WO2005050914A1

WO2005050914A1 - Wireless lan network mobility management system and method thereof

Info

Publication number: WO2005050914A1
Application number: PCT/CN2004/001322
Authority: WO
Inventors: Xingang Liang; Wenlin Zhang
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2003-11-19
Filing date: 2004-11-19
Publication date: 2005-06-02
Also published as: CN100344199C; CN1620176A

Abstract

The invention discloses a wireless LAN network mobility management system, it comprises the user terminal, the wireless LAN access network, the 3GPP access network and the home agent, wherein, the user terminal connects the wireless LAN access network by the wireless way, the home agent provides the route for the data communication of the user terminal, the key is: more than one stages of the foreign agent are set in the system, wherein, the foreign agent connected directly to the user terminal distributes the local farmout address to the user terminal and accomplishes address replacement and data farmout; the foreign agent not connected directly to the user terminal distributes the region farmout address to the user terminal, binds the region farmout address with the local farmout address of the user terminal, and accomplishes address replacement and data farmout. The invention also provides two Wireless LAN network mobility management methods. The system and method enables the mobile terminal maintain the service continuity and improve the network performance when it is in roaming.

Description

Wireless local area network mobility management system and method

The present invention relates to wireless local area network (WLAN) management technology, and particularly to a system and method for implementing WLAN network mobility management. Background of the invention

The wireless network can be roughly divided into a wireless local area network (WLAN, Wireless Local Area Network) and a wireless wide area network. The so-called WLAN is a communication system that uses radio frequency, microwave, or infrared to interconnect devices within a limited area. As users' requirements for wireless access rates become higher and higher, WLANs are used more and more widely. It includes basic 802.11, 802.11b, 802.11a, 802.11g, and Bluetooth standards.

Among them, 802.11b is currently the most widely used standard. It works in the 2.4G frequency band and uses Direct Sequence Spread Spectrum (DSSS) spread spectrum. The highest data transmission rate can reach 11Mbps. 802.11 introduced at the same time as 802.11b a standard, working in the 5.4G frequency band, using orthogonal frequency division multiplexing (OFDM, Orthogonal Frequency Division Multiplexing) spreading mode, the highest data transmission rate can reach 54Mbps. However, due to the poor compatibility of the two, the most likely to replace 802.11b and become the mainstream is the 802.11g standard, which also works in the 2.4G frequency band and uses the OFDM spread spectrum method. The highest speed provided is also 54Mbps.

802.1 la / b / g is currently the only three WLAN wireless standards that have been certified by WiFi. Although there are multiple standards, most WLANs are used to transmit Internet Protocol (IP, Internet Protocol) packet data packets. For a wireless IP network, the specific WLAN access technology it uses is generally transparent to the upper-layer IP. Its basic structure is to use a wireless access point (AP, Access Point) to complete the wireless access of the user terminal, and control and connect the device through the network. The standby connection forms an IP transmission network.

Another wireless network corresponding to WLAN is a wireless wide area network, which generally includes: General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), and Wideband Code Division Multiple Access (WCDMA, Wideband Code division Multiple Access), time division duplex - synchronous Code division Multiple Access (TD-SCDMA, Time division synchronous Code division Multiple Access SCDMA) and CDMA2000 _o in recent years, interworking WLAN and wireless WAN become the focus of current research.

In the 3rd Generation Partnership Project (3GPP) standardization organization, user terminals can be connected to the Internet (Internet) and the corporate intranet (Intranet) through a WLAN access network, and can also be connected to the network via a WLAN access network. The home network of the 3GPP system or the access network connection of the 3GPP system. Specifically, when a LAN user terminal accesses locally, it is connected to the 3GPP home network via a WLAN access network. The system composition structure is shown in Figure 1. The 3GPP-WLAN interactive network local access system 100 is composed of a user terminal 10, a WLAN A (Wireless Local Area Network Access Network) 20, and a 3GPP home network 30. Among them, the user terminal 10 is a mobile terminal device such as various laptop computers and palmtop computers with wireless Internet access functions; the WLAN AN 20 is used to provide the user terminal 10 access function to a wireless network; the 3GPP home network 30 includes 3GPP Authentication, Authorization and Accounting Server (AAA Server, Authentication Authorization and Accounting Server) 31, Home Network Packet Data Gateway (PDG, Packet Data Gateway) 32, Home Subscriber Server (HSS, Home Subscriber Server) 33, Home Location Register (HLR, (Home Location Register) 34, Home Charging Gateway (CGw, Charging Gateway) / Charging Information Collection Function (CCF) 35, Online Charging System (OCS) 36.

