CN101232454B - Integration isomerization wireless network and communication method - Google Patents

Abstract

The invention provides an integrated heterogeneous wireless network and a communication method thereof. The Silkroad access router is located on the boundary between the IPv4 Internet and the IPv6 network; the home agent device serves the IPv4-based wireless wide area network and is located in the IPv6-based network; the multi-mode The mobile terminal passes through the IPv4-based wireless wide area network through the Silkroad tunnel mechanism to establish a tunnel with the IPv6 network; the multi-mode mobile terminal sends corresponding routing advertisements to the corresponding tunnel interface according to the tunnel parameters to realize communication with the IPv6 network. By applying the present invention, the MIPv6 protocol can be implemented in the IPv4 wireless wide area network including network address translation equipment or firewalls, providing a unified seamless mobile environment and complete MIPv6 service functions for multi-mode mobile terminals, greatly reducing the links of the wireless wide area network load.

Description

An integrated heterogeneous wireless network and its communication method

technical field

The present invention relates to the technical field of mobile communication, and more specifically, the present invention relates to an integrated heterogeneous wireless network and a communication method thereof.

Background technique

At present, the development of global communication technology is changing with each passing day, and the development speed and application fields of wireless communication technology have surpassed fixed communication technology. With the rapid development of wireless communication technology, various wireless communication networks have highlighted their own advantages, but there is no single network that can undertake the seamless coverage and broadband required by the development of wireless networks. At the same time, no network alone can meet mobile users' wireless access requirements for any time, any place, and any service, and provide a high data transmission rate.

Wireless Wide Area Network (WWAN) can guarantee the connectivity of mobile terminals at any time and everywhere with a low data transmission rate. After long-term promotion by operators, WWAN has been relatively perfect in network deployment and security control, and has a huge user base group. Wireless local area network (WLAN) is generally deployed in airports, restaurants, schools, etc., especially inside buildings where WWAN signals are not easy to penetrate. It provides high data transmission rate and better supports real-time audio and video transmission services. Users' favor, but WLAN can only cover a small area. Due to the complementarity among various wireless networks, if various wireless networks are integrated, the adaptability of wireless data services can be dynamically improved, and various needs of mobile users can be better met.

In order to achieve a truly seamless mobile environment, it is necessary to integrate various wireless networks and support vertical handover of multi-mode mobile devices, that is, mobile nodes (MNs) can be handed over between heterogeneous networks (networks based on different link layer technologies) . WWAN and WLAN are incompatible with each other at the wireless interface level, so they can only be integrated at the network layer to form a unified framework.

Currently, integration solutions for heterogeneous wireless networks mainly include tight integration and loose integration.

The main idea of tight integration is to make wireless network 1 simulate the function of wireless network 2, and use wireless network 1 as a virtual access network of wireless network 2. The egress gateway of wireless network 1 is directly connected to the core network element of wireless network 2. The traffic of wireless network 1 is directly injected into wireless network 2, which not only increases the load of wireless network 2, but also makes wireless network 2 a bottleneck of the entire network. More importantly, Wi-Fi 2 exposes its interface to Wi-Fi 1, therefore, Wi-Fi 1 and Wi-Fi 2 need to belong to the same operator. In fact, in this case, it is difficult for the independently operated wireless network 1 to be integrated into the wireless network 2 .

Although loose integration also requires the deployment of network elements such as agents or gateways in the wireless network, loosely integrated agents or gateways are connected to the Internet rather than directly to core network elements of other wireless networks. Therefore, the solution does not need to modify the underlying protocol stack of any wireless network, nor does it need to expose the details of one type of wireless network to other types of wireless networks. Moreover, various wireless networks can be independently configured and traffic managed. Due to the above advantages, the loosely integrated solution has been widely recognized, and the mobile IP technology is the current mainstream loosely integrated solution.

The currently running WWAN only supports IPv4 communication at the network layer. However, the Internet address space based on IPv4 is insufficient to meet the needs of many mobile users for network access, especially for countries with large network requirements and insufficient address allocation, such as my country. . Moreover, the network adopts Network Address Translation (NAT) technology, so that the mobile terminal can only obtain a private Internet address based on IPv4, and the mobile IPv4 protocol requires the mobile terminal to have a public Internet address based on IPv4. Therefore, using The mobile IPv4 protocol to integrate WWAN and WLAN is difficult to meet the development requirements of the future mobile environment.

