KR20120008354A - Method for configuring mbile termainal as gateway in wireless network - Google Patents

Abstract

PURPOSE: A method for setting up a mobile terminal as a gateway in a wireless communication network is provided to automatically set up a mobile terminal in order to be operated in a proper gateway. CONSTITUTION: A mobile terminal senses the connection of an external network. The mobile terminal is converted into a gateway terminal(S310). The mobile terminal obtains network configuration information of the external network. The mobile terminal transmits configuration information to the base station(S320). The mobile terminal stops the role of the gateway terminal(S330).

Description

Method for configuring mbile termainal as gateway in wireless network}

According to the present invention, when a mobile terminal belonging to the wireless network is connected to an external network in a wireless network in which the mobile terminal is free to move, the mobile terminal functions as a gateway and is switched to a general mobile terminal when the connection with the external network is lost. To set up the network configuration by automatically detecting changes that are added or removed.

In general, when a specific node including a mobile terminal joins a network, the subscription configuration can be divided into a manual configuration method and an automatic configuration method. In the manual configuration method, the user of the node is given an IP (Internet Protocol) address according to the policy of the subscribing network, and is notified of information such as a subnet mask, a gateway, and a domain name system (DNS) server address. The automatic configuration method is a method in which a node sets itself a network by being notified of an IP address, a subnet mask, a gateway, and a DNS server address from a DHCP (Dynamic Host Configuration Protocol) server as shown in FIG. 1.

That is, when the terminal 110 transmits a DHCPDISCOVER broadcast packet to the DHCP server 120 (step S110), the DHCP server 120 transmits a DHCPOFFER packet including information on available IP addresses that can be provided to the terminal. (Step S120). Next, the terminal 110 transmits a DHCPREQUEST packet requesting to allocate an IP address (step S130). Upon receiving this, the DHCP server transmits a DHCPPACK packet including the IP information allocated to the terminal (step S140). If an extension is necessary before the address allocation expires while performing data transmission / reception using the allocated IP address, an extension request is made to the DHCP server (S150). If the extension is recognized, DHCP server 120 transmits an ACK packet for the extension approval (S160).

In this way, the conventional technology is generally a method designed on the basis of a wired network, which is a method suitable for a situation in which a configuration change of the network hardly occurs, and there is a problem that it is not suitable for a wireless network in which nodes can be moved.

For example, in a network whose configuration changes frequently, such as an ad-hoc network, the network configuration is continuously changed, such as adding or removing gateway nodes connected to other networks. In this case, the manual setting method may not reflect the network setting change in a timely manner, which may cause a network disconnection problem. In addition, since the DHCP protocol does not define an operation for detecting a change in network configuration, the automatic configuration method has a problem that a DHCP server cannot deliver accurate network information to a client.

The technical problem to be achieved by the present invention is to solve the above problems, in the wireless network is constantly changing configuration by allowing the mobile terminal to automatically set to operate as an appropriate gateway, it is possible to maintain a stable connection with the external network To provide a way.

In order to achieve the above technical problem, a method for setting a mobile terminal as a gateway in a wireless network according to the present invention is to set a gateway in a network consisting of a base station, a mobile terminal wirelessly connected to the base station, and an external network to which the mobile terminal is accessible. The method of claim 1, further comprising: switching to a gateway terminal when the mobile terminal detects a connection with the external network; Acquiring, by the mobile terminal, network configuration information of the external network periodically and transmitting it to the base station; And when the mobile terminal is disconnected from the external network, stopping the role of the gateway terminal.

Preferably, the network configuration information of the external network includes an address of the gateway terminal, an address of mobile terminals constituting the external network, a hop from the base station to the gateway terminal, and hops to the mobile terminals. It is characterized by including.

Preferably, the external network is characterized in that the ad hoc network.

In order to achieve the above technical problem, a method for setting a mobile terminal as a gateway in a wireless network according to the present invention is to set a gateway in a network consisting of a base station, a mobile terminal wirelessly connected to the base station, and an external network to which the mobile terminal is accessible. The method of claim 1, further comprising: switching to a gateway terminal when the mobile terminal detects a connection with the external network; Periodically broadcasting, by the gateway terminal, gateway configuration information including connection information with a base station to the external network; Updating, by mobile terminals in the external network, their data connection information based on the gateway configuration information; And stopping the role of the gateway terminal when the connection with the external network is disconnected.