The 3GPP AAA server 31 is responsible for user authentication, authorization, and charging, and collects and transmits the charging information sent by the WLAN AN 20 to the charging system. The home network PDG 32 is responsible for transferring user data Data transmission from WLAN AN 20 to 3GPP network, or other packet networks. HSS 33 is the main database for all contracted users. It is used to support call or session processing services such as General Packet Radio Service Support Node (SGSN) and Call State Control Function (CSCF). Necessary contract-related information is the key to supporting user mobility and call control. The HLR 34 is used to store user-related data, including the user's roaming capabilities, subscription services, and supplementary services. In addition, the HLR 34 also provides information on the actual roaming location of the user terminal 10. The home CGw / CCF 35 is used to receive and record user billing information from the network. OCS 36 can instruct the network to periodically transmit online fee information according to the fee situation of online billing users, and perform statistics and control.

When the WLAN user terminal 10 wants to directly access the Internet intranet, after the user terminal 10 completes the access authentication and authorization through the WLAN AN 20 and the 3GPP AAA server 31, the user terminal 10 can access the Internet / Intranet through the WLAN AN 20.

If the WLAN user terminal 10 also wants to access the 3GPP packet-switched domain service, it may further apply for a service of the interworking scenario 3 (Scenario3) from the 3GPP home network, that is, the WLAN user terminal 10 initiates the interworking scenario 3 to the 3GPP AAA server 31 of the home network 3GPPAAA server 31 performs service authentication and authorization on the service authorization request, and if successful, sends an access permission message to the user terminal 10 and assigns the corresponding home network PDG 32 to the user terminal 10, and the user terminal 10 After establishing a tunnel with the assigned home network PDG 32, it can access 3GPP packet switched domain services. At the same time, the home CGw and CCF 35 and OCS 36 record charging information according to the network usage of the user terminal 10.

During roaming access, as shown in FIG. 2, the WLAN AN 20 is connected to the 3GPP access network 40, and some entities in the 3GPP access network 40 are interconnected with corresponding entities in the 3GPP home network 30. Referring to FIG. 2, the 3GPP-WLAN interactive network roaming access system 200 is composed of a user terminal 10, a WLAN AN 20, a 3GPP home network 30, and a 3GPP access network 40. The composition of the 3GPP home network 30 is as described above, and the 3GPP access network 40 is composed of 3GPP AAA Agent 41, wireless local area network access gate (WAG, Wireless Local Area Network Access Gatewa) 42, access network PDG 43, access to CGw / CCF 44. Here, the 3GPP AAA proxy 41 in the 3GPP access network 40 is connected to the 3GPP AAA server 31 in the 3GPP home network 30, and is used to cooperatively process authentication, authorization, and accounting for roaming users, and collect accounting information sent by the WLAN AN 20 And transmitted to the billing system. The WAG 42 in the 3GPP access network 40 is connected to the home network PDG 32 in the 3GPP home network 30, and is used to coordinate the data transmission of roaming user data from the WLAN AN 20 to the 3GPP network or other packet networks.

When the WLAN user terminal 10 wants to directly access the Internet / Intranet, the user terminal 10 can apply to the 3GPP AAA server 31 in the home network by accessing the 3GPP AAA proxy 41 in the network, and after being authenticated and authorized, it can access the Intemet / Intranet.

If the user terminal 10 also wishes to apply for the interworking scenario 3 service and access the 3GPP packet switched domain service, the user terminal 10 needs to initiate a service authorization process to the 3GPP AAA server 31 of the home network through the access network. After the authorization is successful, the 3GPP AAA server 31 Assign the corresponding home network PDG 32 to the user terminal 10. After the user terminal 10 establishes a tunnel between the WAG 42 in the access network and the allocated home network PDG 32, the user terminal 10 can access the 3GPP packet switched domain services of the home network. .

It can be seen from the above process that after the user terminal 10 successfully authorizes one or a group of services and establishes a channel, the user terminal 10 has a corresponding IP address and can initiate access to the service. At this time, the user terminal 10 can send data to the relevant service equipment of the service; and, because the IP address of the user terminal 10 has been registered for routing upon access, the user terminal 10 can also accept business service equipment or services in the network. Related other user terminals send data to the user terminal 10.

