JP2005341231A - Method of routing and radio equipment using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out routing considering a communication speed in an ad hoc network. <P>SOLUTION: An input part 30 inputs a prescribed signal. A routing information generation part 38 generates routing information and, in each of at least one route of the ad hoc network, leads out the communication speed and line quality between a terminal device to which a data packet has to be transmitted directly, and makes the led out communication speed and line quality correspond to the routing information by a DSDV system, respectively. A storage part 44 stores the routing information. A determination part 32 determines the terminal device to which the data packet has to be transmitted based on the routing information stored in the storage part 44 so as to satisfy a requested condition. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a routing technique, and more particularly to a routing method for determining a route for transmitting a signal in an ad hoc network and a wireless device using the routing method.

An ad hoc network is a network that includes only terminal devices without depending on the configuration of a base station device or backbone network in a wireless communication system such as a mobile communication system. In an ad hoc network, terminal devices communicate with each other on an equal basis. Further, even a terminal device that cannot communicate directly, the signal can be relayed by another terminal device, so that communication can be executed (see Non-Patent Document 1, for example).
Baruch Awakebuch, David Holmer, Herbert Rubens, “High Throughput Route Selection in Multi-Rate Ad Hoc Wireless Network”, First Forest. 251-268, 2004

  Since an ad hoc network does not include a base station device or a switch as in a mobile communication system, control of a signal path to be communicated, that is, control of routing is executed by a terminal device. Therefore, conventionally, a DSDV (Destination Sequential Distance Vector) method or the like is used. In DSDV, terminal devices exchange information about terminal devices that can communicate with each other, and a signal arrives at a terminal device to which a signal should be transmitted directly to transmit a signal to a destination terminal device and a terminal device that is a destination ( Each terminal device manages information such as the number of terminal devices (hereinafter referred to as “hop count”) that are relayed until the combination of terminal devices that are routed to reach each other is called a “route”. When receiving a signal to be relayed, the terminal device confirms the destination of the signal and selects a route that minimizes the number of hops to the signal destination. As a result, the terminal device transmits a signal to the terminal device that should transmit the direct signal included in the selected route.

  Under such circumstances, the present inventor has come to recognize the following problems. When the communication speed in the terminal device used in the ad hoc network is variable, for example, when the modulation scheme and the coding rate can be set variably, the communication speed varies depending on the route selected by the terminal device. Therefore, if a path with a high communication speed, that is, a path that can use a modulation scheme with a large number of modulation multi-values is selected, many signals can be transmitted in the same time. On the other hand, there are various types of data to be transmitted in an ad hoc network, and when data is downloaded from a predetermined server, a route with a high communication speed is required, but an application with high real-time properties such as an IP phone is used. In some cases, a route with less delay is required. Therefore, simply selecting a route with a high communication speed may fail to satisfy the requirements of an application used in an ad hoc network, and traffic on the route may increase.

  The present inventor has recognized the above situation and made the present invention. The purpose of the present invention is to select a route for transmitting data according to the nature of data transmitted in an ad hoc network, and to use the routing method. Is to provide a wireless device.

  One embodiment of the present invention is a wireless device. This device derives and derives a communication speed between a storage unit that stores information related to at least one route of the ad hoc network and a wireless device that should directly transmit a signal in each of the at least one route of the ad hoc network. A deriving unit that associates the information regarding at least one route of the ad hoc network storing the communication speed, a receiving unit that receives a signal from a predetermined wireless device included in the ad hoc network, and a destination of the signal from the received signal And the conditions required up to the destination, and the information on at least one route of the stored ad hoc network is associated with the information based on the acquired signal destination and the conditions required up to the destination. The signal should be sent directly with reference to the communication speed A determination unit for determining a line device, with respect to the determined wireless device, and a transmitter for transmitting the received signals.

The “conditions required by the destination” are, for example, a communication speed and a delay time, which are required by an application corresponding to the signal.
“Route information” includes a terminal device that is a signal destination, a terminal device that is to transmit a signal next, the number of hops to the terminal device that is the signal destination, and the like to execute routing control in an ad hoc network This is necessary information. “Communication speed” means a communication speed per unit time, which is characterized by an error correction coding rate and a modulation method.

  With the above apparatus, communication speed can be considered for routing control in an ad hoc network. Therefore, routing control according to the communication speed required for the signal to be transmitted can be executed.

  The deriving unit also derives the channel quality with the radio apparatus to which the signal should be directly transmitted, and associates the derived channel quality with information on at least one path of the ad hoc network storing the derived channel quality. The wireless device to which the signal should be directly transmitted may be determined with reference to the channel quality associated with the information based on the destination and the conditions required up to the destination. The deriving unit requests the wireless device that should directly transmit the signal to measure the channel quality, and accepts the channel quality measured by the wireless device that should directly transmit the signal, thereby receiving the wireless signal that should directly transmit the signal. The line quality with the apparatus may be derived.

