KR100915087B1 - Method for routing in mobile internet and system thereof - Google Patents

Abstract

According to the present invention, when a mobile terminal connected to the Internet moves in a wireless Internet environment, data transmitted from a counterpart terminal communicating with the mobile terminal to the mobile terminal is transferred directly to the current network without passing through the previous network. The present invention relates to a routing method and a system of the same, and when a range of a wireless network changes according to the movement of a mobile terminal, traffic does not bypass the previous network, thereby reducing traffic, and data is transmitted through an optimal path. Has the effect of improving the speed.

Description

Method for routing in mobile internet and system thereof

The present invention relates to a routing method and a system of the wireless internet, and more particularly, when a mobile terminal connected to the internet moves in a wireless internet environment, data transmitted from a counterpart terminal communicating with the mobile terminal to the mobile terminal The present invention relates to a routing method and a system of the wireless Internet delivered directly to a current network without passing through a previous network.

As computers become smaller and access to the Internet through small terminals such as PDAs (Personal Digital Assistants), wireless Internet access and mobility support are indispensable.

In general, an Internet Protocol (IP) address is required to access the Internet, and IP version 4, which is currently used in most Internet environments, uses an IP address to uniquely identify a terminal such as a computer or a PDA.

This IP address consists of a network address and a terminal (host) address. The 32-bit binary value is divided into dots every 8 bits and converted to decimal.

A network mask is used to classify these IP addresses into network addresses and terminal addresses.

The network mask also uses a decimal value, which is a 32-bit binary number, separated by dots every 8 bits, like an IP address.

In the binary mask value, 1 represents a network and 0 represents a terminal.

If all of the binary values representing the terminal address are 0, the address converted to decimal with 8 dots is called the network address to which the terminal belongs.

In the case of the binary values representing the terminal addresses, all of 1's are divided into dots every 8 bits, and the address converted to decimal is called a broadcast address of the network to which the terminal belongs.

Therefore, in a network using an IP address, an address other than a network address and a broadcast address is used so that terminals do not overlap each other.

In a wireless Internet environment, a triangular routing method using tunneling is used to receive data transmitted to a mobile terminal moving through a network.

1 is a network configuration diagram of a system implementing such a conventional triangular routing method.

In the drawing, router 1, router 2, and router 3 are routers constituting the wired internet 30, and the fixed terminal 130 is a terminal device connected to the wired internet 30 to serve as a server or a host. (Access Point) 1 and AP2 are access devices for wirelessly accessing the Internet, and the mobile terminals 110 and 120 are terminal devices capable of wirelessly accessing and transmitting data.

Reference numerals 10 and 20 denote ranges of networks in which mobile terminals 110 and 120 can wirelessly access the Internet by AP1 and AP2, respectively.

The mobile terminal 110 is connected to the router 1 through the AP1 within the range 10 of the wireless network to which it belongs, and transmits and receives data with the fixed terminal 130 connected to the router3.

Router 1 and Router 3 provide a data path transmitted between terminals using a routing protocol.

In this case, when the mobile terminal 110 moves and moves to the range 20 of the wireless network by AP2, the data transmitted from the mobile terminal 120 to the fixed terminal 130 is transmitted to the router 3 through the router 2 to the fixed terminal. 130 is reached (path A).

Herein, although the mobile terminals 110 and 120 are the same terminal apparatus, reference numbers will be described in order to identify a range of a wireless network due to movement.

On the other hand, since the fixed terminal 130 does not have the mobile information of the mobile terminal 120, the fixed terminal 130 transmits the data to the router 1 through the router 3, and the router 1 relays the data to the router 2 to the mobile terminal 120. The data is passed through (path B).

This routing method is called triangular routing.

Hereinafter, the triangular routing will be described in more detail.

In a wireless Internet environment, a mobile terminal is a mobile node (corresponding to mobile terminals 110 and 120 of FIG. 1), a network to which the mobile node is initially connected to a home network (corresponding to reference numeral 10 of FIG. 1), and a network to which the mobile node is initially connected. Router is called home agent (corresponding to router 1 of FIG. 1), and the router of the network to which the mobile node is moved is called an external agent (corresponding to router 2 of FIG. 1), and it is a server or host communicating with the mobile node. The terminal (corresponds to the fixed terminal 130 of FIG. 1).

