JP2016082465A - Communication apparatus and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication apparatus capable of increasing the reliability and the throughput in communication and capable of distributing the load by using plural channels while reducing the delay at low manufacturing cost, and to provide a communication method.SOLUTION: The communication apparatus has a sub-channel establishment section that establishes a sub-channel via plural nodes which are not included in a node which transmits a data transmission packet via a standard channel passing through plural nodes from a start node to a destination node, and the standard channel which passes through nodes, and which are communicable with neighboring two nodes.SELECTED DRAWING: Figure 10

Description

  Embodiments described herein relate generally to a communication apparatus and a communication method.

  In an ad hoc network in wireless communication, AODV (ad hoc on-demand distance vector routing), DSR (dynamic source routing), etc. are known as protocols for transmitting data to a desired communication device.

  These protocols are for obtaining a single path from a data transmission source communication device to a target communication device and transmitting the data. When data is transmitted through a single route, data cannot be transferred if communication is interrupted even at one location of the communication route. In addition, communication congestion may occur.

  In this regard, various techniques for transmitting data using a plurality of routes have been proposed. For example, a method of performing communication via a wireless communication device other than the shortest route when packets are transmitted to a plurality of wireless communication devices and the wireless communication device of the transmission source determines that communication of the shortest route is stagnant Has been proposed. In this technology, it can be said that different nodes use multiple paths to relay data depending on the communication status, but because different paths are used as alternative paths for the shortest path, communication efficiency over a single path can be achieved. It cannot be realized.

  As another technique, attempts have been made to improve communication reliability, load distribution, and delay reduction by using network coding that can distribute communication traffic to a plurality of paths by encoding communication data.

  However, these proposed technologies increase the manufacturing cost of the communication device because it is necessary to newly design and implement the routing protocol.

  Although there is a method that does not perform routing, data is sent wastefully to nodes that do not participate in relaying, and it is desirable to construct a route from the viewpoint of effective use of network resources.

JP 2008-294605 A

  Accordingly, there is a need for a communication apparatus and a communication method that can be manufactured at low cost and can improve communication reliability and throughput, load distribution, and delay reduction by a plurality of paths.

  The communication device according to an example of the present invention is not included in a node via a reference route that transmits a data transmission packet from a departure node to a destination node via a plurality of nodes, and is a node that passes through the reference route and is adjacent A sub route constructing unit that constructs a sub route via a plurality of nodes that can communicate with the two nodes.

It is a figure which shows the example of the radio | wireless ad hoc network which a radio | wireless communication apparatus forms. It is a figure which shows the structure of a radio | wireless communication apparatus. It is a figure which shows the packet structure of a route request packet. It is a figure which shows the packet structure of a response packet. It is a figure which shows the example of the data which an adjacent node memory | storage part memorize | stores. It is a figure which shows the setting method of a reference | standard route. 7 is a diagram illustrating an example of a route request packet received by a target node E. FIG. It is a figure which shows the packet structure of a data transmission packet. It is a figure which shows the production | generation of the subroute in data transmission. It is a flowchart which shows operation | movement of a radio | wireless communication apparatus.

  Before describing embodiments of the present invention, one feature of the present invention will be briefly described. When a data transmission packet is transmitted from a certain departure node to a destination node, a reference route through each node is determined. As a method for determining the reference path, a protocol such as the above-described AODV can be used. When determining this reference route, apart from the above-mentioned reference route, a sub route from the departure node to the destination node including the reference route node and the other nodes is also determined. The nodes that form this sub route are nodes that satisfy the so-called triangular assist condition. This triangular assist condition is a node that satisfies the two conditions of not being a node forming the reference route and being a node that can communicate with two nodes of the reference route.

  When the reference route and the sub route are determined, data is transmitted through the reference route from the departure node to the destination node, and the same data is transmitted through the sub route. Therefore, for example, even if data transmission through the reference path is interrupted, the same data is transmitted through the sub path. Therefore, the frequency of requesting retransmission from the destination node to the departure node can be reduced, and the amount of data delay can be reduced.

