KR20060068440A - Method for determining routing path in mobile ad hoc network and network apparatus thereof - Google Patents

Abstract

The present invention relates to a method for establishing a routing path in a mobile ad hoc network environment and a network device using the same.

In a mobile ad hoc network environment according to an embodiment of the present invention, a method for establishing a routing path may include selecting one or more routing paths capable of transmitting data packets to a destination node, and each node constituting the routing path among the selected routing paths. Selecting a routing path for which the sum of the weights calculated according to the packet transmission rate between them is minimum, and transmitting the data packet through the selected routing path.

According to the present invention, by setting the routing path in consideration of the packet transmission rate between nodes, the transmission efficiency of data packets can be increased.

Routing, MANET, Packet Rate

Description

Method for determining routing path in mobile ad hoc network and network apparatus

1 is a view showing a routing path in the MANET according to the prior art.

2 is a block diagram schematically illustrating a network device according to an embodiment of the present invention.

3 is a flowchart illustrating a routing information transmission process according to an embodiment of the present invention.

4 is a flowchart illustrating a routing path establishment process according to an embodiment of the present invention.

5 is a diagram illustrating a routing path according to an embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

210: measuring unit 220: transceiver

230: control unit 240: routing unit

250: packet generation unit

The present invention relates to a method for establishing a routing path and a network device using the same, and more particularly, to a method for setting a routing path having a high packet transmission rate in a mobile ad hoc network environment and a network device using the same.

Mobile ad hoc networks (hereinafter referred to as MANETs) are mobile network devices (hereafter referred to as nodes) such as laptops, PDAs, etc., which are not based on infrastructure and are wireless link. ) Is a network formed by interconnecting each other. Therefore, in MANET, individual nodes play a role of relaying data packets transmitted from other nodes.

In this case, the transmitting node sets a path to which the data packet is delivered to a destination node which will finally receive the data packet, which will be described with reference to FIG. 1.

1 is a view showing a routing path in the MANET according to the prior art.

Hereinafter, the prior art will be described based on Node A. Node A receives the control packet from neighbor nodes (Node B, Node C, Node D) located within one-hop area 130 from itself. It detects existence. The control packet includes the routing information of the neighbor node that transmitted it, and Node A determines the network topology by using the routing information of the neighbor nodes included in the control packet. In the illustrated example, the line connecting each node means that each node is directly connected through a wireless link.

Once the network topology is known, Node A calculates a routing path, which allows routing paths for data packets to be sent to the destination node. For example, when the node A intends to transmit data packets to the node F, the first path 110 via the node B and the node E or the second path 120 via the node C may be set as the routing path.

In this case, when the data packet is transmitted through the first path 110, the data packet is transmitted through more nodes than when the data packet is transmitted through the second path 120. This means that the network resource consumption when using the first path 110 to transmit the data packet is higher than the network resource consumption when using the second path 120 to transmit the same data packet. Therefore, according to the related art, the second path 120 is set as the routing path in order to minimize the movement path of the data packet.

As described above, in the related art, in order to efficiently use limited radio network resources, the routing path is set so that the movement path of the data packet is minimized. However, setting the routing path according to the prior art which does not consider the link quality between each node may result in wasting network resources, which will be described below.

Since MANET uses a wireless medium to transmit data packets, when a data packet is transmitted to another node, the success rate of the data packet is affected by the link quality. For example, the signal strength of the data packet is weakened as the transmission distance increases until the data packet output from the transmitting node is relayed by another node due to the characteristics of the wireless medium. This means that the greater the transmission distance of the data packet, the higher the probability that a transmission error of the data packet will occur.

In this case, the packet throughput is lowered, and as a result, the transmission efficiency of the data packet is reduced.

Therefore, a technique for establishing a more effective routing path in consideration of the packet transfer rate between nodes as well as the entire moving path of the data packet has been required.

An object of the present invention is to establish a more efficient routing path in consideration of the packet transmission rate between nodes.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a method for establishing a routing path in a mobile ad hoc network environment according to an embodiment of the present invention comprises the steps of selecting at least one routing path capable of transmitting data packets to a destination node, the selected routing path Selecting a routing path having a minimum sum of weights calculated according to packet transmission rates between nodes constituting the routing path, and transmitting the data packet through the selected routing path.

In order to achieve the above object, a method for establishing a routing path in a mobile ad hoc network environment according to an embodiment of the present invention comprises the steps of receiving a predetermined packet from a neighbor node, the neighbor node via the SNR of the received packet Measuring a packet transmission rate over a link with the network; calculating a weight value of the measured packet transmission rate for the link with the neighbor node; and broadcasting information on the calculated weight value.

