KR20090062277A - Mesh network system, client node, communication method for mesh node and client node - Google Patents

Abstract

A mesh network system, a client node, a communication method in a mesh node of the mesh network system and a communication method in the client node are provided to offer the mobility to the client node easily and efficiently. Each client node(200) transmits only its own packet. The client nodes transmit packets to a mesh node(100) without re-transmitting them to other middle client nodes. The mesh node is directly connected with the other mesh node. The client nodes do not perform the relay. Therefore, the mesh nodes perform communication with other mesh nodes and can transmit packets to a destination client node.

Description

Communication method in mesh network system, client node, mesh node of mesh network system, communication method in client node {MESH NETWORK SYSTEM, CLIENT NODE, COMMUNICATION METHOD FOR MESH NODE AND CLIENT NODE}

The present invention provides a mesh network system, a client node connected to a mesh network backbone network to communicate with a neighboring mesh node, a communication method of a mesh node of a mesh network system, and a communication of a client node connected to a mesh network backbone network to communicate with a neighboring mesh node. It is about a method.

A wireless mesh network is a technology in which each mesh node (or AP) retransmits packets of other node tombs like a wired router so that the entire mesh node forms a network. A simple example is a system that delivers packets through a network of access points that are wirelessly connected to each other instead of wired access points to the Internet.

The range of use of such a wireless mesh network is very diverse, such as home, local area network, metropolitan network, etc. The biggest advantage is that it can provide high quality network service at low cost for backbone network construction.

A wireless mesh network is similar to a traditional AD-HOC network, but is a special type of ad hoc network, where each mesh node is always on, mobile, and mobile with no phase limitations. It will be a network. There are various ad hoc routing schemes proposed in the existing wireless environment based on the existing wireless environment.

As 802.11 WLAN networks become more common today, pilot services using 802.11 based wireless mesh networks are being proposed and installed. Wireless mesh networks offer the convenience of installation without the need for line work and the power supply, and the high speed of 802.11.

Therefore, various services can be provided by using a wireless mesh backbone network in a rural or mountainous area where wires cannot enter, and the client node may be wirelessly connected to the mesh network, thereby supporting mobility of the client node. Many services are raised.

The basic method for providing client node mobility is by using mobile IP. The client node may be given a home address IP address in its home network and recognize its home agent.

Thereafter, each time the client node moves over the network to get a new IP address (Care of Address), it registers the newly obtained address with its home agent. The home agent may retransmit the packet by intercepting the packet transmitted to the client node's home address and tunneling to the registered IP address of the registered client node.

If the above-described method of using mobile IP is used in a wireless mesh network, a separate protocol for adding a home agent to the network or tracking the location of the client node should be prepared.

Therefore, the technical problem to be achieved by the present invention is to provide a technology that can easily provide mobility in the wireless mesh network without the addition of additional equipment or protocol.

Mesh network system according to an embodiment of the present invention for achieving the above technical problem, to check the link quality with the neighbor node by transmitting a first hello message to the neighbor mesh node and the client node, the next mesh node on the packet forwarding path Or it may include a mesh node for transmitting the packet to the client node.

In addition, the client node according to an embodiment of the present invention for achieving the above technical problem is a client node connecting to the mesh network backbone network and communicating with the neighbor mesh node, and transmits a second hello message to link with the neighbor mesh node. It may include a second link status check unit for measuring the quality and notifying the mesh node of its existence, receiving a packet from the mesh node, or transmitting the packet to the next mesh node in the packet forwarding path.

In addition, a method for communicating a mesh node of a mesh network system according to an embodiment of the present invention for achieving the above technical problem, a) by sending a first hello message to the neighboring mesh node and the client node to improve the link quality with the neighboring node; Measuring; And b) transmitting the packet to the next mesh node or client node in the packet delivery path.

In addition, a communication method in a client node according to an embodiment of the present invention for achieving the above technical problem is a communication method of a client node connected to a mesh network backbone network and communicating with a neighboring mesh node, a) a second hello message Measuring a link quality with a neighboring mesh node by transmitting a; And b) receiving the packet from the mesh node or transmitting the packet to the next mesh node in the packet forwarding path.

As described above, according to the present invention, a client node using a mesh network as a backbone can provide mobility of the client node without degrading the performance of the mesh network and without burdening the routing protocol of the mesh network.