  The “line quality” may be a value reflecting the characteristics of the wireless transmission path between wireless devices, and includes an error rate, received power, interference amount, and the like.

  Another aspect of the present invention is also a wireless device. The apparatus includes information relating to at least one route of the ad hoc network and storing information relating to at least one route to the wireless device corresponding to the destination of the signal to be transmitted, and at least one of the ad hoc network A derivation unit that derives a communication speed for each of the routes, associates the derived communication speed with information on at least one route of the ad hoc network storing the signal, a signal destination for the signal to be transmitted in the ad hoc network, and the destination An acquisition unit that acquires the required conditions, information on at least one route of the stored ad hoc network based on the acquired destination of the signal and the conditions required to the destination, and communication associated with the information See speed and A determination unit that determines a route for transmitting a signal among at least one route of the hook network, and a transmission unit that transmits a signal to a wireless device that should directly transmit the signal of the determined route. .

A “destination” is a wireless device that ultimately transmits a signal to be transmitted.
With the above device, the communication speed can be taken into consideration for the routing control in the ad hoc network, and the terminal device corresponding to the transmission source to which the signal should be transmitted can determine the signal path.

  The deriving unit may use a communication speed between predetermined wireless devices among at least one path of the ad hoc network as a communication speed for each of the at least one path of the ad hoc network. The derivation unit also derives line quality for each of at least one route of the ad hoc network, associates the derived line quality with information on at least one route of the ad hoc network that stores the derived line quality, and the determination unit determines the destination of the acquired signal. On the basis of the conditions required up to the destination, the channel quality associated with the information may also be referred to determine a route for transmitting a signal among at least one route of the ad hoc network. The deriving unit may use the line quality between predetermined wireless devices among at least one path of the ad hoc network as the line quality for each of the at least one path of the ad hoc network.

  The “communication speed between predetermined wireless devices” means a communication speed between two wireless devices in a path composed of a plurality of wireless devices. “The channel quality between predetermined radio devices” means the channel quality between two radio devices out of a path composed of a plurality of radio devices.

  Yet another embodiment of the present invention is a routing method. This method stores information on at least one route of the ad hoc network and the communication speed corresponding to the information, and stores the information based on the destination of the signal to be transmitted and the conditions required for the destination. With reference to the information and the communication speed, a wireless device to which a signal is to be transmitted is determined among at least one path of the ad hoc network.

  Yet another aspect of the present invention is also a routing method. The method derives a communication speed between a step of storing information on at least one route of the ad hoc network and a wireless device to which a signal should be transmitted directly in each of the at least one route of the ad hoc network. A step of associating the communication speed with information on at least one route of the ad hoc network, a step of receiving a signal from a predetermined wireless device included in the ad hoc network, and a destination of the signal and the destination from the received signal. Information about the at least one route stored in the ad hoc network based on the acquired signal destination and the conditions required up to the destination, and the communication speed corresponding to the information, respectively. See to send the signal directly It should comprising determining a wireless device, with respect to the determined wireless device, and transmitting the received signal.

  The step of associating also derives the channel quality between the wireless device to which the signal should be transmitted directly and associates the derived channel quality with the information regarding at least one route of the ad hoc network storing the determined channel quality. Based on the destination of the signal and the conditions required up to the destination, the wireless device to which the signal should be directly transmitted may be determined with reference to the line quality associated with the information. The associating step should send the signal directly by requesting the wireless device that should send the signal directly to measure the channel quality and accepting the measured channel quality at the wireless device that should send the signal directly You may derive | lead-out the channel quality between radio | wireless apparatuses.

  Yet another aspect of the present invention is also a routing method. The method comprises the steps of storing information on at least one route of the ad hoc network and information on at least one route to the wireless device corresponding to the destination of the signal to be transmitted; and at least one route of the ad hoc network Deriving the communication speed for each of the above, and associating the derived communication speed with information related to at least one route of the ad hoc network storing the derived communication speed, and for the signal to be transmitted in the ad hoc network, the signal destination and the destination A step of acquiring the required conditions, information on at least one route of the stored ad hoc network based on the acquired signal destination and the conditions required to the destination, and communication associated with the information, respectively. See speed Determining a route for transmitting a signal among at least one route of the ad hoc network, and transmitting a signal to a wireless device to which the signal in the determined route is to be directly transmitted. .

  The step of associating may use a communication speed between predetermined wireless devices among at least one path of the ad hoc network as a communication speed for each of the at least one path of the ad hoc network. The step of associating also derives the line quality for each of at least one route of the ad hoc network, associates the derived line quality with the information regarding at least one route of the ad hoc network, and determines the acquired signal. The route to which a signal should be transmitted may be determined out of at least one route of the ad hoc network with reference to the line quality associated with the information, based on the destination and the conditions required up to the destination. . The step of associating may use the line quality between predetermined wireless devices among at least one path of the ad hoc network as the line quality for each of the at least one path of the ad hoc network.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the path | route which transmits data can be selected according to the property of the data transmitted by an ad hoc network.

