KR20050045228A - Radio link control method and system for providing internet service for moving object in wlan environment - Google Patents

Abstract

The present invention relates to a wireless link establishment method for providing an Internet service to a mobile object in a wireless local area network.

The present invention provides an access point (AP) capable of wireless internet access, a mobile terminal capable of accessing the access point, a router connected to the access point and having a mobile IP function, and the mobile IP function. A wireless link setting method for providing an Internet service to a mobile device in a wireless local area network including a bridge and a mobile device capable of wirelessly transmitting and receiving data connected to a router having a wireless communication, comprising: (a) the mobile terminal providing a wireless Internet service; Connecting to the access point to be provided; (b) the router giving an IP address necessary for providing the wireless Internet service to the mobile terminal accessing the access point; And (c) establishing, by the bridge, a wireless relay link with an operator network providing a wireless local area network service. to provide.

According to the present invention, when a user attempts to use a wireless Internet service using a mobile terminal in a mobile object such as a train, subway, or high-speed bus, which has a wireless local area network environment, the data communication speed decreases and data loss occurs while the mobile object moves. And problems such as disconnection.

Description

Wireless Link Control Method and System for Providing Internet Service for Moving Object in WLAN Environment to Provide Internet Service to Mobile Object in Wireless Local Area Network

The present invention relates to a wireless link establishment method for providing an Internet service to a mobile object in a wireless local area network. More specifically, in the case where a mobile object such as a train, a ship, an aircraft, or a high-speed bus connects to a wireless local area network and performs mutual wireless data communication in order to use a wireless Internet service, the access point changes frequently due to the movement of the mobile object. The present invention relates to a radio link setting method for solving a problem of data loss or data communication interruption.

Today, with the acceleration of infrastructure construction of high-speed Internet network and low Internet usage rate, the spread of Internet service is becoming popular.The continuous development of Code Division Multiple Access (CDMA) mobile communication technology and the provision of wireless Internet service using the Internet anytime, anywhere Connection is now possible. Users who want to use the Internet in an environment where a wireless local area network is established can use a high-speed Internet service at home, school, or office using a mobile terminal.

A wireless local area network (WLAN) may use a high speed internet service through a mobile terminal within a certain distance centering on an access point (AP). Therefore, the wireless local area network overcomes the space limitations of the existing wired Internet access environment and provides a communication environment that can use the Internet anytime and anywhere wirelessly.

Comparing wired and wireless Internet, in terms of transmission speed, wired network is 2 Mbps while wireless network is slow, 64 Kbps. The content for wired Internet access has been standardized globally as HTML using the TCP / IP protocol, but has not been standardized as WML, m-HTML, and c-HTML using the TCP / IP and WAP protocols in the wireless Internet. In addition, in terms of portability, wireless Internet guarantees freedom of mobility, while wired Internet is extremely limited in mobility, and in terms of data storage, many restrictions are imposed due to the capacity and processing speed of mobile terminals, whereas wired Internet has a storage capacity. And superior in speed.

FIG. 1 is a diagram illustrating a wired / wireless integrated network that can receive a wireless Internet service using a mobile terminal.

Unlike data communication through a wired public switched telephone network (PSTN) or a public switched data network (PSDN), wireless data communication uses a notebook PC or a dedicated terminal to propagate data. Is to transmit data through.

The notebook PC 102, the mobile phone 104, and a dedicated terminal (not shown) which are connected to the wireless base station 110 and are capable of mutual wireless data communication are collectively referred to as a mobile terminal 100.

A network structure capable of receiving a wireless Internet service through wireless data communication includes a wireless network 120 and a wired network 130.

The wireless network 120 includes a mobile terminal 100, a wireless base station 110, a mobile communication switching center 112, and an ATM router 114, and the mobile terminal 100 wirelessly transmits to the wireless base station 110. Wireless data communication is started while requesting a data communication service.

The mobile phone 104 used as the mobile terminal 100 includes a wireless application protocol (WAP) which is a wireless Internet access protocol, a Microsoft Internet Explorer (MIE) based on HTML using the HTTP protocol, and a hand. It is equipped with a browser for Internet connection such as a handheld device transport protocol (HDTP), i-Mode of NTT DOKOMO or 'NATE' of SK Telecom, and can connect the notebook PC 102.

Among the Internet access protocols used in the mobile phone 104, MIE uses a shortened version of HTML, which is abbreviated m-HTML, and i-Mode uses a language called compact HTML (c-HTML), which is a subset of HTML. .

The wireless base station 110 includes a base station transmission system (BTS) 106, a base station controller (BSC) 108, and a repeater (Cell Enhancer) (not shown). Here, the base station transmitter 106 is arranged in units of cells and transmits a call request generated by the mobile phone 104 to the mobile switching center 112 or that exists in the cell area under its control. Perform location registration to identify your location.

The base station transmitter 106 transmits the position information of the base station transmitter 106 from the global positioning system (GPS) to the mobile phone 104 through a system parameter message of the forward link call channel. The mobile phone 104 may register new location information by calculating the moving distance of the mobile phone 104 by using the location information of the base station transmitter 106 of the cell to which the mobile phone 104 belongs.