In addition, according to the present invention, it is possible to simply support the mobility of the client node without adding a new protocol or adding new equipment in the mesh network.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

When a part of the specification is to "include" any component, this means that it can further include other components, except to exclude other components unless otherwise stated. In addition, the terms ".. part" ".. group" "module", etc. described in the specification mean a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software.

Now with reference to the drawings with reference to the embodiment of the present invention will be described in detail.

1 is a diagram illustrating a configuration of a mesh network backbone network and client nodes connected thereto. As shown, each mesh node may form a mesh network using, for example, an optimized link state routing protocol (OLSR) and a routing protocol. At this time, each mesh node may broadcast information about its neighboring mesh nodes throughout the network, and may periodically transmit a hello message to measure the radio link quality.

As a result, each mesh node knows the overall network topology, and each mesh node can identify the destination node of the received packet and forward the packet to the corresponding mesh node. In addition, each mesh node may periodically collect information about neighbor links to broadcast neighbor node information.

Client nodes are nodes connected to a mesh network to use a mesh backbone, and are generally connected to an access point or a hub under the mesh node, and may be configured to be transparent to the mesh network.

That is, the access point or hub may recognize the mesh node as its gateway, and the client node using the mesh network may be connected to the access point or hub without being different from the existing wired backbone.

The present invention is a technique for providing mobility by partially using a routing module used by a client node in a mesh network. That is, basically, the client node can use the routing protocol used in the mesh network.

2 is a diagram illustrating a basic routing topology when the client node uses the routing protocol used in the mesh network as it is.

As shown, it is possible to broadcast its link information to each mesh node and client nodes throughout the network. The result is a routing topology that includes the entire node without any distinction between mesh nodes and client nodes. As a result, overhead due to background traffic for network configuration of each mesh node and client nodes may increase exponentially.

In other words, each mesh node periodically broadcasts its link information to the entire network. On the other hand, the number of client nodes is relatively large compared to the number of mesh nodes. In this case, if the client node applies the same routing protocol as the mesh node, and the client node broadcasts its link information over the network, valuable radio resources are used to construct the routing topology, and the actual data transmission is not performed. The bandwidth for this can be drastically reduced.

In addition, since the client node is not only mobile but always connected, the client node may suddenly disappear from the network, or a non-existent client node may suddenly appear on the network. For example, when a user turns off or abruptly turns on his terminal. Therefore, when the client node becomes a node that plays an important role in the routing topology, the link can be drastically changed, resulting in performance degradation of the entire network.

Therefore, in order not to degrade the performance of the mesh network, each client node may use only modules capable of providing mobility.

3 is a configuration diagram of a topology when a client node is recognized as a leaf node according to an embodiment of the present invention.

In other words, when running routing protocols, each mesh node and client nodes know each other's existence and know the entire network topology, where the performance of the mesh network as a whole is ensured if the client nodes are connected only to leaf nodes in the topology. The fall can be prevented.

More specifically, client nodes may transmit only their own packets without forwarding packets of other nodes. The client node can send the packet directly to the mesh node without retransmitting it to another intermediate client node.

Mesh nodes are directly connected to each other, and since client nodes do not relay in the middle, mesh nodes can communicate with each other and send packets to the destination client node.

As a result, a mesh node and a client node as a backbone network can be distinguished while providing mobility to client nodes in a wireless mesh network.

A detailed method of allowing the client node to be recognized only as a leaf node on the network topology will be described later.

4 is a diagram illustrating a format of a hello message according to an embodiment of the present invention.

The hello message is a generic representation of a message used when establishing a peer relationship with neighbor nodes and searching for neighbor nodes.

In the hello message of the nodes according to an embodiment of the present invention, a field indicating whether the message originator is a client node or a mesh node may be added.

The client node may receive a hello message, send a response message when the sender of the received hello message is a mesh node, and discard the message when the sender is another client node.

Each node on the network may periodically send a hello message to measure the link quality with a node in its vicinity. As described above, according to the present invention, link quality between client nodes cannot be measured.

That is, each client node transmits hello messages like mesh nodes to periodically measure the link quality with mesh nodes located nearby, but discards hello messages received from other client nodes, thereby measuring link quality between client nodes. As a result, the computing and memory overhead of the client node can be reduced.

In addition, each client node does not broadcast the information of neighboring neighbor nodes collected by the entire network, so that the overall network performance is not affected.