(Example 1)
Before describing the present invention in detail, an outline will be described. Embodiment 1 of the present invention relates to a communication system including a plurality of terminal devices, and the communication system further forms an ad hoc network. Each of the plurality of terminal devices exchanges routing information including the destination terminal device, the terminal device to which the signal is to be transmitted, the number of hops, etc., and updates its own routing information based on the received routing information. When receiving a signal from a predetermined terminal device, the terminal device determines a terminal device to which the signal is to be transmitted with reference to the routing information based on the destination of the signal. Here, since the terminal apparatus according to the present embodiment can variably set the communication speed, information on the communication speed and the error rate is added to the routing information described above. That is, when determining a terminal device to which a signal is to be transmitted, the degree of communication speed and the line quality can be considered.

  Furthermore, in the communication system according to the present embodiment, information on required quality is included in a data packet that is a signal to be transmitted. The information on the required quality corresponds to contents such as a high communication speed and a small delay time, and these are specified according to the type of data to be transmitted. The terminal device that has received the data packet as described above determines the terminal device to which the data packet is to be transmitted with reference to the stored routing information according to the destination of the data packet and the required quality. For example, when a high communication speed is required, a data packet is transmitted to a terminal device that has a high communication speed on the route to the destination. In addition, when a small delay time is required, a data packet is transmitted to a terminal device having a small delay time in the route to the destination.

  FIG. 1 illustrates a configuration of a communication system 100 according to the first embodiment. The communication system 100 includes a first terminal device 10a, a second terminal device 10b, a third terminal device 10c, a fourth terminal device 10d, a fifth terminal device 10e, and a sixth terminal device 10f, which are collectively referred to as the terminal device 10.

  The terminal device 10 has a function of transmitting, relaying, or receiving data. Here, the terminal device 10 is a wireless LAN compliant with the IEEE802.11b standard, and therefore the communication speed is selected from 11 Mbps, 5.5 Mbps, 2 Mbps, and 1 Mbps. Here, in the case of 11 Mbps, the communication speed is high, but the line quality is likely to deteriorate. On the other hand, in the case of 1 Mbps, the communication speed is low, but the line quality is hardly lowered. Therefore, 1 Mbps has the characteristics that the transmission distance becomes longer and the number of retransmissions also decreases. Although only the terminal device 10 is shown in the figure, a personal computer may be connected to the terminal device 10.

  The plurality of terminal devices 10 constitutes an ad hoc network. As an example, the first terminal device 10a is a data transmission source, and the sixth terminal device 10f is a data destination. Furthermore, as a route from the first terminal device 10a to the sixth terminal device 10f, a route passing through the second terminal device 10b and the third terminal device 10c (hereinafter referred to as “first route”), and a second terminal device 10b. And a route passing through the fourth terminal device 10d and the fifth terminal device 10e (hereinafter referred to as “second route”). Here, the first route has a smaller number of hops than the second route, but the distance between the terminal devices 10 on the second route is shorter than the distance between the terminal devices 10 on the first route. That is, the second route allows a higher transmission rate than the first route. On the other hand, the transmission delay time of the first route can be made smaller than that of the second route.

  Here, as a premise of the present embodiment, it is assumed that the communication system 100 is executing a routing method such as the DSDV method. In other words, each terminal device 10 has a “Destination”, “NextHop (terminal device to which data is to be directly transmitted)”, “Metric (number of hops)”, “Sequence number” with other DSDVs. , “Install” and “Flags” are exchanged. The terminal device 10 updates the latest routing information based on the exchanged routing information. That is, these pieces of information correspond to information related to at least one route of the ad hoc network. In particular, among these, “Destination”, “NextHop”, and “Metric” are related to the description of this embodiment.

  FIG. 2 shows the configuration of the second terminal apparatus 10b. The second terminal device 10b includes an antenna 12, an RF unit 14, a modem unit 16, a processing unit 18, an IF unit 20, and a control unit 22.

  The antenna 12 transmits and receives radio frequency signals. Here, the number of antennas and directivity are arbitrary. The RF unit 14 performs frequency conversion between a radio frequency signal transmitted and received by the antenna 12 and a baseband signal processed by a modem unit 16 described later. Also, amplification processing, analog-digital conversion processing, and digital-analog conversion processing are executed.