Compared with IPv4, the Internet based on IPv6 has the advantages of huge address space and good scalability, which can meet the needs of mobile terminals to obtain globally unique addresses no matter where they are located. It has been used in many WLANs, and in the development of future technologies May gradually replace IPv4 in WWAN to be implemented. At the same time, the Internet Engineering Task Force (IETF), an international organization, proposed Mobile IPv6 (MIPv6) technology (RFC3775), which supports the mobility of the Internet to a certain extent, making MIPv6 a solution for integrating various WWANs and WLANs. However, the standard MIPv6 protocol does not consider the situation that the access network does not support IPv6.

In order to solve the contradiction between WWAN not supporting IPv6 and intending to use MIPv6 to integrate heterogeneous wireless networks, tunneling technology has become a widely used solution. Tunneling is a method of transferring data between networks by using the infrastructure of the Internet. The data (or payload) transmitted through the tunnel may be data frames or packets of different protocols. The tunneling protocol repackages data frames or packets of other protocols, and then sends them through the tunnel. The new frame header (packet header) provides routing information to deliver the encapsulated payload data across the Internet. Therefore, tunnel technology encapsulates IPv6 data packets in the load of IPv4 data packets, and uses the existing IPv4 routing system in WWAN for transmission to solve the problem of communication between mobile terminals accessing WWAN and IPv6 nodes.

However, the current domestic WWAN not only does not support IPv6, but due to insufficient IPv4 address resources, some WWANs (such as GPRS networks) adopt NAT technology, so that mobile terminals can only be assigned private IPv4 addresses, while other WWANs (such as CDMA networks) Even if a public IPv4 address is assigned to the mobile terminal, a firewall is set up at the network entrance in view of factors such as security. These NAT devices and firewalls do not allow 6-in-4 data packets to pass through, so that 6-in-4 tunnel technology cannot support communication between mobile terminals of GPRS, CDMA and other WWANs and other IPv6 nodes.

Contents of the invention

In order to overcome the defect in the prior art that multi-mode mobile terminals cannot realize vertical handover in an IPv4-based wireless network including NAT devices or firewalls, the present invention provides an integrated heterogeneous wireless network and a communication method thereof.

According to one aspect of the present invention, an integrated heterogeneous wireless network is provided, including:

IPv4-based wireless WAN, IPv6-based network, Silkroad access router and home agent device;

The wireless wide area network based on IPv4 has a network address translation device or a firewall; the Silkroad access router is located on the boundary of the IPv4 Internet and the network based on IPv6; in the network;

Through the Silkroad tunnel mechanism, the multi-mode mobile terminal uses the Silkroad access router to traverse the IPv4-based wireless wide area network with network address translation equipment or firewalls to establish a tunnel with the IPv6-based network; the multi-mode mobile terminal automatically maps to the corresponding network according to the tunnel parameters The corresponding tunnel interface sends the corresponding routing advertisement to realize the communication with the IPv6-based network.

Wherein, when the multi-mode mobile terminal is switched out from the wireless WAN or the multi-mode mobile terminal is switched back to the wireless WAN, the home agent device sends a redirection request to the Silkroad access router, and decides to send a redirection request to the multi-mode Modular mobile terminal data packet flow.

Wherein, preferably, the home agent device serving the wireless wide area network and the Silkroad access router are deployed on the same host.

Wherein, the IPv6 address prefix of the home agent device is the same as the IPv6 address prefix assigned to the multi-mode mobile terminal in the wireless wide area network by the Silkroad access router.

Wherein, the multi-mode mobile terminal simultaneously supports the mobile node in MIPv6 and the Silkroad client in the Silkroad tunnel mechanism.

According to a second aspect of the present invention, a method for integrating heterogeneous wireless networks is provided, including:

Step 10), deploying heterogeneous wireless network topology, deploying Silkroad access router on the boundary of IPv4 Internet and IPv6-based network, deploying as the home agent of IPv4-based wireless wide area network service in IPv6-based network;

Step 20), the multimode mobile terminal utilizes the Silkroad tunnel mechanism to pass through the IPv4-based wireless wide area network with network address translation equipment or firewalls, and establish a tunnel with the IPv6-based network;

Step 30), the multi-mode mobile terminal automatically sends the corresponding route advertisement to the corresponding tunnel interface according to the tunnel parameters, so as to realize the communication with the IPv6-based network.

