KR100992485B1 - Wireless mesh network apparatus and routing method using by it - Google Patents

Abstract

The present invention relates to a routing scheme in a wireless mesh network. The present invention relates to a 1-hop neighbor when a potential value for a plurality of mesh nodes is calculated, a potential value for a plurality of gateway nodes is set, and data packets are transmitted from a specific node. By requesting and receiving potential information including potential values for nodes, establishing routing paths according to the potential information, and transmitting data packets in a single path or multiple paths according to such routing paths, This can prevent delay when handover of the mobile mesh node.

Wireless mesh network, routing, handover, multiple distributed transport

Description

Wireless mesh network device and routing method using same {WIRELESS MESH NETWORK APPARATUS AND ROUTING METHOD USING BY IT}

The present invention relates to a wireless mesh network (WMN), and more particularly, to a wireless mesh network device suitable for transmitting a packet in multiple paths by distributing a load in a wireless mesh network, and a routing method using the same.

As is well known, the wireless mesh network is derived from Ad-hoc communication technology, which is a base station-to-base station, not a star-type topology network between a base station and a terminal during fixed or mobile communication in a wireless network environment. It refers to a technology that has introduced a mesh type topology (mesh type topology) having a multi-path through which all nodes, such as terminal to terminal, base station to terminal, can communicate.

The wireless mesh network has advantages in terms of economical network construction, mobility provision, network scalability, and bridging the information gap, and since the wired network is not required for each expensive transmission tower or base station, the overall network configuration cost is low. It is possible to construct an economical network, and based on IP technology, it is easy to interwork with the existing network, and can increase the staged coverage so that a deliberate network can be constructed, and an unlicensed band can be used for VoIP (Voice) over Internet Protocol) and multimedia data services without interruption during high-speed travel.

In addition, the wireless mesh network can easily expand the network through a multi-radio wireless mesh network structure to provide a variety of services such as voice, video, and data, thereby eliminating the shadow area of the wireless, and the basic infrastructure for bridging the information gap. Very economical and flexible to deploy.

In particular, wireless mesh networks have features such as automatic network configuration, automatic network recovery, low-power wide area coverage networks, and high-speed roaming technology, which automatically configure meshed network topologies automatically in a wireless environment. Compared to the multi-point wireless communication method, it is possible to improve the reliability of communication by multipath, and if a node trouble occurs due to physical congestion or traffic overload in the node where communication was performed, the optimal new path is found in the current network. In order to recover the network, every node periodically scans the optimal radio link and calculates the amount of traffic and delay rate processed in its own node so that the optimal network can be configured.

In addition, when existing point-to-multipoint wireless communication requires 100 power, a wireless mesh network that extends communication coverage through multi-hop will take three hops with a low power of 33 and take the same coverage as point-to-multipoint communication. Smart frequency selection automatically generates the optimal frequency reuse effect by creating a spatial frequency reuse effect, and constructs a wide area network when the mesh node is powered. By supporting high speed roaming within, it can be utilized for services for high speed moving objects such as trains and subways.

Meanwhile, referring to the conventional routing scheme in the wireless mesh network, each node included in the wireless mesh network may operate as a router capable of relaying messages to its neighboring nodes. Through the relay process, the wireless data packet finds a path to the destination node and passes through an intermediate node with a reliable communication link, and multiple nodes cooperate with each other to relay messages to the destination node. In consideration of the network, it is being developed in terms of 'Proacitve / Reactive / Hybrid' method or based on geographical information.

However, the conventional routing schemes have a characteristic that the route of the traffic should be constant from user to multi-hop to the gateway, and from gateway to multi-hop to the user in consideration of the wireless ad hoc network. There is a problem that an inappropriate path is formed because it is not reflected, and even when delay information is used as a measure of path selection, since the past information is used, it is impossible to respond quickly. When using geographic information, flows to a specific hop. If the flow is concentrated, there is a limitation that the performance is significantly reduced, and since it is based on 'any-to-any' routing as a whole, there is a problem that it is difficult to apply to a wireless mesh network for multimedia content services.

