a message for completing the activation forwarding service to the GSM module. Step 514A: The IMS domain returns a message for completing the supplementary registration to the IMS SIP UA. Finish Switch to WiFi.

In the embodiment of switching to the WiFi network during the tongue period as shown in FIG. 5, steps 502-504 are performed for IMS domain registration, after the special service switching number (HOServiceNo) call as shown in steps 505-506, step 507 - 510 is to adopt a soft handover mode to delete a GSM session after establishing a WiFi session. In fact, it is also feasible to adopt a hard handover mode, that is, to delete a GSM session and then establish a WiFi session. After the completion of step 510, the session service has been transferred to the WiFi network.

As shown in steps 511A-514A of FIG. 5, the first supplementary registration mode in this embodiment is initiated by the terminal side and completes the process of activating the CS domain forwarding service, and then completing the supplementary registration process, and the process thereof is as shown in the foregoing figure. The process shown in steps 205A - 208A in the first registration mode of 2 is the same.

In the supplementary registration process of this embodiment, the activation of the CS domain forwarding service may be initiated and completed by the network side IMS domain, and then the supplementary registration process is completed, as shown in FIG. 5, 511B-513B, and the process is as shown in FIG. 2 The process shown in steps 204B - 206B in the second registration mode is the same. The second supplementary registration method provided in this embodiment has the following specific steps: Step 511B: The network side IMS domain initiates a process for activating the forwarding service to the CS domain. Step 512B, the CS domain returns a message for completing the activation forwarding service to the IMS domain. Step 513B, the IMS domain returns a message for completing the supplementary registration to the IMS SIP UA. . Finish switching to WiFi.

In this embodiment, the switching to the WiFi network during the session shown in FIG. 5, the switching unit invokes the IMS SIP UA to complete the IMS domain registration, and initiates the special service switching number through the IMS domain.

(HOServiceNo) Call, switch to the IMS network. The network side queries the previous session channel according to the call information, and allocates a new session channel. After the connection destination end is completed, the switch source is released. After the session is successfully switched, steps 511A - 514A or step 511B can be performed immediately.

- The supplementary registration process shown in 513B can also wait for the supplementary registration process to be performed after the end of the call.

6 is a schematic diagram of a signal flow of a first embodiment in which a handover method is implemented by a WiFi network to a GSM network during a handover according to the present invention. The IMS telephone module is an IMS SIP UA, and the CS telephone module is a GSM module. As shown in FIG. 6, the detecting unit periodically detects the current WiFi network status. When it is detected that the WiFi signal is not weakened gradually, the detecting unit notifies the switching unit that the switching unit initiates the handover from WiFi to GSM. Specific steps are as follows:

Step 601: During the session, the detecting unit detects that the WiFi signal is gradually weakened, and notifies the switching unit of the detection result;

Step 602: The switching unit initiates a CS domain special service handover call to the GSM module. Step 603: The GSM module performs a special service handover call (HOServiceNo) to the CS domain. Step 604: The CS domain notifies the IMS domain to perform session switching.

Step 605: The CS domain requests the GSM module to establish a GSM session.

Step 606: The GSM module returns a message to the CS domain to complete the establishment of the GSM session. Step 607: The IMS domain requests the IMS SIP UA to delete the WiFi session.

Step 608, the IMS SIP UA returns a message to complete the deletion of the WiFi session to the IMS domain. Step 609A: The switching unit initiates a supplementary logout process to the IMS SIP UA.

Step 61 OA, IMS SIP UA performs IMS domain logout to the IMS domain;

Step 611 A: The switching unit initiates a deactivation forwarding service flow to the GSM module. Step 612A, the GSM module queries the CS domain for forwarding service. If the user has activated the unconditional forwarding number, the unconditional forwarding service is deactivated and the unconditional condition is deleted. Forwarding number; Step 613A, the CS domain returns a message to the GSM module to complete the deactivation of the forwarding service and complete the message of the supplementary cancellation. Finish switching to GSM.

In the embodiment in which the WiFi signal is gradually weakened due to the gradual weakening of the WiFi signal during the session as shown in FIG. 6, steps 602-604 are to call the GSM network through the special service switching number (HOServiceNo), and the network side CS domain receives the call. Communicate with the switching application server (HO-AS), identify the terminal to be switched and the operation to be performed according to the switching number carried by the call, and go to the IMS domain to complete the special logout; Step 605 _ 608 is to learn the soft switching mode. The WiFi session is deleted after the GSM session is established. In fact, it is also feasible to adopt a hard handover mode, that is, to delete the WiFi session and then establish a GSM session. After the completion of step 608, the session service has been transferred to the GSM network.