Wherein, in step 10), preferably, the home agent serving the wireless wide area network and the Silkroad access router are deployed on the same host.

Wherein, the IPv6 address prefix of the home agent is the same as the IPv6 address prefix assigned to the multi-mode mobile terminal in the wireless wide area network by the Silkroad access router.

Wherein, the multi-mode mobile terminal simultaneously supports the mobile node in MIPv6 and the Silkroad client in the Silkroad tunnel mechanism.

Wherein, step 20) further includes:

Step 210), when the multimode mobile terminal accesses from the wireless wide area network, after the multimode mobile terminal obtains the public IPv4 address of the Silkroad access router, it sends an address request message comprising tunnel parameters to the Silkroad access router;

Step 220), Silkroad access router establishes corresponding IPv6-in-UDP-in-IPv4 tunnel interface for described multimode mobile terminal on described Silkroad access router according to described address request message, and for described The multimode mobile terminal constructs an IPv6 address and returns it to the multimode mobile terminal as a response message;

Step 230), after the multimode mobile terminal receives the response message, extract the IPv6 address, configure the IPv6-in-UDP-in-IPv4 tunnel interface, and set up the multimode mobile terminal and the Silkroad IPv6-in-UDP-in-IPv4 tunnel between access routers.

Wherein, step 220) further includes: configuring corresponding routing rules for the multi-mode mobile terminal on the Silkroad access router, so that the IPv6 route to the multi-mode mobile terminal points to the tunnel interface.

Wherein, in step 220), the Silkroad access router constructs an IPv6 address according to the tunnel parameters extracted from the address request message.

According to a third aspect of the present invention, a method for integrating heterogeneous wireless networks is provided, including:

Step 40), when the multimode mobile terminal is switched out from the wireless wide area network or when the multimode mobile terminal is switched back to the wireless wide area network, the home agent serving the wireless wide area network sends a redirection request to the Silkroad access router, and decides to send to the wireless wide area network. Describe the flow of data packets of the multi-mode mobile terminal.

Wherein, step 40) further includes:

Step 410), when the multi-mode mobile terminal cuts out from the wireless wide area network, send a binding update message to the home agent of the wireless wide area network to establish binding;

Step 420), when the home agent receives the binding update message, it sends a redirection request to the Silkroad access router, notifying the Silkroad access router that the multimode mobile terminal is cut out from the wireless wide area network;

Step 430), when the Silkroad access router receives the redirection request, point the route to the multi-mode mobile terminal to the IPv6 address of the home agent.

Wherein, in step 420), when the multi-mode mobile terminal is switched out from the wireless wide area network, the multi-mode mobile terminal no longer uses the Silkroad tunnel to send and receive data packets.

Wherein, in step 420), the redirection request includes the last 64-bit interface identifier of the home address of the multi-mode mobile terminal and a flag indicating that the multi-mode mobile terminal is cut out from the wireless wide area network.

Wherein, in step 420), when the multi-mode mobile terminal uses the IPv6-based wireless network as the home network to perform vertical handover, the Silkroad access router serving the wireless wide area network is equivalent to a foreign access router.

Wherein, step 40) further includes:

Step 410), when the multi-mode mobile terminal switches back to the wireless wide area network, send a binding update message to the home agent of the wireless wide area network to cancel the binding;

Step 420), after the home agent receives the binding update message, it sends a redirection message to the Silkroad access router, notifying the Silkroad access router that the multimode mobile terminal switches back to the wireless wide area network and needs to re-use the Silkroad tunnel Send and receive data packets;

Step 430), after the Silkroad access router receives the redirection message, redirect the route to the multi-mode mobile terminal to the Silkroad tunnel interface corresponding to the multi-mode mobile terminal.

Wherein, in step 420), the redirection request includes the last 64-bit interface identifier of the home address of the multi-mode mobile terminal and a flag indicating that the multi-mode mobile terminal switches back to the wireless wide area network.