In order to achieve the above object, the network device according to an embodiment of the present invention is a control unit for determining the topology of the mobile ad hoc network, one or more routings capable of transmitting data packets to the destination node through the network topology identified by the control unit A routing section for selecting a routing path and setting a routing path in which the sum of weights calculated according to packet transmission rates among the nodes constituting the routing path is minimized among the selected routing paths, and routing set by the routing section And a transceiver for transmitting the data packet so that the data packet is transmitted through a path.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, the invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

2 is a block diagram schematically illustrating a network device according to an embodiment of the present invention.

The illustrated network device includes a measurement unit 210, a weight calculator 220, a transceiver 230, a controller 240, a router 250, and a packet generator 260.

The measurement unit 210 measures a packet throughput for a neighbor node. Packet transmission rate is an indicator of link quality between nodes, and packet transmission rate directly affects the utilization efficiency of network resources.

The packet transmission rate may be calculated through a signal to noise rate (SNR) measured for a packet received from a neighbor node. An example of calculating the packet transmission rate through SNR is described in detail in ＂Link Adaptation Strategy for IEEE 802.11 WLAN via Received Signal Strength Measurement＂, Javier del Prado Pavon, Sunghyun Choi, IEEE ICC 2003.

Meanwhile, the measurement unit 210 may measure the packet transmission rate according to the SNR value.

The SNR value may be obtained by measuring the received signal strength indication (RSSI) for the packet received by the transceiver 230 from the neighbor node.

The packet used to measure the SNR is preferably a packet that is broadcast periodically from a neighbor node. As a result, the illustrated network device can continuously monitor the link quality with the neighboring nodes at regular time intervals. In this case, the packet periodically broadcasted from the neighbor node may be a control packet including routing information of the neighbor node. An example of a control packet is a hello packet mainly used in a proactive method among routing protocols in MANET.

The weight calculator 220 calculates a weight of a link with a neighbor node according to the packet transmission rate measured by the measurer 210. This weight may be calculated through Equation 1.

[Equation 1]

는 이웃 노드와의 링크를 통한 최대 패킷 전송율이고,

는 이웃 노드와의 링크를 통한 현재 패킷 전송율을 나타낸다. 따라서 가중치 계산부(220)에 의해 계산된 가중치가 작은 값을 가질수록 이웃 노드와의 링크는 높은 데이터 전송 효율을 나타냄을 의미한다. In Equation 1

Is the maximum packet rate over the link with a neighbor node,

Denotes the current packet rate on the link with the neighbor node. Therefore, as the weight calculated by the weight calculator 220 has a small value, it means that the link with the neighbor node shows high data transmission efficiency.

The weight for the link with the neighbor node calculated by the weight calculator 220 is included in the control packet generated by the packet generator 260 and provided to the neighbor nodes.

The transceiver 230 is responsible for packet transmission and reception with a neighbor node through a wireless medium. When the packet is received from the neighbor node, the transceiver 230 outputs the received packet to the controller 240.

In addition, the transceiver 230 transmits a packet generated by the packet generator 260 to a neighbor node. If the packet generated by the packet generator 260 is a control packet, a transmission method of the control packet may be broadcast.

The controller 240 manages information about neighbor nodes. The information on the neighboring node may include a node identifier for identifying the neighboring node, a link state with the neighboring node, routing information of the neighboring node, weights calculated according to packet transmission rate between each node constituting the mobile ad hoc network, and the like. Can be.

The weight is a value calculated by each node, and each node may calculate a weight of a link with its neighbor node according to Equation 1.

Information managed by the controller 240 may be obtained through a control packet received from a neighbor node.

Meanwhile, the controller 240 may determine the network topology through routing information about neighbor nodes.

The routing unit 250 selects one or more routing paths capable of transmitting data packets to the destination node through the network topology identified by the control unit 240. At this time, the routing unit 250 calculates the sum of the weights of the links between the nodes constituting the routing path among the selected routing paths, and sets the path of which the sum is the minimum as the routing path. The weight for the link between each node may be provided from the controller 240.

The packet generator 260 generates a data packet to be transmitted to another node by the illustrated network device. When the packet generator 260 generates a control packet, the control packet may include routing information and weights managed by the controller 240.

Meanwhile, packets other than the control packet generated by the packet generator 260 may be transmitted to the destination node through the routing path set by the routing unit 250.

Hereinafter, an operation process between blocks constituting a network device according to an embodiment of the present invention will be described in more detail with reference to FIGS. 3 and 4.