  The modem unit 16 performs modulation processing and spreading processing on the signal to be transmitted, and performs despreading processing and demodulation processing on the received signal. Also, error correction processing and the like are executed. As described above, since the terminal apparatus 10 supports a plurality of communication speeds, the modem unit 16 corresponds to a plurality of modulation schemes. It is assumed that the modulation method used by the modem unit 16 in the modulation process is specified by the processing unit 18 or the control unit 22. The processing unit 18 executes routing processing corresponding to the ad hoc network. Details will be described later. The IF unit 20 connects a personal computer (not shown) or a wired network. The control unit 22 controls processing necessary for the operation of the terminal device 10 such as timing control. In addition, although the 2nd terminal device 10b was demonstrated among several terminal devices 10 here, it is for the convenience with respect to the below-mentioned description, and the other terminal devices 10 also have the same structure.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of an arbitrary computer, and in terms of software, it is realized by a program having a reservation management function loaded in memory. The functional block realized by those cooperation is drawn. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.

  FIG. 3 shows the configuration of the processing unit 18. The processing unit 18 includes an input unit 30, a determination unit 32, a data packet generation unit 34, an output unit 36, and a routing information generation unit 38. The routing information generator 38 includes a generator 40, a notification message processor 42, a storage unit 44, a message transmission controller 46, a request message generator 48, a request message processor 50, a response message generator 52, and a response message process. Unit 54, measurement message generation unit 56, measurement message processing unit 58, and notification message generation unit 60.

  The input unit 30 inputs a predetermined signal from the modem unit 16 in FIG. The signal includes not only a data packet transmitted by the communication system 100, that is, a data packet received from a predetermined terminal device 10 included in the ad hoc network, but also a data packet used to generate routing information.

  The routing information generation unit 38 generates routing information. Here, the routing information generation unit 38 derives the communication speed and the line quality with the terminal device 10 that should directly transmit the data packet in each of at least one route of the ad hoc network, and the derived communication speed and the line quality. Are respectively associated with the routing information in the DSDV system. In particular, since the communication speed and the line quality cannot be determined by only one terminal apparatus 10, the terminal apparatus 10 requests the predetermined terminal apparatus 10 to measure the communication speed and the line quality, and the predetermined terminal apparatus 10 Accepts the line quality measured at.

  The above will be described in accordance with the configuration of the figure as follows. Message transmission controller 46, request message generator 48, request message processor 50, response message generator 52, response message processor 54, measurement message generator 56, measurement message processor 58, notification message generator 60, notification message The processing unit 42 derives the communication speed and the line quality with the terminal device 10 that should directly transmit the signal. The generation unit 40 associates the derived communication speed and line quality with the routing information based on the DSDV method. Here, since the communication speed and the line quality are measured between the two terminal devices 10, these will be described as the acquisition-side terminal device 10 and the measurement-side terminal device 10, but one terminal device 10 has both functions. Have The acquisition-side terminal device 10 is a terminal device 10 that finally acquires information on communication speed and line quality, and the measurement-side terminal apparatus 10 provides the acquisition-side terminal apparatus 10 with communication speed and line quality. The terminal device 10 measures these.

  The message transmission control unit 46 determines that the acquisition-side terminal device 10 newly acquires or updates the communication speed and line quality. This is determined at a regular timing or an arbitrary timing. Arbitrary timing is the timing recognized that the communication state of the terminal device 10 changed, for example. The request message generation unit 48 generates and transmits a request message for notifying the measurement side terminal device 10 of the determination made by the message transmission control unit 46. The request message includes the communication speed to be measured by the measurement-side terminal device 10 and the number of times a measurement message to be described later is transmitted at the communication speed.

  The request message processing unit 50 receives the request message from the acquisition-side terminal device 10 in the measurement-side terminal device 10 and determines whether or not measurement is possible. The measurement-side terminal device 10 determines to reject the measurement if the data packet communication load is high. Moreover, you may decide to refuse measurement for reasons other than this. The response message generation unit 52 generates and transmits a response message for notifying the acquisition-side terminal apparatus 10 of the determined measurement availability. The response message includes information regarding whether or not measurement is possible.

  The response message processing unit 54 receives the response message from the measurement-side terminal device 10 in the acquisition-side terminal device 10 and confirms whether measurement is possible. The measurement message generator 56 transmits a measurement message to be used when the measurement-side terminal device 10 measures the line quality. At that time, the measurement message is transmitted a plurality of times while changing the communication speed. For example, first, a measurement message of 11 Mbps is transmitted, then a measurement message of 5.5 Mbps is transmitted, and subsequently, a measurement message of 2 Mbps and a measurement message of 1 Mbps are transmitted. The number of transmissions is in accordance with the information included in the request message.

  The measurement message processing unit 58 receives the measurement message at the measurement-side terminal device 10 and measures the error rate at the communication speed corresponding to the received measurement message. For example, a measurement message corresponding to 11 Mbps is received a plurality of times, and the error rate is measured by counting the number of measurement messages correctly received. If all measurement messages at a predetermined communication speed can be received correctly, the error rate is 0%. If all measurement messages at a predetermined communication speed cannot be received, the communication speed cannot be used. The notification message generator 60 generates and transmits a notification message for notifying the acquisition side terminal device 10 of the measurement result. The notification message includes the measured communication speed and the error rate at the communication speed.

