KR20040040093A - Apparatus and method of offering mobile IP function in Wireless-LAN System, and Data Transmission Method of Mobile Node using Mobile IP Function - Google Patents

Abstract

PURPOSE: An apparatus and method for providing a mobile IP(Internet Protocol) function of a wireless LAN and a data transmission method of a mobile node using the mobile IP function are provided to allow a user to use a wireless Internet service by using a mobile IP function without re-setting an IP address by enabling an AP(Access Point) to perform a function performed by a mobile node. CONSTITUTION: An HA(Home Agent)(110) maintains position information of a mobile node(400) and transmits data to the mobile node(400) which has been moved and connected to an FA(Foreign Agent)(210). The FA(210) is connected to a wireless mobile communication network to which the mobile node has been wirelessly connected and transmits data to the mobile node(400) in cooperation with the HA(110). An AP2(200) stores an IP address of the FA(210) and information contained in an agent advertisement message by using the agent advertisement message the FA(210) periodically transmits. The AP2(200) determines whether the mobile node(400) requires a mobile IP function by using the stored IP address of the FA(210) and provides the mobile IP function to the mobile node(400) as required by the mobile node. In case that a host(310) transmits data to the mobile node(400), the host(310) first transmits data to the mobile node(400) through an IP network(300). Then, the IP network(300) transfers the data to the HA(110).

Description

Apparatus and method of offering mobile IP function in Wireless-LAN System, and Data Transmission Method of Mobile Node using Mobile IP Function }

The present invention relates to an apparatus and method for providing a mobile IP (Internet Protocol) function in a wireless LAN system. In particular, the present invention relates to a mobile node in which an access point (AP) does not have a mobile IP function. An apparatus and method for providing a mobile IP function of a WLAN system for providing a method for providing the same, and a data transmission method for a mobile node using a mobile IP function.

The Internet currently uses IPv4 (hereinafter referred to as IP) address system. This IPv4 addressing system uses a longest prefix matching algorithm based on network address. While the Longest Prefix Match method maintains the efficiency and simplicity of the routing table, the final destination is limited to routers in the subnet, so the existing routing mechanism does not provide mobility when nodes move through the subnet.

Therefore, in order to provide mobility between the IP subnet and the media, the mobile IP was proposed by the IETF mobile IP working group.

The mobile IP technology is mainly composed of a home agent (Home Agent) (hereinafter referred to as HA) that is a router of a home network and a foreign agent (hereinafter referred to as FA) which is a mobile processable router of a visited network. In order to support mobility of mobile hosts, periodic registration of mobile hosts to HA and tunneling between external agents or between home agents and mobile hosts are supported.

However, in the above mobile IP technology, since the mobile host must receive a unique IP address in order to receive the mobile IP service, when the number of subscribers to use the mobile IP service increases, the IP address to be allocated to these subscribers becomes insufficient. Symptoms may occur and the use of mobile IP services may be limited due to the lack of IP address resources.

In order to solve the above address shortage problem, there is a method of dynamically allocating an IP address to a mobile host that requires an IP address instead of assigning a unique IP to the mobile host.

In dynamically assigning a mobile IP address as described above, in the Republic of Korea Patent Publication No. 2002-0023917 (Application No. 10-2001-0087889, Handoff method in a WLAN-based access network) different from the other network or the same network When moving to an access point (hereinafter referred to as an AP), a handoff method for shortening a connection setup time between an AP and a user terminal and minimizing data loss is proposed.

The above patent secures the mobility of the user and provides a quick handoff method, so that the operation and function of the wireless LAN is operated in the media access control (MAC) layer based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. When the user moves to different APs in different networks, it reduces the connection setup time between the AP and the user terminal, minimizes data loss, and applies mobile IP technology, which is a technology for network layer mobility. It provides the function to maintain the continuous connection even if the network connection interval is changed and maintained in the upper layer application.

However, the above patent has a problem that a user terminal without a mobile IP function cannot be used.

Components and their respective necessary functions to achieve general Mobile IP functionality are defined in the RFC2002 (Request for Comments) standard specification. According to the RFC2002 standard, the mobile IP operation is composed of a mobile node (FA), FA, and HA.