  Hereinafter, an embodiment of a communication device and a wireless communication method will be described in detail with reference to the drawings.

  FIG. 1 is a diagram illustrating an example of a wireless ad hoc network formed by the wireless communication device 1 of the present embodiment. A to I denote independent wireless communication apparatuses. As shown in FIG. 1, a case will be described as an example in which data is transmitted from a departure node A which is a data transmission source to a destination node E which is a wireless communication apparatus which is a data arrival purpose.

  A route from the departure node A to the destination node via the transit nodes B, C, and D, which are wireless communication devices that transfer data, is referred to as a reference route. This reference path is obtained by an existing proven method such as the Dijkstra method. The reference path varies depending on the communication path status, distance, and the like, and is not always the shortest path. The reference path may be the shortest path or the maximum bandwidth path depending on the reference information.

  On the other hand, a route that passes through one or more of the transit nodes F, G, H, and I is called a sub route. This sub route can be obtained at low cost from information of adjacent nodes that can be acquired by the reference route. The route is a route other than the reference route. As described above, the nodes constituting the sub route are nodes that satisfy the triangle assist condition.

  In the wireless communication device according to the present embodiment, the target node E first obtains a reference route and transmits the reference route to each wireless communication device. Each wireless communication device stores a reference route. Each wireless communication device stores an adjacent node that is a wireless communication device with which the own device can communicate. When a wireless communication device that is not on the reference path receives a data transmission packet for transmitting data, and determines that the own device belongs to the reference path or is an adjacent node, the wireless communication apparatus transmits the received data transmission packet as an intermediary. To participate in data relay.

  In the embodiment of the present invention, so-called triangular assist can be formed by the sub route based on the information of the adjacent nodes forming the reference route.

  FIG. 2 is a diagram illustrating a configuration of the wireless communication device 1 according to the present embodiment. As illustrated in FIG. 2, the wireless communication device 1 includes a control unit 101, a storage unit 102, a communication unit 103, an input / output unit 104, a power supply unit 105, a reference route construction unit 106, and a sub route construction unit. 107.

  The control unit 101 includes a CPU that is an arithmetic device. The storage unit 102 includes a storage device such as a memory and a hard disk drive. The storage unit 102 includes a reference route storage unit 102A and a sub route storage unit 102B.

  The reference route storage unit 102A stores a reference route, and includes a response packet storage unit 111. The response packet storage unit 111 stores a response packet in which the reference route is described.

  The sub route storage unit 102B stores the sub route, and includes an adjacent node storage unit 114 and a response packet storage unit 115.

  The adjacent node storage unit 114 sets the adjacent node identifier indicating the wireless communication device 1 immediately before transmitting the route request packet for obtaining the reference route, the departure node identifier indicating the wireless communication device 1 that issued the route request packet, and the arrival purpose. Is stored for each target node identifier indicating the wireless communication device 1.

  The response packet storage unit 115 stores a response packet in which the sub route is described. The communication unit 103 performs wireless communication with other wireless communication devices. The input / output unit 104 includes an input / output device that inputs and outputs information such as a touch panel or a display, a keyboard, a microphone, and a speaker. The power supply unit 105 supplies power.

  The reference route construction unit 106 constructs the above-described reference route, and the constructed reference route is stored in the reference route storage unit 102A as a node of the route.

  The sub route construction unit 107 constructs the above-mentioned sub route, and the constructed reference route is stored in the sub route storage unit 102B as a node of the route.

  FIG. 3 is a diagram illustrating a packet configuration of the route request packet. The route request packet is generated and transmitted by the data transmission source. When the wireless communication apparatus 1 uses AODV, the data request packet may use an RREQ (route request) packet or a hello message.

  The route request packet includes a header, a route request packet ID indicating that the packet is a route request packet, a departure node identifier, a destination node identifier, a routed node identifier indicating a routed node, and additional information. .