The first supplementary deregistration method in this embodiment is shown in steps 609-613A in FIG. 6, and the process is the same as the process shown in steps 302-306A in the first deregistration mode in FIG. 3, that is, The IMS domain logout is performed first, as shown in steps 609-610, and then the terminal side initiates and completes the process of deactivating the CS domain forwarding service, as shown in steps 611A-613A.

In the supplementary deregistration process of this embodiment, the deactivation of the CS domain forwarding service may also be initiated and completed by the network side IMS domain. Therefore, correspondingly, the embodiment further provides a second supplementary deregistration mode, as shown in steps 609-613B, the process is the same as the process shown in the foregoing second logout mode steps 302-306B in FIG. That is, the IMS domain is first logged out, as shown in steps 609-610, and then initiated and completed by the network side IMS domain before deactivating the CS domain. The process of transferring the business, as shown in steps 611B-612B, completes the supplementary logout. Steps 611B, 612B, and 613B are as follows:

Step 611B: The network side IMS domain initiates a process of deactivating the forwarding service to the CS domain. Step 612B, the CS domain returns a message for completing the deactivation forwarding service to the IMS domain. Step 613B, the CS domain returns to the GSM module to complete the supplementary logout. Message. Complete the switch to GSM.

In this embodiment, which switches to the GSM network due to the gradual weakening of the WiFi signal during the session as shown in FIG. 6, the switching unit invokes the GSM module to initiate a special service handover number (HOServiceNo) call in the CS domain, which is already registered. The network side sends the information to the terminal through signaling. Since the handover initiates a new call from the terminal to the network, the network side needs to associate the new call with the previous session, and replaces the previous call with the new call. Therefore, the network side queries the previous session according to the call information. Channel, and assign a new session channel, release the switch source after the switch destination is connected. After the session is successfully switched, the supplementary logout process as shown in steps 609-613A or steps 609-613B may be performed immediately, or the supplementary logout process may be performed after the end of the call.

FIG. 7 is a schematic diagram of a signal flow of a second embodiment in which a handover method is implemented by a WiFi network to a GSM network during a handover according to the present invention. The IMS telephone module is an IMS SIP UA, and the CS telephone module is a GSM module. As shown in FIG. 7, the detecting unit periodically detects the current WiFi network condition. When detecting that the WiFi signal suddenly disappears, the detecting unit notifies the switching unit, and the switching unit initiates switching from WiFi to GSM. Specific steps are as follows:

Step 701: During the session, the detecting unit detects that the WiFi signal suddenly disappears, and notifies the switching unit of the detection result;

Step 702: The switching unit initiates a CS domain special service handover call to the GSM module. Step 703: The GSM module performs a special service handover call (HOServiceNo) to the CS domain. Step 704: The CS domain notifies the IMS domain to perform session switching. Step 705: The CS domain requests the GSM module to establish a GSM session. Step 706: The GSM module returns a message to complete the establishment of the GSM session to the CS domain. Step 707: The IMS domain requests the IMS SIP UA to delete the WiFi session.

Step 708: The IMS SIP UA returns a message for completing the deletion of the WiFi session to the IMS domain. Step 709: The switching unit initiates a supplementary special cancellation process to the GSM module.

Step 710, the GSM module sends a special service number (DeregisterNo) call to the CS domain; Step 711, the CS domain notifies the IMS domain, and the IMS domain changes the user state to the unregistered state; Step 712A, the switching unit initiates a deactivation forward to the GSM module. Step 713A: The GSM module queries the CS domain for forwarding services. If the user has activated the unconditional forwarding number, the unconditional forwarding service is deactivated and the unconditional forwarding number is deleted. Step 714A, the CS domain returns to the GSM module. Complete the message to deactivate the forwarded service and complete the message to supplement the special logout. Finish switching to GSM.

In the embodiment in which the WiFi signal is suddenly lost due to the sudden disappearance of the WiFi signal during the session as shown in FIG. 7, steps 702-704 are to call the GSM network through the special service switching number (HOServiceNo), and the network side CS domain receives the call. Communicate with the switching application server (HO-AS), identify the terminal to be switched and the operation to be performed according to the switching number carried by the call, and notify the IMS domain to prepare for session switching; Steps 705-708 are to learn the soft switching mode. The WiFi session is deleted after the GSM session is established. In fact, it is also feasible to adopt a hard handover mode, that is, to delete the WiFi session and then establish a GSM session. After the completion of step 708, the session service has been transferred to the GSM network.