Location registration is a processing procedure that informs the mobile communication station 112 via the base station transmitter 106 of the location, status, identifier, slot period, and other features of the mobile phone 104, and moves through the base station transmitter 106. This is a procedure for effectively calling the mobile phone 104 when the incoming call is to be established to the communication switching center 112. Such a location registration of the mobile phone 104 is performed when the mobile phone 104 is turned on or off, when the mobile phone 104 moves between mobile communication stations 112, and when the system parameters of the mobile phone 104 are changed. Is carried out.

The base station controller 108 performs various functions required for radio call processing such as handoff while controlling and managing a plurality of wireless base stations 110. The base station controller 108 also communicates subscriber information of the location registered cell phone 104 to the mobile communication switching center 112.

The Mobile Switching Center (MSC) 112 has a control function for allowing the wireless base stations 110 to operate efficiently and an interworking function with an exchange of a public telephone network. When the mobile communication switching center 112 registers the location of the mobile phone 104 through the wireless base station 110, the visitor location register (VLR) in the mobile communication switching center 112 is referred to as a 'VLR'. After the subscriber information of the mobile phone 104 is temporarily stored in the mobile station 104, a location registration request for a home location register (HLR) is called.

Here, the HLR (not shown) is a database that stores a service profile regarding subscriber information of the user of the mobile phone 104, and has information on the MIN, ESN, and service type of the mobile phone 104, including the subscriber's telephone number. have.

The HLR performs the function of storing subscriber information including information of the wireless base station 110 and the mobile switching center 112 where the mobile phone 104 is located. The mobile communication switching center 112 is composed of a control unit, a call path unit and a peripheral device, and also has a charging data collection function for the mobile phone 104.

When the mobile phone 104 performs location registration, the VLR (not shown) temporarily stores subscriber information and notifies the HLR, and copies the terminal identification number, terminal unique number, and service information of the mobile phone 104 from the HLR. It takes over and manages the function to utilize the location control, call processing, external operation processing of the mobile phone 104.

The ATM router 114 is responsible for connecting local Ethernet traffic to an ATM switch (not shown) in the wired network 130 using an ATM network. Since the protocol is different between the local area network (LAN) environment using the Ethernet standard and the high speed national network using the Asynchronous Transfer Mode (ATM) protocol, expensive LAN signal conversion (emulation) is required to access the high speed national network. Must be connected to an ATM switch with

The Ethernet standard is one of LAN models, and is a local network that can exchange information at a transmission speed of 10 Mbps between up to 1,024 terminals within a distance of about 2.5 km, and is one of the models implementing the IEEE 802.3 standard.

The asynchronous transmission mode is decided by the ITU-T in 1988 as a transmission method of the broadband integrated information network (B-ISDN), which is the core transmission and / or switching technology of the B-ISDN. (Byte) and the information field is divided into 53 bytes of ATM cells of 48 bytes and sequentially transmitted.

The wired network 130 includes a forest agent 132, an IP router 134, a home agent 136, and an internet server 138, and accesses a wireless network to receive a wireless internet service. One mobile terminal 100 and the Internet server 138 are interconnected.

In the wired / wireless integrated network structure, the wired network 130 serves as a back-bone network, and the wireless network 120 is connected in the form of a sub-network. The backbone network refers to a main transmission path for transmitting data between small LANs or branch LANs, and the subnetwork refers to a branch network connected to the backbone network.

The foreign agent (FA) 132 informs the home agent 136 of the management and the current location of the mobile terminal 100 entering its area when the mobile terminal 100 moves to another cell. Is a kind of router.

The IP router 134 is a system for relaying data on the Internet. The function and purpose of an IP router is to deliver data packets to a desired network using IP addresses, which are the basis for identifying different networks on the Internet. This means sending data packets sent and received from one network to another network according to the interpretation of the Internet address.

The home agent (HA) 136 is a router that manages the mobile terminal 100 in a wired network.

In the wired / wireless integrated network, location tracking of the mobile terminal 100 is managed by the home agent 136 and the forin agent 132. The home agent 136 is a router that manages the mobile terminal 100 in the wired network 130, and the forin agent 132 is a mobile terminal that enters its area when the mobile terminal 100 moves to another cell ( A function of informing the home agent 132 of the current position of the server 100 is performed.

In order to receive the Internet service, the mobile terminal 100 connected to the wired / wireless integrated network is assigned an IP address for identifying the mobile terminal 100 in the home agent 136. The IP address is fixedly used in the Internet service area provided by the home agent 136 and is used as a temporary address for data communication with the mobile terminal 100 by a counterpart wishing to transmit data to the mobile terminal 100. .

When the mobile terminal 100 moves to another cell, a temporary IP address is given by the forin agent 132 in the other cell. This temporary IP address represents a subnetwork of the Internet service area provided by the home agent 136 in which the mobile terminal 100 is currently located.

The forin agent 132 and the home agent 136 track and manage the current location of the mobile terminal 100 by exchanging a temporary IP address with a fixed IP address of the mobile terminal 100. Therefore, the mobile terminal 100 can use the Internet service wirelessly regardless of the current location.

The IP router 134 refers to a network device that checks an IP address of a data transmission destination and delivers a data packet to a corresponding destination.