Preferably, the gateway setting information includes an address of the gateway terminal, an address of a base station to which the gateway terminal is connected, and hop information to the base station.

Preferably, in the updating of the own data connection information, when the mobile terminal in the external network has no information on the gateway terminal, the mobile terminal in the external network is initially configured based on the gateway configuration information, and is configured for another gateway terminal. If present, the gateway terminal according to the gateway setting information is added.

In order to achieve the above technical problem, a method of setting a mobile terminal as a gateway in a wireless network according to the present invention includes a mobile terminal connected to a base station wirelessly with an external network to perform a gateway function to a first external network. A method for searching a gateway by a first mobile terminal when a mobile terminal enters a new terminal, the method comprising: broadcasting a discovery message for searching for a gateway terminal by the first mobile terminal; Transmitting, by the gateway terminal, a response message in response to the discovery message; And updating, by the first mobile terminal, the gateway setting based on the response message.

Preferably, the discovery message is characterized in that it comprises a field containing the content of the address of the first mobile terminal, the address of the gateway terminal.

Preferably, the response message is characterized in that it comprises a field containing the address of the gateway terminal, the address of the first mobile terminal, the content confirming that the gateway is a gateway that the first mobile terminal searches.

Preferably, the gateway terminal is connected to the base station by one hop distance.

As described above, according to the method of setting a mobile terminal as a gateway in a wireless network according to the present invention, even if the gateway is changed due to a change in the network to which the mobile terminal accesses, the network configuration is automatically changed to be used as another network. Can be linked seamlessly.

FIG. 1 is a diagram illustrating a process of configuring a network by a node by itself notified by a Dynamic Host Configuration Protocol (DHCP) server.
2 is a diagram illustrating an example of a network to which a method for setting a mobile terminal as a gateway in a wireless network according to the present invention is applied.
3 is a flowchart illustrating a process of performing communication with a base station after switching a mode to a gateway in a method for setting a mobile terminal as a gateway in a wireless network according to the present invention.
4 is a flowchart illustrating the process of FIG. 3 in more detail.
5 is a flowchart illustrating a process of performing communication with mobile terminals of an external network after mode switching to a gateway in a method for setting a mobile terminal as a gateway in a wireless network according to the present invention.
6 is a flowchart illustrating the process of FIG. 5 in more detail.
7 is a flowchart illustrating a process of finding and responding to a gateway when a mobile terminal newly enters an external network in a method for setting a mobile terminal as a gateway in a wireless network according to the present invention.
8 is a flowchart clearly showing the process of FIG. 7.
FIG. 9A illustrates an example of a data frame when the mobile station sends configuration information of an external network to a base station in FIG. 3.
FIG. 9B is a diagram illustrating an example of a data frame in which a mobile station informs information to mobile terminals of an external network in FIG. 5.
FIG. 9C is a diagram illustrating an example of a data frame transmitted by a newly entered mobile terminal to find a gateway in FIG. 7.
FIG. 9D is a diagram illustrating an example of a data frame transmitted by a gateway terminal to a newly entered mobile terminal in FIG. 7.

Hereinafter, a method of setting a mobile terminal as a gateway in a wireless network according to the present invention will be described in detail with reference to the accompanying drawings. However, terms and technical details that can be understood by anyone having ordinary skill in the art will be omitted.

2 is a diagram illustrating an example of a network to which a method for setting a mobile terminal as a gateway in a wireless network according to the present invention is applied. 3 is a flowchart illustrating a process of performing communication with a base station after switching a mode to a gateway in a method of setting a mobile terminal as a gateway in a wireless network according to the present invention, and FIG. 4 illustrates the process of FIG. 3 in more detail. A flow chart is shown. 5 is a flowchart illustrating a process of performing communication with mobile terminals of an external network after switching to a gateway in a method of setting a mobile terminal as a gateway in a wireless network according to the present invention, and FIG. A flow chart showing the process in more detail. 7 is a flowchart illustrating a process of finding and responding to a gateway when a new terminal enters an external network in a method of setting a mobile terminal as a gateway in a wireless network according to the present invention, and FIG. 8 is easily understood by the process of FIG. A flow chart is shown. Finally, FIG. 9A is a diagram illustrating an example of a data frame when the mobile terminal sends configuration information of an external network to the base station in FIG. 3, and FIG. 9B is a mobile terminal of the external network in FIG. 5. FIG. 9C is a diagram illustrating an example of a data frame informing information. FIG. 9C is a diagram illustrating an example of a data frame transmitted by a mobile terminal newly entering to find a gateway. FIG. 9D is a diagram of FIG. 7. FIG. Is a diagram illustrating an example of a data frame transmitted by a gateway terminal to a newly entered mobile terminal.

