JP4641245B2 - Ad hoc network system, wireless ad hoc terminal and failure detection method thereof - Google Patents

Description

  The present invention relates to an ad hoc network system, a wireless ad hoc terminal constituting the ad hoc network system, and a failure detection method for the wireless ad hoc terminal.

With the recent progress of wireless communication technology and the miniaturization and advancement of electronic devices, communication between communication devices is possible without using existing network infrastructure, compared to the conventional infrastructure type communication form. Interest in ad hoc network systems is growing. This ad hoc network system has the following characteristics, unlike a conventional fixed infrastructure type network (for example, a network system configured to communicate via an access point). .
(1) Communication between objects and devices.
(2) It is possible to construct an autonomous network with a huge number of objects and devices.
(3) A network independent of existing communication infrastructure can be constructed.
(4) A simple and temporary network can be constructed.
(5) Autonomy is required to cope with topology changes.

  Currently, various routing protocols (ad hoc routing protocols) for application to ad hoc network systems have been proposed in order to satisfy the above characteristics. (For example, Non-Patent Documents 1 to 3 shown below).

  Here, Non-Patent Document 1 (DSR) and Non-Patent Document 2 (AODV) are documents showing an on-demand type routing protocol. According to these protocols, when a communication request occurs, a route from the transmission source to the transmission destination is set, and an environment for performing predetermined communication is provided.

  Non-Patent Document 3 (OLSR) is a document showing a routing protocol of a proactive direction. According to this protocol, by constantly exchanging route information, an environment is provided that allows communication to be started based on the route information held when a communication request occurs.

  In addition, Patent Document 1 discloses a control method for shortening the route reconstruction time when a radio link is disconnected. In this method, the terminal that detects the disconnection of the radio link notifies the path disconnection detection packet that notifies the disconnection of the radio link, and the path information for the terminal indicated by the path disconnection detection packet is received by the receiving terminal of the path disconnection detection packet. When holding, the route is shortened by notifying the terminal that has detected the disconnection of the wireless link of the discovery of the route.

  On the other hand, in order for an ad hoc network system to become widespread, state management (network management) of devices constituting the ad hoc network system is required. In a conventional infrastructure type IP network system, a management method based on SNMP (Simple Network Management Protocol) is generally applied. In this management method, the managing side is called a “manager”, and the managed side is called an “agent”. By performing communication based on SNMP between the two, the manager collects / controls various management information. Yes. For example, the manager makes an inquiry to each agent at intervals of 15 minutes by default to confirm the agent's “dead or alive”.

JP 2001-127797 A DSR (Dynamic Source Routing) -draft-ietf-manet-dsr-10. txt AODV (Ad Hoc On-demand-Distance Vector Routing): RFC3561 OLSR (Optimized Link State Routing): RFC3626 SNMP (Simple Network Management Protocol): RFC1157

  In the conventional infrastructure-type IP network system, as described above, the manager periodically sends out an SNMP-based inquiry message (by default, every 15 minutes) to each agent. "Death" is managed. On the other hand, in an ad hoc network system, as the scale of the system increases, the network configuration constantly changes as the wireless ad hoc terminals that make up the system move, join the system, or leave the system. To do. Therefore, from the viewpoint of appropriately managing the ad hoc network system, it is necessary to set the transmission cycle of the inquiry message based on SNMP shorter than the transmission cycle applied to the conventional infrastructure type IP network system. There is. However, in an ad hoc network system composed of a large number of wireless ad hoc terminals, there are certain restrictions on the wireless resources of the wireless ad hoc terminals, and the traffic required for network management is reduced as the query message transmission period is shortened. Since it increases rapidly, there is a limit to shortening the inquiry message cycle.

  In addition, in the wireless environment, the wireless environment between adjacent nodes changes due to temporary factors such as interference, so that it is not possible to determine the failure of an adjacent node based on only information on changes in the wireless state. there were.

  Further, in the ad hoc network system to which the technologies such as Non-Patent Documents 1 to 3 described above are applied, when the disconnection of the wireless link with the adjacent node due to the change of the wireless state is detected, the route is re-established. However, there is a problem that a wireless ad hoc terminal is isolated because a failed (or possibly failed) wireless ad hoc terminal is not detected.

  In addition, the ad hoc network system to which the technology of Patent Document 1 is applied embodies the reconstruction of a detour route that avoids a terminal that may have failed or moved from the network. There is a problem in that it is not possible to manage a faulty terminal or a faulty terminal because it has not been detected whether it has failed or whether the wireless environment has changed due to movement of the terminal.