In addition, since the user terminal 10 is movable, the problem that the user terminal 10 roams to a network area different from the IP address set in the device will inevitably be involved. Mobile IP can be used to solve the problem. Solve the problem of Internet node movement. Mobile IP is a solution that provides mobile functions on the global Internet, enabling mobile nodes (MNs) to connect to any link with a permanent IP address and still maintain ongoing communication when switching links. Among the many issues involved in mobile IP, mobility management is the most important. The existing mobile IP generally includes a home agent (HA, Home Agent) and a foreign agent (FA, Foreign Agent). The HA is used in the home network to intercept information sent to the user terminal. The FA is in the visited network. Used to receive information from the home agent and send the information to the user terminal.

In practical applications, if mobile IP technology is not used, 3GPP-WLAN interworking has the following problems: a) Although the user terminal 10 has accessed the WLAN network, the channel connection with the network service has not yet been established through the home network PDG 32 Or, a channel for a service or a group of services has not been established, and at this time, there is a service that needs to send data to the user terminal 10, and then the user terminal 10 cannot be found; 2) When the user terminal 10 moves between WLANs, Assigning different IP addresses to the new WLAN access network will result in interruption of services and connections, which will require re-initiating services. If a general mobile IP technology is used, as the user terminal 10 moves, the WLAN AN 20 will frequently register with the HA and waste network resources; or the WLAN AN 20 cannot register with the WAG 42, resulting in communication failure.

The main reasons for this are: The TCP / IP protocol-based network does not support roaming when communicating. The general mobile IP technology has only one FA, which cannot handle the small coverage area of WLAN AN 20 and the absence of WLAN AN 20 and WAG 42 at the same time. Problems with the same operating network. Summary of the invention

In view of this, the main object of the present invention is to provide a wireless local area network network mobility management system, which can support mobile terminals to achieve service continuity while roaming, and improve the overall performance of the network.

Another object of the present invention is to provide a wireless local area network network mobility management method, so that The mobile terminal can maintain service continuity while roaming, and at the same time improve the working efficiency of FA in mobile IP and improve network performance.

In order to solve the above technical problems, the present invention provides a wireless local area network network mobility management system, including a user terminal, a wireless local area network access network, a third-generation partnership project home network, and a third-generation partnership project access network. The user terminal is wirelessly connected to the wireless local area network access network. The key is: The system is provided with a home agent in the home network of the third generation partnership project, and the home agent is used to provide a route for data communication of the user terminal. ; The system also has more than one level of foreign agents, of which,

A foreign agent directly connected to a user terminal, configured to allocate a local care-of address to the user terminal, and complete address replacement and data transfer;

A foreign agent that is not directly connected to the user terminal, and is used to allocate an area transfer address to the user terminal, bind the area transfer address of the user terminal to a local care-of address, and complete address replacement and data transfer;

The user terminal accesses the business network through the home agent or through the home agent and one or more foreign agents; and the business network communicates with the user terminal through one or more foreign agents and home agents or through the home agent.

In the above solution, the foreign agent includes two levels. The first-level foreign agent is set in the wireless local area network access network and is directly connected to the user terminal. Address replacement and data are performed between the user terminal and the second-level foreign agent. Transfer; the second-level foreign agent is set in the access network where the user terminal is currently located, and performs address replacement and data transfer between the first-level foreign agent and the home agent. Wherein, the second-level foreign agent is set in the wireless LAN access gateway of the network where the user terminal is currently visiting.

In the above solution, the home agent is set in the packet data gateway of the home network of the user terminal.

Method for managing mobility of wireless local area network, user terminal is in third generation partner In the project access network, the method includes the following steps:

When a user terminal sends data to a service network, the user terminal uses its own private address as the source address, and then sequentially transmits the data to be transmitted to the home agent through the tunnel transmission of each level of foreign agent set between itself and the home agent. ; The home agent replaces the source address in the received data with the public address, and then sends the modified data to the business network;

When the service network sends data to the user terminal, the service network sends the data to be transmitted to the home agent of the user terminal with a public address; the home agent replaces the public address in the received data with the private address of the user terminal The address is then transmitted through the tunnel of each level of foreign agent set between the home agent and the user terminal in turn, and the data with the modified address is sent to the user terminal.

In the above solution, a two-level foreign agent is set between the user terminal and the home agent or between the home agent and the user terminal, the first-level foreign agent is set in the wireless LAN access network, and the second-level foreign agent is set In the visited network where the user terminal is currently located.