  The notification message processing unit 42 receives the notification message at the acquisition-side terminal device 10 and outputs the notification message to the generation unit 40. As described above, the generation unit 40 generates routing information by the DSDV method. Further, the communication speed and the line quality notified from the notification message processing unit 42 are associated with the routing information to obtain new routing information. The storage unit 44 stores the routing information generated by the generation unit 40. FIG. 4 shows the data structure of the routing information stored in the storage unit 44. “Destination” indicates the terminal device 10 to which the data packet is to be finally transmitted. Here, the sixth terminal device 10f is illustrated, but it is assumed that information regarding the other terminal devices 10 is also included. “Destination” indicates the terminal device 10 to which the data packet is to be directly transmitted. “Metric” indicates the number of hops to the terminal device 10 corresponding to “destination”. The above is generated by the DSDV method. Furthermore, “communication speed” and “error rate” are values measured as described above.

  Returning to FIG. The determination unit 32 determines the destination terminal device 10 when relaying the data packet. The determination unit 32 acquires the condition and destination required for the data packet from the received data packet, and refers to the routing information stored in the storage unit 44 based on the acquired condition and the destination of the signal to determine the signal. The terminal device 10 to be directly transmitted is determined. The required conditions are, for example, a communication speed, a transmission delay time, and a line quality. FIGS. 5A to 5C show the format of the data packet according to the first embodiment. These all target IP packets. In the wireless section between the plurality of terminal apparatuses 10, a wireless header signal or preamble signal is added to the IP packet as shown in the figure, but is omitted here.

  FIG. 5A shows a case where a required condition is included in the TOS (Service of Type) field of the IP header. Here, QoS requirement conditions defined in the TOS field can be specified, and the requirement conditions correspond to priority, delay, throughput, and reliability. FIG. 5B shows the case where the request condition is included in the option field of the IP header, and FIG. 5C shows the case where the request condition is included in the TCP / UDP data. In these cases, the required conditions are specified according to a predetermined rule. For example, “throughput of 500 kbps or more”, “error rate of 5% or less”, “delay of 100 msec or less” is designated.

  Returning to FIG. An example of the operation of the determination unit 32 is shown below. Here, it is assumed that a predetermined terminal device 10 is designated as the destination. For example, if the requested conditions are “high throughput” and “no delay request”, the determination unit 32 selects the destination terminal device 10 having a high communication speed. As a result, the number of hops tends to increase. If the requested condition is “no throughput required” or “low delay”, the determination unit 32 selects the terminal device 10 having a small metric so as to reduce the number of hops. If the requested conditions are “high throughput” and “low delay”, the determination unit 32 selects a terminal device 10 that has a high communication speed and a small metric. If the requested conditions are “no request for throughput”, “no delay request”, and “low error rate”, the determination unit 32 selects a terminal apparatus 10 that has a low error rate. The data packet generation unit 34 generates a data packet for the terminal device 10 determined by the determination unit 32, and the output unit 36 outputs the generated data packet to the terminal device 10 determined by the determination unit 32.

  FIG. 6 is a sequence diagram showing a procedure for generating routing information in the second terminal apparatus 10b. Here, the second terminal device 10b corresponds to the acquisition-side terminal device 10 described above, and the third terminal device 10c corresponds to the measurement-side terminal device 10 described above. The second terminal device 10b transmits a request message to the third terminal device 10c (S10). The third terminal device 10c transmits a response message to the second terminal device 10b (S12). At the same time, the third terminal device 10 prepares for measurement. The second terminal device 10b transmits the measurement message to the third terminal device 10c a plurality of times (S14 to S20). Here, the number of transmissions of the measurement message is four, but it may be other than this. The third terminal device 10c includes the measurement result in the notification message and transmits it to the second terminal device 10b (S22).

  FIG. 7 is a flowchart showing a processing procedure in the request message generator 48. The request message generator 48 receives a request message transmission instruction from the message transmission controller 46 (S30). If the terminal device 10 is not performing processing such as data packet relay (N in S32), the request message generator 48 generates a request message (S34) and transmits the request message from the output unit 36 (S36). . On the other hand, if the terminal device 10 is performing processing such as data packet relaying (Y in S32), the processing is terminated without generating a request message.

  FIG. 8 is a flowchart showing a processing procedure in the response message generator 52. When the request message processing unit 50 receives the request message (S40), if the response message generating unit 52 can execute the measurement process (Y in S42), for example, if the terminal device 10 is not performing the data packet relay process, the measurement is performed. A response message indicating the possibility is generated (S44). On the other hand, if the response message generation unit 52 cannot execute the measurement process (N in S42), for example, if the terminal device 10 is performing a data packet relay process, the response message generation unit 52 generates a response message indicating that measurement is not possible ( S46). The output unit 36 transmits the generated response message (S48).