As a result, each client node does not forward packets from other client nodes and broadcasts its own link information to the network, thereby improving overall network performance and link quality with neighboring mesh nodes through hello messages. Can be measured periodically and notified of its presence to the mesh node. Thus, the mesh node can track the position of the client node and provide mobility of the client node.

5 is a detailed configuration diagram of a mesh node and a client node according to an embodiment of the present invention.

The mesh node 100 includes a link state checking unit 101, a topology information storing unit 103, a data receiving unit 105, a data transferring unit 107, and a data transmitting unit 109. Packets can be sent between nodes or to client nodes.

The link state checking unit 101 may periodically measure the link quality by transmitting a hello message to the neighboring mesh node 100 or the neighboring client node 200.

The link state checking unit 101 may periodically check the connection state with the neighboring mesh node 100 or the client node 200 by transmitting a hello message, and collect network neighbor information to determine network topology information. have.

In addition, the link status checking unit 101 periodically broadcasts its neighbor node information to the entire network, so that the mesh node or the client node receiving the corresponding information can grasp the network topology information.

The topology information storage unit 103 may store topology information composed of the mesh node 100 and the client node 103.

The packet receiver 105 may receive a packet transmitted from the surrounding mesh node 100 or the client node 103.

The packet processing unit 107 may process the received packet, and may identify a next mesh node or a client node on a delivery path of the packet.

The packet transmitter 109 may transmit the packet to the mesh node or the client node identified by the packet processor 107.

The client node 200 includes a link state checking unit 201, a topology information storing unit 203, a packet receiving unit 205, a packet processing unit 207, and a packet forwarding unit 209, and a neighboring mesh node. The link quality may be periodically measured and its packet may be transmitted to the mesh node.

The link state checking unit 201 may periodically broadcast a hello message to measure the link quality. More specifically, the link state checking unit 201 may transmit a hello message to neighboring nodes, inform the mesh node 100 of its existence, and periodically measure the link quality with the mesh node 100.

More specifically, when the hello message is transmitted from another node, the link state checking unit 201 may determine whether the destination of the message is another mesh node 100 or the client node 200.

The link state checking unit 201 may discard the message when the hello message sending destination is another client node 200. Therefore, link quality between client nodes is not measured. As a result, the computing and memory overhead of the client node can be reduced.

In addition, the link status checking unit 201 periodically checks the connection status with neighboring nodes by broadcasting a hello message, collects neighboring neighbor node information, and grasps network topology information. Do not broadcast across the network. Thus, it may not affect overall network performance.

The topology information storage unit 203 may store topology information composed of the mesh node 100 and the client node 103.

The packet receiver 205 may receive a packet transmitted from the surrounding mesh nodes 100.

The packet processor 207 may process the received packet, and may grasp the destination client node 200 to which the corresponding data is to be transferred, and then identify the next mesh node 100 on the delivery path.

The packet transmitter 209 may identify the packet processor 207 and then transmit the packet to the mesh node 100.

6 is a diagram illustrating a communication method in a client node according to an embodiment of the present invention.

As shown, the client node 200 may periodically broadcast a hello message to measure the link quality with the neighboring nodes. That is, the client node 200 broadcasts the hello message and may measure the link quality between the client node 200 and the mesh node 100 based on the response message received from the surrounding mesh nodes 100 (S100, FIG. S101, S103).

Meanwhile, the client node 200 may receive a hello message from other client nodes 200 around the client node 200. When the destination of the received hello message is another client node 200, the client node 200 may discard the corresponding message (S105 and S107).

Therefore, the link quality between the client nodes 200 is not measured.

The client node 200 may measure the link quality with the neighboring mesh nodes 100 and determine a network topology based on link information broadcast from each mesh node 100 (S109).

The client node 200 may receive a packet destined for itself as a final destination from the surrounding mesh nodes 100. Alternatively, the client node 200 may identify the final destination client node 200 of the delivery target packet and transmit the packet to the next mesh node 100 on the delivery path (S111).

7 is a diagram illustrating a communication method in a mesh node according to an embodiment of the present invention.

As shown, the mesh node 100 may periodically broadcast a hello message to measure a link quality with neighboring nodes. That is, the mesh node 100 broadcasts a hello message, and between the mesh nodes 100 or between the mesh node 100 and the client node based on the response message received from the surrounding mesh node 100 or the client node 200. The link quality between the 200 can be measured (S200, S201, S203).