  When the wireless communication device 1 receives the route request packet, the wireless communication device 1 loads and broadcasts the route request packet with the identifier indicating the own device as a transit node identifier. Accordingly, since the route request packet is broadcast by each of the plurality of wireless communication apparatuses 1, it is propagated one after another. This is called flooding of route request packets.

  FIG. 4 is a diagram illustrating a packet configuration of the response packet. The response packet is generated and broadcast by the target node. When the wireless communication apparatus 1 uses AODV, the response packet may use an RREP (route reply) packet.

  As shown in FIG. 4, the response packet includes a header, a departure node identifier, a destination node identifier, a transit node identifier, and additional information.

  When the destination node receives route request packets from a plurality of routes, the destination node determines, for example, a route with the smallest number of wireless communication devices 1 that have passed through as a reference route. The target node writes a relay node identifier indicating the wireless communication device 1 belonging to the reference path in the response packet and broadcasts it.

  FIG. 5 is a diagram illustrating an example of data stored in the adjacent node storage unit 114. As illustrated in FIG. 5, the adjacent node storage unit 114 stores the adjacent node identifier as information regarding the adjacent node for each departure node identifier and destination node identifier.

  The wireless communication device 1 stores the nearest node identifier described in the route request packet in the adjacent node storage unit 114 as an adjacent node identifier.

(Setting of reference route (reference route))
6A to 6C are diagrams illustrating a method for setting a reference route. As shown in FIG. 6A, it is assumed that a departure node A, transit nodes B to D and F to I, and a destination node E are arranged. A route for transmitting data from the departure node A to the destination node E is indicated as a route “A → E”, and a header and additional information are omitted from the route request packet. A corresponds to the departure node identifier, and E corresponds to the destination node identifier.

  The departure node A broadcasts a route request packet. The route request packet 601 from A to B and A to F has a route “A → E” and a transit node identifier “A”.

  Assume that the route node B and the route node F receive this route request packet 601.

  The transit node F stores “A” that is the transit node identifier of the latest transit node in the adjacent node storage unit 114. The transit node F adds an identifier indicating its own device to the route request packet 601 to generate a route request packet 602 and broadcasts it.

  The transit node B stores “A” that is the transit node identifier of the latest transit node in the adjacent node storage unit 114. The transit node B adds an identifier indicating its own device to the route request packet 601 to generate a route request packet 603 and broadcasts it.

  A route request packet 602 and a route request packet 603 arrive at the transit node G.

  The transit node G stores “F” and “B” which are transit node identifiers of the latest transit node in the adjacent node storage unit 114. The transit node G adds an identifier indicating its own device to the route request packet 602 and the route request packet 603, generates a route request packet, and broadcasts it.

  By repeating this operation, the route request packet reaches the target node E.

  FIGS. 7A and 7B are diagrams illustrating examples of route request packets received by the target node E. FIG. Assume that the destination node E receives the route request packet 604 and the route request packet 605.

  The destination node E compares the number of hops of the received route request packet, and selects the transit node described in the route request packet with the smallest number of hops as the reference route.

  In the route request packet 604 shown in FIG. 7A and the route request packet 605 shown in FIG. 7B, the route request packet 604 has a small number of hops, so that “ABCD” described in the route request packet 604 is changed. Selected as the reference route.

  Here, a node included in the sub route, for example, the node G will be described. The nodes included in the sub route are nodes that satisfy the triangle assist condition. The triangular assist conditions are two conditions: (1) a node that is not a reference route and (2) a node that can communicate with an adjacent node on the reference route.

  The destination node E generates and broadcasts a response packet based on the selected reference route. Each relay node that has received the response packet stores the response packet in the response packet storage unit 111 and broadcasts the response packet.

  By repeating this operation, the response packet reaches the departure node.