First, reference is made to FIG. 2. The present invention consists of terminals 233, 235 and 237 included in a network (here, ad hoc network), a gateway terminal 231 for interworking with an external network, and a base station 215 for managing a 1-hop network. In this case, the base station 215 and the terminals 231, 233, 235, 237 preferably have the ability to support two or more types of networks and the ability to perform a function as a gateway terminal as well as a function as a general terminal.

That is, the network considered in the present invention is the 1-hop wireless network 210 in which the base station 215 exists, the ad hoc network 230 in which the base station does not exist, and for example, the gateway terminal 231 in the case shown in FIG. If the 1) belongs to the 1-hop network and enters the ad hoc network 230, it functions as a gateway, and this configuration allows the terminals and the base stations belonging to the ad hoc network 230 to communicate with each other.

Under the same network configuration as that of FIG. 2, a preferred embodiment of the present invention will be described with reference to FIGS. 3 to 9D. In the case of the 1-hop wireless network 210 in which the base station exists, the case where the base station is interworked with other networks is generally defined in the corresponding network, and thus is considered to be outside the scope of the present invention. However, if the mobile terminal is interworked with another network, it must be propagated to the base station to support smooth inter-network interworking. To this end, the base station and the mobile terminal operates as follows. First, a case in which the mobile terminal 231 detects a connection with an adjacent external network (hereinafter, used in the same sense as an ad hoc network) will be described. First, when the mobile terminal 231 detects the connection with the external network, the mobile terminal 231 performs only the function of the general mobile terminal and then switches to the gateway terminal (step S310). In this state, network configuration information of the external network, that is, the ad hoc network 230, for example, information such as the number or address of mobile terminals constituting the ad hoc network is periodically acquired and transmitted to the base station 215. Here, an example of a method of periodically obtaining information will be described. The method of periodically acquiring the information is one of the routing algorithms of a general ad hoc network. That is, the network composed of general terminals in FIG. 2 has a routing table between terminals while a routing protocol operates. Routing protocols send and receive routing messages on a periodic or event basis, depending on which one you choose. For example, a routing protocol such as AODV (Ad-hoc On-demnad Distance Vector) periodically transmits a routing message in order to detect a change in the network, and determines the number of terminals in the network and a routing path to the corresponding terminal. Figure out. When the mobile terminal communicating with the base station operates as a gateway terminal, the ad hoc routing protocol operates, thereby acquiring periodic information.

The base station may use this information to send traffic to the mobile terminal in the ad hoc network (step S320). Now, when the mobile terminal 231 operating as a gateway is disconnected from the external network, the mobile terminal 231 stops the role of the gateway terminal and switches the function to the original mobile terminal (S330).

With reference to Figure 4 will be described in more detail.

When the mobile terminal communicating with the base station in the 1-hop network 210 enters into the area of the ad hoc network 230 as an external network and detects it (step S410), it switches the function as a terminal performing a gateway function (S415). step). After determining the network configuration of the connected external network, that is, the ad hoc network (step S420), the information is transmitted to the base station in the form of data shown in FIG. 9A (step S425). Here, grasping the network configuration refers to grasping the number of terminals constituting the network, routing paths between the terminals, and the like through the general operation of the ad hoc routing protocol, and the technical contents are generally known in the art. Anyone who understands the contents can understand, so the detailed description is omitted.