Accordingly, the present invention provides a wireless mesh network device and a routing method using the same, which selects a path based on the potential information allocated to each node constituting the wireless mesh network, distributes load, and reduces transmission delay. I would like to.

In addition, the present invention provides a wireless mesh network device capable of constructing a new transmission path based on potential information upon handover of a wireless mesh network, distributing load by updating path information, and reducing transmission delay, and a routing method using the same. To provide.

According to an aspect of the present invention, a routing path is established according to potential information of one hop neighbor node at a specific node, and a data packet is transmitted to one of the selected neighbor nodes or a plurality of the selected nodes are selected according to the potential information. Provided are a wireless mesh network apparatus including a plurality of mesh nodes for multiple distributed transmission of data packets to neighbor nodes, and a gateway node serving as a gateway to another network.

In another aspect, the present invention provides a method for computing a potential value for a plurality of mesh nodes, setting the potential value for a plurality of gateway nodes, and the potential for one-hop neighbor nodes in each of the plurality of mesh nodes. Periodically requesting and receiving potential information including a value; setting a routing path according to the potential information when transmitting a data packet from a specific node; Provided is a routing method using a wireless mesh network device including transmitting a data packet.

The present invention calculates potential values for a plurality of mesh nodes, sets potential values for a plurality of gateway nodes, and then includes potential values for one-hop neighbor nodes when data packets are transmitted from a specific node. By requesting and receiving information, setting up routing paths according to potential information, and transmitting data packets in a single path or in multiple paths according to these routing paths, load balancing can be efficiently utilized in a wireless mesh network. Only local information can be used to provide a lightweight routing technique that reflects the overall network situation, and can effectively transmit data packets by preventing unnecessary delays even during handover.

In addition, this technique can be maximized when applied to the 4G mesh network's Traffic Engineering and QoS (QoS of Service) optimization technology, and the numerical analysis method focuses on connectivity by considering efficiency and connectivity at the same time. We can expect several times the performance improvement over IEEE 802.11s technology. In addition, it can provide various access network technologies such as WiBro, 3GPP / LTE and WiFi and convergence functions.

In accordance with an aspect of the present invention, after setting potential values for a plurality of mesh nodes and gateway nodes, a routing path is set according to potential information for one-hop neighbor nodes when data packets are transmitted, and thus a single path or It is to transmit the data packet in the multi-path, and the technical means can solve the problems in the prior art.

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

1 is a diagram illustrating a structure of a wireless mesh network suitable for transmitting a packet by selecting a path based on potential information according to a preferred embodiment of the present invention, and includes a plurality of meshes including mesh nodes 102a, 102b, and 102c. And a plurality of gateway nodes, including nodes and gateway node 104.

Referring to FIG. 1, a number of mesh nodes, including mesh nodes 102a, 102b, 102c, may include a Node-B, a base station, a site controller, an access point (AP), a wireless transmit / receive unit, a transceiver, a user equipment, a mobile station, a fixed station. Or a mobile subscriber unit, any interface device in a wireless environment, and the like, transmitting data packets in a wireless mesh network environment from one mesh node to another mesh node.

In addition, any one of a number of mesh nodes, including mesh nodes 102a, 102b, 102c, receives and transmits its own traffic while serving as a router for other mesh nodes, and automatically transmits a wireless mesh network. It can be configured as a function, and it recognizes the overload state of a specific mesh node and adjusts the use.

In addition, the gateway node 104 serves as a gateway between a plurality of mesh nodes including the mesh nodes 102a, 102b, and 102c and another network environment, and transmits data packets transmitted from one mesh node to another network environment. It transmits to specific node of and transmits data packet received from specific node of other network environment to corresponding mesh node.