2 is a diagram illustrating a mobile terminal that receives an IP address as a mobile IP when accessing a wired / wireless integrated network and using the Internet.

Mobile IP is a method introduced to use the Internet 206 without being disconnected from the wired network Internet 206 even when the mobile terminal 100 is connected to the wired or wireless integrated network.

Mobile IP supports the mobility of the mobile terminal 100 using two IP addresses. One of these IP addresses refers to the home IP address assigned to the home agent 136. The other IP address is a care-of address indicating a current location of the mobile terminal 100 moving according to an access point (AP) 200. The care-of address is the address of a mobility support agent (MA: Mobile Agent) currently supporting wireless access or a temporary IP address temporarily assigned by the mobility support agent.

A mobility support agent connected to the Internet 206 and the access point 200 and referred to as the upper network of the access point 200 is the home network 202, and supports mobility of the mobile terminal 100 in the home network 202. Called home agent 136.

On the contrary, the network connected to the access point 200 that changes as the mobile terminal 100 moves is called the forin network 204, and the forin agent 132 includes a mobility support agent that supports the mobility of the mobile terminal 100 in the forin network 204. ).

The mobility support procedure of a mobile terminal consists of a process of discovery, registration, and routing of a mobility support agent.

Mobility support agent discovery is based on an agent discovery mechanism that identifies the network to which the mobile terminal 100 belongs by periodically advertising the Beacon and / or Preamble signals.

The mobility support agent registration refers to a procedure in which the mobile terminal 100 notifies the home agent 136 of the current Care-of address. When the mobile terminal 100 connects to the forest network 204 where the access point 200 is installed, and the home agent 202 discovers the forest network 204 to which the mobile terminal 100 is connected by the agent discovery mechanism, The home agent 136 generates mobility binding information that pairs the care-of address allocated based on the home IP address of the mobile terminal 100 and the current location. If the home IP address of the mobile terminal 100 is "0.0.0.0" or "255.255.255.255", since the mobile terminal 100 is not yet assigned a home IP address, the home agent 136 may use the mobile terminal 100. ) Will be assigned a home IP address.

All data packets sent to the mobile terminal 100 by the hosts present on the Internet 206 are once sent to the home agent 136. The home agent 136 retrieves the destination address for the received data packet from the binding information, derives a Care-of address for the destination address, and transmits it to the forest agent 132 through tunneling. Tunneling is an encapsulation of data packets of a lower layer communication protocol into a higher layer communication protocol to enable communication between two points on a communication network.

3 is a diagram schematically illustrating a process of routing a mobile terminal by a binding table.

The mobile IP gives the mobile terminal 100 the home IP address of the home agent 136 through an agent registration procedure based on an agent discovery mechanism in order to ensure the mobility of the mobile terminal 100. The Core-of address, which is a temporary IP address, uses an IP address assigned to the mobile terminal 100 by the home agent 136 or to the mobile terminal 100 by the forest agent 134. In the method in which the mobile terminal 100 has a care-of address, since the mobile terminal 100 terminates tunneling, the mobile terminal 100 has a home IP address and a care-of address. The home agent 136 enables routing to the mobile terminal 100 by generating a binding table 306 that pairs the home IP address and the core-of address of the mobile terminal 100.

The care-of IP address of the mobile station 100 temporarily assigned by the base station A 300 is (1.1.1.3), and when the mobile station 100 moves to the base station 302, the mobile station 100 is assigned by the B base station 302. The care-of IP address (1.1.1.5) of the mobile terminal 100 is assigned.

When the mobile terminal 100 moves to the C base station 304, the care-of IP address (1.1.1.7) of the mobile terminal 100 assigned by the C base station 304 is reassigned.

Since the home agent 136 manages the reassigned IP address through the binding table 306, the home agent 136 transmits data to a recently registered base station to ensure hand-off between base stations.

When the mobile terminal 100 moves out of the serving cell (or sector) area to another cell (or sector), hand-off of changing a call path to a moved cell in order to maintain communication. Or hand-over.

4 is a diagram illustrating a handoff process of a mobile terminal according to a change of an access point in a wireless local area network.

The wireless local area network may use the Internet by accessing a high-speed communication network using a mobile phone, a PDA, a notebook PC, or the like within a predetermined distance around the place where the access point 200 is installed.

There is no need for telephone line or dedicated line because it uses radio frequency for communication, but PDA or notebook PC should be equipped with wireless LAN card. Early wireless local area networks had a radio range of only 10 m, but in the 2000s, they significantly increased to 50-200 m. The transmission speed was 4-11 Mbps, which allowed large amounts of multimedia information to be sent and received.

However, when using a wireless data service on a mobile moving object has a disadvantage that the data transmission speed is reduced by about several tens of Kbps. The wireless local area network supports the mobility of the terminal using the Inter Access Point Protocol (IAPP) to use the wireless data service on the mobile. The IAPP defines a technique for mobile radio access equipment to handoff at the access point 200. In the drawing, the access point 200 periodically broadcasts a Beacon signal. The beacon signal includes information corresponding to the corresponding access point 200 such as a time stamp, signal interval, capability, ess ID, and traffic indication map (TIM).

