WO2014104454A1

WO2014104454A1 - Routing system and method using geographic information

Info

Publication number: WO2014104454A1
Application number: PCT/KR2012/011841
Authority: WO
Inventors: 강현국; 최대인; 김민수; 이수진
Original assignee: 인텔렉추얼디스커버리 주식회사
Priority date: 2012-12-31
Filing date: 2012-12-31
Publication date: 2014-07-03

Abstract

The present invention relates to a routing system for routing a source node for transmitting a packet, a destination node for receiving the packet, and a plurality of middle nodes located between the source node and the destination node, and the routing system comprises: a node selection unit for selecting the middle node, located at the shortest distance from the destination node, from among the plurality of middle nodes within a possible packet transmission distance of the source node or each of the middle nodes; and a packet transmitting unit for transmitting the packet by selecting a routing path which passes through the selected middle node, wherein the node selection unit selects the middle node which minimizes a distance cost and an interference cost when an obstacle is present on a packet path that corresponds to the shortest distance, wherein the distance cost increases as the distance between the plurality of middle nodes within the possible packet transmission distance and the destination node increases, and wherein the interference cost increases as the possibility of the obstacle on the packet path causing interference increases.

Description

Routing System and Method Using Geographic Information

The present invention relates to a routing system and method using geographic information.

Routing using geographical information can solve the limitation of topology based routing by using additional information. Each node participating in the communication uses its own location information, and each node obtains its own location information through GPS or other types of location services. In other words, the location service information is included in the sender's packet.

Meanwhile, the location-based routing protocol uses location information and movement information for routing processing. For this, there are Location Aided Routing (LAR), The Distence Routing Effect Algorithm for Mobility (GREA), and The Grid Location Service (GLS), which are location-based routing protocols, but each use information in different ways. Providing.

The LAR is one of the reactive routing protocols, and transmits a route request packet in a limited manner to perform route discovery more efficiently. The transmitting node includes its location information in the transport packet.

DREAM is one of the proactive root protocols. Every node contains location information of every node participating in the network. At this time, the update period of the location information is determined according to the characteristics of the distance and mobility between nodes.

GLS is a location information service, not a routing protocol, and every node in GLS has a number of servers that provide location information in the network.

Both LAR and DREAM using location information are not suitable for large scale ad-hoc networks because both routing paths are searched through flooding. GLS, on the other hand, can be used in dense, large-scale mobile ad hoc networks. GLS has a server that provides a variety of location information in the network to obtain location information through this server. In addition, LAR and DREAM use flooding to update and query location information, but GLS does not use flooding.

1 is a diagram illustrating a conventional routing method.

The routing system includes a source node 10, a destination node 15, and a plurality of intermediate nodes. First, the source node 10 serves to transmit a packet. Next, the destination node 15 serves to receive a packet. In addition, a plurality of intermediate nodes are located between the source node 10 and the destination node 15 to provide a packet transmission path.

Meanwhile, when the source node 10 transmits a packet to the destination node 15, the source node 10 selects an intermediate node based on the shortest distance or the shortest hop. The source node 10 selects and transmits the first intermediate node 11, which is the node closest to the destination node 15, among the plurality of intermediate nodes included in the packet transmission distance that is the distance at which the radio waves can be reached.

The first intermediate node 11 selects the next intermediate node in the same way as the source node 10 selects the intermediate node. Accordingly, the second intermediate node 13, which is the node closest to the destination node, is selected and transmitted among the nodes whose radio waves can be reached. However, between the first intermediate node 11 and the second intermediate node 13, there are buildings, trees, and the like, which can cause radio interference, so that radio waves are disturbed during packet transmission. Therefore, there is a problem in that the probability that a packet transmitted from the first intermediate node 11 to the second intermediate node 13 arrives normally decreases.

In this regard, Korean Laid-Open Patent Publication No. 2012-0042089 (name of the invention: a cluster head node and a communication method thereof) is used in communication between communication interfaces in a cluster head node that performs communication using two different types of communication interfaces. Disclosed are a cluster head node and a communication method thereof capable of minimizing interference and improving communication performance.

In addition, Korean Patent Application Publication No. 2010-0034324 (name of the invention: apparatus and method for transmitting a packet in a node of a wireless sensor network) uses a priority queue in a node to minimize delay of a packet requiring real time, Disclosed is a packet transmission apparatus and method for a node of a wireless sensor network that implements reliable routing using queue information.

The present invention is to solve the above-described problems of the prior art, some embodiments of the present invention, when an obstacle is located in the packet path at the time of packet transmission in each node, select the node with the minimum distance cost and interference cost to transmit It is an object of the present invention to provide a routing system and method using geographical information.