When a mobile node connected to AP1 of a home network moves to a different external network, a mobile node without a mobile IP function has to inconvenience its own IP address.

However, if the mobile node is provided with the mobile IP function, it is possible to use the Internet service without changing the IP address even when accessing AP2 of the external network using the IP address assigned when the mobile node is connected to AP1.

In more detail, when the mobile node is connected to AP1 of the home network and moves to an external network, the mobile node first makes a re-association request to AP2 of the external network, and when AP2 responds, AP2 completes roaming for the mobile node by a roaming procedure.

Thereafter, the mobile node transmits a mobile IP registration request message to the FA of the external network according to the mobile IP procedure through AP2.

The registration request message includes an IP address of the HA, a care-of-address (COA) value indicating a tunneling end point in which the HA tunnels data coming into the mobile node from the Internet network, and a COA value of the mobile node. IP address value, etc. are included.

The FA that receives this registration request message delivers the registration request message to the HA by the procedure defined in the mobile IP specification, and the received HA receives the binding information for the mobile node according to the procedure defined in the mobile IP specification. After creating a tunnel to the COA address in the registration request message and sending a response signal to the FA, the mobile node to enable the Internet service according to the mobile IP function.

When transmitting data from the host to the registered mobile node by using the mobile IP registration procedure, the HA transmits data encapsulated in the middle and then tunnels to the COA IP address.

However, in the conventional mobile IP function and data transmission / reception procedure, when a mobile node moves from a home network to an external network, FA and HA functions must be provided in a network, and a user side can perform necessary functions of a mobile node defined in RFC2002. It should be possible.

Therefore, only the terminal supporting the mobile IP technology can use the mobile IP technology. Accordingly, the user has a burden of newly purchasing a terminal having the mobile IP function.

In order to solve the above problems, the present invention enables the AP to perform a function performed in the mobile node of the mobile IP function, so that when the user moves from the home network to the external network even in a mobile node without the mobile IP function, The present invention provides an apparatus and method for providing a mobile IP function of a wireless LAN system that enables a wireless Internet service using a mobile IP function without resetting an address, and a data transmission method of a mobile node using the mobile IP function. There is this.

1 is a block diagram illustrating a structure of an apparatus for providing a mobile IP function of a WLAN system according to an exemplary embodiment of the present invention.

2 is a signal flowchart of a method of providing data of a mobile node using a mobile IP function of a WLAN system according to an embodiment of the present invention.

3 is a signal flow diagram of a method for obtaining an IP address and message information of a FA according to a method of providing a data of a mobile node using a mobile IP function of a WLAN system according to an embodiment of the present invention.

<Brief description of the main parts of the drawings>

100: Home Network 110: HA (Home Agent)

120: AP 1 (Access Point) 200: Foreign Network

210: FA (Foreign Agent) 220: AP 2

300: IP network 310: host

According to the present invention, a method for providing a mobile IP function of a WLAN system,

A home agent that is a router of a home network, a first access point that allows a mobile node to access a home network, and receives a service, an external agent that is a mobile processing router of an external network, and a mobile node connected to the external network A method of providing a mobile IP function in a WLAN system including a second access point for receiving a service, an IP network connected to the home network and an external network, and a host connected to the IP network, the method comprising: (a) When a mobile node connected to the first access point and using a wireless Internet service moves from a home network to an external network, the mobile node does not have a mobile IP function and transmits an access request message to a second access point of an external network. step; (b) the second access point receiving the access request message transmitted from the mobile node performs roaming procedure with the first access point of the home network to obtain IP address information of the mobile node, and the mobile node has a mobile IP function; Determining whether or not it requires; (c) when the mobile node needs a mobile IP function as a result of the determination, constructing a mobile IP registration request message by the second access point and transmitting the mobile IP registration request message to a home agent through the foreign agent; And (d) performing binding by the home agent using a mobile IP registration request message received from an external agent, and creating a tunnel for data transmission to provide a mobile IP function to the mobile node.

Advantageously, the external agent periodically sends an agent advertisement message to a second access point; And acquiring and storing the external agent IP information included in the agent advertisement message transmitted from the external agent by the second access point, and transmitting a response message to the external agent.

Preferably, requesting an agent advertisement message from the second access point to an external agent and receiving an agent advertisement message from the external agent; And acquiring and storing, by the second access point, an external agent IP address included in an agent advertisement message received from an external agent.