Then, the method further includes: after the user terminal logs in through the access network and passes authentication, the first-level foreign agent assigns a local care-of address to the user terminal, and the second-level foreign agent assigns the user terminal to the user terminal. A user terminal assigns an area care-of address; the user terminal registers the local care-of address with the second-level foreign agent, and the second-level foreign agent binds the local care-of address to the area care-of address; The user terminal registers the area care-of address with the home agent, and the home agent binds the area care-of address with the private address of the user terminal.

Wherein, when the user terminal sends data to the service network, the tunneling of the foreign agent at each level is specifically that the first-level foreign agent replaces the destination address in the data from the user terminal with the local care-of address. Sending it to the second-level foreign agent; the second-level foreign agent replacing the destination address in the data from the first-level foreign agent with a private address, and sending it to the home agent; When the service network sends data to the user terminal, the tunneling of each level of the foreign agent is specifically: the second-level foreign agent replaces the destination address in the data from the home agent with the area care-of address. And sending to the first-level foreign agent; the first-level foreign agent replaces the destination address in the data from the second-level foreign agent with the local care-of address, and sends it to the user terminal.

For the above solution, the method further includes: after the user terminal authenticates through a home network, the home network assigns a private address to the user terminal, and binds the allocated private address to a public address; and updates A domain name service system of the home network. Wherein, when the service network actively initiates a service, the method further includes: the service network obtains a public address of the user terminal from a domain name service system of the home network.

A method for managing mobility of a wireless local area network. A user terminal is located in a third-generation partner project home network. The method includes the following steps:

When the user terminal sends data to the service network, the user terminal sends the data to be transmitted to the home agent with the private address as the source address; the home agent replaces the source address of the received data with the public address and sends it to the service network. ;

When the business network sends data to the user terminal, the business network sends the data to be transmitted to the home agent with a public address; the home agent replaces the public address of the received data with the private address of the user terminal Send the address to the user terminal.

In the above solution, the method further includes: after the user terminal authenticates through a home network, the home network allocates a private address to the user terminal, and binds the allocated private address to a public address; and updates A domain name service system of the home network. Wherein, when the business network actively initiates a service, the method further includes: the business network obtains a public address of the user terminal from a domain name service system of the home network.

By comparison, it is found that the technical solution of the present invention is different from the prior art in that: mobile IP technology and principles are applied to implement mobility management of the operating WLAN network, and a hierarchical FA architecture is adopted. That is, LFA and RFA, different levels of FA can be placed in different levels of WLAN A and WAG.

This technical solution difference has a more obvious beneficial effect, that is, by using mobile IP technology, it can ensure that the user terminal can maintain a two-way business connection with the home service network without changing the IP address or domain name when the user terminal is roaming. .

By adopting a hierarchical FA architecture, the FA is prevented from frequently registering with the HA due to the small coverage area of the WLAN AN, which can effectively reduce the signaling load between the FA and the HA, improve bandwidth utilization, and improve network support for real-time services.

With the improvement of network mobility management, the operation mode of the 3GPP-WLAN network can be effectively extended, and the overall performance of the network can be improved, thereby providing users with better services. Brief description of the drawings

Figure 1 is a structural diagram of the local access system of the 3GPP-WLAN interactive network;

Figure 2 is a structural diagram of a 3GPP-WLAN interactive network roaming access system;

FIG. 3 is a system structure diagram of an embodiment of a hierarchical FA architecture of a 3GPP-WLAN interactive network according to the present invention;

4a to 4c are flowcharts of an embodiment of a user terminal of the present invention accessing a public network service through local access of a private IP address of a home network dynamically allocated;

5a to 5c are flowcharts of an embodiment of a user terminal of the present invention roaming through a dynamically assigned home network private IP address to access public network services. Mode of Carrying Out the Invention

In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The idea of the present invention is to realize the mobility management of operating wireless networks by applying Mobile IP technology. It uses a hierarchical FA architecture. Specifically, the gateway device operating the home network is used as an HA or HA proxy; the gateway device operating the access network and the wireless LAN access gateway device are respectively different levels of FA to implement a hierarchical FA architecture.

Also, in actual networking, the access network usually forms a tree-like multi-level network topology according to the size of the area covered, for example: Network A includes subnetworks Al, A2, A3, and subnetwork A1 further covers the area All , A12, A13, A14, then if FA is set in each level of the network, a multi-level FA structure can be formed in the access network. In the following, only two-level FA architecture is taken as an example to illustrate the specific implementation of the system and method of the present invention. Among them, one-level FA is set in the WLAN AN, and only one-level FA is set in the access network. Other multi-level FA architectures and two-level FA architectures The implementation principle is completely similar.