The mobile terminal 100 uses a beacon signal to distinguish different access points 200. When the beacon signal received by the mobile terminal 100 from the access point 200 is weakened, the mobile terminal 100 transmits from the adjacent access point 200. The access point 200 is changed by comparing the strength of the beacon signal.

The process of handoff by the mobile terminal 100 in a wireless local area network is as follows. The mobile terminal 100 transmits a probe signal to all the access points 200 in the vicinity. Regarding the probe signal, each access point 200 transmits a probe response signal including a beacon signal (except TIM information) that is periodically broadcast. The mobile terminal 100 transmits the radio relay link setting signal to the selected access point 200 by selecting the access point 200 that transmits the Beacon signal most strongly or the probe response signal. Upon receiving the radio relay link establishment signal, the access point 200 generates a supported bit rate, a station ID, and information necessary to resume communication as a reconnection response signal, and transmits it to the mobile terminal 100.

However, even if a mobile terminal using IAPP in a wireless local area network uses a wireless Internet service, a single access point can provide a mobile internet service such as a train, subway, or high-speed bus, while using a wireless Internet service at a high speed. Not only is the service coverage limited, there are problems such as data loss and connection interruption due to frequent changes of the access point. In addition, problems such as data loss and connection interruption also occur due to fading occurring as the terminal moves at a high speed.

In order to solve the above-mentioned problems, the present invention is to provide a mobile, such as a train, a ship, an aircraft, a high-speed bus connected to a wireless local area network to perform wireless data communication in order to use a wireless Internet service, Accordingly, an object of the present invention is to provide a method and a system for establishing a wireless link for solving a problem of data loss or data communication interruption caused by frequent connection change of an access point.

Accordingly, according to a first object of the present invention, an access point (AP) capable of wireless internet access, a mobile terminal accessible to the access point, a router connected to the access point and having a mobile IP function ( A wireless link setting method for providing an Internet service to a mobile object in a wireless local area network including a router, a bridge capable of transmitting and receiving data wirelessly connected to a router having a mobile IP function, and a mobile object, the method comprising: (a) The mobile terminal accessing the access point to receive a wireless Internet service; (b) the router giving an IP address necessary for providing the wireless Internet service to the mobile terminal accessing the access point; And (c) establishing, by the bridge, a wireless relay link with an operator network providing a wireless local area network service, the wireless link setting method for providing an internet service to a mobile object in a wireless local area network. .

According to a second object of the present invention, a mobile agent in a wireless local area network includes a home agent (HA) connected to the Internet, a router connected to the home agent, and a bridge connected to the router to wirelessly transmit and receive data. A method of establishing a radio link for providing a service, the method comprising: (a) establishing a wireless relay link between the mobile body and a bridge capable of transmitting and receiving data wirelessly; (b) handing off a bridge capable of transmitting and receiving data wirelessly with the mobile body; (c) the router routing the data packet to a bridge whose wireless relay link configuration has changed; And (d) transmitting a data packet from the home agent connected to the internet to the router, wherein the wireless link setting method for providing an internet service to a mobile object in a wireless local area network is provided.

According to a third object of the present invention, a wireless link system for receiving an Internet service without data interruption and connection interruption to a mobile terminal within a mobile device even if the mobile object moves at high speed in a wireless local area network. AP: Access Point); A mobile terminal connected to the access point and capable of transmitting and receiving data; A router connected to the access point and having a mobile IP function; And a bridge connected to a router having the mobile IP function and capable of wirelessly transmitting and receiving data. The wireless link system for providing an Internet service to a mobile object in a wireless local area network is provided.

Below. Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

5 is a diagram illustrating a network configuration for providing a wireless Internet service to a moving mobile device according to a preferred embodiment of the present invention.

When the mobile object 500 moves at a high speed in a wireless local area network, the access point 200 changes frequently, causing problems such as data transmission interruption, connection interruption, and fading. Fading is a phenomenon in which the received electric field intensity fluctuates in time due to the change of the atmospheric refractive index in the wireless line and the change of the line due to the interference, connection, divergence, or obstacle of multiple waves at the reception point.

Accordingly, in the present invention, in order to minimize the change of the access point 200 and to remove the fading effect due to the high speed movement of the moving object 500, the router adding the access point 200, the bridge, and the mobile IP function to the moving object 500 is provided. Install.

A router is one of devices that connect and transmit data to and from a plurality of LANs. A bridge refers to a device used to interconnect a plurality of communication networks, partial networks, channels, and the like to aggregate circuits and for accurate and rapid data transmission. The functionality of a router is basically the same as a bridge, but the router selects paths at the physical, data link and network layers of the OSI basic reference model, while the bridge operates at the physical and data link layers of the OSI basic reference model. It can also relay frames between two different LANs. The bridge simply determines whether to pass the data packet, but the router interprets the protocol contained in the data packet and selects the optimal path to transmit the data.

In the drawing, a router in which the mobile IP function to be installed in the mobile unit 500 and the WLAN carrier network 524 is added to the MR (504), FR (1) 510, FR (2) 512, and FR (3) ( 514).