The home agent exists in the mobile network of the mobile node and maintains the location information of the mobile node and transmits data to the node that is mobilely connected to the external network.

The foreign agent is responsible for transmitting data to the mobile node in cooperation with the home network in the external network that the mobile node is visiting.

When a mobile node moves from a home network to an external network, the mobile node makes a registration request to register with its external network.

The external agent receiving the registration request message announces its existence through the agent advertisement message.

The mobile node receives this agent advertisement message and determines if it is in the home network.

When it is determined by the agent discovery procedure that the mobile node is in an external network, the mobile node and the home agent register a care-of address (COA) with the home agent by exchanging a registration request and a registration response message.

If registration is successfully performed between the home agent and the mobile node, the datagram sent from the outside to the mobile node's home address is tunneled by the home agent to the mobile node's temporary address.

Tunneling can be configured in many ways, and basically the tunneling algorithm should provide the function of delivering using IP packet.

If a temporary address is specified as an external agent, the external agent takes care of it.

Datagrams sent from mobile nodes to external nodes are delivered to their destinations using standard IP routing methods without having to go through a home agent.

The transmission of data using the triangular routing method does not provide an optimized data transmission path between the mobile node and the counterpart communication terminal, and the traffic that the counterpart terminal sends to the mobile node passes through the home agent and thus the traffic is bypassed. have.

This bypass of traffic not only wastes network resources but can also cause congestion in the network, which adversely affects the network.

In addition, the home agent has a problem of managing information about the mobile node.

In order to solve the above-mentioned problem, an object of the present invention is to directly transmit data transmitted to a mobile node moving in a wireless Internet environment to a network to which the mobile node belongs without detouring to another network.

To this end, the routing method of the wireless Internet according to the present invention, in a method for routing for communication between the first terminal and the second terminal in the wireless Internet, the first terminal searches for a DHCP (Dynamic Host Configuration Protocol) server, Requesting information required for network configuration from the DHCP server, network configuration setting, address resolution protocol (ARP) request, and DNS (Domain Name System) server inquiry process are sequentially performed to communicate with the second terminal. The first process of doing; If the communication of the first process is disabled, a query for determining whether to change the wireless network according to the movement of the first terminal is performed by sequentially performing a query to the DNS server and a check process of the ARP performed in the first process. 2 courses; As a result of the second process, if the wireless network of the first terminal is changed, the first terminal requests a DHCP server for information necessary for network configuration, uses the information to set a network configuration, an ARP request, and a DNS server. A third step of resuming communication with the second terminal by sequentially performing an inquiry process; And a fourth process of searching for and discovering the DHCP server, and then performing the third process if the information is not transmitted from the DHCP server in the third process.

And a routing system of the wireless Internet according to the present invention, a plurality of routers for providing a data path between terminals using a protocol; A DHCP server that provides the terminal with network configuration information including an IP address so that the terminal accesses the Internet using the router; A DNS server for providing an IP address for the domain name of the Internet; An AP connected to the router to allow the terminal to wirelessly access the Internet; Connect to the router through the AP to perform wireless Internet communication. If the communication is not possible, query the DNS server and check ARP. If the DNS server query and ARP check fail, configure the network to the DHCP server. After setting up the network by requesting the information, resuming the communication by performing an ARP request and DNS server querying process. If the requested network configuration information is not transmitted to the DHCP server, the DHCP server is searched and the network server is found. And a mobile terminal for requesting network configuration information.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a network configuration diagram of a system implementing the wireless Internet routing method according to the present invention.

In the drawing, router 1, router 2, and router 3 are routers constituting the wired internet 230, and the fixed terminal 330 is a terminal device connected to the wired internet 230 and acts as a server or a host. And AP2 are connection devices for wirelessly accessing the Internet, and the mobile terminals 310 and 320 are terminal devices capable of wirelessly accessing and transmitting data.