FIG. 3 is a schematic diagram of a system composition structure of an embodiment of a hierarchical FA architecture of a 3GPP-WLAN interactive network according to the present invention. As shown in FIG. , A business network 50, and an external domain name server (DNS, Domain Name Server) 60. Among them, 3GPP home network 30 is composed of home network PDG 32 and home network DNS 37; 3GPP access network 40 is composed of WAG 42 and access network PDG 43. The user terminal is wirelessly connected to the WLAN AN, and the WLAN AN is connected to the 3GPP access network 40. In practical applications, the WLAN AN can also be directly connected to the 3GPP home network 30.

It is worth noting that: in this embodiment, HA 70 (or HA proxy) is placed on the home network PDG 32, and a regional FA agent (RFA, Regional Address Agent) 80 of the hierarchical FA structure is placed on WAG 42, a part of the hierarchical FA architecture. A foreign agent (LFA, Local Address Agent) 90 is placed on the WLAN AN 20, and the WLAN AN 20 is a default gateway of the user terminal 10. In this embodiment, the hierarchical FA structure is a two-level FA, and LFA and RFA are first-level FA and second-level FA, respectively.

Among them, HA 70 is used to transfer the home address (Home Address) to the corresponding area. Address (RCoA, Regional Care-of Address) to bind, intercept the information sent to the user terminal, and send the information to the corresponding RFA 80.

The RFA 80 is used to assign a regional care-of address RCoA to a user terminal, bind the RCoA to a corresponding local care-of address (LCoA, Local Care-of Address), receive information from the HA 70, and send the corresponding information to the LFA 90.

The LFA 90 is used to assign a local care-of address LCoA to the user terminal, receives information from the RFA 80, and sends the information to the corresponding user terminal. The LFA is directly connected to the user terminal.

Down,

Examples.

Embodiment one:

In this embodiment, the user terminal 10 is in a home network, and the user terminal 10 accesses a service network on the public network using a private IP address used internally by the dynamically allocated home network. Fig. 4a, Fig. 4b and Fig. 4c respectively show the processing flow for the home network PDG32 to assign an IP address to the user terminal 10, the user terminal 10 to initiate a service, and the service network 50 to initiate a service. As shown in FIG. 4a, in this embodiment, the process of assigning an IP address to the user terminal 10 by the home network PDG32 includes: Step 4a1: The user terminal 10 first establishes a wireless connection on the home network, and after passing the home network authentication, the home network PDG 32 will assign a private IP address for home terminal 10 to be used as the Home Address for this user terminal 10;

Step 4a2: The home network PDG 32 uses its own NAT (Network Address Translation) function to bind the private IP address of the user terminal 10 to a public IP address, and binds the public IP address to the user terminal 10's The domain name information is registered in the home network DNS 37 together.

Referring to FIG. 4b, the process of initiating a service by the user terminal 10 in this embodiment includes: Step 4M: The user terminal 10 uses the private IP address as the source address to send data to the home network PDG 32, and then proceeds to step 4b2; Step 4b2: The home network PDG 32 converts the private source IP address of the data packet of the user terminal 10 into a public source IP address through its NAT function and sends the data to the service network 50; Step 4b3: When the service network 50 sends the user terminal 10 When transmitting data, the data is sent to the corresponding home network PDG 32 according to the public IP address;

Step 4b4: The corresponding home network PDG 32 replaces this public IP address with a private IP address and sends it to the user terminal 10.

Referring to FIG. 4b, in this embodiment, the process of initiating a service by the service network 50 includes: Step 4c1: The service network 50 queries the IP address of the user terminal 10, and the inquiry process is: The service network 50 searches for the Network DNS 60, the external network DNS 60 will query the home network DNS 37, and then enter step 4c2;

Step 4c2: The home network DNS 37 returns to the service network 50 the public IP address bound to the domain name when the IP address is allocated;

Step 4c3: The service network 50 sends the data to the public IP address returned by the home network DNS 37 in step 4c2, that is, the data is routed to the home network PDG 32;

Step 4c4: The home network PDG 32 performs the conversion through its NAT function, replaces the public IP address with a private IP address, and then forwards the data to the corresponding user terminal 10.