In the figure, a bridge installed in the mobile unit 500 and the WLAN operator network 524 includes a module capable of wireless data communication, and includes MB 502, FB (1) 506, FB (2) 508, and FB. (3) 510, FB (4) 512, FB (5) 514, and FB (6) 516, respectively.

In the process of installing the access point 200 in the moving object 500, the access point 200 is disposed at intervals where the beacon and / or preamble signals of the access point 200 weaken around the point where the access point 200 is installed. Install.

Based on the MB 502 installed in the moving object 500, the moving object 500 itself can be viewed as a network, and the area in which the access point 200 is installed in the moving object 500 becomes a subnetwork. Therefore, the MR 504 of the moving object 500 only needs to manage the path setting of the subnetwork divided by the unit in which the access point 200 is installed. Since the mobile 500 forms a single network, problems such as IP address reallocation and traffic load increase due to frequent access point changes of the mobile terminal 100 in the mobile 500 may be solved.

If the MB 500 is directly connected to the access point 200 without installing the MR 504 on the mobile device 500, the MB 502 of the mobile device 500 establishes an appropriate data packet transmission path for a plurality of LANs. Since the data packet is transmitted without the traffic load increases.

In addition, the mobile terminal 100, the MB 502, and the access point 200 in which the mobile IP module is installed may be constructed in the mobile object 500 without installing the MR 504. In this case, the mobile terminal 100 in which the mobile IP module is installed becomes one independent network. Therefore, the FR (1) 518, the FR (2) 520, and the FR (3) 522, in which the wireless relay link is formed with the MB 502 of the mobile body 500, are respectively associated with the movement of the mobile body 500. Since the mobile terminal 100 needs to perform a mobile IP registration procedure, a heavy load is placed on the home agent 136 of the WLAN operator network 524.

WLAN carrier network 524 is composed of a plurality of sub-network in the form of connecting the router and the bridge. That is, the subnetwork of the WLAN operator network 524 is configured to connect the FB (1) 506 and the FB (2) 508 to the FR (1) 518 as shown in the figure.

The bridge having a module capable of wireless data communication is arranged such that interference between the local area network service shadow area and inter-cell interference is minimized for the moving section of the mobile object 500. For example, a range in which the beacon and / or preamble signal transmitted by the FB (1) 506 is weakened forms a cell and is a subnetwork connected to the WLAN operator network 524.

MB 502 of mobile 500 that connects to FB (1) 506 or FB (2) 508 of WLAN carrier network 524 forms a wireless relay link, Internet 206 and mobile 500 Establish a communication channel capable of wireless data communication between the < RTI ID = 0.0 >

When the moving object 500 moves to the FB 2, the mobile object 500 is out of the wireless local area network service providing range of the FB 1 and 506. When the mobile object 500 hands off with the FB 1 and establishes a wireless relay link with the FB 2, the mobile object 500 updates the IP routing path required for the wireless Internet connection to the FB 2.

Up to a certain range of beacon and / or preamble signals transmitted by the FB (1) 506 or FB (2) 508 of a cell capable of wireless local area network service, wireless data communication is possible without interruption of connection or loss of data packets. However, if the mobile unit 500 is out of range of a cell capable of providing a wireless local area network service, wireless data communication is impossible. Therefore, a process of reestablishing a wireless relay link by finding a bridge of a new cell is required.

The MB 502 of the moving vehicle 500 changes the radio relay link after searching for a bridge that can be connected while maintaining the existing radio relay link. For example, when a mobile object communicates with the FB (2) 508 to perform wireless data communication, the beacon and / or preamble signal transmitted by the FB (3) 510 or the FB (4) 512 may have an FB (2). If it is greater than the Beacon and / or Preamble signal strength received at 508, the radio relay link setting is changed to FB (3) 510 or FB (4) 512.

In addition, when the wireless relay link is released from the FB (2) 508 due to the movement of the mobile object 500 and a new wireless relay link is established with the FB (3) 510, the mobile object 500 is transmitted from the Internet 206 to the mobile object 500. Receiving the data packet, the FB (2) 508 forwards to the FB (3) (510).

The CN 516 is connected to the Internet 206 as a server that provides various Internet services, such as broadcasting, video, language learning, and finance. When the mobile terminal 100 requests various Internet services to the CN 516 through the WLAN service provider network 520, the server providing the service transmits a data packet corresponding to the requested service to the mobile terminal 100. .

6 is a flowchart illustrating a process of setting up a wireless relay link for a mobile terminal of a moving mobile device to receive a wireless Internet service according to a preferred embodiment of the present invention.

At the point of access point 200 capable of wireless local area network connection within the mobile unit 500, the user attempts to access the wireless local area network using the mobile terminal 100 (S600).

If the mobile object 500 is in a cell area in which the FB (1) 506 provides wireless local area network service, the FB (1) 506 and the MB 502 are interconnected to establish a wireless relay link capable of data communication. (S602).

When the wireless relay link is established, the MR 504 of the mobile object 500 performs a mobile IP registration procedure (S604).

The mobile IP registration request message of the MR 504 is delivered to the FR of the WLAN operator network 524 that performs the forin agent function (S606). The FB is a bridge of the WLAN service provider network 520, which is an FB (1) 506, FB (2) 508, FB (3) 510, FB (4) 512, FB (5) 514 , FB (6) 516, and likewise FR refers to FR (1) 510, FR (2) 512, FR (3) 514 as routers in the WLAN operator network 524.