Referring to FIG. 9A, the gateway terminal, that is, the address of the mobile terminal 231 which has switched functions as a gateway, the destination to which the base station should send data, that is, the address 915 of the mobile terminal in the ad hoc network, from the base station to the gateway terminal Hop number 920 and hop number 925 to the mobile terminal as a destination. In the example of Fig. 2, the hops to the gateway are all 1, the number of hops to the general terminal 1 233 as the destination is 1, the number of hops to the general terminal 2 235 is 2, and the general terminal 3 to 237. Hop count is three. Therefore, the total number of hops from the base station to the general terminal 1 is 2, the total number of hops to the general terminal 2 is 3, and the total number of hops to the general terminal 3 is 4.

The base station adds this information as its terminal information to its database and updates its routing table because it must transmit data to the mobile terminal in the ad hoc network (step S430).

In this state, the terminal 231 performing the gateway function waits for a predetermined time as long as it does not leave the ad hoc network, that is, periodically for a predetermined time (step S440), and continuously identifies the configuration information of the ad hoc network (step S440). This informs the base station (step S450). The base station updates the routing table based on the information. That is, when the mobile terminal in the ad hoc network is separated or added, the routing table is updated accordingly (step S455).

If the terminal 231 performing the gateway function is disconnected from the external network, that is, the ad hoc network (step S460), the terminal 231 does not need to perform the connection function with the ad hoc network. (Step S465). The base station deletes the information on the terminal switched to the normal terminal and updates the routing table corresponding thereto (step S470). The terminal that performed the gateway function now performs only the function as a general terminal which performs only communication with the base station (step S475).

5, 6, and 9B, a process of communicating with mobile terminals in an external network, that is, an ad hoc network, after switching modes to a gateway will be described. First, when the mobile terminal detects a connection with an external network, switching to the gateway terminal (step S510) is the same as described above. The mobile terminal 231 performing the function switching to the gateway periodically broadcasts gateway setting information including connection information with the base station to the external network (S520). The mobile terminals 233, 235 and 237 in the external network update their own data connection information, such as which gateway terminal the gateway terminal is based on, and thus which gateway should be selected when transmitting and receiving data (S530). ). In this state, when the connection with the external network is disconnected, the gateway terminal 231 stops the role of the gateway terminal and performs a function as a general terminal (S540).

See FIG. 6 and FIG. 9B. When the mobile terminal communicating with the base station in the 1-hop network 210 enters into the area of the ad hoc network 230 which is an external network and detects it (step S610), the mobile station performs a function switching as a terminal performing a gateway function (S615). step). After determining the network configuration of the connected external network, that is, the ad hoc network (step S620), the information is transmitted to the mobile terminals 233, 235 and 237 in the ad hoc in the form of data shown in FIG. 9B. Since broadcasting is to be expressed in the drawing (S630). Referring to FIG. 9B, an address 930 of a mobile station 231 that has changed its function as a gateway, a destination to which data are to be transmitted by mobile stations in an ad hoc network, that is, an address 935 of a base station, from a gateway terminal. Hop number 940 to the destination, i.e., the base station.

The mobile terminals 233, 235 and 237 update the gateway setting information in their database based on the information (step S635).

In this state, the terminal 231 performing the gateway function waits for a predetermined time as long as it does not leave the ad hoc network, that is, periodically for a predetermined time (step S640), and continuously identifies the configuration information of the ad hoc network (step S645). , And continuously informs the mobile terminals (step S650). The mobile terminals continue to update the gateway setting information based on the information (step S655).

If the terminal 231 performing the gateway function is disconnected from the external network, that is, the ad hoc network (step S670), since the terminal 231 does not need to perform the connection function with the ad hoc network, the terminal 231 switches to a normal terminal and informs the base station of the fact. (Step S675). In addition, by notifying the general terminals in the ad hoc to stop their gateway function execution, the mobile terminals update the gateway setting information based on this (step S680).

Now, the terminal that performed the gateway function performs only the function as a general terminal that performs only communication with the base station (S685).

7, 8, 9c, and 9d, a process of finding and responding to a gateway when a mobile terminal newly enters an external network will be described.

It is assumed that the mobile terminal 231 wirelessly connected to the base station 215 accesses the external network to the external network 230 in a network that performs a gateway function. Since a newly entered mobile terminal needs to have configuration information on the gateway terminal, a process as shown in FIGS. 7 and 8 should be performed.