Step 4c5: When the user terminal 10 sends data to the service network 50, the user terminal 10 sends the data to the home network PDG 32 using the private IP address as the source address, and then proceeds to step 4c6; Step 4c6: The home network PDG 32 performs its own NAT function Convert, replace the private IP address with the public IP address, and then transfer the data to the business network 50.

Those skilled in the art can understand whether the service is initiated by the user terminal 10 or the service network 50. Depending on the actual application, the present invention does not limit the execution order of steps 4bl ~ 4b4 and steps 4cl ~ 4c6. . Embodiment two:

In this embodiment, the user terminal 10 is in an access network, and the user terminal 10 uses dynamic analysis. The private IP address used inside the assigned home network accesses the business network on the public network. Figures 5a, 5b, and 5c respectively show the processing flow for the home network PDG32 to assign the home address and care-of address to the user terminal 10, the service initiated by the user terminal 10, and the service initiated by the service network 50. As shown in FIG. 5a, in this embodiment, a process in which the home network PDG32 allocates an IP address to the user terminal 10 includes:

Step 5al: The user terminal 10 first establishes a wireless connection, and after passing the authentication of the home network and the visited network, the home network PDG 32 assigns the user terminal 10 a private IP address used in the home network as the Home Address.

Step 5a2: At this time, the home network PDG 32 binds the private IP address of the user terminal 10 to a public IP address through its NAT function, and registers the bound public IP address with the domain name information of the user terminal 10 to Home network DNS 37.

Here, if the user terminal 10 is moved to the access network during the service, the user terminal 10 still maintains its original Home Address, and steps 5 Γ and 5a2 can be omitted, and the process proceeds directly to step 5a3; if the user terminal 10 is accessing If the user logs on to the network through the network, the user terminal 10 needs to execute from step 5a1.

Step 5a3: WLAN AN 20, as LFA 90, is assigned to the user terminal 10—a local care-of address LCoA. This address can be a public IP address or a private IP address.

Step 5a4: As the RFA 80, the WAG 42 is allocated to the user terminal 10-area care-of address RCoA. This address may be a public IP address or a private IP address.

Step 5a5: The user terminal 10 sends a registration request to the RFA 80 in the WAG 42 and requests the RFA 80 to bind RCoA and LCoA together.

Step 5a6: The WAG 42 sends a registration request to the HA 70 in the home network PDG 32, and requests the HA 70 to bind the RCoA and the Home Address of the user terminal 10 together. The HA 70 can intercept all data sent to the user terminal 10 and forward it to the RFA 80. The user terminal 10 uses RCoA as the real care-of address. It should be noted that when the user terminal 10 moves between different WLAN ANs accessing the network, the new LFA 90 will allocate a new LCoA to the user terminal 10, and the user terminal 10 will send a registration request to the RFA 80 to update the binding of LCoA and RCoA. The RFA 80 will not initiate a registration request to the HA 70 as long as the user terminal 10 has not left the original RFA 80.

As shown in FIG. 5b, in this embodiment, a process in which a user terminal 10 initiates a service to a service network 50 includes:

Step 5bl: The user terminal 10 uses the Home Address as the source IP address, and sends data to the default gateway LFA 90 of the WLAN AN 20;

Step 5b2: The LFA 90 establishes a tunnel to the RFA 80, for example, establishes a Site-to-Site tunnel, and sends data to the RFA 80 through the established tunnel;

Step 5b3: RFA 80 re-establishes a tunnel to home network PDG 32, and sends data to HA 70 through the established tunnel;

Step 5b4: The HA 70 converts the private source IP address to the bound public IP address through the NAT translation of the home network PDG 32, and transfers the data to the service network 50 through the public network.

Step 5b5: The service network 50 sends the data sent to the user terminal 10 to the corresponding home network PDG 32 according to the public IP address;

Step 5b6: The home network PDG 32 converts the public IP address to a private source IP address through its NAT function, and transmits the data to the RJFA 80 of WAG 42 through the tunnel;

Step 5b7: RFA 80 establishes a tunnel to LFA 90, and sends data to LFA 90 through the established tunnel.

Step 5b8: The LFA 90 transmits the received data to the user terminal 10.

So far, the process of the user terminal 10 initiating a service to the service network 50 is completed.