As a technical means for achieving the above-described technical problem, a first aspect of the present invention provides a source node for transmitting a packet, a destination node for receiving a packet, and routing in a plurality of intermediate nodes located between the source node and the destination node. A system, comprising: a node selector for selecting an intermediate node located at a shortest distance from the destination node among a plurality of intermediate nodes included in a packet transmission distance of the source node or each intermediate node, and a routing path via the selected intermediate node And a packet transmitter for transmitting a packet by selecting a node, wherein the node selector selects an intermediate node having a minimum distance cost and an interference cost when an obstacle is located in a packet path corresponding to the shortest distance, and selects the distance cost. Is a plurality of intermediate nodes included in the packet transmittable distance and the destination; The distance between the edge nodes increases as the distance increases, and the interference cost increases as the probability of causing interference by obstacles located in the packet path increases.

In addition, a second aspect of the present invention provides a routing method in a source node for transmitting a packet, a destination node for receiving a packet, and a plurality of intermediate nodes located between the source node and the destination node, wherein the source node or each intermediate node is provided. Selecting an intermediate node located at the shortest distance from the destination node among a plurality of intermediate nodes included in the packet transmission distance of the node, and transmitting a packet by selecting a routing path through the selected intermediate node; When an obstacle is located in the packet path corresponding to the shortest distance, an intermediate node having a minimum distance cost and an interference cost is selected, and the distance cost is between a plurality of intermediate nodes included in the packet transmission distance and the destination node. Increases as the distance is greater, and the interference cost is located in the packet path. The more likely to cause interference due to the obstacles to provide a routing method to increase.

According to the above-described problem solving means of the present invention, by using the geographic information in the packet transmission, the packet can be transmitted by avoiding the section causing the radio interference, so that the packet can reach the destination node normally.

In addition, since the location information is not shared on the basis of flooding, determinism and efficiency are good.

1 is a diagram illustrating a conventional routing method.

2 is a block diagram of a routing system according to an embodiment of the present invention.

3A and 3B are diagrams illustrating an increase in distance cost in the present invention.

4A and 4B are diagrams illustrating an increase in interference cost in the present invention.

5 is a diagram illustrating a node selection method in the present invention.

6 is a flowchart of a routing method according to an embodiment of the present invention.

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.

Throughout the specification, when a part is "connected" to another part, this includes not only "directly connected" but also "electrically connected" with another element in between. . In addition, when a part is said to "include" a certain component, which means that it may further include other components, except to exclude other components unless otherwise stated. As used throughout this specification, the term "step to" or "step of" does not mean "step for."

2 is a block diagram of a routing system 100 in accordance with an embodiment of the present invention.

The routing system 100 using geographic information according to the present invention includes a node selector 110 and a packet transmitter 120.

For reference, the components illustrated in FIG. 2 according to an embodiment of the present invention mean software components or hardware components such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and perform predetermined roles. .

However, 'components' are not meant to be limited to software or hardware, and each component may be configured to be in an addressable storage medium or may be configured to reproduce one or more processors.

Thus, as an example, a component may include components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, and subs. Routines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables.

Components and the functionality provided within those components may be combined into a smaller number of components or further separated into additional components.

The node selector 110 selects an intermediate node located at the shortest distance from the destination node among a plurality of intermediate nodes included in the packet transmission distance of the source node or each intermediate node. In this case, when an obstacle is located in the packet path corresponding to the shortest distance, the node selector 110 selects an intermediate node having a minimum distance cost and an interference cost.

Meanwhile, the node selector 110 may be located in a form included in each of the source node and the plurality of intermediate nodes to select an intermediate node to transmit the next packet from each node. However, the position of the node selector 110 is not limited thereto and may be included in one server or the control management unit, instead of being included in each node, to select an intermediate node to transmit the next packet.

The node selector 110 determines whether an obstacle is located between packet paths based on a terrain map previously held. Therefore, the interference cost can be calculated by determining the presence of obstacles as well as the distance cost based on the terrain map stored in the DB. In this case, the topographic map includes topographic information on the presence or absence of a road, a building, and the like. Specifically, the topographic map may include information about a structure such as a height of a building, a width of a building, and a number of buildings. However, the topographic map is not limited to storing only the information of the structure, but may also include information about natural objects. Therefore, the topographic map may also include information about the size, width, and location of natural objects such as trees, mountains, and rivers.

