WO2012174944A1

WO2012174944A1 - Network switching method and system

Info

Publication number: WO2012174944A1
Application number: PCT/CN2012/074678
Authority: WO
Inventors: 黄亮
Original assignee: 中兴通讯股份有限公司
Priority date: 2011-06-24
Filing date: 2012-04-25
Publication date: 2012-12-27
Also published as: CN102244912A

Abstract

Disclosed are a network switching method and a network switching system. The method comprises the following steps: binding a point-to-point link established by a wireless terminal through a first access network and a core network to a network interface of a second access network (S102); and releasing the binding between a network port of the first access network and the point-to-point link (S104). The present invention improves the user experience.

Description

TECHNICAL FIELD The present invention relates to the field of communications, and in particular to a network switching method and system. BACKGROUND OF THE INVENTION Currently, a wireless terminal device (for example, a wireless terminal device based on a monitoring system application context) performs switching between two networks, usually by manual switching, and a wireless local area network (WLAN). For example, the switching of the code division multiple access (CDMA) system is performed by manually detecting the network signal of the WLAN after the device is started. When the signal strength meets the requirements, the CDMA module is first turned off. The network access is disconnected, and then the WLAN module is enabled to re-initiate the access request to access the WLAN network, thereby completing the handover from the CDMA network to the WLAN network. However, manually determining whether to perform the network switching method, when performing network switching, it is necessary to manually stop the currently accessed network module, disconnect the network connection, and then enable another network module to re-access the network, and the entire switching process requires the user. Manual participation and switching can result in disruption of data traffic. In view of the problem that the data service existing in the manual handover between networks is interrupted in the related art, an effective solution has not been proposed yet. SUMMARY OF THE INVENTION The present invention provides a network switching method and system to solve at least the above problems. According to an aspect of the present invention, a network handover method is provided, the method comprising the steps of: binding a point-to-point link established by a wireless terminal through a first access network and a core network to a network of a second access network And acknowledging the binding of the network port of the first access network and the point-to-point link. Preferably, before the wireless terminal is bound to the network interface of the second access network by using the first access network and the point-to-point link established by the core network, the wireless terminal The monitored second network satisfies a preset handover condition and initiates a handover from the first access network to the second access network. Preferably, the switching condition includes: the signal strength of the second access network is greater than a threshold. Preferably, the wireless terminal switches the point-to-point link in the wireless terminal from a first module to a second module, where the first module is configured to access the first Accessing the network, the second module is configured to access the second access network: acquire an available transmission channel for the network port corresponding to the second module; and use the available transmission channel and the wireless The interface unit in the terminal is connected, wherein the interface unit is configured to provide a point-to-point link interface; disconnecting the first module from the interface unit. Preferably, the wireless terminal is a wireless monitoring device. According to another aspect of the present invention, a network switching system is further provided, the system comprising: a wireless terminal, a first access network, a second access network, and a core network, where the core network includes: a binding module, and a setting Binding a point-to-point link established by the wireless terminal through the first access network and the core network to a network interface of the second access network; and releasing the module, configured to release the network of the first access network Binding of the port to the point-to-point link. Preferably, the wireless terminal comprises: an initiating module, configured to bind the point-to-point link established by the wireless terminal through the first access network and the core network to the second connection Before entering the network interface of the network, when the monitored second access network meets a preset handover condition, a handover from the first access network to the second access network is initiated. Preferably, the switching condition includes: the signal strength of the second access network is greater than a threshold. Preferably, the wireless terminal includes: the first module is configured to be connected to the first access network; the second module is configured to access to the second access network; Set to obtain an available transmission channel for the network port corresponding to the second module; a connection module, configured to connect the available transmission channel with an interface unit in the wireless terminal, and disconnect the first module a connection with the interface unit; the interface unit is configured to provide a point-to-point link interface. Preferably, the wireless terminal is a wireless monitoring device. With the present invention, a point-to-point link established by the wireless terminal through the first access network and the core network is bound to the network interface of the second access network; then the network port and point of the first access network are released. The binding of the link to the point solves the problem that the data service that is interrupted during the manual handover between the networks in the related art is interrupted, thereby achieving the automatic seamless switching effect of the service being interrupted, and improving the user experience. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, In the drawing: 1 is a flowchart of a network switching method according to an embodiment of the present invention; FIG. 2 is a structural block diagram of a network switching system according to an embodiment of the present invention; and FIG. 3 is a network access of a wireless video monitoring device according to a preferred embodiment of the present invention. FIG. 4 is a schematic diagram of network switching networking according to a preferred embodiment of the present invention; FIG. 5 is a flow chart of network switching of a wireless video monitoring device according to a preferred embodiment of the present invention; FIG. 6 is a schematic diagram of network switching according to a preferred embodiment of the present invention. FIG. 7 is a schematic diagram of dynamic binding of a PPP link network port in accordance with a preferred embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments may be combined with each other without conflict. The network switching in this embodiment is a terminal device that accesses the communication network through a network access technology. When an accessable signal of another network is detected, the access can be obtained from the current network based on a certain requirement. Switch to another network access method. 