Preferably, the step (b), the second access point to obtain the IP address information of the mobile node, determining whether the corresponding IP address is the IP address of the external network to which it belongs; And determining that the mobile node requires the mobile IP function if the IP address of the mobile node is not the IP address of the external network to which the mobile node belongs.

The mobile IP registration request message of step (c) may include a home agent IP address obtained by the second access point in a roaming procedure with the first access point, and an IP address of the mobile node; A second access point address corresponding to the tunnel end point for providing mobile IP function; And a bit indicating to perform a decapsulation operation at the second access point.

In addition, the step (d), the home agent to analyze the mobile IP registration request message received from the external agent, performing a bounding using the IP address of the mobile node; And creating a tunnel having an end point as a second access point address included in the mobile IP registration request message.

In addition, the data transmission method of the mobile node using the mobile IP function of the wireless LAN system according to the present invention, a home agent which is a router of a home network, and a first access point that allows the mobile node to be connected to the home network to receive services An external agent that is a mobile processable router of an external network, a second access point that allows a mobile node to access the external network, and receives a service, an internet network connected to the external network, and an internet network connected to the external network A data transmission method of a mobile node using a mobile IP function of a WLAN system configured as a host, the method comprising: transmitting, by the host, data destined for a mobile node to a home agent; Encapsulating the data received from the host by the home agent and transmitting the encapsulated data to the second access point through a tunnel created using the second access point as an end point when performing the mobile IP function; And decapsulating the encapsulated data received by the second access point through the tunnel, and transmitting the decapsulated data to the mobile node.

Preferably, when transmitting data from the mobile node to a host, the mobile node transmits data destined for the host to a second access point, and the second access point moves to a host of an IP network through an external agent. Delivering data transmitted from the node.

In addition, the apparatus for providing a mobile IP function of a WLAN system according to the present invention provides a WLAN service to a mobile node moving from a home network to an external network in a WLAN system including a home network and an external network connected to an IP network. An apparatus for providing a mobile IP function, comprising: a first access point for allowing the mobile node to access and receive a wireless LAN service from a home network; A home agent managing a mobile node connected to the first access point and responsible for data transmission to a mobile node connected to an external network; When the mobile node moves from the currently connected home network to another external network, the external agent responsible for transmitting and receiving data between the mobile node through the message transmission and reception with the home agent; And a mobile IP registration request message generation and transmission and tunneling endpoint for providing a mobile IP function to receive a wireless LAN service when a mobile node having no mobile IP function is connected to the external agent. And a second access point for decapsulating and encapsulating the encapsulated data transmitted from the mobile node to the mobile node.

Preferably, the IP network is connected to the external network by wire and provide the Internet service to the mobile node; And a host connected to the IP network to transmit and receive data with the mobile node.

Preferably, the second access point is characterized in that to obtain and store the IP address information of the external agent using the agent advertisement message transmitted from the external agent.

Preferably, the second access point performs a tunnel end point function for receiving data transmitted from the host to the mobile node.

Preferably, the second access point has a function of decapsulating encapsulated data transmitted through a tunnel by encapsulation in the home agent.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention;

1 is a block diagram illustrating a structure of an apparatus for providing a mobile IP function of a WLAN system according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the apparatus for providing a mobile IP function of a WLAN system includes an HA 110 of an home network 100, an AP1 120, an FA 210 of an external network 200, and an AP2 220. And a host 310 of the IP network 300 and a mobile node 400.

The HA 110 is a router that maintains location information of the mobile node 400 and transmits data to the mobile node 400 that is connected to and connected to the FA 210.

In addition, although only one HA 110 has been described herein, the HA 110 may be added due to an increase in the number of mobile IP service users.

In addition, when the mobile node 400 does not specify a specific HA (110), one HA (110) dynamically selects.

The FA 210 is a router that is connected to the wireless mobile communication network to which the mobile node 400 is wirelessly connected, and is responsible for data transmission to the mobile node 400 in cooperation with the HA 110.

Due to the characteristics of the mobile communication network, the FA 210 may be in charge of a separate service area, and each service area may be configured as a separate AP2 220.