Referring to FIG. 5b, in this embodiment, the processing process of the service initiated by the service network 50 to the user terminal 10 includes:

Step 5cl: The business network 50 searches the external network DNS 60 according to the domain name of the user terminal 10, The external network DNS 60 will query the home network DNS 37;

Step 5c2: At this time, the home network DNS 37 will return the public IP address bound to the domain name of user terminal 10;

Step 5c3: The service network 50 sends the data to the public IP address described in step 5c2, that is, the data is routed to the home network PDG 32;

Step 5c4: Since the home network PDG 32 is HA 70, the home network PDG 32 knows the current RFA 80 location of the user terminal 10, so the home network PDG 32 establishes a tunnel to the RFA 80, such as establishing a MIP tunnel, IP-in- IP tunnel, etc., transfer the data to RFA 80; Step 5c5: RFA 80 fetches the data from the tunnel, then establishes a tunnel from RFA 80 to LFA 90, and transfers the data to LFA 90;

Step 5c6: The LFA 90 takes the data from the tunnel and forwards it directly to the user terminal 10. So far, the data transmission from the service network 50 to the user terminal 10 is completed. Starting from step 5c7, it indicates the process in which the user terminal 10 sends data to the service network 50 after the service is initiated.

Step 5c7: The user terminal 10 uses the Home Address as the source IP address and sends data to the default gateway LFA 90 of the WLAN AN 20;

Step 5c8: The LFA 90 establishes a tunnel to the RFA 80, for example, establishes a Site-to-Site tunnel, and sends data to the RFA 80 through the established tunnel;

Step 5c9: RFA 80 then establishes a tunnel to home network PDG 32, and sends data to HA 70 through the established tunnel;

Step 5cl0: The HA 70 converts the private source IP address to the bound public IP address through the NAT translation of the home network PDG 32, and transfers the data to the service network 50 through the public network. Example three:

In this embodiment, the user terminal 10 accesses the mobile VPN network using a private IP address in a dynamically allocated virtual private network (VPN, Virtual Private Networking).

In this embodiment, after the user terminal 10 passes the authentication of the home network, the user terminal 10 The home network PDG 32 connected to the external mobile VPN serves as the HA 70 Proxy, and assigns a private IP address used in the mobile VPN as the Home Address to the user terminal 10. Otherwise, the settings and operations of the LFA 90 and RFA 80 are the same as those of the second embodiment. Those skilled in the art can understand that when the user terminal 10 uses the private IP address in the dynamically allocated VPN to access the mobile VPN network, different home address setting methods can be adopted without affecting the essence and scope of the present invention.

Embodiment 4:

In this embodiment, the user terminal 10 uses a statically assigned public IP address to access the service network 50 on the public network. In this embodiment, the user terminal 10 uses a statically assigned public IP address. Therefore, when accessing the home network and accessing the network, the steps of binding the public IP address and the private IP are omitted, and the remaining steps are the same as The corresponding steps of other embodiments are basically the same. Those skilled in the art can understand that a user terminal may statically allocate a public IP address for accessing a service network using different methods without affecting the essence and scope of the present invention.

From the above embodiments, those skilled in the art can understand that the Home Address of the user terminal 10 may be dynamic or static; it may be private or public, without affecting the present invention. Substance and scope.

In an actual operating network, the user terminal 10 may maintain a corresponding relationship with the WAG 42 after the network authentication and authorization. The following uses a specific example to illustrate:

When the user terminal 10 is accessing the network, if the user terminal 10 maintains the corresponding relationship with the WAG 42 after authorization, the function of the LFA 90 has been very weakened, and the LFA 90 only serves as an address proxy to allocate LCoA to the user terminal. WAG 42 is assigned as RFA 80 to user terminal 10 RCoA. User terminal 10 will not send a registration request to WAG 42, because WAG 42 will automatically bind RCoA and LCoA together after registration is completed. The reason for this is often because WLAN AN 20 and WAG 42 belong to the same operator, so the function of LFA 90 can be weakened. Those skilled in the art can understand that the user terminal 10 and the WAG 42 In the case of maintaining the corresponding relationship, the weakening of the function of the LFA 90 does not affect the essence and scope of the present invention.