In the embodiment shown in FIG. 7, since the WiFi signal suddenly disappears and the IMS domain cannot be logged out through the IMS domain, the IMS domain logout process in the supplementary logout process performed after step 708 is performed as shown in FIG. The normal IMS domain logout mode shown in 609-610 is different. The IMS domain deregistration process in the supplementary deregistration process described in this embodiment can only use the special IMS domain deregistration method as described above, and go to the IMS domain to complete the IMS domain annotation. The pin, thus, the supplemental logout that is performed after step 708 is referred to as a supplemental special logout. In this embodiment, the special IMS domain deregistration process in the supplementary special deregistration process adopts the special IMS domain deregistration mode A as described above, that is, by calling the special service number (DeregisterNo) call from the CS domain to In the IMS domain, the IMS domain changes the user state to the unregistered state, thereby completing the special IMS domain logout. The specific steps are as shown in steps 402-404 of FIG. In the supplementary special deregistration process performed after step 708 in this embodiment, either the first special deregistration mode as shown in steps 402-407A in FIG. 4 or the step 402 in FIG. 4 may be employed. The second special deregistration method shown in 406B.

As shown in steps 709-714A in FIG. 7, the first special special deregistration process in this embodiment is performed, in which the special deregistration is performed by using the first special deregistration method shown in steps 402-407A in FIG. 4, that is, The special IMS domain deregistration is performed by initiating a special service number (DeregisterNo) call from the CS domain, as shown in steps 709-711, and then the terminal side initiates and completes the process of deactivating the CS domain forwarding service, such as a step. 712A - 714A are shown to complete the supplemental special logout process.

As shown in steps 709-713B in FIG. 7, the second special special deregistration process in this embodiment is performed, in which the second special deregistration method shown in steps 402-406B of FIG. 4 is used to complete the special deregistration, that is, The special IMS domain deregistration is performed by initiating a special service number (DeregisterNo) call from the CS domain, as shown in steps 709-711, and then the network side initiates and completes the process of deactivating the CS domain forwarding service, such as steps. 712B, thus completing the supplemental special cancellation process. Steps 712B and 713B are as follows:

Step 712B: The process of deactivating the forwarding service is initiated and completed by the CS domain on the network side. Step 713B: The CS domain returns a message to complete the special deregistration to the GSM module. Finish Switch to GSM.

In the embodiment in which the handover to the GSM network occurs due to the sudden disappearance of the WiFi signal during the session as shown in FIG. 7, the switching unit invokes the GSM module to initiate the special service switching number in the CS domain. (HOServiceNo) Call, which has been signaled to the terminal by the network side during registration. Since the handover initiates a new call from the terminal to the network, the network side needs to associate the new call with the previous session, and replaces the previous call with the new call. Therefore, the network side queries the previous session according to the call information. Channel, and assign a new session channel, release the switch source after the switch destination is connected. After the session is successfully switched, the supplementary special logout process as shown in steps 709-714A or steps 709-713B may be performed immediately, or the supplementary special logout process may be performed after the end of the call.

It can be seen from the description of the foregoing embodiments that the terminal and the method for seamlessly switching between different communication networks provided by the embodiments of the present invention perform real-time detection on the communication network signals of the IMS domain and the CS domain, and determine that the detection result is satisfied according to the obtained detection result. When the switching strategy is set, seamless switching between different communication networks is achieved, which ensures the continuity of the session during the handover. The IMS-based terminal and method can support mobility in a SIP session for multiple access technologies from the service layer, and seamlessly switch between the IMS domain network and the CS domain network.

Meanwhile, the terminal provided by the embodiment of the present invention includes an IMS telephone module, so the terminal can support multiple access technologies, and adopts SIP as a session control protocol, thereby providing an effective technology for further development of a fixed mobile network (FMC). Guarantee.

In addition, the embodiment of the present invention further provides a registration process, a logout process, and an implementation method of a handover process in a switching process between multiple IMS domain networks and a CS network.

In summary, the above description is only the preferred embodiment of the present invention and is not intended to limit the scope of the present invention.

Claims

Claim

A communication terminal, comprising:

2. The terminal according to claim 1, wherein the call unit comprises: a CS phone module, configured to provide a human-machine interaction interface of the CS phone, complete a call function of the CS phone; and through the network communication unit The CS domain network performs information exchange, and according to the control of the switching unit, implements handover between the IMS domain network and the CS domain network in the standby or talk state; sends handover signaling to the CS domain network side. ;

An IMS telephone module, configured to provide a human-computer interaction interface of the IMS phone, complete a call function of the IMS phone; perform information interaction with the IMS domain network by using the network communication unit, and implement the terminal to stand by according to control of the switching unit In the call state, the handover between the IMS domain network and the CS domain network sends the handover signaling to the IMS domain network side.

3. The terminal according to claim 2, wherein: said network communication unit package Includes:

a communication protocol module, configured to process received signaling and voice data according to a CS domain and an IMS domain network communication protocol; acquire communication network information from the hardware module for periodic acquisition by the detecting unit; and receive from the calling unit Switching signaling, and transmitting the handover signaling to the hardware module;

And the hardware module is configured to collect the communication network information, and send the handover signaling from the communication protocol module to the network side.

The terminal according to claim 3, wherein the communication protocol module is further connected to the switching unit, and is configured to operate the network interface according to the control of the switching unit.