Based on the Silkroad tunnel access technology, the present invention realizes the function of providing complete MIPv6 services for WWAN users by combining the Silkroad access router with the home agent in MIPv6; integrating WLAN with various WWANs including NAT equipment and firewalls , successfully deploying home agent for WWAN terminals, forming a unified seamless mobile environment, providing complete MIPv6 service functions for vertical handover of multi-mode mobile terminals, and greatly reducing the link load of WWAN through the method of mobile terminal spontaneous route notification .

Description of drawings

FIG. 1 is a topology diagram of an integrated heterogeneous network in the prior art;

Fig. 2 is a topological diagram of an integrated heterogeneous network according to the present invention;

Fig. 3 is a process diagram of a multi-mode mobile terminal accessing from an IPv4-based WWAN and using the Silkroad tunnel mechanism to intercommunicate with an IPv6 network;

Fig. 4 is a process diagram of a multimode mobile terminal performing vertical handover with an IPv6-based wireless network as a home network;

FIG. 5 is a process diagram of vertical handover of a multi-mode mobile terminal using an IPv4-based WWAN as a home network.

Detailed ways

An integrated heterogeneous wireless network and a communication method thereof provided by the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Currently, there are two tunnel mechanisms that penetrate NAT devices to realize IPv6 terminal interconnection: Teredo (RFC 4380) and Silkroad (draft-liumin-v6ops-silkroad-03). An IPv6/IPv4 dual-stack host can use its own IPv4 private address to traverse the IPv4 network and establish connections with other IPv6 hosts.

The Teredo tunnel mechanism can traverse all NAT types except Symmetric NAT (Symmetric NAT), but it can only assign temporary IPv6 addresses to NAT users. Teredo's IPv6 address is embedded with the Teredo server's IPv4 address, as well as the client's mapped IPv4 address and port. Therefore, its IPv6 address will change with the change of the embedded IPv4 address and port. However, IPv4 address allocation and mapping in WWAN are all dynamic allocation. Since the Teredo tunnel mechanism cannot guarantee that the mobile terminal obtains the same IPv6 address each time it accesses the same WWAN, it is difficult to integrate various WWANs into a unified heterogeneous wireless environment by using the Teredo tunnel mechanism.

The Silkroad tunnel mechanism can assign temporary or fixed IPv6 addresses to NAT users, and supports all existing NAT types. Therefore, using the Silkroad tunnel mechanism can integrate various WWANs into a unified heterogeneous wireless network environment. The Silkroad mechanism mainly involves three entities, namely Silkroad Client (SC), Silkroad Access Router (SAR) and Silkroad Navigator (SN). SC is an IPv6/IPv4 dual-stack node that is located in the NAT domain and supports the Silkroad tunnel interface. It can establish IPv6 communication with other SCs or other nodes on the IPv6 Internet through the Silkroad protocol. SAR is an IPv6/IPv4 dual-stack router that can access the IPv4 Internet through a public IPv4 address, and is used to help SC establish an IPv6 connection. SN is a node used to help Silkroad access routers route each other. The process of SC accessing the IPv6 network is as follows: In order to obtain the address of the SAR, the SC first sends an access request to the SN; the SN specifies a suitable SAR for the user according to the scheduling algorithm, and returns its public IPv4 address; the SC then sends a request to the designated SAR. Address request message; SAR extracts tunnel parameters from the request message and saves them, constructs an IPv6 address, and returns it to SC as a response message; SC extracts the IPv6 address for configuration after receiving the response message, and establishes a link with SAR The IPv6-in-UDP-in-IPv4 tunnel between them completes the initialization process. After this, the SC can communicate with other IPv6 nodes.

At present, the existing technology for integrating heterogeneous wireless networks (such as WLAN and IPv4-based WWAN) is to simply combine the tunnel mechanism and the MIPv6 protocol, and choose the Silkroad tunnel mechanism to traverse the WWAN with NAT or firewall. The network deployment is shown in Fig. 1. Deploy a home agent (HA) in each WLAN, and the HA in the WLAN is generally deployed together with the access router (AR) of the WLAN. Deploy SAR on the border between IPv4 Internet and IPv6 network. The mobile terminal and the SAR establish an IPv6-in-UDP-in-IPv4 tunnel, and the SAR periodically sends a route advertisement (RA) to the mobile terminal through the tunnel.

