KR20030064719A - Mobile Router apparatus for supporting Mobile IP - Google Patents

Abstract

PURPOSE: A mobile router device supporting a mobile IP(Internet Protocol) is provided to enable routing to a corresponding network when a terminal moves to the network, so as to transmit packets to the terminal in the corresponding network. CONSTITUTION: The first and the second fixed networks(200,300) connected to the Internet(100) are fixed at specific positions. A mobile network(400) performs data interface wirelessly with the first and the second fixed networks(200,300) and moves by the mobile network(400) itself. The mobile network(400) comprises a wireless bridge(410) performing data interface wirelessly with the first and the second fixed network(200,300), a mobile router(420) providing a user terminal function for an HA(Home Agent)(220) and an FA(Foreign Agent)(320) of the first and the second fixed network(200,300) and providing a router function for a user terminal(440) in the mobile network(400), and a wireless LAN(Local Area Network) access point(430) connected to the mobile router(420) performing packet data interface wirelessly with the user terminal(440).

Description

Mobile router apparatus for supporting mobile IP

The present invention relates to a mobile router (router) supporting a mobile IP (IP: Internet Protocol), and in particular, even when the network to which the terminal belongs moves by routing to the corresponding network, the packet to the terminal in the mobile network The present invention relates to a mobile router device supporting a mobile IP that enables transmission.

In general, as Internet devices become wireless and miniaturized, there is a need for an environment in which users can continuously receive Internet services while moving and functions that support them.

For this user mobility, the IETF enacted the Mobile IP standard and defines functions for these services. Based on this standard, equipment and user devices capable of supporting mobile IP are being implemented. This standard and the system implemented based on this standard prescribe the basic condition that each user uses public IP.

Currently, the mobile IP standard defined by the IETF should allow the user terminal to route IP packets to the terminal. In addition, even when the terminal moves to another network, the IP address used by the terminal remains unchanged, and thus the existing packet can be continuously received.

1 is a diagram illustrating a general mobile IPv4 network.

A user terminal (MN: Mobile Node) 11 normally communicates with a counterpart terminal (CN: Corresponding Node) 20 in a home network (HN: Home Network) 10, and then another network (FN: Foreign Network). When moving to 30, communication between the user terminal 11 and the counterpart terminal 20 should be maintained, and the IP address used by the existing user terminal 11 in the home network 10 should not be changed.

To this end, the user terminal 11 transmits a registration message (Registration Request) indicating that it has moved to the new network 30 to the foreign agent (FA) 31.

Upon receiving this, the FA 31 transmits a registration message to the HA (Home Agent) 12 in the home network 10 of the user terminal 11 to inform that the user terminal 11 is in another network 30. .

The HA 12 receiving the registration message manages the IP address (Home Address) originally used by the user terminal 11 and the address of the FA 31 where the user terminal 11 is currently located, thereby providing a home network 10. The packets transmitted to the user terminal 11 of the 1) may be tuned back to the location where the current user terminal 11 is located. That is, the counterpart terminal 20 cannot know that the user terminal 11 has moved, and transmits a packet using the IP address of the only user terminal 11 in the IP network, so that the user terminal 11 has a different network. Even if it moves to 30, the packet transmitted from the counterpart terminal 20 continues to be transmitted to the home network 10 of the user terminal 11.

Therefore, the HA 12 forwards the packet transmitted to the home network 10 of the user terminal 11 to the network 30 where the user terminal 11 is currently located, so that the user terminal 11 may move to another network. It can continuously receive the packet received from the previous network. To this end, the HA 12 tunnels the packet coming to the IP address of the user terminal 11 to the FA 31, and the FA 31 transmits the tunneled packet back to the user terminal 11. It plays a role.

In FIG. 1, reference numeral 40 denotes the Internet.

In this case, the operation is performed when only the user terminal 11 moves while each network is fixed.

If the network to which the user terminal has moved moves, the router should be able to receive a packet routed to an existing area and transmit it to a terminal in the network.

To provide this function, data must be able to be transmitted from the previous area to the current area of the mobile network, and the mobile router of the current area should receive the packet transmitted to the corresponding area and transmit it to the inside of the mobile network. To this end, existing routers need to support a function that can support a mobile router, which will incur additional costs such as changes to the existing router.