  FIG. 9 is a flowchart showing a processing procedure in the measurement message generator 56. The response message processing unit 54 receives the response message (S50). If measurement is permitted in the received response message (Y in S52), the measurement message generator 56 generates a measurement message (S54). The output unit 36 transmits the generated measurement message (S56). On the other hand, if measurement is not permitted in the received response message (N in S52), the measurement message generator 56 ends the process without generating a measurement message.

  FIG. 10 is a flowchart showing a processing procedure in the notification message generator 60. The measurement message processing unit 58 receives the measurement message (S60) and measures the error rate (S62). If the measurement has not been completed (N in S64), these processes are repeated. When the measurement is completed (Y in S64), the notification message generating unit 60 generates a notification message including the measurement result (S66). The output unit 36 transmits a notification message (S68).

  FIG. 11 is a flowchart illustrating a processing procedure in the generation unit 40. The notification message processing unit 42 receives the notification message (S70). If the content of the received notification message, that is, the value of the communication speed and the error rate is different from the routing information stored in the storage unit 44 (Y in S72), the generating unit 40 generates the routing information (S74). The storage unit 44 stores the generated routing information (S76). On the other hand, when the content of the received notification message is the same as the routing information stored in the storage unit 44 (N in S72), the generation unit 40 ends the process.

  FIG. 12 is a flowchart illustrating a processing procedure in the determination unit 32. The input unit 30 receives the data packet (S80). Based on the request condition, the determination unit 32 refers to the routing information stored in the storage unit 44 and determines the destination terminal device 10 and the communication speed (S82). The data packet generator 34 generates a data packet (S84). The output unit 36 transmits a data packet (S36).

  According to the embodiment of the present invention, since the communication speed is considered in the routing control, it is possible to select a route on which the high communication speed is executed when relaying data requiring a high communication speed. In addition, since the line quality is taken into consideration in the routing control, it is possible to select a route for executing the high line quality when relaying data requiring high line quality. Further, since the route is changed even if the destination is the same, the concentration of traffic can be prevented. In addition, since the data communication is prioritized over the measurement of the communication speed and the line quality, the measurement does not affect the data communication. In addition, the measurement of the communication speed and the line quality does not require real-time property, so that the processing need not be fast. QoS can also be considered in ad hoc networks. Further, it can be easily applied to table-driven routing.

(Example 2)
The second embodiment of the present invention relates to a communication system that forms an ad hoc network as in the first embodiment. Further, when routing is performed in the same manner as in the first embodiment, communication speed and error rate information is added to routing information including a destination terminal device, a terminal device to which a signal is to be transmitted, and the number of hops. The first embodiment is so-called table-driven routing in which each terminal device performs routing for relaying a data packet based on routing information that each of a plurality of terminal devices included in the ad hoc network has. However, the second embodiment relates to so-called source routing in which a terminal device that is a transmission source of a data packet determines a route of the data packet, and a terminal device included in the route relays the data packet as determined. .

  The processing unit 18 according to the second embodiment is the same type as the processing unit 18 of FIG. Here, it demonstrates centering on the difference of each component. The storage unit 44 stores routing information as in the first embodiment. However, in the second embodiment, routing information corresponding to source routing is stored. That is, the storage unit 44 stores information on at least one route of the ad hoc network and information on at least one route to the terminal device 10 corresponding to the destination of the data packet to be transmitted.

  FIG. 13 shows the data structure of the routing information stored in the storage unit 44, which corresponds to the routing information stored in the first terminal device 10a of FIG. The “destination” and “destination” included in the storage unit 44 of FIG. 13 are the same as those of the storage unit 44 of FIG. “Via” indicates the terminal device 10 that is relayed on the route from the first terminal device 10a of “transmission source” to the sixth terminal device 10f of “destination”. That is, the upper stage corresponds to the aforementioned first path, and the lower stage corresponds to the aforementioned second path. Of the paths from the first terminal apparatus 10a to the sixth terminal apparatus 10f, the first terminal apparatus 10a corresponding to the data transmission source controls the path. In the case of the first route, the second terminal device 10b and the third terminal device 10c relay the data packet based on an instruction from the first terminal device 10a. The same applies to the second route.

  The storage unit 44 of the second embodiment also stores “communication speed” and “error rate” as in the first embodiment. That is, the communication speed and line quality for each of at least one route of the ad hoc network are derived. Here, since the route such as the first route and the second route includes a plurality of terminal devices 10, the communication speed and the line quality between the predetermined terminal devices 10 are used. For example, the communication speed and line quality in the second terminal device 10b and the third terminal device 10c are used in the first route, and the communication speed in the second terminal device 10b and the fourth terminal device 10d in the second route. Assume that you are using line quality. It is assumed that these sections are sections in which the communication speed is low and the line quality is poor in each of the first route and the second route. This is because the communication speed and the line quality for the route are affected by a section where the communication speed is low and the line quality is bad.