The mobile IP registration request message of the MR 504 forwarded to the FR is forwarded to the home agent 136 (S608). The home agent 136 recognizes the MR 504 of the mobile object 500 as a subnetwork, generates binding information, and then sends a mobile IP registration response message to the MR of the mobile object 500 through the FR of the WLAN operator network 524. 504).

The mobile terminal 100 of the user who attempts to access the Internet 206 from the access point 200 of the mobile 500 receives an IP address from the MR 504 of the mobile 500 (S610).

Since the IP address is managed by the MR 504 of the moving object 500, the IP address does not need to be reassigned unless the user's mobile terminal 200 leaves the moving object 500.

The mobile terminal 200 of the user assigned the IP address receives data from the CN 516 connected to the Internet 206 through the wireless relay link (S612).

7 is a flowchart illustrating a process of setting up a wireless relay link when a router change of a WLAN operator network occurs due to movement of a moving object according to an exemplary embodiment of the present invention.

When the mobile unit 500 moves from the FR (1) 518 to the FR (2) 520, the router is changed, so that the transmission path of the data packet is changed to a new routing path (S700).

The data packet transmitted to the disconnected FR (1) 518 is forwarded to a new router FR (2) 520 (S702). Data forwarded between the mobile unit 500 and the FR (1) 518 in which the wireless relay link setting is released and the mobile unit 500 and the FR (2) 520 in which the new wireless relay link setting has been established are data using tunneling. Send it.

The MB 502 of the moving object 500 releases the radio relay link with the FB (2) 508 of the FR (1) 518 (S704). The MB 502 of the moving object 500 changes the radio relay link to the FB (3) 510 of the FR (2) 520 (S706). The change of the radio relay link from FR (1) 518 to FR (2) 508 as the mobile 500 moves means that the subnetwork in which the mobile 500 receives wireless local area network service changes. The mobile IP registration is newly performed with the IP address range provided by the router of the subnetwork (S708).

8 is a flowchart illustrating an operation of a bridge connected to a router of a WLAN operator network according to an embodiment of the present invention.

FB (1) 506, FB (2) 508, FB (3) 510, FB (4) 512, FB (5) 514, FB (connected to WLAN carrier network 524) 6) 516 is collectively referred to as FB.

When power is supplied to the FB, the system initializes and transmits a beacon and / or preamble signal (S800). Preamble signals are used for signal detection, time and frequency synchronization, and channel estimation. Beacon signals contain information such as time stamps, signal intervals, capability, ess ID, and traffic indication map (TIM).

The MB 502 of the mobile object 500 establishes a wireless relay link with an FB transmitting strong Beacon and / or Preamble signals among the FBs (S802). The FB determines whether the data packet transmitted from the Internet 206 is a data packet to be transmitted to the mobile object 500 currently maintaining the wireless relay link (S804).

If the mobile 500 moves and the FB that establishes the wireless relay link is changed, the data packet transmitted from the Internet 206 is forwarded to the neighboring FB. If the wireless relay link is stopped, the data packet is deleted from the buffer register of the FB. (S812).

If the data packet transmitted from the Internet 206 is a data packet to be transmitted to the MB 502 of the mobile object 500 which currently forms the wireless relay link, the data packet is buffered in the buffer register of the FB (S806).

If the MB 502 of the mobile unit 500 maintains the wireless relay link without handing off with the FB which currently forms the wireless relay link (S808), the data packet buffered by the MB 502 of the mobile unit 500 is stored. Transmit (S810).

If the MB 502 of the mobile object 500 is handed off with the FB that currently forms the wireless relay link or the wireless relay link is stopped (S808), if it is handed off with the FB, the data packet is forwarded to the adjacent FB, and the wireless relay link If is stopped, the data packet is deleted from the buffer register of the FB (S812).

After step S812, the FB waits while transmitting a Beacon and / or Preamble signal until a new wireless relay link is established with the moving object 500.

9 is a flowchart illustrating the operation of a bridge connected to a moving body according to a preferred embodiment of the present invention.

When power is applied to the MB, the system performs initialization and finds a strong Beacon and / or Preamble signal among the Beacon and / or Preamble signals transmitted by the FB connected to the WLAN service provider network 524 to determine the FB to be connected (S900).

The wireless relay link is established with the FB transmitting the strong beacon signal, and the wireless relay link setting information is transmitted to the MR (S902).

A data communication line is formed between the WLAN operator network 524 and the mobile unit 500 and the Internet can be used (S904).

The MB periodically measures the beacon and / or preamble signal strengths transmitted from the neighboring FBs and determines whether to change the connection of the FBs (S906). If there is no connection change of the FB, the WLAN service provider network 524 and the mobile 500 continue wireless data communication.

If it is necessary to change the connection of the FB, the wireless relay link setting is changed to the new FB (S908).

The wireless relay link setting information of the FB whose connection with the MB is changed is transmitted to the MR (S910).

Upon receiving the radio relay link setting information of the FB, the MR performs Mobile IP registration with respect to the access point 200 of the mobile object 500 (S912).