In addition, when the address of the router of the mobile network is changed, there has been a problem that all of the corresponding addresses must be changed to correspond to the address of the mobile router whose nodes such as terminals in the network are changed.

Accordingly, the present invention is proposed to solve the additional cost incurred due to the change of the existing router that is generated to support the mobile router when the network is moved to the conventional terminal as described above,

An object of the present invention is to provide a mobile router apparatus for supporting a mobile IP to enable the packet transmission to the terminal in the mobile network by performing routing to the network even if the network to which the terminal belongs. .

The present invention for achieving the above object,

A mobile router for packet routing in a mobile network performs a terminal function for a mobile IP in a fixed network, and provides a function for converting into an IP address type used in the mobile network in the mobile router.

There are HA and FA for mobile IP in fixed network, and mobile router performs terminal function for mobile IP function of fixed network. Therefore, even if the router of the mobile network moves to another network, the packet can be transmitted to the area currently moved by the existing mobile IP operation.

When the mobile router receives the packet transmitted from the fixed network and transmits the packet to the terminal by changing the address of the corresponding terminal used in the mobile network, the terminal in the mobile network can continuously receive the packet regardless of the current network position.

1 is a general mobile IPv4 network configuration diagram,

2 is a configuration diagram of a mobile IPv4 network to which a mobile router apparatus supporting mobile IP according to the present invention is applied,

3 is a block diagram showing an embodiment configuration of the mobile router of FIG.

4A to 4D are diagrams illustrating operation scenarios of a mobile router.

<Explanation of symbols for the main parts of the drawings>

200, 300 ..... 1st and 2nd fixed net

400 ..... mobile network

410 ..... Wireless Bridge

420 ..... Mobile Router

430 ..... WLAN Access Point

421 Network address translator

422 ..... user terminal function execution unit

423 ..... Address Management Department

424 ..... Performing agent function

425 ..... Packet Transmitter

426 ..... Router Function Execution Unit

Hereinafter, described in detail with reference to the accompanying drawings, preferred embodiments of the present invention according to the technical spirit as described above.

HA, FA, MN are needed as a function for mobile IP, and NAT is required for external internet access in a private network environment. NAT is not an additional component for Mobile IP for Existing Private IP and is assumed to be used in Existing Equipment or Existing Environment.

The functional elements and operation of HA and MN among the functional elements of the mobile IP network for applying the present invention are the same as the operation of HA and MN in the existing mobile IP. In addition, HA and MN must provide reverse tunneling function, which is defined in Mobile IP. The FA must additionally provide MAC address and IP address management to distinguish terminals having the same IP address from the existing mobile IP.

Reverse tunneling is a method of transmitting a packet for an existing connection through the HA of the mobile IP even if the user terminal moves from the mobile IP to another network. By using this method, the counterpart terminal can always receive the packet transmitted from the HA even if the corresponding terminal moves to another network, so that the corresponding terminal can be recognized as not moving. In addition, this method can apply mobile IP in private IP environment by communicating with outside using HA and NAT addresses in the original network when transmitting and receiving packets through NAT in private IP environment.

In addition, the user terminal identification method using the MAC address uses that the interface card of each user has a unique MAC address. That is, since all network interface cards have a unique MAC address, the terminal can be distinguished using the same MAC address, and the packets can be transmitted to the terminal, even if there is a terminal having the same private IP address.

Referring to the accompanying drawings, preferred embodiments in consideration of the concept of the present invention as described above in detail as follows.

2 is a configuration diagram of a mobile IPv4 network to which a mobile router apparatus supporting mobile IP according to the present invention is applied.

As shown therein, the Internet 100, first and second fixed networks 200 and 300 connected to the Internet 100 and fixed to a specific location, and the first and second fixed networks 200 (300) and a wireless interface to the data and the network itself is composed of a mobile network 400 to move.

The first fixed network 200 is a router 210 for interfacing data with the Internet 100, an IP address (Home Address) originally used by the user terminal (MN), and a FA where the user terminal is currently located. A home agent (HA) 220 that manages an address, a WLAN access point 230 for wirelessly interfacing packets with a user terminal, and a wireless bridge for transmitting and receiving packets wirelessly with the mobile network 400 ( 240).

In addition, the second fixed network 300 registers a registration message to a router 310 for interfacing data with the internet 100 and a home agent (HA) 220 in a home network of a user terminal (MN). A transmission agent (FA) 320 for transmitting and notifying that the user terminal is in the second fixed network 300, a WLAN access point 330 for wirelessly interfacing the packet with the user terminal, and the mobile network 400 And a wireless bridge 340 for transmitting and receiving packets wirelessly.