At this time, the mobile node 400 connected to each other through the FA 210 in each area is required to dynamically receive an IP address belonging to the AP2 220 to transmit and receive data packets.

In the above configuration according to an embodiment of the present invention, the mobile node 400 that received the wireless Internet service in the area 1 of the AP1 120 of the home network 100 moves to the external network 200 to connect to the AP2 220. When setting, when the mobile node 400 does not have a mobile IP function, the mobile node 400 provides a mobile IP function to continuously receive a wireless Internet service.

The AP2 220 may store an IP address of the FA 210 and information included in the agent advertisement message by using an agent advertisement message periodically transmitted by the FA 210. The IP address determines whether the mobile node 400 needs the mobile IP function, and provides the mobile node 400 with the mobile IP function.

In this case, the mobile node 400 refers to a mobile communication device capable of wireless connection such as a laptop, a PDA (Personal Digital Assistant) or a portable Internet access device equipped with a wireless LAN card.

That is, the mobile node 400 has a function of a mobile host described in RFC2002 of IEFT, and can be connected to a mobile communication network through a wireless channel, respectively.

A method of providing a mobile IP function to a mobile node 400 in a WLAN system according to an embodiment of the present invention configured as described above is as follows.

2 is a signal flowchart of a method for providing a mobile IP function of a WLAN system according to an exemplary embodiment of the present invention.

Referring to FIG. 2, when the mobile node 400 accessing AP1 120 of the home network 100 and using the wireless Internet service moves to area 2 where AP2 220 of the external network 200 is located, the mobile node ( 400 requests IP recombination to AP2 220 and receives a response from AP2 220 (S201).

At this time, the mobile node 400 is a device that does not have a mobile IP function, AP2 (220) determines that the mobile node 400 to be connected does not have a mobile IP function, the mobile node does not have a mobile IP function When the IP re-combination request is received at 400, the AP2 220 operates to provide a mobile IP function.

The AP2 220, which transmits the response, performs a roaming procedure with the AP1 120 (S202), and the IP address information of the mobile node 400 entering its area and the mobile node 400 are mobile IP. Determine if you want a feature.

In this case, the AP2 220 determines whether the mobile node 400 wants the mobile IP function by determining whether the IP address of the mobile node 400 obtained in the roaming procedure is an IP address managed by the AP2 220. If the IP address is not managed, it is determined by the mobile node 400 moving from another subnet, and it is determined that the mobile IP function should be provided.

The AP2 220 transmits a mobile IP registration request message to the FA 210 on behalf of the mobile node 400 that has entered its area by using the information received in step S202 (S203).

At this time, the mobile IP registration request message includes the IP address and COA value of the mobile node, and the address of the HA 110 previously assigned to the AP2 220 by the user, or of the HA 110 moved from the mobile node 400. The address value and the like are included, and the AP2 220 inputs the IP address of the mobile node obtained in the roaming procedure of step S201, and inputs its IP address as the COA value.

And, the address of the HA 110 inputs the HA 110 address of the mobile node 400 obtained in the roaming procedure or the address of the HA 110 previously set in the AP2 220 by the user.

The address of the HA 110 set by the user means the IP address of the HA 110 to be connected when the user provides the mobile IP function in advance in order to provide the mobile IP function in the AP2 220.

In addition, the 'D' bit of the mobile IP registration request message is set to '1', wherein setting the 'D' bit to '1' means that AP2 220 itself tunnels the HA 110 by encapsulation. Decapsulating data.

When the AP2 220 transmits the mobile IP registration request message to the FA 110 as in step S203, the FA 110 receives the mobile IP registration request message, transmits the message to the HA 110, and requests the mobile IP registration. (S204).

The HA 110 performs binding using the IP address of the mobile node 400 included in the mobile IP registration request message received from the FA 210, and generates a tunnel using the COA (S205).

In addition, the HA 110 transmits a response message for the mobile IP registration request message to the FA 210 (S206), and the FA 210 receiving the mobile IP registration request message response from the HA 110 transmits this to the AP 210 (220). Transfer to (S207).

The AP2 220 informs that the mobile node 400 can transmit data according to the mobile IP registration request message response received from the FA 210 (S208).

In step S201 to S208, when the mobile node 400 does not have a mobile IP function, the AP2 220 provides a mobile IP function.