In the wireless mesh network environment including a plurality of mesh nodes and a plurality of gateway nodes, the routing path setting according to the potential assignment will be described. First, according to Equation 1 (Poisson Equation), Set the routing path.

Here, φ means the potential of each mesh node, and ρ means the length of the queue waiting to be transmitted.

Then, the potential of the gateway nodes is set to the lowest, and each mesh node calculates its own potential according to Equation (1). As an example, FIG. 2 is a diagram illustrating potentials of all mesh nodes and all gateway nodes calculated according to the present invention, wherein the x-axis and the y-axis represent coordinates of each mesh node, and the z-axis represents an assigned potential. This potential is determined by the potential of its neighboring mesh nodes, but can reflect the situation of the entire mesh network.

On the other hand, in the lattice structure shown in Figure 1 when the potential is derived by using a numerical analysis method such as FDM (Finite Diffrence Method) can be represented by Equation 2 below.

Here, h is a constant representing a relationship between potential traffic and a specific mesh node, and when a value is assigned according to Equation 2, each mesh node has its own hop as shown in the arrow direction of FIG. 1. The path is selected using the potential information of neighboring mesh nodes. Accordingly, as shown in FIGS. 3 and 4, the load of the control packet is significantly reduced compared to the existing routing, thereby increasing the capacity of the wireless mesh network and improving performance such as increased throughput. Can be.

In addition, in any network structure other than the lattice structure, a numerical analysis method such as finite element method (FEM) and boundary element method (BEM) may be applied to allocate potentials for each node, and the finite element method may be used. In order to derive potential using), the solution for φ satisfying Equation 3 below can be obtained.

Here, k and s represent each element, that is, a node identifier, and may indicate the influence of traffic through η and ρ. In addition, n _k and n _s may be calculated as shown in Equation 4 below to obtain a solution for φ that satisfies Equation 3 above.

In addition, in order to determine the shape of its neighbor nodes in an arbitrary network structure, as shown in FIG. 10, elements that influence its potential are defined by using geographic information, using a finite element method (FEM). In order to apply the potential, we designate the nodes that affect their potential as elements, move their position to the origin, and move the neighboring nodes to equilibrium to apply Equation 3 above. After that, the nodes may be selected to select the nodes such that the angles between the two neighboring nodes are minimized, and a plurality of triangles may be derived around them, and then potentials may be calculated by substituting the values derived from the variables of Equation 3 above.

When a routing path is established based on this potential information, each mesh node compares the potentials of its 1-hop neighbor mesh nodes and transmits a data packet to a specific mesh node having the lowest value. If it is higher, it determines that the network is congested and suspends data packet transmission. If the difference is within a predetermined range, the data packet is transmitted.

When transmitting such a data packet, multi-distribution transmission can be performed by using multiple paths. The potential of the neighboring mesh nodes is compared and analyzed according to the calculated potential information, distributed by a certain ratio, and distributed to multiple neighboring mesh nodes. Send the packet separately. Here, in the transmission of the data packet, the path may be selected without considering the interference of the corresponding mesh nodes or the path may be selected in consideration of the interference of the corresponding mesh nodes.

On the other hand, when one gateway node transmits a data packet to each mesh node, each mesh node uses a routing path used for uplink traffic transmission, and the mesh nodes transmitting uplink traffic are SA (the source address). Routing information including the Source Address (hereinafter referred to as 'SA') and the MAC address (ie, NA: Neighbor Address) of the corresponding mesh nodes responsible for forwarding to it is stored. The data packet is transmitted from one gateway node to each mesh node according to the MAC address of the neighboring mesh node used as the routing path during traffic transmission.

In case of handover of the mobile mesh node in the wireless mesh network, the potential of the mesh nodes is automatically determined according to Equation 2 above, and each mesh for the mobile mesh node that attempts handover at the handover time point. Since the routing information (eg, SA, MAC address, etc.) of the nodes is information before handover, the corresponding routing information must be updated, and the routing information is deleted when a predetermined time elapses at the time of handover. Accordingly, the routing information after the handover is newly generated and stored after the data packet transmission of the mobile mesh node.