However, this technical solution has the following defects: (1) According to the MIPv6 protocol, RA is the basis for network layer mobility detection. Every 30 milliseconds to 70 milliseconds, the access router needs to send RA to all mobile terminals within its jurisdiction. For wireless wide area networks (such as GPRS, CDMA, etc.) with lower data transmission rates, such frequent RA transmissions will increase the link load of WWAN, and even take up most of the network bandwidth; (2) the existing scheme can only Deploying HA in a wireless network that supports IPv6, while an IPv4-based WWAN can only be used as a foreign network, which makes it impossible for mobile terminals that first access from an IPv4 WWAN to enjoy mobility management services.

In the embodiment according to the present invention, the SAR is deployed on the boundary between the IPv4 Internet and the IPv6 network, and the HA serving as the IPv4-based WWAN is deployed in the IPv6 network. In order to reduce unnecessary routing process, it is preferable to deploy the HA and SAR serving the WWAN on the same host, and the IPv6 address prefix of the HA should be the same as the IPv6 address prefix assigned by the SAR to the mobile terminal in the WWAN. The HA is deployed in each WLAN. Similarly, the HA in the WLAN can also be deployed together with the access router (AR) of the WLAN.

As shown in FIG. 2 , in this embodiment, the GPRS network and the CDMA network are selected to represent two WWANs with NAT devices and firewalls respectively. Deploy the HA and SAR1 serving the GPRS network on a dual-stack host at the junction of the IPv4 Internet and the IPv6 network. The IPv6 address prefix of the host should be the same as the IPv6 address prefix assigned to the GPRS terminal by SAR1; The HA and SAR2 of the service are deployed on another dual-stack host at the junction of the IPv4 Internet and the IPv6 network. The IPv6 address prefix of this host should be the same as the IPv6 address prefix assigned to the CDMA terminal by SAR2; in each WLAN that needs to be integrated In the configuration, the HA and the AR connected to the AP are deployed together.

In this embodiment, the multi-mode mobile terminal is required to have the function of simultaneously supporting the mobile node (MN) in MIPv6 and the SC in the Silkroad tunnel mechanism.

As shown in Figure 3, the multi-mode mobile terminal realizes intercommunication with the IPv6 network through the IPv4-based WWAN.

1-1. When the multi-mode mobile terminal accesses from the WWAN, in order to obtain the address of the SAR, the multi-mode mobile terminal first sends an access request to the SN through the corresponding Modem interface;

1-2. The SN specifies an appropriate SAR for the mobile terminal according to the scheduling algorithm, and returns an access response with a public IPv4 address with the SAR;

1-3. The mobile terminal encapsulates the address request message containing the tunnel parameters using the User Datagram Protocol (UDP), and then sends it to the SAR from the corresponding Modem interface through the IPv4 network, wherein the tunnel parameters mainly include the mobile terminal’s IPv4 address and UDP port, if mapped by NAT, the tunnel parameters mainly include the mapped public IPv4 address and port;

1-4. The SAR extracts the tunnel parameters from the request message and saves them, and then establishes the corresponding IPv6-in-UDP-in-IPv4 tunnel interface for the mobile terminal on the SAR according to the saved tunnel parameters, and configures the corresponding Routing rules, so that the IPv6 route to the mobile terminal points to the tunnel interface;

1-5. Construct a complete IPv6 address for the mobile terminal, put it in the response message, encapsulate it with UDP, and return it to the mobile terminal through the IPv4 network;

1-6. After the mobile terminal receives the response message, it extracts the IPv6 address, configures the IPv6-in-UDP-in-IPv4 tunnel interface and corresponding routing rules on the mobile terminal, and establishes a connection between the mobile terminal and the SAR. IPv6-in-UDP-in-IPv4 tunneling.

1-7. The mobile terminal can automatically send a corresponding route advertisement (RA) to its own tunnel interface according to the tunnel parameters (IPv6 network prefix, IPv6 link local address of the SAR, etc.).

After the above initialization process is completed, the mobile terminal can communicate with other IPv6 nodes through the WWAN. The mobile terminal needs to perform the above steps each time it initially accesses the IPv4-based WWAN or before switching to the IPv4-based WWAN. The following For the sake of simplicity, the above steps will not be reiterated in the process of describing the vertical handover.