The mobile node 400 may be notified from the AP2 220 that data transmission is allowed (step S208), and may transmit data to the host 310 connected to the IP network 300.

At this time, the data transmitted from the mobile node 400 to the host 310 is transmitted to the IP network 300 through the AP2 220, and is again transmitted to the host 310 (S209).

When transmitting data from the host 310 to the mobile node 400, first, when the data is transmitted from the host 310 to the mobile node 400 through the IP network 300 (S210), the IP network 300 is transmitted. ) Transfers data transmitted from the host 310 to the mobile node 400 to the HA 110.

The HA 110 encapsulates the data transmitted from the host 310 and performs tunneling through the tunnel generated using the COA (S211).

At this time, since the COA is inputted to its IP address by AP2 220 in step S203, data is transmitted to AP2 220 (S212).

The AP2 220 decapsulates data from the host 310 received through the tunnel (S213), and delivers the decapsulated data to the mobile node 400 (S214).

As described above, in order to provide the mobile IP function in the AP2 220, the AP2 220 must know the IP address information of the FA in order to transmit the mobile IP registration request message to the FA 210 in step S203. .

3 is a signal flowchart of a method for obtaining IP address and message information of a FA according to a method for providing a mobile IP function of a WLAN system according to an embodiment of the present invention.

Referring to FIG. 3, the AP2 220 receives an agent advertisement message (agent advertisement; Agent Advertisement) periodically transmitted from the FA 210 (S301) and the FA 210 included in the agent advertisement message. Obtain an IP address of the server and store information included in the agent advertisement message (S302).

The AP2 220 transmits an agent solicitation message informing that the agent 210 performs the agent advertisement message normally (S303).

In addition, different from the steps S301 to S304, the AP2 220 first transmits an agent solicitation message, which is a request message for sending an agent advertisement message to the FA 210 (S311), and accordingly the agent at the FA 210. The advertisement message is transmitted to the AP2 220 (S312).

The AP2 220 receives the agent advertisement message transmitted from the FA 210, obtains and stores an IP address and information included in the agent advertisement message (S313).

As described above, the AP2 220 uses an agent advertisement message that the FA 210 periodically transmits to the AP2 220 to obtain the IP address information of the FA 210.

The AP2 220 determines whether the mobile node 400 needs the mobile IP function by using the IP address of the FA 210 obtained from the agent advertisement message.

That is, when the AP2 220 receives the recombination request from the mobile node 400, the AP2 220 determines whether the IP address of the mobile node 400 is the address of the FA 210 to which it belongs, or the address of another subnetwork. In case of an address of a sub network, it is determined that the corresponding mobile node 400 should be provided with a mobile IP address function.

And even if the mobile node 400 does not have a mobile IP function, the AP2 200 provides a mobile IP function.

As described above, the apparatus and method for providing a mobile IP function of a wireless LAN system according to the present invention, and the data transmission method of a mobile node using the mobile IP function are used in the mobile IP at the AP instead of the mobile node having no mobile IP function. By providing a function, if a mobile node without a mobile IP function moves from a home network to an external network, a mobile IP function provided by an external network AP can be used without any inconvenience of resetting its own IP address. The internet service can be used continuously.

In addition, there is an effect of reducing the cost of adding a mobile IP function or replacing equipment in order to receive a wireless Internet service from a mobile node having no mobile IP function.

Claims (13)