The distance cost used as a criterion for selecting an intermediate node in the node selector 110 increases as the distance between a plurality of intermediate nodes and a destination node included in the packet transmission distance increases. In addition, the cost of interference increases as the probability of causing interference by obstacles located in the packet path increases.

The distance cost and the interference cost will be described with reference to FIGS. 3A to 4B.

The distance cost is used both when there is a possibility of causing radio interference between the current node and a neighboring node and when there is no possibility of causing interference. In this case, the distance cost may increase in five types as shown in FIGS. 3A and 3B.

First, as shown in FIG. 3A, the distance cost may appear in a form in which the considered cost increases as the distance increases. That is, the cost may increase in the form of a straight line in proportion to the distance, or the cost may increase in the form of an exponential function or a logarithmic function.

In addition, the distance cost may appear in a form in which the cost increases as the distance increases as shown in FIG. 3B. However, the increased form of the distance cost is not limited thereto, and the cost increases as the distance increases to a predetermined distance as shown in FIG. 3A, and the cost may increase stepwise as the distance increases as shown in FIG. 3B. . In addition, the cost increases as the distance increases up to a certain distance as shown in FIG. 3A, and after that, the cost may be maintained even if the distance increases. In addition, up to a certain distance, as the distance increases, as shown in FIG. 3B, the cost increases in a stepped manner, and after that, the same cost may be maintained even if the distance increases.

The interference cost is used only if there is a possibility of causing radio interference between the current node and the neighbor node. In this case, the interference cost may be greatly increased in five forms as shown in FIGS. 4A and 4B.

As shown in FIG. 4A, the interference cost may appear in a form in which the cost considered increases as the degree of interference increases. That is, the cost may increase in a linear form in proportion to the degree of radio wave interference, or the cost may increase in the form of a quadratic function.

In addition, the interference cost may appear in a form in which the cost increases as the degree of interference increases as shown in FIG. 4B. However, the type of increase in the cost of interference is not limited thereto, and the cost increases as the level of interference increases as shown in FIG. 4A until a certain level of interference, and the cost increases stepwise as the level of interference increases in FIG. 4B. You may. In addition, up to a certain degree of interference, the cost increases as the degree of interference increases, as shown in FIG. 4A. After that, the same cost may be maintained even if the degree of interference increases. In addition, up to a certain degree of interference, as the degree of interference increases as shown in FIG. 4B, the cost increases in a stepped manner, and after that, the same cost may be maintained even if the degree of interference increases.

Referring back to FIG. 2, when an obstacle is located in a packet path corresponding to the shortest distance, the node selector 110 selects an intermediate node located in a packet path without an obstacle among a plurality of intermediate nodes included in the packet transmission distance. Can be. At this time, the selected intermediate node is selected to be located at the shortest distance from the destination node.

In addition, when the obstacle is not located in the packet path corresponding to the shortest distance, the node selector 110 may select the intermediate node based on the distance cost without considering the interference cost. Meanwhile, the node selector 110 will be described with reference to FIG. 5.

5 is a view showing an example of a node selection method in the present invention. In this case, the node selection unit 110 has been described as being located in a form included in each node, but is not necessarily limited thereto.

The node selector 110 included in the source node 50 selects an intermediate node located at the shortest distance from the destination node 57 among the plurality of intermediate nodes included in the packet transmission distance 60 of the source node to select a packet. send. In this case, since there is no obstacle between packet paths for intermediate nodes located within the packet transmission possible distance 60 of the source node, the node selector 110 included in the source node 50 may be configured for each intermediate node. The intermediate node is selected by considering only the distance cost without considering the interference cost. Therefore, since the first intermediate node 51 has a minimum distance cost, the node selector 110 included in the source node 50 selects the first intermediate node 51 as the next transmission node.

Next, the node selector 110 included in the first intermediate node 51 transmits a packet by selecting one intermediate node among a plurality of intermediate nodes included in the packet transmission distance 70 of the first intermediate node 51. Done. In this case, the node selector 110 included in the first intermediate node 51 determines whether an obstacle is located between packet paths with a plurality of intermediate nodes included in the packet transmission distance 70 of the first intermediate node 51. To judge.

Meanwhile, in FIG. 5, an obstacle is located between the packet paths between the first intermediate node 51 and the third intermediate node 55. Therefore, the node selector 110 included in the first intermediate node 51 selects the intermediate node in consideration of the distance cost as well as the interference cost. If the node selector 110 included in the first intermediate node 51 selects the third intermediate node 55 and transmits the packet, since there is an obstacle in the packet path, the second intermediate node has no obstacle in the packet path. The cost of interference is greater than that of node 53. Therefore, the node selector 110 included in the first intermediate node 51 does not select the third intermediate node 55 having the minimum distance cost, and selects the second intermediate node 53 in consideration of the interference cost. To send the packet.