In addition, the present invention includes a DNS server 335 for converting the Internet domain name into an IP address in order to find the location of the Internet domain name, and reference numerals 210 and 220 are wirelessly connected to the mobile terminals 310 and 320 by AP1 and AP2, respectively. This is the range of networks that can connect to the Internet.

The wired internet 230 serves as a backbone network for providing wireless internet.

The mobile terminal 310 communicates with the fixed terminal 330 on the wired internet 230, where router 1 transmits the user's data to the wired internet 230 when the mobile terminal 310 first communicates. Provide a routing path.

The fixed terminal 330 is a terminal device that the user can communicate using the Internet, such as a file server, a web server, and an e-mail server, or a terminal device of another Internet user, and router 3 is connected to the fixed terminal 330. Configure the network and provide a routing path for the fixed terminal 330.

Router 1 and Router 3 route between AS such as Autonomous System (AS) internal routing protocol such as Open Shortest Path First (OSPF) and Intermediate System-Intermediate System (ISI) and Border Gateway Protocol (BGP) to provide a routing path. By using a protocol, a data transmission path between the mobile terminal 310 and the fixed terminal 330 is provided.

In this case, when the user of the mobile terminal 310 moves to another area while using the Internet, and the mobile terminal 310 moves out of the range of 210 wireless network to the range of 220 wireless network, the router 2 is connected to the mobile terminal 320. ) Provides a routing path for delivering data in the range 220 of the new wireless network.

Herein, although the mobile terminals 310 and 320 are the same terminal apparatus, reference numbers are distinguished to identify ranges of wireless networks due to movement.

The mobile terminal 320 transmits data to the fixed terminal 330 through the router 2 and the router 3 (path C), and the fixed terminal 330 transmits the data to the mobile terminal 320 through the router 3 and the router 2. Pass (path D).

That is, in the present invention, even when the mobile terminal 320 moves, the fixed terminal 330 does not go through the router 1 used when communicating in the wireless network range 210 when transmitting data from the fixed terminal 330 to the mobile terminal 320. It provides two-way routing directly from Router 3 to Router 2.

3A and 3B illustrate a method of automatically setting bidirectional routing in a boundary area of a wireless network when a mobile terminal moves in a wireless Internet environment according to the present invention. This is a flow chart showing the process of communicating over the Internet.

3A and 3B will be described using an automatic setting method as a method for setting an address for network configuration of a mobile terminal.

First, when a user attempts to access the Internet using a mobile terminal, the mobile terminal searches for a DHCP server (not shown in FIG. 2) by transmitting a DHCP server discovery message to set a network configuration (S340).

At this time, if the mobile terminal does not find a DHCP server (S350), it fails to set the network configuration and thus cannot access the Internet (S360).

However, if the DHCP server is found (S350), the mobile terminal requests information necessary for network configuration from the DHCP server (S370), and receives information necessary for network configuration from the DHCP server (S380) and automatically sets the network configuration (S390). .

The information required to configure the network includes the IP address for identifying the mobile terminal in the network, the subnet mask indicating the network range, the IP address of the router to which the mobile terminal will send data, and the address of the DNS server for identifying the counterpart terminal by name. And the like.

When all the network configurations are set, the mobile terminal requests an ARP to match the IP address assigned to the mobile terminal with the physical network address of the mobile terminal (here, a MAC (Media Access Control) address) (S400).

When the response to the ARP is transmitted and the IP address and the physical network address correspond (S410), the mobile terminal queries the DNS server to find out the IP address of the counterpart terminal with which the communication is to be performed (S420).

When the IP address of the other terminal is transmitted in response to the DNS server (S430), the mobile terminal communicates with the other terminal using the transmitted IP address of the other terminal (S440).

However, if there is no response from the DNS server (S430), communication is repeatedly attempted from the above-described ARP request process (S400).

On the other hand, during the process, by requesting the information necessary for the network configuration to the DHCP server (S370) does not receive the information necessary for the network configuration from the DHCP server (S380) or if the response to the ARP request (S400) is not transmitted (S410) ), The network configuration of the mobile terminal is not set and internet access is impossible (S360).