The mesh node 100 may collect neighboring neighbor node information and broadcast the corresponding information to the entire network, while measuring link quality with the neighboring node. In addition, the mesh node 100 may grasp the network topology based on the neighboring node information broadcast from the other mesh node 100 (S205).

The mesh node 100 may receive a packet transmitted from the neighboring mesh node 100 or the client node 200, and identify the next mesh node 100 or the next client node 200 on the forwarding path of the packet. Can be. The mesh node 100 may transmit a corresponding packet to the next mesh node 100 or the client node 200 on the delivery path (S207).

What has been described above is only an embodiment of the present invention, and the scope of the present invention is not limited thereto, and various modifications can be made to those skilled in the art. For example, the nodes constituting the mesh network system according to the embodiment of the present invention and the modules constituting the nodes may be additionally configured or merged according to their function.

In addition, of course, the communication method according to the embodiment of the present invention can be configured so that the order is changed.

The scope of the present invention will include all the technical elements recognized as the claims described below and equivalents thereof.

1 is a diagram illustrating a configuration of a mesh network backbone network and client nodes connected thereto.

2 is a diagram illustrating a basic routing topology when a client node uses a routing protocol used by a mesh node as it is.

3 is a configuration diagram of a topology when a client node is recognized only as a leaf node according to an embodiment of the present invention.

4 is a format of a hello message according to an embodiment of the present invention.

5 is a detailed configuration diagram of a mesh node and a client node according to another embodiment of the present invention.

6 is a diagram illustrating a communication method in a client node according to an embodiment of the present invention.

7 is a diagram illustrating a communication method in a mesh node according to an embodiment of the present invention.

Claims (14)

In a mesh network system, The first hello message is transmitted to the neighboring mesh node and the client node to check the link quality with the neighboring node, and includes a mesh node transmitting the packet to the next mesh node or the client node in the packet forwarding path. Mesh network system. The method of claim 1, The mesh node, Link quality is periodically measured by sending a first hello message to neighboring mesh nodes and client nodes. Check the first link status by broadcasting the collected neighbor node information through the network and receiving the neighbor node information broadcasted from other mesh nodes to identify the network topology and transmitting the packet to the next mesh node or client node in the packet forwarding path. Containing wealth Mesh network system. The method of claim 2, The first hello message, Contains a field value indicating that the message sender is a mesh node Mesh network system. A client node connected to a mesh network backbone network and communicating with a neighboring mesh node, Send a second hello message to measure the link quality with the surrounding mesh nodes and inform the mesh nodes of their existence; Receiving a packet from the mesh node, or including a second link status check unit for transmitting the packet to the next mesh node in the packet forwarding path Client node. The method of claim 4, wherein The second link state checking unit, If a second hello message is received from another client node, the second hello message is discarded. Client node. The method of claim 5, The second hello message is Contains a field value indicating that the message sender is a client node. Client node. The method according to claim 4 to 6, The second link state checking unit, DISABLE the collected neighbor node information broadcasting function Client node. In the communication method of the mesh node of the mesh network system, a) transmitting a first hello message to the surrounding mesh node and the client node to measure a link quality with the neighboring node; And b) sending the packet to the next mesh node or client node in the packet delivery path. How to communicate mesh nodes. The method of claim 8, After step a), Broadcasting the collected neighbor node information through the network; Determining a network topology by receiving neighbor node information broadcast from another mesh node; Identifying the next mesh node or client node on the packet forwarding path based on the topology information; How to communicate mesh nodes. The method of claim 9, The first hello message is Contains a field value indicating that the message sender is a mesh node How to communicate mesh nodes. In a communication method of a client node connected to a mesh network backbone network and communicating with a neighboring mesh node, a) transmitting a second hello message to measure a link quality with a neighboring mesh node; And b) receiving a packet from a mesh node or transmitting the packet to a next mesh node in a packet forwarding path; How the client node communicates. The method of claim 11, Discarding the second hello message when receiving the second hello message from another client node; How the client node communicates. The method of claim 12, After step a), Determining a network topology by receiving neighbor node information broadcast from another mesh node; And Identifying the next mesh node in the packet forwarding path based on the topology information; How the client node communicates. The method of claim 12, The second hello message is, Contains a field value indicating that the message sender is a client node. How the client node communicates.

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