(Sub route setting)
On the other hand, the setting of the sub route is set as a route different from the reference route determined as described above. In other words, the route starts from the departure node A and reaches the destination node E. In the middle of the route, the reference route and at least a part of the transit nodes are set as a route including an adjacent node that satisfies the triangle assist condition. To do. There may be a plurality of sub-routes.

(Data transmission)
FIG. 8 is a diagram illustrating a packet configuration of a data transmission packet. As shown in FIG. 8, the data transmission packet includes a header, a data transmission packet ID indicating that the packet is a data transmission packet, a transmission source node identifier indicating the transmission source of the packet, and data to be transmitted. ,including.

  FIG. 9 is a diagram illustrating generation of a sub route in data transmission. As shown in FIG. 9, the departure node A broadcasts a data transmission packet 901.

  The data transmission packet 901 reaches the transit node F and the transit node B. The transit node B searches the response packet storage unit 111 based on “A → E” which is the route of the received data transmission packet 901, and reads the response packet having the corresponding route.

  When the identifier of the own device is described as the reference route in the response packet, the transit node B rewrites the source node identifier with the identifier of the own device and broadcasts.

  By repeating this operation, the data transmission packet is transmitted to the target node by the reference route.

  On the other hand, the transit node F searches the response packet storage unit 115 based on “A → E” which is the route of the received data transmission packet 901, and reads the response packet having the corresponding route.

  However, in this example, the identifier of the own device is not described as the reference route in the response packet. In this case, the transit node F searches the adjacent node storage unit 114 based on “A → E” that is the route of the received data transmission packet 901 and determines whether the transmission source node identifier “A” is included. .

  When it is determined that the adjacent node storage unit 114 includes the transmission source node identifier “A”, the relay node F participates in data relay by rewriting the transmission source node identifier with its own identifier and broadcasting. The transit node F does nothing when it is determined that the adjacent node storage unit 114 does not include the transmission source node identifier “A”.

  The data transmission packet 902 from the relay node F and the data transmission packet 903 from the relay node B arrive at the relay node G.

  The relay node G searches the response packet storage unit 115 based on “A → E” that is the route of the received data transmission packet 902 and data transmission packet 903, and reads the response packet having the corresponding route.

  However, in this example, the identifier of the own device is not described as the reference route in the response packet. In this case, the transit node F searches the adjacent node storage unit 114 based on “A → E” which is the route of the received data transmission packet 902 and data transmission packet 903, and transmits the source node identifier “B” or “F "Is included.

  When determining that the adjacent node storage unit 114 includes the transmission source node identifier “B” or the transmission source node identifier “F”, the relay node G rewrites the transmission source node identifier with the identifier of the own device and broadcasts it. To participate in data relay. The transit node F does nothing if it determines that the adjacent node storage unit 114 does not include the source node identifier “B” and the source node identifier “F”.

  FIG. 10 is a flowchart showing the operation of the wireless communication device 1. As shown in FIG. 10, in step 1001, the control unit 101 receives a packet.

  In step 1002, the control unit 101 determines the type of packet. The control unit 101 proceeds to step 1003 when the received packet is a route request packet, proceeds to step 1006 when it is a response packet, and proceeds to step 1008 when it is a data transmission packet.

  In step 1003, the control unit 101 updates the adjacent node storage unit 114 based on the received route packet. In step 1004, the control unit 101 generates a new route request packet by adding the identifier of the own device to the route request packet as a transit node identifier.

  In step 1005, the control unit 101 broadcasts the generated route request packet and returns to step 1001. In step 1006, the control unit 101 stores the received response packet in the response packet storage unit 111.

  In step 1007, the control unit 101 broadcasts a response packet and returns to step 1001.

  In step 1008, the control unit 101 determines whether the identifier of the own device is included in the reference route. When it is determined that the identifier of the own device is included in the reference route, the control unit 101 proceeds to step 1010. When it is determined that the identifier is not included, the control unit 101 proceeds to step 1009.