The terminal according to claim 2, wherein the CS telephone module is connected to the IMS telephone module to implement sharing and interaction of communication information.

The terminal according to any one of claims 1 to 5, wherein the terminal further comprises: a configuration management unit, configured to save configuration information of the remaining units in the terminal, and connect with the remaining units. Information exchange.

The terminal according to any one of claims 1 to 5, characterized in that: the CS domain network is a global mobile communication system GSM/GPRS/EDGE network, a wideband code division multiple access WCDMA network or a code division Address access to the CDMA2000 network;

The IMS domain network is a wireless fidelity WiFi network, a Bluetooth network, a global microwave access interoperability WiMAX network, or a fixed IP access network.

A method for implementing communication switching between different communication networks, which is applicable to handover between a CS domain network and an IMS domain network, wherein: the method comprises the following steps: detecting the acquired CS domain network and the IMS domain network Communication network information;

If the detection result is that the IMS domain network is in good condition, determining a handover timing according to the detection result and the set handover policy; At the determined switching opportunity, the terminal side initiates and completes the IMS domain registration process to the network side; determines the special service call number, initiates and completes the process of activating the CS domain forwarding service.

9. The method according to claim 8, wherein: the special service call number comprises: a special service forwarding number, a special service cancellation call number, and a special service switching call number;

The process of initiating and completing the activation of the CS domain forwarding service is as follows: 发起 Initiating and completing the process of activating the CS domain forwarding service by using the special service forwarding number.

The method according to claim 9, wherein before the terminal side initiates and completes the process of registering the IMS domain to the network side, the method further includes the steps of: detecting whether the user is in a session state, and if the user is in a session state, After determining the special service call number, the method further includes the following steps: the terminal side initiates a special service switching number call to the IMS domain on the network side; the IMS domain side and the terminal side establish an IMS domain session on the network side; The voice data stream is switched to the established IMS domain session.

The method according to claim 10, further comprising the step of deleting the CS domain session on the CS side or the terminal side of the network side after or before the process of initiating and completing the activation of the CS domain forwarding service.

The method according to any one of claims 8 to 11, wherein the starting and completing is: the terminal side initiates and completes to the network side, or the network side initiates and completes.

The method according to any one of claims 8 to 11, wherein the method for determining the special service call number is: when the terminal side initiates an IMS registration process to the network side, the network side determines the special service call number. And returning the special service call number to the terminal side; or

A method for implementing communication switching between different communication networks, which is applicable to handover between a CS domain network and an IMS domain network, and is characterized by:

Detecting the communication network information of the obtained CS domain network and the IMS domain network;

If the detection result is that the IMS domain network is not in good condition, according to the detection result and setting Switching strategy determines the timing of switching;

At the determined switching opportunity, the terminal side initiates and completes the process of IMS domain logout to the network side;

Initiate and complete the process of deactivating the CS domain forwarding service.

The method of claim 14, wherein: the terminal side initiates and completes the IMS domain logout process before the network side further includes: detecting whether the user is in a session state,

If the user is in the session state, the terminal side initiates and completes the IMS domain logout process to the network side, and further includes:

The terminal side initiates a special service switching number call to the CS domain on the network side;

The network side CS domain notifies the IMS domain to prepare session switching.

The CS domain and the terminal side on the network side establish a CS domain session; the IMS domain on the network side switches the voice data stream of the current session to the established CS domain session.

The method of claim 15, wherein the step of deleting the IMS domain session by the IMS domain or the terminal side on the network side after the CS domain session and the terminal side of the network side establish a CS domain session .

The method according to any one of claims 14 to 16, wherein: when the detection result is that the IMS domain network signal suddenly disappears, the terminal side initiates and completes the IMS domain logout process specific to the network side. For:

18. The method of claim 17 wherein:

The step of the terminal side initiating and forwarding to the IMS domain to perform the IMS domain logout is as follows: The terminal side initiates a special service cancellation number call to the network side CS domain, and the CS domain notifies the IMS domain to perform the IMS domain logout;

Or: the terminal side sends a logout short message including the special service cancellation number to the network side CS domain. The CS domain notifies the IMS domain to perform IMS domain logout;

Or: Detect whether the GPRS connection is valid. If the GPRS connection is detected, the terminal side sends a cancellation signaling message containing the special service cancellation number to the network side CS domain through the GPRS service, and the CS domain notifies the IMS domain to perform the IMS domain logout.

The method according to any one of claims 14 to 16, wherein the initiating and completing is: the terminal side initiates and completes to the network side, or the network side initiates and completes.

20. The method according to claim 14, wherein: the CS domain network is: a GSM/GPRS/EDGE network, a WCDMA network or a CDMA2000 network; the IMS domain network is: a WiFi network, a Bluetooth network, a WiMAX network Or fixed IP access to the network.