1 is a flowchart of a network switching method according to an embodiment of the present invention. As shown in FIG. 1, the process includes the following steps: Step S102: Pass a wireless terminal (also referred to as a terminal device, for example, a wireless monitoring terminal) through the first The point-to-point link established by the access network and the core network is bound to the network interface of the second access network. Step S104, the binding of the network port of the first access network and the point-to-point link is cancelled. After the PPP is bound to the network interface of the second access network, the binding of the network interface of the first access network is cancelled, and the data service that is interrupted during manual handover between the networks in the related art is interrupted. The problem, in turn, achieves an automatic seamless switching effect in which data services are not interrupted, improving the user experience. For handover, in a preferred embodiment, handover conditions (eg, handover conditions from the first access network to the second access network, or handovers from the second access network to the first access network) may be set in advance Condition), then, after the second access network monitored by the wireless terminal meets the preset handover condition, the handover from the first access network to the second access network is initiated. With the preferred embodiment, automatic detection of the wireless terminal and automatic switching can be fully implemented. For example, the handover condition may include: the signal strength of the second access network is greater than a threshold. It is relatively simple to judge by the signal strength. In addition, other conditions can be considered. For example, some operators have relatively favorable expenses in some time periods, and can switch to the preferential network during these periods. For the internal handover of the wireless terminal, a preferred embodiment is also provided in the embodiment: the wireless terminal realizes switching the point-to-point link from the first module to the second module in the wireless terminal by using the following steps. a module is configured to access the first access network, and the second module is configured to access the second access network: Step S202, obtaining an available transmission channel for the network port corresponding to the second module; Step S204, The available transmission channel is connected to the interface unit in the wireless terminal, wherein the interface unit is configured to provide a point-to-point link interface; disconnecting the first module from the interface unit. Through the above steps, the handover can be completed relatively reliably in the terminal. In this embodiment, a network switching system is further provided to implement the foregoing embodiments and preferred embodiments thereof. The descriptions of the modules involved in the system are described below. As used hereinafter, the term "module" may implement a combination of software and/or hardware of a predetermined function. Although the systems and methods described in the following embodiments are preferably implemented in software, hardware, or a combination of software and hardware, is also possible and contemplated. 2 is a structural block diagram of a network switching system according to an embodiment of the present invention. As shown in FIG. 2, the system includes: a wireless terminal, a first access network, a second access network, and a core network, where the core network includes The module 20 and the release module 22 are described below, and the respective modules of the system are described below. The binding module 20 is configured to bind the point-to-point link established by the wireless terminal through the first access network and the core network to the network interface of the second access network; and the releasing module 22 is configured to release the first access Binding of network ports and point-to-point links of the network. Preferably, the wireless terminal comprises: an initiating module, configured to be monitored before the point-to-point link established by the wireless terminal through the first access network and the core network is bound to the network interface of the second access network When the second access network satisfies a preset handover condition, a handover from the first access network to the second access network is initiated. Preferably, the handover condition comprises: the signal strength of the second access network is greater than a threshold. Preferably, the wireless terminal further includes a first module configured to access the first access network; a second module configured to access the second access network; and an acquisition module configured to be a network corresponding to the second module The port acquires an available transmission channel; the connection module is configured to connect the available transmission channel with the interface unit in the wireless terminal, and disconnect the first module from the interface unit, and the interface unit is configured to provide a point-to-point link interface. Preferably, the wireless terminal is a wireless monitoring device. The following is an example of switching between CDMA and WLAN. In the network switching between CDMA and WLAN, the UIM card can be used for unified authentication when the client accesses the network, and then the two-way seamless automatic switching function of the data service between the CDMA and the WLAN network is provided, wherein the seamless network switching is It refers to the switching technology that the user's data service can be uninterrupted when switching between two different network access modes, and the entire switching process can be not perceived by the user. In the preferred embodiment, first, the C+W (bidirectional handover process between CDMA and WLAN) handover refers to the same Packet Data Serving Node (PDSN) and Packet Control Function (Packet Control Function). The process of switching between PCFs is not changed on the network side. Secondly, in the entire handover process, the data link between the user equipment (User Equipment, UE for short) and the PDSN (that is, the point-to-point link) A point-to-point link (referred to as a PPP link) is always maintained. The only switch is the air interface link and the All tunnel between the PCF and the PDSN. Therefore, the PPP link is not re-initiated, and the IP address of the UE is not changed. The terminal service is not interrupted, and the user is not aware of the handover process. Finally, the C+W function is used to flexibly implement the end user of the multi-network module holding CDMA and WLAN, and the purpose of using the corresponding service in the WLAN network coverage area through the WLAN network at high speed and fast. . The wireless terminal in the preferred embodiment can be implemented between the two networks under the premise that the user data service is not interrupted and the user is not aware of the switching process according to the actual network condition in the coverage area of the WLAN and the CDMA network. The two-way switching, and the method for implementing seamless handover of the network in a similar application scenario is explained by the device, so as to better meet the user's demand for the service. The following is an example of a wireless video surveillance device. The wireless video surveillance device is a terminal device that has dual wireless network access modules and only allows a PPP link to be established with the PDSN access unit of the core network. In this case, the switching scheme described in this embodiment can be adopted. 3 is a schematic diagram of network access of a wireless video monitoring device according to a preferred embodiment of the present invention. As shown in FIG. 3, the network device must have both CDMA and WIFI wireless network modules, and can respectively pass the two network modules. Network access. The device or system unit device involved in FIG. 3 includes: a wireless video monitoring terminal, a base network access unit base station (Base Transceiver Station, BTS for short), a PCF, and a wireless access gateway (WAG). , Access Point (AP) and Packet Data Service Node (PDSN for short). The wireless video monitoring terminal initiates a network connection to each access unit of the core network, monitors network signals that can access the WLAN hotspot in real time, controls network switching, and provides data services to users. The terminal device has two The network access module, for example, is a CDMA module and a Wireless Fidelity (WIFI) module, and the terminal can select any one of the network modules to access the core network according to the actual network condition. After the access is successful, The PPP link port dynamic binding technology in this embodiment can also implement seamless handover of the network.