A home agent that is a router of a home network, a first access point that allows a mobile node to access a home network, and receives a service, an external agent that is a mobile processing router of an external network, and a mobile node connected to the external network A method of providing a mobile IP function in a WLAN system including a second access point for receiving a service, an IP network connected to the home network and an external network, and a host connected to the IP network, (a) When a mobile node connected to the first access point and using a wireless Internet service moves from a home network to an external network, the mobile node does not have a mobile IP function and access message to a second access point of the external network. Transmitting; (b) the second access point receiving the access request message transmitted from the mobile node performs roaming procedure with the first access point of the home network to obtain IP address information of the mobile node, and the mobile node has a mobile IP function; Determining whether or not it requires; (c) when the mobile node needs a mobile IP function as a result of the determination, constructing a mobile IP registration request message by the second access point and transmitting the mobile IP registration request message to a home agent through the foreign agent; And (d) the home agent performing binding using a mobile IP registration request message received from an external agent, creating a tunnel for data transmission, and providing a mobile IP function to the mobile node; Method of providing a mobile IP function of a wireless LAN system comprising a The method of claim 1, Periodically transmitting, by the foreign agent, an agent advertisement message to a second access point; And Acquiring and storing the external agent IP information included in the agent advertisement message transmitted from the external agent by the second access point, and transmitting a response message to the external agent Mobile IP function providing method of a wireless LAN system further comprising. The method of claim 1, Requesting an agent advertisement message from the second access point to an external agent and receiving an agent advertisement message from the external agent; And Acquiring and storing, by the second access point, an external agent IP address included in an agent advertisement message received from an external agent; Mobile IP function providing method of a wireless LAN system further comprising. The method of claim 1, In step (b), Obtaining, by the second access point, IP address information of the mobile node and determining whether the corresponding IP address is an IP address of an external network to which the mobile station belongs; And If it is determined that the IP address of the mobile node is not the IP address of the external network to which it belongs, determining that the mobile IP function is required. Mobile IP function providing method of a wireless LAN system comprising a. The method of claim 1, The mobile IP registration request message of step (c), A home agent IP address obtained by the second access point in a roaming procedure with the first access point, and an IP address of the mobile node; A second access point address corresponding to the tunnel end point for providing mobile IP function; And And a bit indicating to perform a decapsulation operation in the second access point. The method of claim 1, In step (d), Analyzing, by the home agent, a mobile IP registration request message received from an external agent, and performing bounding using an IP address of the mobile node; And Generating a tunnel having an end point as a second access point address included in the mobile IP registration request message; Mobile IP function providing method of a wireless LAN system comprising a. A home agent that is a router of a home network, a first access point that allows a mobile node to access a home network, and receives a service, an external agent that is a mobile processing router of an external network, and a mobile node connected to the external network In the data transmission method of a mobile node using a mobile IP function of a wireless LAN system comprising a second access point to receive a service, an internet network connected to the external network and a host connected to the internet network, Sending, by the host, data destined for a mobile node to a home agent; Encapsulating the data received from the host by the home agent and transmitting the encapsulated data to the second access point through a tunnel created using the second access point as an end point when performing the mobile IP function; And The second access point decapsulates the encapsulated data received through the tunnel, and transmits the decapsulated data to the mobile node Data transmission method of a mobile node using a mobile IP function of a wireless LAN system comprising a. The method of claim 7, wherein When transmitting data from the mobile node to the host, The mobile node transmits data destined for the host from the mobile node to a second access point, and forwards the data transmitted from the mobile node to a host of an IP network through an external agent. Data Transfer Method of Mobile Node Using Mobile IP Function An apparatus for providing a mobile IP function for providing a wireless LAN service to a mobile node moving from a home network to an external network in a wireless LAN system including a home network and an external network connected to an IP network, A first access point for allowing the mobile node to access and receive wireless LAN services from a home network; A home agent managing a mobile node connected to the first access point and responsible for data transmission to a mobile node connected to an external network; When the mobile node moves from the currently connected home network to another external network, the external agent responsible for transmitting and receiving data between the mobile node through the message transmission and reception with the home agent; And When a mobile node that does not have a mobile IP function accesses the external agent, a mobile IP registration request message is generated and transmitted and a tunneling endpoint is provided to provide a mobile IP function to receive a wireless LAN service. A second access point for decapsulating and transferring the encapsulated data transmitted to the mobile node to the mobile node Mobile IP function providing apparatus of a wireless LAN system comprising a. The method of claim 9, An IP network wired to the external network and configured to provide an Internet service to the mobile node; And A host connected to the IP network to transmit and receive data with the mobile node Mobile IP function providing apparatus of a wireless LAN system comprising a. The method of claim 9, And the second access point acquires and stores IP address information of the external agent using an agent advertisement message transmitted from the external agent. The method of claim 9, And the second access point performs a tunnel end point function for receiving data transmitted from the host to the mobile node. The method of claim 9, And the second access point has a function of decapsulating encapsulated data transmitted through a tunnel by encapsulating in the home agent.