In addition, the normal reception of the response to the ARP request in step S410 described above means that the local network to which the mobile terminal belongs normally operates.

Referring to FIG. 2, router 1 constituting network 210 is composed of three local networks, that is, a network to which router 1 and router 2 are connected, a network to which router 1 and router 3 are connected, and router 1. This is the network to which AP1 is connected.

If the response to the ARP request is not received in step S410 described above, it means that the local network does not operate normally, and also includes a case where a problem occurs in the local network of Router 1 and AP1.

When the network setting is completed as the DHCP server and the ARP as described above, if there is no response from the DNS server in the above-described S430 process, this is a case in which the communication with the DNS server 335 is not performed at Router 1 of FIG. 2. The reason for this is that router 1 does not have a routing path to DNS server 335 or a failure of DNS server 335 does not perform a normal function.

By the above-described process, the mobile terminal communicates with the counterpart terminal, and when communication is not performed during the communication (S450), a change of the network capable of wireless connection (hereinafter, the mobile terminal is changed from the network 210 to the 220 in FIG. 2). The following process is performed to determine whether or not communication is disabled according to the case of moving).

If the mobile terminal does not communicate during the communication, the mobile terminal queries the DNS server to find out the IP address of the counterpart terminal that was communicating first (S460).

In this case, the DNS server queried by the mobile terminal is the DNS server queried in step S420 described above, and if there is a response from the DNS server, it means that the mobile terminal is still located in the network 210 without changing the network.

However, if there is no response from the DNS server, this means that there is no routing path to the DNS server 335 in Router 1 without a network change of the mobile terminal in FIG. 2 or the failure of the DNS server 335 or the mobile terminal moves. In this case, the network is changed from 210 to 220 and does not match the configuration of the network 210 set in the above-described S390 process.

Accordingly, when a response is transmitted from the DNS server (S470), the mobile terminal communicates again with the counterpart terminal according to the configuration of the network previously set in step S390 (S440). If the response is not transmitted, the mobile terminal returns to the above-described steps S400 and S410. In order to check the corresponding IP address and the physical network address again, ARP is required (S480).

If there is an ARP response, this means that there is no routing path to the DNS server 335 in Router 1 or the local network is operating normally because there is no change in the network even if the DNS server 335 fails. The local network operates because the IP address corresponding to the physical network address of the mobile terminal is stored by the temporary storage function of the mobile terminal even though the configuration is changed to 220 and does not match the configuration of the network 210 set in the above-described step S390.

On the other hand, if there is no ARP response, this means that even if there is no change in the network, router 1 does not have a routing path to DNS server 335 or DNS server 335 fails, causing DNS server not to respond and AP1 to fail. In this case, the local network to which the AP1 is connected also does not operate, or the network is changed from 210 to 220 and does not match the configuration of the network 210 set up in the above-mentioned S390 process. This is a case where there is no ARP response because the local network setting is not made because the network setting of is not made.

If there is an ARP response (S490), the communication with the counterpart terminal is performed according to the configuration of the network previously set in step S390 (S440). If there is no ARP response, the mobile terminal requests information required for network configuration from the DHCP server (S500). ).

The reason why the mobile terminal requests the DHCP server for information necessary for network configuration is that the absence of both the DNS server response and the ARP response during communication is due to the change of the network capable of wireless connection, and thus the configuration of the network is reset. .

As described above, when it is determined that the cause of the inability to communicate is due to the change of the network that is wirelessly accessible, the DHCP server requests information necessary for network configuration to reset the network configuration. In this case, the present invention provides the above-described S340 to S390. If the DHCP server is found after searching for a DHCP server as shown in the above procedure, it does not request information necessary for network configuration, but skips the discovery process of the DHCP server and immediately requests the DHCP server for information necessary for network configuration. This is a method for reducing the time of communication inactivity by reducing the execution process.

However, if it does not receive the information necessary for network configuration from the DHCP server, it will start again from the process of searching for the DHCP server.

In detail, if there is no response of the ARP requested in step S480 described above (S490), the mobile terminal requests information required for network configuration from the DHCP server (S500).