  The input unit 30 acquires a request condition and a destination for the data packet to be transmitted through the ad hoc network from the IF unit 20 of FIG. Although not shown, it is assumed that these pieces of information are input from a predetermined application via the IF unit 20. The determination unit 32 refers to the routing information stored in the storage unit 44 based on the request condition and the destination, selects a route, and identifies the terminal device 10 corresponding to the “transmission destination” of the route. The data packet generation unit 34 and the output unit 36 transmit a data packet to the identified terminal device 10. When the terminal device 10 relays the data packet, the routing control is not executed and the data packet is transmitted to the next terminal device 10 according to the route information included in the data packet.

  FIG. 14 is a sequence diagram illustrating the routing information generation procedure according to the second embodiment. As a premise, it is assumed that the first terminal device 10a to the sixth terminal device 10f have already acquired information on the communication speed and line quality with any terminal device 10 by the method described in the first embodiment. . Here, a process will be described in which the first terminal device 10a collects information on the communication speed and the line quality acquired by the second terminal device 10b to the sixth terminal device 10f, respectively. The first terminal apparatus 10a transmits a request signal to the second terminal apparatus 10b (S100). The second terminal device 10b transmits a request signal to the third terminal device 10c (S102), and the third terminal device 10c transmits a request signal to the sixth terminal device 10f (S104). The second terminal device 10b transmits a request signal to the fourth terminal device 10d (S106), and the fourth terminal device 10d transmits a request signal to the fifth terminal device 10e (S108). 10e transmits a request signal to the sixth terminal apparatus 10f (S110).

  The sixth terminal device 10f notifies the third terminal device 10c of information (S112), and the third terminal device 10c adds its own information to the received information and notifies the second terminal device 10b (S114). The sixth terminal device 10f notifies the fifth terminal device 10e of information (S116), and the fifth terminal device 10e adds its own information to the received information and notifies the fourth terminal device 10d (S118). The fourth terminal apparatus 10d adds its own information to the received information and notifies the second terminal apparatus 10b (S120). Finally, the second terminal apparatus 10b adds its own information to the received information and notifies the first terminal apparatus 10a (S122). The 1st terminal device 10a produces | generates the routing information shown in FIG. 13 based on the information acquired in this way.

  According to an embodiment of the present invention, the present invention can be applied to source routing. In addition, since the communication speed is taken into consideration in the routing control, it is possible to select a route on which the high communication speed is executed when data requiring a high communication speed is relayed. In addition, since the line quality is taken into consideration in the routing control, it is possible to select a route for executing the high line quality when relaying data requiring high line quality. Further, since the route is changed even if the destination is the same, the concentration of traffic can be prevented. In addition, since data communication is given priority over measurement of communication speed and line quality, measurement does not affect data communication. In addition, the measurement of the communication speed and the line quality does not require real-time property, so that the processing need not be fast. QoS can also be considered in ad hoc networks. Further, since the communication speed and line quality use values in a section that most affects communication, the entire route can be controlled with a margin.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the first and second embodiments of the present invention, the communication system 100 has been described as a wireless LAN compliant with the IEEE802.11b standard. However, the present invention is not limited to this. For example, the communication system 100 may be another wireless communication system. For example, a wireless LAN conforming to the IEEE 802.11a standard. According to this modification, the present invention can be applied to various wireless communication systems. That is, any wireless communication system compatible with an ad hoc network may be used.

  In the first and second embodiments of the present invention, the communication speed has been described as the communication speed defined by the wireless LAN. However, the present invention is not limited to this. For example, the communication speed may be an effective throughput. The throughput may be measured by ping or the like, or may be derived from the communication speed and error rate. According to this modification, routing control can be executed at a substantial communication speed. That is, it is only necessary to recognize the communication speed.

  In Embodiments 1 and 2 of the present invention, description has been made assuming that the channel quality is an error rate. However, the present invention is not limited to this. For example, reception power or interference amount may be used. In that case, the received power and the amount of interference are measured in the same sequence as in the first and second embodiments. According to this modification, routing control can be executed based on a measurement amount that affects the wireless communication system being used. That is, it is only necessary to recognize the line quality.

  In the second embodiment of the present invention, the terminal device 10 uses the values in the section where the communication speed is low and the line quality is poor among the routes to the terminal apparatus 10 corresponding to the destination as the communication speed and the line quality of the route. . However, the present invention is not limited to this. For example, the communication speed and line quality in each section of the route may be averaged to obtain the communication speed and line quality of the route. The statistical processing is not limited to the average. According to this modification, routing control can be executed based on the overall communication speed and line quality of the route. That is, it is only necessary to recognize the communication speed and line quality corresponding to the route.

  An invention combining the first and second embodiments of the present invention is also effective. According to this modification, an effect obtained by combining the first embodiment and the second embodiment can be obtained.