In addition, the mobile network 400, a wireless bridge 410 for interfacing the packet with the first fixed network 200 or the second fixed network 300, and the first and second fixed network 200 A mobile router 420 performing a user terminal function with respect to the HA 220 and the FA 320 of the 300, and also performing a basic router function with respect to the user terminal 440 in the mobile network 400, Connected to the mobile router 420 is composed of a wireless LAN access point 430 for interfacing packet data with the user terminal 440.

4A to 4D are diagrams illustrating operation scenarios of the mobile router 420 according to the present invention.

FIG. 4A is a diagram illustrating that the initial user terminal 440 is located in the first fixed network 200, and FIG. 4B is a diagram of a user terminal 440 located in the first fixed network 200 moving to the mobile network 400. 4C is a view showing that the mobile network 400 moves and is located in an area of the second fixed network 300. FIG. 4D is a view illustrating a user terminal 440 in the mobile network 400. FIG. 2 is a view showing the movement to the fixed network (300).

The operation of the mobile router apparatus supporting the mobile IP according to the present invention configured as described above will be described in detail with reference to the accompanying drawings.

First, as shown in FIG. 4A, when the user terminal 440 is initially located in the first fixed network 200 to start a service, the HA 220 in the first fixed network 200 determines the current position of the user terminal 440. In order to designate, the user terminal 440 manages the CoA.

Thereafter, even when the user terminal 440 moves to the mobile network 400, the user terminal 440 must maintain communication with the counterpart terminal CN.

Accordingly, in the present invention, the mobile router 420 performs a user terminal function with respect to the HA 220 of the first fixed network 200 in the mobile network 400, and the router for the user terminal 440 within the mobile network 400. Perform the function.

The mobile router 420, as shown in Figure 3, the network address translation unit 421 for changing between the IP address used in the mobile network and the IP address used in the fixed network, and the address for internal routing and The user terminal function performing unit 422 for internally changing the address used by the user, the address manager 423 for managing the IP address used in the fixed network and the IP address used in the mobile network, and in the mobile network. A mobile agent function performing unit 424 supporting mobile IP, a packet transmitting unit 425 delivering a packet to a user terminal in a mobile network, and a packet transmitted by the user terminal using a routing protocol to deliver a packet to an appropriate router. The router function performing unit 426 is configured.

Looking at the operation of the mobile router 420 configured as described above in more detail as follows.

First, the network address translator 421 performs a change between a private IP and a public IP in order to deliver a packet from a network using a private IP to an external public network. That is, it changes the private IP in the private IP network (mobile network) to the public IP of the external network (fixed network) and transmits the packet to the external network (fixed network). In addition, when a packet is transmitted from an external network (fixed network) to an internal network (mobile network), a change is made from a public IP to a private IP (or a function of managing MAC addresses instead of changing from a public IP to a private IP). The packet may be directly transmitted to the corresponding terminal using the MAC address through the packet transmission unit).

In other words, when the user terminal 440 moves from the fixed network 200 to the mobile network 400, the user terminal 440 is changed to the IP used in the mobile network 400 based on the IP address used by the fixed network 200. The packet may be transmitted to the user terminal 440 in 400.

In this case, the user terminal 440 is internally changed to the IP address used in the mobile network 400 after moving from the fixed network 200 to the mobile network 400. This changed IP address is changed so that the user can't know it. It is actually used only for routing.

Next, the operation of the user terminal function performing unit 422 will be described.

In order to access the Internet from a specific network, the Internet network must use an IP address corresponding to the network to access the Internet network. Therefore, when the user terminal 440 is moved from the current network to another network, it cannot be accessed from the Internet network using the IP address used in the previous network, and needs to be changed back to the IP address corresponding to the current network. Mobile IP is a function that allows the user terminal 440 to continue to use the existing IP without changing, even if it moves to another network. With this feature, the user appears to be using the original IP address, but is actually changed to an IP address that matches the current network. That is, it internally changes the address for routing and the address used by the user. For this function, the user terminal 440 should perform a function specified in the mobile IP standard, and the main functions include a motion detection function and a registration function.