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, an access point of a mobile terminal is constructed in a mobile object to solve a problem of changing an access point according to the movement of the mobile terminal. In other words, by installing a bridge and a router in a mobile device, the mobile device itself is formed as a single subnetwork. This allows a bridge or a router that manages an access point to reassign an IP address. Reassigned a problem. And even if the mobile moves at a high speed, since the router with the mobile IP function performs the mobile IP registration procedure while handing off, the mobile terminal does not update the mobile IP registration information and change the IP address at the same time. There is an advantage to reducing.

In addition, since the access point is not responsible for establishing a wireless relay link with a bridge of a wireless local area network, there is an advantage of being less affected by fading due to high-speed movement of a moving object.

1 is a view showing a wired and wireless integrated network that can be provided with a wireless Internet service using a mobile terminal,

2 is a diagram schematically illustrating a mobile terminal receiving an IP address with a mobile IP in accessing a wired / wireless integrated network and using the Internet;

3 is a diagram briefly illustrating a process of routing a mobile terminal by a binding table;

4 is a diagram illustrating a handoff process of a mobile terminal according to a change of an access point in a wireless local area network;

5 is a diagram illustrating a network configuration for providing a wireless Internet service to a moving mobile device according to a preferred embodiment of the present invention;

6 is a flowchart illustrating a process of setting up a wireless relay link for a mobile terminal of a mobile according to a preferred embodiment of the present invention to receive a wireless Internet service;

7 is a flowchart illustrating a process of setting up a wireless relay link when a router change of a WLAN operator network occurs due to movement of a moving object according to an exemplary embodiment of the present invention;

8 is a flowchart illustrating the operation of a bridge connected to a router of a WLAN operator network according to an embodiment of the present invention;

9 is a flowchart illustrating the operation of a bridge connected to a moving body according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: mobile terminal 102: notebook PC

104: mobile phone 106: base station transmitter

108: base station controller 110: wireless base station

112: mobile switching center 114: ATM router

120: wireless network 130: wired network

132: Forin Agent 134: IP Router

136: Home Agent 138: Internet Server

200: access point 202: home network

204: Forin Network 206: Internet

300: A base station 302: B base station

304: C base station 500: mobile body

502: MB 504: MR

506: FB (1) 508: FB (2)

510: FB (3) 512: FB (4)

514: FB (5) 516: FB (6)

518: FR (1) 520: FR (2)

522: FR (3) 524: WLAN operator network

526: CN

Claims (31)