In an actual operating network, the user terminal 10 may maintain a corresponding relationship with the WAG 42 and the home network PDG 32 after the network authentication and authorization. In this case, since the user terminal 10 has a correspondence relationship with the WAG 42 and the home network PDG 32, as long as the external network can send data to the home network PDG 32, the home network PDG 32 can The data is easily transferred to the user terminal 10. At this time, the home network PDG 32 only acts as an HA proxy, while the FA functions of the WAG 42 and WLAN AN 20 are weakened. There is no need to implement the true FA function. They are only responsible for assigning IP addresses in the corresponding range. There is no longer a need to establish tunnels in two directions between the home network PDG 32 and WAG 42. Therefore, this embodiment actually applies the principle of MIP and does not use MIP technology. Those skilled in the art can understand that the weakening of the functions of the LFA 90 and RFA 80 does not affect the essence and scope of the present invention in the case that the user terminal 10 and the WAG 42 and the home network PDG 32 maintain a corresponding relationship.

The above description is only the preferred embodiments of the present invention, and is not intended to limit the protection scope of the present invention.

Claims

Claim

1. A wireless local area network network mobility management system, including a user terminal, a wireless local area network access network, a third generation partnership project home network, and a third generation partnership project access network, wherein the user terminal communicates wirelessly with The wireless LAN access network is connected, and is characterized in that the system is provided with a home agent in the home network of the third generation partner project, and the home agent is used to provide a route for data communication of the user terminal;

There are also more than one level of field representatives in the system. Among them,

2. The system according to claim 1, wherein the foreign agent comprises two levels, and the foreign agent of the first level is set in a wireless local area network access network, which is directly connected to the user terminal, and Address replacement and data transfer between the terminal and the second-level foreign agent; The second-level foreign agent is set in the access network where the user terminal is currently located, and performs address replacement and data transfer between the first-level foreign agent and the home agent. .

3. The system according to claim 2, wherein the second-level foreign agent is set in a wireless local area network (LAN) access gateway where the user terminal is currently accessing the network.

4. The system according to claim 1, 2 or 3, wherein the home agent is set in a packet data gateway of a home network of the user terminal.

5. A mobility management method for a wireless local area network, in which a user terminal is in a third-generation partner project access network, which is characterized in that the method includes the following steps:

When a user terminal sends data to a service network, the user terminal uses its own private address as the source address, and then sequentially transmits the data to be transmitted to the home agent through the tunnel transmission of each level of foreign agent set between itself and the home agent ; The home agent replaces the source address in the received data with the public address, and then sends the modified data to the business network;

6. The method according to claim 5, wherein a two-level foreign agent is set between the user terminal and the home agent or between the home agent and the user terminal, and the first-level foreign agent is set on the wireless local area network. In the access network, the second-level foreign agent is set in the access network where the user terminal is currently located.

7. The method according to claim 6, further comprising: after the user terminal logs in through the access network and passes the authentication, the first-level foreign agent assigns a partial transfer to the user terminal. Address, and the second-level foreign agent assigns an area care-of address to the user terminal;

The user terminal registers the local care-of address with the second-level foreign agent, and the user terminal registers the area care-of address with the home agent, and the home agent forwards the area care-of address Bound to the private address of the user terminal.

8. The method according to claim 7, wherein when the user terminal sends data to the service network, the tunnel transmission of each level of foreign agent is specifically: The first-level foreign agent replaces the destination address in the data from the user terminal with the local care-of address, and sends it to the second-level foreign agent; the second-level foreign agent will come from the first The destination address in the data of the first-level foreign agent is replaced with a private address and sent to the home agent;

When the service network sends data to the user terminal, the tunnel transmission of each level of the foreign agent is specifically:

The second-level foreign agent replaces the destination address in the data from the home agent with the area care-of address, and sends it to the first-level foreign agent; the first-level foreign agent will The destination address in the data of the second-level foreign agent is replaced with the local care-of address, and is sent to the user terminal.

9. The method according to any one of claims 5 to 8, further comprising: after the user terminal authenticates through a home network, the home network assigns a private address to the user terminal, And bind the assigned private address with a public address; and update the domain name service system of the home network.

10. The method according to claim 9, wherein, when the service network actively initiates a service, the method further comprises: the service network obtaining a public address of the user terminal from a domain name service system of the home network.

11. A method for managing mobility of a wireless local area network, wherein a user terminal is located in a home network of a third-generation partnership project, and is characterized in that the method includes the following steps:

12. The method according to claim 11, further comprising: after the user terminal authenticates through a home network, the home network assigns a private address to the user terminal, and assigns the assigned address to the user terminal. The private address is bound to a public address; and the domain name service system of the home network is updated.

13. The method according to claim 12, wherein when the service network actively initiates a service, the method further comprises: the service network obtaining a public address of the user terminal from a domain name service system of the home network.