The movement detection function is a function of determining whether the user terminal 440 has moved from the current network to another network, and is based on information (server IP, server MAC address, etc.) of a message periodically transmitted from a server. Perform the move detection.

Next, the registration function transmits this fact to the network server HA when moving to a new network after performing the movement detection. This procedure is called registration. After the registration procedure is performed, the network server HA performs a management function for the current location of the terminal and transmits data to the current location of the terminal.

Next, the operation of the address manager 423 is as follows.

When the user terminal 440 moves from the fixed network 200 to the mobile network 400, the user terminal 440 uses the IP address used in the mobile network 400 and performs data transfer (the user terminal is a mobile IP). Since the application uses the original address to perform data transmission, the actual data transmission is sent using the IP address assigned by the mobile network. Accordingly, since the mapping information between the IP address used in the fixed network and the IP address used in the mobile network must be maintained, the address management unit 423 manages these addresses.

Next, the operation of the forin agent function performing unit 424 is as follows.

The FA function in the mobile router 420 is necessary when the mobile IP is supported in the mobile network 400, and the user terminal 440 moves between networks having different subnets in the mobile network 400. If it is a necessary feature. The overall operation is the same as that of the FA defined in Mobile IP.

Next, the operation of the packet transmitter 425 will be described.

The packet transmission function is a function of delivering a packet to the user terminal 440 in the mobile network 400, and finally delivers a packet through the address manager 423 and the network address translator 421 into the mobile network. In this function, a packet is usually transmitted to an address of a corresponding user terminal 440 by performing a procedure for knowing a MAC address.

Next, the operation of the router function performing unit 426 will be described.

The router function primarily processes a packet transmitted by the user terminals when the user terminals in the mobile network transmit the packet to the external network. In general, when transmitting packets from the Internet, the terminals are directly transmitted within the same network instead of through the default router, but when transmitting to the outside, the existing router first receives the packet, and the packet is transferred to an appropriate router using a routing protocol. It performs the function of passing. Accordingly, the router function performing unit 426 primarily receives a packet transmitted from the mobile network for packet transmission between the fixed network 200 and the mobile network 400 and transmits the packet to the outside in a proper manner.

That is, in the present invention, the mobile router 420 for packet routing in the mobile network 400 performs a terminal function with respect to the mobile IP in the fixed network 200 and 300, and the mobile network (in the mobile router 420). It is converted to the IP address type used in 400).

The fixed network 200, 300 has a HA 220 and FA 320 for the mobile IP, the mobile router 420 performs a terminal function for the mobile IP function of the fixed network 200. Therefore, even if the mobile router 420 of the mobile network 400 moves to another network, the mobile router 420 can receive the packet to the area currently moved by the existing mobile IP operation.

The mobile router 420 receiving the packet transmitted from the fixed network 200 or 300 changes the address of the corresponding terminal 440 used in the mobile network 400 and transmits the packet to the terminal 440. The terminal 440 within) can continue to receive the packet regardless of the location of the current network.

According to the present invention as described above, there is an effect to efficiently use the limited IPv4 address resources in the network that requires IP address, such as wireless LAN, home networking that is emerging.

In addition, since the Internet service can be provided in a specific mobile, there is an effect that can be easily applied to the future construction of the mobile Internet industry and environment.

Claims (2)

In a mobile IPv4 system consisting of the Internet, the first and second fixed network connected to the Internet and fixed at a specific location, and the mobile network to interface data wirelessly with the first and second fixed network and to move the network itself. , The mobile network, A wireless bridge for wirelessly interfacing packets with the first fixed network or the second fixed network; A mobile router which performs a user terminal function with respect to the HA and FA of the first and second fixed network and performs a router function with respect to the user terminal in the mobile network; And a wireless LAN access point connected to the mobile router and wirelessly interfacing packet data with the user terminal. According to claim 1, The mobile router, A network address conversion unit for changing between an IP address used in the mobile network and an IP address used in the fixed network; A user terminal function performing unit for internally changing the internally having an address for routing and an address originally used by the user; An address manager for managing an IP address used in the fixed network and an IP address used in the mobile network; A forest agent function performing unit supporting mobile IP in the mobile network; A packet transmitter for transmitting a packet to a user terminal in the mobile network; A mobile router apparatus for supporting mobile IPs, comprising: a router function performing unit for delivering a packet transmitted by the user terminal to a suitable router using a routing protocol.