An access point (AP) capable of wireless internet access, a mobile terminal accessible to the access point, a router connected to the access point and having a mobile IP function, and the mobile IP function A wireless link setting method for providing an Internet service to a mobile device in a wireless local area network including a bridge and a mobile device capable of wirelessly transmitting and receiving data connected to a router, (a) the mobile terminal accessing the access point to receive a wireless Internet service; (b) the router giving an IP address necessary for providing the wireless Internet service to the mobile terminal accessing the access point; And (c) the bridge establishing a wireless relay link with an operator network providing wireless local area network service; Wireless link setting method for providing an Internet service to a mobile object in a wireless local area network comprising a. The method of claim 1, The mobile terminal includes a notebook PC, a PDA, a mobile phone, and a dedicated terminal having a wireless LAN card capable of wireless data communication. The method of claim 1, The mobile device includes a subway, a railroad, a vehicle, a marine transport, a ship, and an aircraft, which is a public transport. The wireless link setting method for providing an Internet service to a mobile in a wireless local area network. The method of claim 1, The access point, the router and the bridge is installed in the mobile unit, the mobile unit is a sub-network (Subnetwork) of the wireless local area network, the wireless link setting for providing the Internet service to the mobile station in the wireless local area network Way. The method of claim 1, And a network of a service provider serving the wireless local area network comprises a plurality of fixed stations provided with the bridges. The method of claim 1, wherein in step (a), And the access point forms a data communication channel using radio waves when the mobile terminal requests access, and a wireless link setting method for providing an internet service to a mobile object in a wireless local area network. The method of claim 1, wherein in step (b), In the wireless local area network, the mobile IP includes an IP address of an operator providing the wireless local area network service and a care-of address representing routing information to a current location of the moving object moving along the wireless local area network. A method of establishing a wireless link for providing an Internet service to a mobile object. The method of claim 1, wherein in step (b), The router having the mobile IP function provides an Internet service to a mobile object in a wireless local area network, when the Core-of address of the mobile device is changed, a mobile IP-based registration procedure is performed for the access point of the mobile device. How to set up a wireless link. The method of claim 1, The bridge is a method for establishing a radio link for providing an Internet service to a mobile object in a wireless local area network, characterized in that the fading (fading) prevention antenna. The method of claim 1, wherein in step (c), The bridge capable of transmitting and receiving data wirelessly may establish a wireless relay link with a fixed station of the wireless local area network that transmits a signal having a high beacon and / or preamble signal among the beacon and / or preamble signals transmitted by the wireless local area network. A wireless link establishment method for providing an Internet service to a mobile object in a wireless local area network, characterized in that. The method of claim 10, The preamble signal is used for signal detection, time and frequency synchronization, channel estimation, and the like. The beacon signal includes information such as a time stamp, signal interval, capability, ess ID, and traffic indication map (TIM). A method of establishing a wireless link for providing an Internet service to a mobile object in a wireless local area network. The method of claim 1, And the bridge monitors the beacon and / or preamble signal strengths transmitted from the fixed station of the wireless local area network even after the wireless relay link is established. The method of claim 1, The bridge hands-off with the fixed station according to the beacon and / or preamble signal strength transmitted from the fixed station of the wireless local area network. How to set up a link. A method for establishing a wireless link for providing an Internet service to a mobile object in a wireless local area network including a home agent (HA) connected to the Internet, a router connected to the home agent, and a bridge connected to the router to wirelessly transmit and receive data. As (a) establishing a wireless relay link between the mobile unit and a bridge capable of transmitting and receiving data wirelessly; (b) handing off a bridge capable of transmitting and receiving data wirelessly with the mobile body; (c) the router routing the data packet to a bridge whose wireless relay link configuration has changed; And (d) transmitting a data packet from the home agent connected to the internet to the router; Wireless link setting method for providing an Internet service to a mobile object in a wireless local area network comprising a. 15. The method according to claim 14, wherein in step (a) The bridge capable of transmitting and receiving data wirelessly transmits a beacon signal and / or a preamble signal, and when the mobile body receiving the beacon signal and / or preamble signal transmits a connection request to the bridge capable of transmitting and receiving data wirelessly, a radio relay is performed. A method for establishing a wireless link for providing an Internet service to a mobile object in a wireless local area network, characterized by setting up a link. The method of claim 15, And the bridge transmits the data packet transmitted to the mobile body after buffering the data packet in the buffer register of the bridge. The method of claim 14, wherein in step (b) And disabling a wireless relay link when the mobile unit requests a handoff from the bridge that currently forms a wireless relay link. The method of claim 17, When a data packet to be transmitted to the mobile is transmitted to the bridge from which the wireless relay link is released, forwarding of the data packet to a neighboring bridge establishes a wireless link for providing an Internet service to the mobile in a wireless local area network. Way. The method of claim 14, wherein in step (c) When a wireless relay link is formed between the router and the bridge, the router becomes a subnetwork of the home agent through tunneling with the home agent and routes data packets transmitted from the home agent to the mobile station. A method of establishing a wireless link for providing Internet service to a mobile object in a network. The method of claim 19, The tunneling encapsulates the data packet transmitted between a home agent assigned an IP address to a mobile IP and a bridge that transmits and receives data wirelessly, thereby enabling communication between two points on a communication network. A method of establishing a wireless link for providing an Internet service to a mobile object in a wireless local area network. The method of claim 20, The mobile IP assigns a core-of address, which is a temporary IP address, to a router that forms a wireless relay link with the mobile object to ensure mobility of the mobile object, and pairs the home agent and core-of address of the home agent. A method of establishing a wireless link for providing an Internet service to a mobile object in a wireless local area network, characterized by generating a binding table. The method of claim 14, wherein in step (d) The home agent tracks the router on which a wireless relay link is formed by using a binding table generated by mobile IP, and routes data packets transmitted to the router. How to set up a wireless link. In the wireless local area network, even if the mobile moves at high speed, a wireless link system for receiving Internet service without interruption of data and connection to the mobile terminal in the mobile, An access point (AP) capable of wireless internet access; A mobile terminal connected to the access point and capable of transmitting and receiving data; A router connected to the access point and having a mobile IP function; And Bridge connected to the router with the mobile IP function and capable of transmitting and receiving data wirelessly Wireless link system for providing an Internet service to a mobile object in a wireless local area network comprising a. The method of claim 23, The access point, the router and the bridge is connected to the router to the bridge, the access point to the router and the wireless link for providing the Internet service to the mobile in the mobile local area, characterized in that installed in the mobile system. The method of claim 24, The mobile link system includes a subway, a railroad, a vehicle, a marine transport, a ship, and an air vehicle. The wireless link system for providing an Internet service to a mobile vehicle in a wireless local area network. The method of claim 23 or 24, And the access point forms a data communication channel using radio waves when the mobile terminal requests access. The method of claim 23, The mobile terminal includes a notebook PC, a PDA, a mobile phone, and a dedicated terminal having a wireless LAN card capable of wireless data communication. The wireless link system for providing an Internet service to a mobile object in a wireless local area network. The method of claim 23, The router provides an IP address to the mobile with an IP address of an operator providing the wireless local area network service and a care-of address indicating a current location of the mobile moving along the wireless local area network. A wireless link system for providing Internet services to mobile objects in a network. The method of claim 23, The bridge monitors the beacon and / or preamble signal strengths transmitted from a fixed station of the wireless local area network even after a wireless relay link is established with the wireless local area network. Wireless link system. The method of claim 23, The bridge hands-off with the fixed station according to the beacon and / or preamble signal strength transmitted from the fixed station of the wireless local area network. Wireless link system. The method of claim 23, The bridge is a radio link system for providing Internet services to a mobile object in a wireless local area network, characterized in that the fading (fading) prevention antenna.