At this time, since the mobile terminal does not have an IP address set, its source address is set to 0.0.0.0, and a destination address for designating a DHCP server is set to 255.255.255.255.

When the mobile terminal receives the information necessary for the network configuration from the DHCP server (S510), the mobile terminal automatically sets the network configuration (S520), and resumes the communication by the steps S530 to S570 as in the above-described steps S400 to S440.

However, if the information necessary for network configuration is not received from the DHCP server (S510), the first time of accessing the wireless access network, the DHCP server is searched (S580), as in the above-described S340 process, and the DHCP server is found and the above-mentioned S500 process is repeated again. To set up the network and resume communication.

In this case, since the IP address is not set, the mobile station sends a DHCP server discovery message with its source address set to 0.0.0.0 and the destination address for specifying a DHCP server set to 255.255.255.255.

As described above, the mobile terminal can continuously communicate with each other even if the mobile terminal moves through the wirelessly accessible network according to the process described with reference to FIGS. 3A and 3B.

3A and 3B illustrate two-way routing according to one wireless network change when the first mobile terminal accesses the wireless Internet environment, but S450 to S590 described above are described even if the mobile network continuously changes due to the movement of the mobile terminal. By repeating the process, communication can be continued by performing bidirectional routing continuously.

FIG. 4 shows the results of an empirical test for automatically setting bidirectional routing in accordance with the present invention in the boundary region of a wirelessly accessible network as the mobile terminal moves through FIGS. 3A and 3B.

Referring to the drawings, when a mobile terminal is initially connected to the Internet, the mobile terminal is set to an IP address of 203.255.252.103 to communicate with a fixed terminal of krwww.yahoo.co.kr. Since the IP address of the mobile terminal is set to 147.6.75.103, it communicates with the fixed terminal again using the IP address of 147.6.75.103.

More specifically, No. 148 indicates that the mobile terminal transmits data to the fixed terminal of krwww.yahoo.co.kr with an IP address of 203.255.252.103, and No. 149 indicates that the fixed terminal has an IP address of 203.255.252.103. Indicates that data is transmitted to the mobile terminal set to.

However, due to the characteristics of the mobile terminal, the mobile terminal transmits data to the fixed terminal in No. 150, but the fixed terminal cannot transmit data to the mobile terminal and the IP address of the mobile terminal is changed to 147.6.75.103. In the case where the mobile terminal transmits data to the fixed terminal using the changed IP address, in step 191, the fixed terminal transmits data to the mobile terminal having the changed IP address.

That is, from No. 160 to No. 189, the mobile terminal changes the range of the wireless network as the mobile device moves to check whether the communication area is changed.

This will be described in more detail as follows.

No. 161 is step S460 of FIG. 3A for checking the coverage area, and indicates that the mobile terminal queries the DNS server.

No. 162, No. 164, and No. 166 show that the ARP request process of Fig. 3A S480 is performed because there is no response from the DNS server for the content requested in No. 161.

No. 168 shows the process of requesting the network configuration information to the DHCP server in step S500 of FIG. 3B without ARP response to the contents requested by Nos. 162, No. 164, and No. 166. In response to this, there is no response from the DHCP server, and No. 177 shows a process of delivering a DHCP server discovery message to find a DHCP server according to S580 of FIG. 3B.

And No. 178 indicates that the DHCP server was found by the DHCP server discovery message of No. 177, and No. 179 indicates that the request for configuration information of the network to the DHCP server, as in the S500 process of Fig. 3b, No. 180 indicates that the new IP address of the mobile terminal is automatically set in response to the DHCP server.

The IP address of the mobile terminal set at this time is 147.6.75.103, and the subnet mask necessary for the configuration of the network, the IP address of the router to which the terminal transmits data, and the address of the DNS server are also set.

The mobile terminal performs an ARP request in Nos. 182 to 189 to correspond to the IP address assigned to the mobile terminal with the physical network address of the mobile terminal (corresponding to S530 and S540 in FIG. 3B).

On the other hand, Figure 4 shows that the mobile terminal knows the IP address of the fixed terminal by the temporary storage function, and S550 of FIG. 3b is omitted. On the other hand, if the mobile terminal does not provide a temporary storage function for the communication counterpart, Figure 3b. S550 process should be performed.