As such, when there are no obstacles between packet paths, the intermediate node may be selected by considering only the distance cost of which the distance from the destination node is the closest. However, when there is an obstacle, not only the distance cost but also the interference cost is considered. To select an intermediate node.

Referring back to FIG. 2, the packet transmitter 120 selects a routing path via the selected intermediate node and transmits a packet. As such, when the intermediate node is selected and the packet is transmitted according to whether there is an obstacle in the packet transmission path using geographic information, a section that causes radio interference can be avoided, which increases the probability of the packet reaching the destination node normally. There is an effective aspect.

First, the source node or each intermediate node determines whether an obstacle exists between packet paths to a plurality of intermediate nodes included in the packet transmission distance (S610).

In this case, when there is no obstacle between the packet paths, the intermediate node is selected in consideration of only the distance cost (S630 and S640). On the other hand, if an obstacle exists between the packet paths, the interference cost is first considered (S620), and then the intermediate node is selected in consideration of the distance cost (S630 and S640).

Meanwhile, the distance cost increases as the distance between the plurality of intermediate nodes and the destination node included in the packet transmission distance increases, and the interference cost increases as the possibility of causing interference by obstacles located in the packet path increases. However, the distance cost and the interference cost are not limited thereto, and may be represented by various types of increase as described above with reference to FIGS. 3A to 4B.

Next, the routing path via the selected intermediate node is selected to transmit the packet (S630). As described above, when the packet is transmitted using geographic information, a section causing radio wave interference can be avoided, thereby increasing the probability that the packet arrives normally.

One embodiment of the present invention can also be implemented in the form of a recording medium containing instructions executable by a computer, such as a program module executed by the computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, computer readable media may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transmission mechanism, and includes any information delivery media.

The foregoing description of the present invention is intended for illustration, and it will be understood by those skilled in the art that the present invention may be easily modified in other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

Claims

A routing system in a source node for transmitting a packet, a destination node for receiving a packet, and a plurality of intermediate nodes located between the source node and the destination node,

A node selector for selecting an intermediate node located at a shortest distance from the destination node among a plurality of intermediate nodes included in the packet transmission distance of the source node or each intermediate node;

Including a packet transmission unit for transmitting a packet by selecting the routing path via the selected intermediate node,

The node selector,

When an obstacle is located in the packet path corresponding to the shortest distance, the intermediate node having the minimum distance cost and interference cost is selected,

The distance cost increases as the distance between the plurality of intermediate nodes and the destination node included in the packet transmission distance increases;

The interference cost increases as the probability of causing interference by obstacles located in the packet path increases.
The method of claim 1,

The node selector,

When an obstacle is located in the packet path corresponding to the shortest distance, it selects an intermediate node located in the packet path without an obstacle among the plurality of intermediate nodes included in the packet transmission distance and located at the shortest distance from the destination node. Routing system.
The method of claim 1,

When the obstacle is not located in the packet path corresponding to the shortest distance, the node selector selects an intermediate node based on a distance cost,

The distance cost increases as the distance between the plurality of intermediate nodes and the destination node included in the packet transmittable distance increases.
A routing method in a source node for transmitting a packet, a destination node for receiving a packet, and a plurality of intermediate nodes located between the source node and the destination node,

Selecting an intermediate node located at the shortest distance from the destination node among a plurality of intermediate nodes included in the packet transmission distance of the source node or each intermediate node;

Selecting a routing path via the selected intermediate node to transmit a packet;

When an obstacle is located in the packet path corresponding to the shortest distance, the intermediate node having the minimum distance cost and interference cost is selected,

The distance cost increases as the distance between the plurality of intermediate nodes and the destination node included in the packet transmission distance increases;

The interference cost increases as the probability of causing interference by obstacles located in the packet path increases.
The method of claim 4, wherein

When an obstacle is located in the packet path corresponding to the shortest distance, it selects an intermediate node located in the unobstructed packet path among the plurality of intermediate nodes included in the packet transmission distance and located at the shortest distance from the destination node. Routing method.
The method of claim 4, wherein

Selecting the middle node located at the shortest distance,

If the obstacle is not located in the packet path corresponding to the shortest distance, the intermediate node is selected based on the distance cost,

The distance cost increases as the distance between the plurality of intermediate nodes and the destination node included in the packet transmittable distance increases.