1 is a diagram illustrating a configuration of a communication system according to a first embodiment. It is a figure which shows the structure of the 2nd terminal device of FIG. It is a figure which shows the structure of the process part of FIG. It is a figure which shows the data structure of the routing information memorize | stored in the memory | storage part of FIG. FIGS. 5A to 5C are diagrams illustrating the format of the data packet according to the first embodiment. It is a sequence diagram which shows the production | generation procedure of the routing information in the 2nd terminal device of FIG. It is a flowchart which shows the process sequence in the request message production | generation part of FIG. It is a flowchart which shows the process sequence in the response message production | generation part of FIG. It is a flowchart which shows the process sequence in the measurement message production | generation part of FIG. It is a flowchart which shows the process sequence in the notification message production | generation part of FIG. It is a flowchart which shows the process sequence in the production | generation part of FIG. It is a flowchart which shows the process sequence in the determination part of FIG. It is a figure which shows the data structure of the routing information memorize | stored in the memory | storage part which concerns on Example 2. FIG. FIG. 10 is a sequence diagram illustrating a routing information generation procedure according to the second embodiment.

Explanation of symbols

10 terminal devices, 12 antennas, 14 RF units, 16 modulation / demodulation units, 18 processing units, 20 IF units, 22 control units, 30 input units, 32 determination units, 34 data packet generation units, 36 output units, 38 routing information generation units , 40 generation unit, 42 notification message processing unit, 44 storage unit, 46 message transmission control unit, 48 request message generation unit, 50 request message processing unit, 52 response message generation unit, 54 response message processing unit, 56 measurement message generation unit 58 Measurement message processing unit, 60 Notification message generation unit, 100 Communication system.

Claims (8)

A storage unit for storing information on at least one route of the ad hoc network;
In each of at least one path of the ad hoc network, a communication speed with a wireless device to which a signal is to be directly transmitted is derived, and the derived communication speed is stored in the stored information on at least one path of the ad hoc network. A derivation unit to associate with,
A receiver for receiving a signal from a predetermined wireless device included in the ad hoc network;
From the received signal, a signal destination and a condition required to the destination are acquired, and based on the acquired signal destination and a condition required to the destination, at least one of the stored ad hoc networks A determination unit that determines a wireless device to which a signal is to be directly transmitted with reference to information on a route and a communication speed associated with the information;
A transmitter that transmits the received signal to the determined wireless device;
A wireless device comprising: The derivation unit also derives channel quality with a radio apparatus that should directly transmit a signal, and associates the derived channel quality with information related to at least one route of the stored ad hoc network,
The determining unit determines a wireless device to which a signal is to be directly transmitted, referring to the channel quality associated with the information, based on the destination of the acquired signal and the conditions required for the destination. The wireless device according to claim 1.   The derivation unit requests the wireless device that should directly transmit the signal to measure the channel quality, and accepts the channel quality measured by the wireless device that should directly transmit the signal, thereby directly transmitting the signal. 3. The radio apparatus according to claim 2, wherein a channel quality with respect to the radio apparatus to be transmitted is derived. A storage unit that stores information on at least one route to the wireless device corresponding to a destination of a signal to be transmitted, which is information on at least one route of the ad hoc network;
A deriving unit for deriving a communication speed for each of at least one path of the ad hoc network, and associating the derived communication speed with information on at least one path of the stored ad hoc network;
For a signal to be transmitted on the ad hoc network, an acquisition unit that acquires a destination of the signal and a condition required until the destination;
Based on the destination of the acquired signal and the conditions required to the destination, the ad hoc network is referred to by referring to the information related to at least one route of the stored ad hoc network and the communication speed associated with the information. A determination unit that determines a route for transmitting a signal among at least one of the routes;
A transmitter that transmits a signal to a wireless device that should directly transmit the signal in the determined path;
A wireless device comprising:   5. The derivation unit according to claim 4, wherein a communication speed between predetermined wireless devices among at least one path of the ad hoc network is set as a communication speed for each of at least one path of the ad hoc network. Wireless devices. The derivation unit also derives line quality for each of at least one route of the ad hoc network, and associates the derived line quality with information related to at least one route of the stored ad hoc network,
The determining unit refers to a line quality associated with the information based on a destination of the acquired signal and a condition required to the destination, and determines a signal among at least one path of the ad hoc network. 6. The wireless device according to claim 4 or 5, wherein a route for transmitting a message is determined.   7. The derivation unit according to claim 6, wherein, among at least one route of the ad hoc network, the line quality between predetermined wireless devices is set as a line quality for each of at least one route of the ad hoc network. Wireless devices. Information on at least one route of the ad hoc network and the communication speed corresponding to the information are stored, and the stored information and communication are based on the destination of the signal to be transmitted and the conditions required for the destination. A routing method, wherein a wireless device to which a signal is to be transmitted is determined from at least one path of the ad hoc network with reference to speed.

Images