BS, PCF, WAG, AP, and PSDN are all network access equipment units of the telecom network. BS refers to the radio signal base station, PCF is the packet control function unit, WAG is the access gateway of the WLAN network, and the AP is the WLAN network. Access point, PDSN refers to the packet data service node. The working principle and access mode of the above-mentioned core network access unit can refer to relevant telecommunication technical specifications. The following description will be made in conjunction with the above devices. After the power-on is started, the wireless terminal establishes a network connection through the CDMA network and the platform, and simultaneously starts the WIFI module to search for the accessible WLAN AP hotspot, and monitors the WLAN network signal in real time. When the signal strength is greater than the cut-in value, the terminal and the AP perform the The association is performed, and the AP is registered and authenticated to the WAG through the AP. After the authentication succeeds, the network transmission unit corresponding to the PPP link is bound to the physical network port corresponding to the WLAN through the PPP link network port fixed binding mode. The service data is transmitted and received through the physical network port of the WIFI, and then the transmission unit of the CDMA network and the PPP link are unbound, and the CDMA network is disconnected, thereby implementing network switching. If the terminal device registers with the WAG gateway or fails to authenticate, it searches for an available AP again and initiates a registration authentication request again. If it has failed, the process is repeated and the CDMA network is kept disconnected. 4 is a schematic diagram of a network switching network according to a preferred embodiment of the present invention. As shown in FIG. 4, in the network switching network, when a dual-mode network terminal is in a WLAN coverage area, it can be connected to a WLAN AP and access the core through the WAG. In the CDMA network coverage area, the PCF can access the core network. When the network is switched (for example, from CDMA to WLAN), the terminal only needs to complete the registration and authentication to the WAG, and the PSDN stops. The PCF sends the downlink data, and instead sends the downlink data to the WAG, and the terminal network access mode is switched. FIG. 5 is a flowchart of a network switching of a wireless video monitoring device according to a preferred embodiment of the present invention. As shown in FIG. 5, the process includes the following steps: Step S502: Turn on the terminal device, power on, δΡ, and power on the wireless video monitoring device. start up. Step S504, the wireless video monitoring device turns on the WIFI module. Step S506, accessing the core network through the CDMA wireless module, and establishing a PPP link with the PDSN to meet the data service requirements of the user. It should be noted that the order of execution of step S504 and step S506 is not limited thereto, and may be changed or may be performed at the same time. Step S508, searching for the currently available AP hotspot, and monitoring the signal strength of the AP in real time. Step S510, determining whether the searched AP signal strength satisfies the condition of the network handover, for example, whether the signal strength is greater than the cut-in value. If yes, step S512 is performed, and if the handover condition is not met, step S508 is performed. It should be noted that the determination of the network switching condition may be set according to the comparison result of the current WIFI signal strength and the WLAN network cut-in value and the cut-out value. In order to avoid repeated network switching, the switching from the CDMA network to the WLAN is respectively set. The critical value of the network and the threshold for switching from the WLAN network to the CDMA network are called the cut-in value and the cut-out value. When the WIFI signal strength is greater than the cut-in value, it is determined that the network switching condition from CDMA to WLAN is satisfied, and vice versa. When the signal strength is less than the cut-out value, it is determined that the handover condition from the WLAN network to the CDMA network is satisfied. In general, the cut-in is always greater than the cut-out value. Step S512: When it is detected that the signal strength of an AP is greater than the cut-in value, the terminal device associates with the AP, that is, the terminal device initiates network handover from the CDMA network to the WLAN network. If the association fails, the process returns to step S508 to re-detect the network signal, and if the association is successful, step S514 is performed. Step S514: The wireless video monitoring terminal initiates a registration and authentication request to the WAG of the core network by using the associated AP. In step S516, it is determined whether the authentication is successful. If the step S518 is successfully performed, the association between the terminal and the AP is disconnected, and the process returns to step S512 to re-initiate the association request with the AP, or returns to step S508. Step S518, the PPP link established by the terminal through the CDMA network and the PDSN is bound to the network interface of the WLAN network by means of dynamic binding of the PPP link port, and then the network interface and the PPP link of the CDMA network are solved. Bind. Step S520, disconnecting the 3G network. Through the above steps, the replacement of the transmission unit corresponding to the PPP link terminal is implemented without re-initiating the PPP link negotiation, so that the subsequent service data is transmitted and received through the network interface corresponding to the WLAN, and the network is switched. The handover process is completely triggered by the terminal device, is not perceived by the user, and does not need to renegotiate the PPP link, thereby implementing seamless network switching between networks. In step S522, the heartbeat packet keeps alive and continues to detect the Wifi signal strength. In step S524, it is determined whether the network signal of the associated AP is smaller than the cut-out value. If not