Next, a process of requesting and receiving potential information of mesh nodes in a wireless mesh network having the above-described configuration, selecting a routing path according to the potential information, and transmitting a data packet will be described.

5 is a flowchart illustrating a process of transmitting a data packet according to potential information of mesh nodes according to the present invention.

Referring to FIG. 5, in a wireless mesh networking mode of a wireless mesh network including a plurality of mesh nodes and a plurality of gateway nodes as shown in FIG. 1 (step 502), the plurality of gateway nodes may include a plurality of mesh nodes. A relatively low value is set to a preset potential value (step 504), and the plurality of mesh nodes calculate their potential (step 506). Here, the potentials of the plurality of mesh nodes may be sequentially calculated according to the Poisson equation such as Equation 1 according to a preset potential value for the gateway nodes.

In operation 508, the specific mesh node requests potential information (eg, mesh node identifier, potential value, etc.) from its one-hop neighboring mesh nodes according to a predetermined period. As an example, the particular mesh node 102a shown in FIG. 1 may request potential information from multiple mesh nodes 102b and 102c, which are one-hop neighbor nodes, for data packet transmission.

Next, neighboring mesh nodes transmit potential information including the calculated potential value to the corresponding mesh node (step 510). As an example, the plurality of mesh nodes 102b and 102c, which are one-hop neighbor nodes of the specific mesh node 102a illustrated in FIG. 1, may transmit corresponding potential information to the specific mesh node 102a.

Accordingly, the specific mesh node compares and analyzes potential information from a plurality of 1-hop neighbor mesh nodes (step 512), and selects a routing path to the corresponding mesh node having the lowest potential value and transmits a data packet to be transmitted ( Step 514).

Accordingly, when a specific mesh node wants to transmit a data packet, the data packet can be efficiently transmitted by selecting a routing path according to the potential information of its one-hop neighbor mesh node.

Next, a process of multi-distributing and transmitting data packets using a plurality of mesh nodes in a specific mesh node using a technique of selecting a routing path according to the potential information as described above will be described.

6 is a flowchart illustrating a process of multi-distributing and transmitting data packets according to potential information according to the present invention.

Referring to FIG. 6, in a wireless mesh networking mode of a wireless mesh network including a plurality of mesh nodes and a plurality of gateway nodes as shown in FIG. 1 (step 602), the plurality of gateway nodes may include a plurality of mesh nodes. A predetermined potential value of a relatively lower value is set, and the plurality of mesh nodes calculate their potential (step 604). Here, the potentials of the plurality of mesh nodes may be sequentially calculated according to the Poisson equation such as Equation 1 according to a preset potential value for the gateway nodes.

Then, the specific mesh node requests potential information (eg, mesh node identifier, potential value, etc.) from its one-hop neighboring mesh nodes according to a preset period (step 606). As an example, the particular mesh node 102a shown in FIG. 1 may request potential information from multiple mesh nodes 102b and 102c, which are one-hop neighbor nodes, for data packet transmission.

Next, the neighboring mesh nodes transmit potential information including the calculated potential value to the corresponding mesh node (step 608). As an example, the plurality of mesh nodes 102b and 102c, which are one-hop neighbor nodes of the specific mesh node 102a illustrated in FIG. 1, may transmit corresponding potential information to the specific mesh node 102a.

Accordingly, the specific mesh node compares and analyzes potential information from a plurality of one-hop neighboring mesh nodes (step 610) to separate transport packets (data packets) according to the potential ratios of the respective potential values (step 612).

Subsequently, the specific mesh node multi-transmits each of the transport packets separated according to the corresponding potential ratio among the plurality of 1-hop neighboring mesh nodes according to the routing path corresponding to the corresponding potential ratio (step 614).