First, the newly entered mobile terminal (step S710) broadcasts a discovery message for finding a gateway into the ad hoc network (step S720). The mobile terminal 213 performing the gateway function transmits a response message that it is a gateway in response to the discovery message transmitted by the newly entered mobile terminal (step S730). Accordingly, the newly entered mobile terminal updates the gateway configuration based on the response message (step S740).

See FIG. 8. In FIG. 8, it is assumed that the general terminals MT1 and 233 are newly entered mobile terminals. This mobile terminal 233 broadcasts a discovery message that it finds a gateway with data in the format shown in FIG. 9C. That is, the address 950 and the destination are not specified because they are broadcasted (955), and broadcasts including a field 960 containing the contents of the message asking for the gateway address (step S810).

When the gateway terminal 213 receives the discovery message, the gateway terminal 213 informs itself that the gateway is the data of the format shown in FIG. 9D (step S820). As shown, the address 970 of the gateway as a starting address, the address of the destination here is a gateway searched by the address 975 of the mobile terminal 1 233 and the mobile terminal 233 to which the user has newly entered. It includes a field 980 containing the contents to confirm.

Upon receipt of the response message, the newly entered mobile terminal updates the gateway configuration based on the response message (step S830).

On the other hand, when there are a plurality of gateway terminals connected to the same network, it is preferable that the general terminal selects a gateway terminal most suitable for data transmission under conditions such as better transmission status or a smaller hop number.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

The method of the present invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission via the Internet) . The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

Claims (10)

In a method for setting a gateway in a network consisting of a base station, a mobile terminal wirelessly connected to the base station, and an external network to which the mobile terminal is accessible,
Switching to a gateway terminal when the mobile terminal detects a connection with the external network;
Acquiring, by the mobile terminal, network configuration information of the external network periodically and transmitting it to the base station; And
And stopping the role of the gateway terminal as a gateway terminal when the mobile terminal is disconnected from the external network. The network configuration information of claim 1, wherein
A mobile station in a wireless network comprising an address of the gateway terminal, an address of mobile terminals constituting the external network, a hop number from the base station to the gateway terminal, and a hop number to the mobile terminals To set up as a gateway. The method of claim 1, wherein the external network is an ad hoc network. In a method for setting a gateway in a network consisting of a base station, a mobile terminal wirelessly connected to the base station, and an external network to which the mobile terminal is accessible,
Switching to a gateway terminal when the mobile terminal detects a connection with the external network;
Periodically broadcasting, by the gateway terminal, gateway configuration information including connection information with a base station to the external network;
Updating, by mobile terminals in the external network, their data connection information based on the gateway configuration information; And
And stopping the role of the gateway terminal when the connection with the external network is disconnected. The method of claim 4, wherein the gateway setting information is
And a hop address to the base station, the address of the gateway terminal, the address of the base station to which the gateway terminal is connected, and a mobile terminal as a gateway. The method of claim 4, wherein the updating of the own data connection information is performed.
When the mobile terminal in the external network has no information on the gateway terminal, the mobile terminal initially makes the setting based on the gateway setting information.
If there is a setting for another gateway terminal, a method for setting a mobile terminal as a gateway in a wireless network, characterized in that for adding the gateway terminal according to the gateway setting information. In a method in which a first mobile terminal searches for a gateway when a first mobile terminal newly enters the external network from a network in which a mobile terminal connected to a base station wirelessly connects to an external network and performs a gateway terminal function,
Broadcasting, by the first mobile terminal, a discovery message for finding a gateway terminal;
Transmitting, by the gateway terminal, a response message in response to the discovery message; And
And updating, by the first mobile terminal, the gateway setting based on the response message. 8. The method of claim 7, wherein the discovery message is
And a field containing contents of asking for the address of the first mobile terminal and the address of the gateway terminal. The method of claim 7, wherein the response message is
The mobile terminal is set as a gateway in a wireless network, comprising a field containing the address of the gateway, the address of the first mobile terminal, and the gateway terminal confirming that the first mobile terminal is a gateway for searching. How to. 10. The method according to any one of claims 1 to 9, wherein the gateway terminal is connected to the base station at a hop distance.

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