less, step S522 is performed, and if less, the access network of the wireless video monitoring device is switched from WLAN to CDMA. Need It should be noted that the handover procedure is similar to the previously described procedure for switching from CDMA to WLAN network, and has not been described again. In step S526, after the terminal device is cut out from the WLAN network, the association between the terminal device and the current AP needs to be disconnected, and step S508 is performed to re-detect the WLAN network signal. According to the foregoing implementation manner, compared with the existing dual-network wireless video monitoring device and the network switching mode thereof, the device can automatically complete the network switching, the switching process does not require manual user participation, and the user has no perception, and the data service is not Interrupted, enabling seamless network switching. Therefore, the wireless video monitoring device and the network switching method in this embodiment can greatly improve the user's perception of the application of the wireless video surveillance and promote the development of the wireless video surveillance technology. 6 is a schematic diagram of network switching according to a preferred embodiment of the present invention. As shown in FIG. 6, the handover process from CDMA to WLAN is taken as an example. The entire handover process includes a preparation process and an execution process. In the preparation process, the terminal selects first. The AP can obtain the access IP of the WLAN layer, register and authenticate the WAG gateway, and maintain the CDMA connection and data transmission during the period. The implementation process is that the terminal successfully authenticates the WAG and re-binds the PPP link network port. , disconnect the CDMA connection, PSDN does not need to perform PPP renegotiation and PPP authentication. After the terminal is associated with the AP, the handover procedure is initiated to the WAG, and then the WAG initiates registration with the PSDN. After the success, the PSDN responds to the WAG with a registration message, and the PDSN establishes a new service connection with the target WAG, and the PDSN updates the service of the user. Go to the new connection. The PDSN sends a service update message to the PCF accessed by the CDMA network, informing the PCF to release the original service connection. After receiving the update message, the PCF responds to the PSDN-ACK message, and then sends a service stop message to the PSDN. The PSDN responds to the PCF stop message, the CDMA network connection is released, and the network handover procedure is completed. FIG. 7 is a schematic diagram of dynamic binding of a PPP link network port according to a preferred embodiment of the present invention. As shown in FIG. 7, the wireless video monitoring terminal adopts a user space PPP implementation manner, and in the PPP driver, each network interface corresponds to one PPP transmission channel (channel), each core PPP device corresponds to a PPP interface unit (unit). When a PPP link is established, the corresponding transmission channel of the network port and the interface unit corresponding to the kernel PPP device (PPP0) are connected together for data. Send and receive. If, after the PPP link is established, the transmission channel corresponding to the other network port is connected to the interface unit to disconnect the original transmission channel, the PPP link can transmit and receive data through another physical network, thereby completing the network. Switching. The process includes: After the terminal is powered on, the PPP link is established through the ttyUsBO device of the CDMA wireless module and the PSDN. When switching to the WLAN network, first obtain an available transmission channel for the wlanO network port corresponding to the WLAN wireless module through the system call. The interface call can be as follows: but not limited to: nNewFd = open( dev/ttyAMAl", O NO BLOCK | O RDWR, 0); Ioctl(nNewFd, PPPIOCGCHAN, &nNewChann) == -1) Open the device file /dev/ppp of the kernel PPP module and bind it to the transmission channel corresponding to wlanO. New_ppp_fd = open("/dev/ppp", O RDWR); ioctl(new_ppp_fd, PPPIOCATTCHAN, & nNewChann) Unlink the interface unit and the PPP device file, and then connect the device file and interface unit bound to the wlanO network port. Through the above operations, the port dynamic binding when switching from the CDMA network to the WLAN network is completed. In another embodiment, a network switching software is also provided, which is used to implement the technical solutions described in the foregoing embodiments and preferred embodiments. In another embodiment, a storage medium is provided, in which the above-described transmission delay control software is stored, including but not limited to an optical disk, a floppy disk, a hard disk, a rewritable memory, and the like. Through the above embodiments and preferred embodiments thereof, a mobile communication terminal and method for seamless network switching between a 3G network such as CDMA and a WLAN network can switch from a 3G network to a WLAN or a WLAN network when detecting a WLAN network signal When the signal disappears, it can switch from the WLAN network to the 3G network, ensuring that the data service is not interrupted during the handover process, and the handover process is not perceived by the user as a seamless network handover technology. Obviously, those skilled in the art should understand that the above modules or steps of the present invention can be implemented by a general-purpose computing device, which can be concentrated on a single computing device or distributed over a network composed of multiple computing devices. Alternatively, they may be implemented by program code executable by the computing device so that they may be stored in the storage device by the computing device, or they may be separately fabricated into individual integrated circuit modules, or Multiple modules or steps are made into a single integrated circuit module. Thus, the invention is not limited to any specific combination of hardware and software. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