No. 190 and No. 191 represent a state in which communication is resumed as in step S570 of FIG. 3B, and it can be seen that a mobile terminal set to an IP address of 147.6.75.103 exchanges data with a fixed terminal.

5 shows a state in which a fixed terminal of krwww.yahoo.co.kr continues to communicate with the mobile terminal as the IP address changes due to the movement of the mobile terminal.

As described above, the present invention has the effect of reducing traffic because the traffic does not bypass the previous network when the range of the wireless network according to the movement of the mobile terminal is changed, the speed of communication because the data is transmitted through the optimal path Has the effect of improving.

1 is a network diagram of a system implementing a conventional wireless Internet routing method.

2 is a network diagram of a system for implementing a method for routing wireless Internet according to the present invention;

3A and 3B are flow charts of a routing method of the wireless Internet according to the present invention.

4 is an exemplary view illustrating a process of automatically setting routing according to movement of a mobile terminal according to a routing method according to the present invention.

5 is an exemplary view of a communication result according to movement of a mobile terminal by a routing method according to the present invention;

Claims (6)

In the method for routing for communication between the first terminal and the second terminal in the wireless Internet, The first terminal sequentially searches for a DHCP server, requests the DHCP server for information necessary for network configuration, performs a network configuration setting, an ARP request, and a DNS server query process using the information in order to communicate with the second terminal. The first process of doing; If the communication of the first process is disabled, a query for determining whether to change the wireless network according to the movement of the first terminal is performed by sequentially performing a query to the DNS server and a check process of the ARP performed in the first process. 2 courses; As a result of the second process, if the wireless network of the first terminal is changed, the first terminal requests a DHCP server for information necessary for network configuration, uses the information to set a network configuration, an ARP request, and a DNS server. A third step of resuming communication with the second terminal by sequentially performing an inquiry process; And And if the information is not transmitted from the DHCP server in the third process, searching and finding the DHCP server, and thereafter, performing a third process. The method of claim 1, Information necessary for the network configuration, The wireless network includes an IP address for identifying the first terminal in the network, a subnet mask indicating the network range, an IP address of a router to which the first terminal transmits data, and an address of the DNS server. Routing method of the Internet. The method of claim 2, The first process, A first step of the first terminal searching for the DHCP server; A second step of, if the DHCP server is found, requesting, by the first terminal, information necessary for configuration of a network from the DHCP server; A third step of setting, by the first terminal, a network configuration using the information when the information is transmitted from the DHCP server; A fourth step in which the first terminal requires the ARP; A fifth step of querying, by the first terminal, the DNS server if there is a response to the ARP request; And And a sixth step of communicating if there is a response from the DNS server. The method of claim 3, wherein The second process, A first step of querying the DNS server if communication of the first process is disabled; A second step of checking an ARP performed in the first step if there is no response from the DNS server; And And a third step of determining whether the ARP responds as a result of the checking of the ARP. The method according to any one of claims 1 to 4, The third process, A first step of requesting, by the first terminal, information necessary for network configuration from the DHCP server; A second step of setting, by the first terminal, a network configuration using the information when the information is transmitted from the DHCP server; A third step in which the first terminal requires the ARP; A fourth step of the first terminal querying the DNS server if there is a response to the ARP request; And And a fifth step of resuming the communication if there is a response from the DNS server. A plurality of routers providing a data path between terminals using a protocol; A DHCP server that provides the terminal with network configuration information including an IP address so that the terminal accesses the Internet using the router; A DNS server for providing an IP address for the domain name of the Internet; An AP connected to the router to allow the terminal to wirelessly access the Internet; Connect to the router through the AP to perform wireless Internet communication. If the communication is not possible, query the DNS server and check ARP. If the DNS server query and ARP check fail, configure the network to the DHCP server. After setting up the network by requesting the information, resuming the communication by performing an ARP request and DNS server query process, and searching the DHCP server if the network configuration information is not transmitted to the DHCP server, And a mobile terminal for requesting network configuration information.