3 is a flowchart illustrating a routing information transmission process according to an embodiment of the present invention.

The measurement unit 210 measures the packet transmission rate for the neighbor node when the transceiver 230 receives a packet from the neighbor node (S110). Packet transmission rate may be measured using SNR for packets received from neighboring nodes.

When the packet transmission rate of the neighboring node is measured by the measuring unit 210, the weight calculator 220 calculates a weight in which the packet transmission rate is reflected for the link with the neighboring node (S120). The weight may be calculated through Equation 1 described above.

When the weight for the link with the neighbor node is calculated, the packet generator 260 generates a control packet including information on the weight (S130). The control packet may further include routing information, and the control packet may be a hello packet mainly used in a proactive method of the conventional routing protocol.

The control packet generated by the packet generator 260 is broadcast to neighboring nodes through the transceiver 230 (S140).

Accordingly, the nodes constituting the mobile ad hoc network can grasp the network topology and the weight of the links between the nodes constituting the network through control packets.

4 is a flowchart illustrating a routing path establishment process according to an embodiment of the present invention.

When the control packet is received from the neighbor node through the transceiver 230, the controller 240 determines the topology of the mobile ad hoc network through routing information included in the received control packet (S210).

Accordingly, when there is a data packet to be transmitted to the destination node, the routing unit 250 selects routing paths through which the data packet can be transmitted to the destination node through the network topology determined by the controller 240 (S220).

Thereafter, the routing unit 250 calculates a sum of weights for the links between the nodes constituting the routing path among the selected routing paths, and selects the routing path whose sum is the minimum (S230).

When the routing path is selected by the routing unit 250, the data packet generated by the packet generator 260 is transmitted through the transceiver 230 (S240).

5 is a diagram illustrating a routing path according to an embodiment of the present invention.

The location of the nodes shown is the same as the location of the nodes shown in FIG. According to an embodiment of the present invention, the nodes constituting the MANET transmit information on the weight reflecting the packet transmission rate for the neighboring node to the neighboring node as described above with reference to FIG. 3. This allows the nodes that make up the MANET to grasp the weights of the links between the nodes in the MANET. 5 shows the weights for each link.

When Node A wants to send a data packet to Node F, Node A first selects the two paths 310 and 320 that can be transmitted. The sum of the weights for the links between the nodes constituting the selected path is then calculated.

In the illustrated example, the sum of weights for the links between the nodes constituting the first path 310 is 5, and the sum of the weights for the links between the nodes constituting the second path 320 is 7. Since the weight represents the relative packet transmission rate of the corresponding link as described in Equation 1, it means that the second path 320 having a high sum of weight has a lower link quality than the first path 310. Therefore, the transmission rate of the data packet when using the second path 320 is lower than the transmission rate of the data packet when using the first path 310.

As such, when the second path 320 is used, the transmission efficiency of the data packet is reduced. According to the present invention, even if the number of hops constituting the routing path is higher, the first path having a relatively high packet transmission rate (lower sum of weights) is used. Set 310 as a routing path.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. You will understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.

According to the method for establishing a routing path in the mobile ad hoc network environment and the network apparatus using the same according to the present invention, the transmission efficiency of data packets can be increased by setting the routing path in consideration of the packet transmission rate between nodes.

Claims (5)

Selecting one or more routing paths to which data packets can be sent to the destination node; Selecting a routing path of the selected routing paths having a minimum sum of weights calculated according to packet transmission rates between nodes constituting the selected routing paths; And Transmitting the data packet through the selected routing path. The method of claim 1, wherein the weight is

Is calculated as above

Is the maximum packet transfer rate between each node, and

Is a method of establishing a routing path in a mobile ad hoc network, the current packet transfer rate between each node. Receiving a predetermined packet from a neighbor node; Measuring a packet transmission rate at the time of packet transmission on the link with the neighbor node through the SNR of the received packet; Calculating a weighting value of the measured packet transmission rate for the link with the neighbor node; And And broadcasting the information about the calculated weight. The method of claim 3, wherein the weight is

Is calculated as above

Is the maximum packet rate for the neighbor node, and

Is a method of establishing a routing path in a mobile ad hoc network that is a current packet rate for the neighbor node. A control unit for identifying a topology of the mobile ad hoc network; Selecting one or more routing paths that can transmit data packets to a destination node through the network topology identified by the control unit, and calculates according to the packet transmission rate between the nodes constituting the selected routing path from the selected routing paths A routing unit for selecting a routing path of which the sum of the weighted values becomes the minimum; And And a transceiver for transmitting the data packet such that the data packet is transmitted through a routing path selected by the routing part.

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