Claim

A network switching method, comprising:

Binding a point-to-point link established by the wireless terminal through the first access network and the core network to a network interface of the second access network; releasing the network port of the first access network and the point-to-point chain The binding of the road.

2. The method according to claim 1, wherein the point-to-point link established by the wireless terminal through the first access network and the core network is bound to the second access network Before the network interface, the second network monitored by the wireless terminal satisfies a preset handover condition, and initiates a handover from the first access network to the second access network.

The method according to claim 2, wherein the handover condition comprises: a signal strength of the second access network is greater than a threshold.

4. The method according to claim 1, wherein the wireless terminal switches the point-to-point link in the wireless terminal from a first module to a second module, where the first The module is configured to access the first access network, and the second module is configured to access the second access network: obtain an available transmission channel for the network port corresponding to the second module;

Connecting the available transmission channel to an interface unit in the wireless terminal, wherein the interface unit is configured to provide a point-to-point link interface;

Disconnecting the first module from the interface unit.

The method according to any one of claims 1 to 4, wherein the wireless terminal is a wireless monitoring device.

A network switching system, comprising: a wireless terminal, a first access network, a second access network, and a core network, where the core network includes:

a binding module, configured to bind a point-to-point link established by the wireless terminal through the first access network and the core network to a network interface of the second access network;

And releasing the module, configured to release the binding of the network port of the first access network and the point-to-point link. The system according to claim 6, wherein the wireless terminal comprises: an initiating module, configured to set the point-to-point link established by the wireless terminal through the first access network and the core network Before being bound to the network interface of the second access network, initiating from the first access network to the second access when the monitored second access network meets a preset handover condition Network switching. The system according to claim 7, wherein the switching condition comprises: a signal strength of the second access network is greater than a threshold. The system according to claim 6, wherein the wireless terminal comprises: the first module, configured to access the first access network;

The second module is configured to access to the second access network;

An obtaining module, configured to acquire an available transmission channel for the network port corresponding to the second module; and a connection module, configured to connect the available transmission channel with an interface unit in the wireless terminal, and disconnect the a connection of the first module to the interface unit;

The interface unit is configured to provide a point-to-point link interface. The system according to any one of claims 6 to 9, wherein the wireless terminal is a wireless monitoring device.