Therefore, when a specific mesh node wants to transmit a data packet, the data packet may be divided into a plurality of data packets according to the potential information of its one-hop neighboring mesh node, and then a routing path may be selected to efficiently multi-distribute the data packet.

Next, a process of transmitting a data packet upon handover of a moving mesh node in a wireless mesh network that performs data packet transmission and multiple distributed transmission according to the potential information as described above will be described.

7 is a flowchart illustrating a process of transmitting a data packet during handover of a mobile mesh node according to the present invention.

Referring to FIG. 7, in a wireless mesh networking mode of a wireless mesh network including a plurality of mesh nodes and a plurality of gateway nodes as shown in FIG. 1 (step 702), the plurality of gateway nodes may include a plurality of mesh nodes. A predetermined potential value of a relatively lower value is set, and the plurality of mesh nodes calculate their potential (step 704).

In addition, when one mesh node wants to transmit a data packet, a single routing or multiple distribution is performed by selecting a routing path according to potential information (for example, mesh node identifier, potential value, etc.) of one-hop neighbor mesh nodes. The data packet is transmitted in the manner of transmission (step 706). In this case, the mesh node may store routing information including the SA, which is a source address, and MAC addresses of corresponding mesh nodes that are in charge of forwarding them. For example, FIG. 9 illustrates a mobile mesh according to the present invention. A diagram illustrating a table frame of routing information when handing over a node.

At this time, it is checked if a specific mesh node on the routing path moves to handover to another network (step 708).

As a result of the check in step 708, if the handover of the mesh node does not occur, the wireless mesh networking mode is continued (step 702), and if the handover of a specific mesh node on the routing path occurs (in this case, When a mesh node is selected, the mesh node deletes the stored routing information (ie, SA and MAC addresses as path information) after a predetermined time has elapsed (step). 710).

Then, the mesh node checks whether transmission of the data packet to be transmitted is completed (step 712). At this time, the data packet transmission after the handover may be performed by performing the steps 704 and 706 on the mesh nodes after the handover to transmit the data packet.

As a result of the check in step 712, when transmission of the data packet to be transmitted is completed, the path information (eg, SA, MAC address, etc.) for the mobile mesh node is updated (step 714). Here, updating of the route information is performed in a manner of storing routing information corresponding to the selected routing path for transmitting data packets after handover of a particular mesh node on the routing path.

As an example, FIG. 8 illustrates a handover of a mobile mesh node according to the present invention. When a handover of a specific mobile node on a routing path occurs, the potential field is automatically changed in a mesh node transmitting a data packet. It can be seen that the routing information can be updated after deleting the routing information.

Therefore, when a handover to another network occurs during transmission of a data packet from a particular mesh node, the corresponding routing information may be deleted, and the data packet may be transmitted by updating the stored routing information when transmitting the data packet after the handover.

In the foregoing description, the present invention has been described with reference to preferred embodiments, but the present invention is not necessarily limited thereto. Those skilled in the art will appreciate that the present invention may be modified without departing from the spirit of the present invention. It will be readily appreciated that branch substitutions, modifications and variations are possible.

1 is a diagram illustrating a structure of a wireless mesh network suitable for transmitting a packet by selecting a path based on potential information according to a preferred embodiment of the present invention;

2 is a diagram illustrating potentials of all mesh nodes and all gateway nodes calculated according to the present invention;

3 is a view comparing the performance of the control packet load (Control Overhead) of the data transmission scheme and AODV according to the present invention,

4 is a view comparing throughput of AODV and data transmission scheme according to the present invention;

5 is a flowchart illustrating a process of transmitting a data packet according to potential information of mesh nodes according to the present invention;

6 is a flowchart illustrating a process of multi-distributing and transmitting a data packet according to potential information according to the present invention;

7 is a flowchart illustrating a process of transmitting a data packet during handover of a mobile mesh node according to the present invention;

8 illustrates a handover of a mobile mesh node according to the present invention;

9 is a diagram illustrating a table frame of routing information when handover of a mobile mesh node according to the present invention;

10 illustrates the constituent nodes of a finite element in accordance with the present invention.