  In step 1009, the control unit 101 determines whether the transmission source node identifier of the data transmission packet is stored in the adjacent node storage unit 114. When it is determined that the transmission source node identifier of the data transmission packet is stored in the adjacent node storage unit 114, the control unit 101 proceeds to step 1010. When it is determined that the data transmission packet is not stored, the control unit 101 returns to step 1001.

  In step 1010, the control unit 101 rewrites the transmission source node identifier of the data transmission packet with its own identifier. In step 1011, the control unit 101 broadcasts the rewritten data transmission packet and returns to step 1001.

  As described above, the wireless communication device 1 of the present embodiment stores the response packet in which the adjacent relay node describes the reference route and the information about the adjacent node in the storage unit when the reference route is set, and receives the data transmission packet In this case, it is determined whether or not the transit node participates in data relay based on information on the reference route and the adjacent node.

  Therefore, the data transmission packet is transmitted through the reference route and simultaneously through the sub route.

  In the above embodiment, the case where AODV is used as the protocol for determining the reference route has been described. However, in the present invention, other protocols may be used instead of this protocol. In the above embodiment, the wireless communication device and the wireless communication method have been described. However, the present invention can be applied not only to wireless communication but also to wired communication devices and communication methods.

  According to the present invention, it is possible to create a sub route at a low cost as described above, and to produce a plurality of routes at a low cost.

  In addition to the reference route, a sub route is also formed, and the same data transmission packet is also sent to this route, so even if data cannot be sent in the middle of the reference route, the data may be transmitted on the sub route, It is possible to reduce retransmission requests from the destination node to the departure node. Therefore, there is an advantage that the data delay amount can be reduced.

  Therefore, there is an effect that the communication speed does not decrease even if a communication failure occurs between the communication devices.

  Although several embodiments have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

1: wireless communication device 101: control unit 102: storage unit 102A: reference path storage unit 102B: sub-path storage unit 103: communication unit 111, 115: response packet storage unit 114: adjacent node storage unit

Claims (7)

  A plurality of nodes that are not included in a node through a reference route for transmitting a data transmission packet from a departure node to a destination node via a plurality of nodes, and that can communicate with two adjacent nodes through the reference route. The communication apparatus which has a sub route construction part which constructs | assembles the sub route which passes through the node of. An adjacent node storage unit that stores information on adjacent nodes based on a route request packet that requests setting of a reference route;
A response packet storage unit for storing response packets;
When a data transmission packet describing data to be transmitted is received, its own identifier is not included in the reference path, and a transmission source node identifier indicating a transmission source of the data transmission packet is stored in the adjacent node storage unit. If stored, a control unit for rewriting the source node identifier of the data transmission packet with its own identifier and broadcasting,
A communication device comprising: The controller is
When the data transmission packet is received, if the identifier of its own device is not included in the reference path, and the transmission source node identifier of the data transmission packet is not stored in the adjacent node storage unit, the data transmission packet The communication apparatus according to claim 2, wherein no broadcasting is performed. The controller is
The communication apparatus according to claim 3, wherein when the route request packet is received, the route request packet is broadcast by adding its own identifier as a route node identifier to the route request packet. Receive a data transmission packet that describes the data to be transmitted,
If it is determined that the identifier of the own device is not included in the reference route and the transmission source node identifier indicating the transmission source of the data transmission packet is stored in the adjacent node storage unit that stores information on the adjacent node, A communication method in which a transmission source node identifier of a data transmission packet is rewritten with an identifier of the own device and broadcast.   When receiving the data transmission packet, if it is determined that the identifier of its own device is not included in the reference path and the transmission source node identifier of the data transmission packet is not stored in the adjacent node storage unit, 6. The communication method according to claim 5, wherein the data transmission packet is not broadcast.   7. The communication method according to claim 6, wherein, when a route request packet requesting setting of a reference route is received, an identifier of the own device is added to the route request packet as a route node identifier and broadcasted.

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