In this embodiment, when the multi-mode mobile terminal performs vertical handover with the IPv6 wireless network as the home network, the SAR serving the WWAN is equivalent to a foreign access router (FAR). As shown in FIG. The process described is similar to:

2-1. When the multi-mode mobile terminal switches from the IPv6 wireless network to the IPv4-based WWAN, after the initialization is completed, it sends a BU to the HA serving the WWAN to establish or update the binding, and the BU is routed to the HA through the SAR;

2-2. When the HA receives the BU, it establishes or updates the corresponding binding, and returns the corresponding binding confirmation message (BA) to the mobile terminal, and the BA is forwarded to the mobile terminal through the SAR; after the vertical handover is completed, the mobile terminal Send and receive packets from IPv4-based WWAN;

2-3. If the multi-mode mobile terminal switches from an IPv4-based WWAN to another IPv4-based WWAN, after reinitialization in the new WWAN, send a BU to its HA to update the binding, and the BU passes through the SAR serving the new WWAN Route to HA;

2-4. When the HA receives the BU, it updates the corresponding binding and returns the corresponding BA to the mobile terminal. The BA is forwarded to the mobile terminal through the SAR serving the new WWAN. After the vertical handover is completed, the mobile terminal transmits and receives data from the new WWAN. data pack;

2-5. If a multi-mode mobile terminal switches from an IPv4-based WWAN to an IPv6 foreign wireless network or a home network, the mobile terminal sends a BU to its HA to update the binding or cancel the binding, and receives the return message from the HA after processing the BU. BA, after completing the vertical handover, the mobile terminal sends and receives data packets from the IPv6 wireless network where it is located;

In order to provide mobility support after vertical handover for multi-mode mobile terminals with WWAN with NAT or firewall as their home network, the present invention implements the SAR function described in draft-liumin-v6ops-silkroad-03 and the MIPv6 The HA function is improved, and the interactive function between HA and SAR is increased. When a multimode mobile terminal switches out from its IPv4-based home WWAN, it sends a Binding Update message (BU) to the HA of the WWAN to establish a binding. After receiving the BU, the HA knows that the mobile terminal will switch out of the home WWAN. Then, the HA sends a redirection request to the SAR, notifying the SAR that a certain mobile terminal has been switched out of the WWAN, and no longer uses the Silkroad tunnel to send and receive data packets. When the SAR receives the redirection request, it no longer directs the route to the mobile terminal to the corresponding Silkroad tunnel interface, but to the IPv6 address of the HA. When a multimode mobile terminal switches back to its IPv4-based home WWAN, it sends a BU to its HA to unbind. After receiving the BU, the HA knows that the mobile terminal will switch back to the home WWAN. Then, the HA sends a redirection message to the SAR again, notifying the SAR that a certain mobile terminal has switched back to the WWAN, and needs to use the Silkroad tunnel to send and receive data packets again. When the SAR receives the redirection message, it no longer directs the route to the mobile terminal to the IPv6 address of its HA, but redirects to the Silkroad tunnel interface corresponding to the mobile terminal.

In this embodiment, when the multi-mode mobile terminal uses IPv4-based WWAN as the home network for vertical handover, as shown in Figure 5, the steps are as follows:

3-1. When a multi-mode mobile terminal switches from its home WWAN to other networks (including IPv6 wireless networks and other IPv4-based WWANs, etc.), the mobile terminal sends a BU to its HA to establish binding;

3-2. When the HA receives the BU, it will know that the mobile terminal will switch to another network, so the HA sends a redirection request to the home SAR, notifying the home SAR that a mobile terminal has been switched out of the home WWAN , no longer use the IPv6-in-UDP-in-IPv4 tunnel to send and receive data packets; wherein the redirection request includes the last 64-bit interface identifier of the mobile terminal home address (HoA) and the flag bit indicating that the mobile terminal is cut out from the home WWAN, and set the flag to 1;