<Description of the symbols for the main parts of the drawings>

102a, 102b, 102c: mesh node 104: gateway node

Claims (19)

A routing node establishes a routing path according to potential information of one hop neighbor node in a specific node, and transmits a data packet to any one selected neighbor node or multiplexes data packets to a plurality of selected neighbor nodes according to the potential information. Multiple mesh nodes for distributed transmission, Gateway node acting as a gateway to another network Wireless mesh network device comprising a. The method of claim 1, And the plurality of mesh nodes establish the routing path according to the potential information including a node identifier and a potential value, respectively. The method of claim 2, The plurality of mesh nodes may be configured to calculate and set the potential value by applying a numerical analysis method of any one of a finite difference method (FDM), a finite element method (FEM), and a boundary element method (BEM), respectively. Wireless mesh network device. The method of claim 2, The plurality of mesh nodes, respectively, the wireless mesh network device, characterized in that for calculating the potential value in accordance with Poisson equation (Poisson Equation). The method of claim 2, And the plurality of mesh nodes each store routing information corresponding to each data packet when the data packet is transmitted. The method of claim 5, The routing information includes a source address (SA) and a MAC address. The method of claim 2, The plurality of mesh nodes, each of the plurality of mesh nodes, the wireless mesh network device, characterized in that for updating the routing information including the SA (Source Address) and MAC address when handing over a specific node on the routing path. The method of claim 2, Each of the plurality of mesh nodes separates the data packet according to the ratio of the potential value during the multi-distribution transmission, and transmits the data packet according to the routing path corresponding to the ratio of the potential value. Wireless mesh network device. The method according to any one of claims 2 to 8, And the gateway node sets the potential value to a value lower than that of the plurality of mesh nodes. Calculating potential values for the plurality of mesh nodes and setting the potential values for the plurality of gateway nodes; Periodically requesting and receiving potential information including the potential value for one-hop neighbor nodes at each of the plurality of mesh nodes; Establishing a routing path according to the potential information when transmitting a data packet from a specific node; Transmitting the data packet in a single path or multiple paths according to the set routing path Routing method using a wireless mesh network device comprising a. The method of claim 10, In the routing method, the potential value for the gateway node is set to a value that is relatively lower than the potential value for the plurality of mesh nodes in the setting of the potential value. Routing method. The method of claim 11, The potential value is calculated according to Poisson equation (Poisson Equation) characterized in that the routing method using a wireless mesh network device. 13. The method of claim 12, The potential value is calculated and set by applying any one of numerical analysis techniques such as Finite Diffrence Method (FDM), Finite Element Method (FEM), and Boundary Element Method (BEM). Way. The method of claim 13, The FEM defines, as triangle element components, neighbor nodes among the plurality of mesh nodes that affect the potential value corresponding to the specific node, and then moves the position of the specific node to the origin, After driving the algorithm to move to equilibrium, the nodes are selected so that the values between the two neighboring nodes are minimized to derive a plurality of triangles around the specific node, and then calculate the respective potentials. Routing method using a network device. The method of claim 11, The potential information includes the potential value and a node identifier. The method of claim 11, The routing method is a routing method using a wireless mesh network device, characterized in that for setting the routing path to the multi-path corresponding to the ratio of the potential value. The method of claim 16, The routing method is a routing method using a wireless mesh network device, characterized in that for distributing and transmitting the data packet in response to the multi-path. The method according to any one of claims 11 to 17, The routing method, And routing information is updated after transmission of the data packet when a handover of a specific node on the routing path occurs. The method of claim 18, The routing information comprises a SA (Source Address) and a MAC address, characterized in that the routing method using a wireless mesh network device.

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