3-3. When the home SAR receives the redirection request, it no longer directs the route to the mobile terminal to its corresponding IPv6-in-UDP-in-IPv4 tunnel interface, but to the IPv6 address of the HA; after that, the home SAR returns the success or failure of route redirection to HA through the "Redirection Confirmation" message. "Redirection Confirmation" contains the redirection status flag, which is set to 0 if successful, and set to 1 if it fails;

3-4. When the HA receives the "redirection confirmation", it decides whether to establish or update the corresponding binding for the MN according to the success or failure of the redirection, and returns the corresponding BA to the mobile terminal;

3-5. When the mobile terminal switches between IPv6 wireless networks or between the IPv6 wireless network and the IPv4-based foreign WWAN, similar to the process described in MIPv6, the mobile terminal sends BU to its HA and receives HA-to-BU The BA returned after processing; if the target network is a foreign WWAN based on IPv4, it needs to be re-initialized on the new WWAN before this step;

3-6. When the multi-mode mobile terminal switches back to the home WWAN from the IPv6 wireless network or the IPv4-based foreign WWAN, after re-initialization, the terminal sends a BU to its HA to unbind;

3-7. When the HA receives the BU, it will know that the mobile terminal will switch back to the home WWAN, so the HA sends a redirection request to the home SAR again, notifying the home SAR that a certain mobile terminal has switched back to the home WWAN, It is necessary to re-use the IPv6-in-UDP-in-IPv4 tunnel to send and receive data packets, where the redirection request contains the last 64-bit interface identifier of the mobile terminal HoA and the flag indicating that the mobile terminal switches back to its home WWAN, and the flag is cleared to 0 ;

3-8. When the home SAR receives the redirection request, it no longer directs the route to the mobile terminal to the IPv6 address of its HA, but redirects to the IPv6-in-UDP-in-IPv4 tunnel corresponding to the mobile terminal Afterwards, the home SAR will return the success or failure of the route redirection to the HA through the "redirection confirmation" message again;

3-9. When the HA receives the "redirection confirmation", it decides whether to cancel the corresponding binding for the MN according to the success or failure of the redirection, and returns the corresponding BA to the mobile terminal.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limited thereto, but can be extended to other modifications, changes, applications and embodiments in application, and therefore all such modifications, Variations, applications, and embodiments are all within the spirit and scope of the invention.

Claims (17)

1. An integrated heterogeneous wireless network comprising: IPv4-based wireless WAN, IPv6-based network, Silkroad access router and home agent device; The wireless wide area network based on IPv4 has a network address translation device or a firewall; the Silkroad access router is located on the boundary of the IPv4 Internet and the network based on IPv6; in the network; Through the Silkroad tunnel mechanism, the multi-mode mobile terminal uses the Silkroad access router to traverse the IPv4-based wireless wide area network with network address translation equipment or firewalls to establish a tunnel with the IPv6-based network; the multi-mode mobile terminal automatically maps to the corresponding network according to the tunnel parameters The tunnel interface sends the corresponding routing advertisement to realize the communication with the IPv6-based network. Wherein, when the multi-mode mobile terminal is switched out from the wireless WAN or the multi-mode mobile terminal is switched back to the wireless WAN, the home agent device sends a redirection request to the Silkroad access router, and decides to send a redirection request to the multi-mode Modular mobile terminal data packet flow. 2. The integrated heterogeneous wireless network according to claim 1, wherein the home agent device serving the wireless wide area network and the Silkroad access router are deployed on the same host. 3. The integrated heterogeneous wireless network of claim 1, wherein the IPv6 address prefix of the home agent device is the same as the IPv6 address prefix assigned to the multi-mode mobile terminal in the wireless wide area network by the Silkroad access router. the 4. The integrated heterogeneous wireless network according to claim 1, wherein the multi-mode mobile terminal simultaneously supports the mobile node in MIPv6 and the Silkroad client in the Silkroad tunnel mechanism. 5. A method for integrating heterogeneous wireless networks, comprising: Step 10), deploying heterogeneous wireless network topology, deploying Silkroad access router on the boundary of IPv4 Internet and IPv6-based network, deploying as the home agent of IPv4-based wireless wide area network service in IPv6-based network; Step 20), the multimode mobile terminal utilizes the Silkroad tunnel mechanism to pass through the IPv4-based wireless wide area network with network address translation equipment or firewalls, and establish a tunnel with the IPv6-based network; Step 30), the multimode mobile terminal automatically sends a corresponding routing advertisement to the corresponding tunnel interface according to the tunnel parameters, so as to realize communication with the IPv6-based network; Step 40), when the multimode mobile terminal is switched out from the wireless wide area network or when the multimode mobile terminal is switched back to the wireless wide area network, the home agent serving the wireless wide area network sends a redirection request to the Silkroad access router, and decides to send to the wireless wide area network. Describe the flow of data packets of the multi-mode mobile terminal. 6. The method according to claim 5, wherein, in step 10), the home agent serving the wireless wide area network and the Silkroad access router are deployed on the same host. 7. The method of claim 5, wherein the IPv6 address prefix of the home agent is assigned to the IPv6 address prefix of the multimode mobile terminal in the wireless wide area network by the Silkroad access router identically. 8. The method according to claim 5, wherein the multi-mode mobile terminal simultaneously supports the mobile node in MIPv6 and the Silkroad client in the Silkroad tunnel mechanism. 9. The method of claim 5, wherein, step 20) further comprises: Step 210), when the multimode mobile terminal accesses from the wireless wide area network, after the multimode mobile terminal obtains the public IPv4 address of the Silkroad access router, it sends an address request message comprising tunnel parameters to the Silkroad access router; Step 220), Silkroad access router establishes corresponding IPv6-in-UDP-in-IPv4 tunnel interface for described multimode mobile terminal on described Silkroad access router according to described address request message, and for described The multimode mobile terminal constructs an IPv6 address and returns it to the multimode mobile terminal as a response message; Step 230), after the multimode mobile terminal receives the response message, extract the IPv6 address, configure the IPv6-in-UDP-in-IPv4 tunnel interface, and set up the multimode mobile terminal and the Silkroad IPv6-in-UDP-in-IPv4 tunnel between access routers. 10. The method according to claim 9, wherein, step 220) further comprises: on the Silkroad access router, configure corresponding routing rules for the multimode mobile terminal, so that the IPv6 routing to the multimode mobile terminal Point to the tunnel interface. 11. The method according to claim 9, wherein, in step 220), the Silkroad access router constructs an IPv6 address according to tunnel parameters extracted in the address request message. 12. The method of claim 5, wherein step 40) further comprises: Step 410), when the multimode mobile terminal is switched out from the wireless wide area network, send a binding update message to the home agent of the wireless wide area network to establish binding; Step 420), when the home agent receives the binding update message, it sends a redirection request to the Silkroad access router, notifying the Silkroad access router that the multimode mobile terminal is cut out from the wireless wide area network; Step 430), when the Silkroad access router receives the redirection request, point the route to the multi-mode mobile terminal to the IPv6 address of the home agent. 13. The method of claim 5, wherein step 40) further comprises: Step 410), when the multi-mode mobile terminal switches back to the wireless wide area network, send a binding update message to the home agent of the wireless wide area network to cancel the binding; Step 420), after the home agent receives the binding update message, it sends a redirection message to the Silkroad access router, notifying the Silkroad access router that the multimode mobile terminal switches back to the wireless wide area network and needs to re-use the Silkroad tunnel Send and receive data packets; Step 430), after the Silkroad access router receives the redirection message, redirect the route to the multi-mode mobile terminal to the Silkroad tunnel interface corresponding to the multi-mode mobile terminal. 14. The method according to claim 12, wherein, in step 420), when the multi-mode mobile terminal is switched out from the wireless wide area network, the multi-mode mobile terminal no longer uses the Silkroad tunnel to send and receive data packets. 15. The method of claim 12, wherein, in step 420), the redirection request includes the last 64 interface identifiers of the home address of the multi-mode mobile terminal and the representation of the multi-mode mobile terminal from the wireless wide area network Cut out the flag bits. 16. The method according to claim 12, wherein, in step 420), when the multi-mode mobile terminal performs vertical handover with the IPv6-based wireless network as the home network, the Silkroad access router serving the wireless wide area network is equivalent to the field Access the router. 17. The method according to claim 13, wherein, in step 420), the redirection request includes the last 64-bit interface identifier of the home address of the multi-mode mobile terminal and the indication that the multi-mode mobile terminal switches back to the wireless The flag bit of the WAN. the

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