  The present invention has been made in view of the above, and an object of the present invention is to provide a method for detecting a wireless ad hoc terminal that has left the system due to a failure or the like in an ad hoc network system. Further, in an ad hoc network system, an ad hoc network composed of a wireless ad hoc terminal equipped with a function for quickly detecting departure from the system due to a failure or the like and a plurality of wireless ad hoc terminals equipped with the function. The purpose is to provide a system.

  In order to solve the above-described problems and achieve the object, the present invention forms an ad hoc network system and notifies the existence of the own terminal in a wireless ad hoc terminal that communicates with other terminals through a wireless interface. Means for generating a presence notification message, means for generating a first failure diagnosis message for performing a first failure diagnosis, means for generating a failure diagnosis request message for requesting a failure diagnosis, Means for generating a second failure diagnosis message for performing a second failure diagnosis, and means for generating a diagnosis result message with a diagnosis result for a wireless ad hoc terminal subject to failure diagnosis; Wireless link based on information about wireless ad hoc terminals or wireless interfaces that did not receive The wireless ad hoc terminal that has detected the possibility of disconnection transmits, as the wireless ad hoc terminal that performs the first failure diagnosis, the first failure diagnosis message that obligates a response to the failure diagnosis target wireless ad hoc terminal, and the first When there is no response to the first failure diagnosis message, the wireless ad hoc terminal that performs one failure diagnosis transmits the failure diagnosis request message, and the wireless ad hoc terminal that has received the failure diagnosis request message The wireless ad hoc terminal that performs the second failure diagnosis transmits the second failure diagnosis message that obligates a response to the failure diagnosis target wireless ad hoc terminal included in the request message, and the second failure diagnosis message Based on whether or not there is a response to the wireless ad hoc terminal that has performed the first failure diagnosis. And transmitting the message.

  According to the present invention, a wireless ad hoc terminal that has not received a presence notification message within a predetermined time or a wireless ad hoc terminal that has detected the possibility of wireless link disconnection based on information about a wireless interface performs a first failure diagnosis When a wireless ad hoc terminal that performs a first failure diagnosis transmits a first failure diagnosis message that requires a response to the wireless ad hoc terminal subject to failure diagnosis as a wireless ad hoc terminal, and does not respond to the first failure diagnosis message The wireless ad hoc terminal that has transmitted the failure diagnosis request message and has received the failure diagnosis request message transmits a second failure diagnosis message that obligates a response to the wireless ad hoc terminal to be diagnosed included in the failure diagnosis request message. The wireless ad hoc terminal performing the second failure diagnosis performs the second failure diagnosis. Since the diagnosis result message is transmitted to the wireless ad hoc terminal that has performed the first failure diagnosis based on the presence or absence of a response to the message, it is possible to quickly detect the wireless ad hoc terminal that has left the system due to a failure or the like. The effect is obtained.

  Embodiments of a wireless ad hoc terminal and an ad hoc network system according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Ad-hoc network system configuration)
First, an ad hoc network system according to the present invention will be described. FIG. 1 is a diagram showing a configuration of an ad hoc network system constituted by a plurality of aggregates of wireless ad hoc terminals according to the present invention. In the ad hoc network system shown in the figure, wireless ad hoc terminals 101 constituting the system are connected by one or more wireless links 102 (in the figure, wireless ad hoc terminals 101-a to i are illustrated). In this system, a predetermined communication based on an ad hoc routing protocol such as the above-described on-demand DSR, AODV, or pro-active OLSR is executed between the wireless links 102, so The function of is demonstrated.

  In addition, in the ad hoc network system shown in FIG. 1, a specific wireless ad hoc terminal operates as a manager of the management method by SNMP, and other wireless ad hoc terminals operate as agents, and the manager makes a response to each agent. , Periodic inquiries are made to confirm “dead or alive”. In the following description, it is assumed that the wireless ad hoc terminal 101-y is handled as a manager.

(Function of wireless ad hoc terminal)
Next, functions of the wireless ad hoc terminal according to the present invention will be described. FIG. 2 is a block diagram showing a functional configuration of the wireless ad hoc terminal 101. The wireless ad hoc terminal 101 shown in the figure includes a transmission / reception unit 10, a message processing unit 12, an adjacent node list holding unit 14, and a co-adjacent node table holding unit 16. The transmission / reception unit 10 transmits a predetermined message to another wireless ad hoc terminal and receives a message from the other wireless ad hoc terminal. The message processing unit 12 generates various messages defined in this embodiment, grasps the content of a message transmitted from another wireless ad hoc terminal, and stores the content in the adjacent node list holding unit 14 and the co-adjacent This is transmitted to the node table holding unit 16 and the like. The adjacent node list holding unit 14 holds information on identifiers of wireless ad hoc terminals called adjacent nodes. In addition, the co-adjacent node table holding unit 16 holds information on identifiers of wireless ad hoc terminals called co-adjacent nodes for each adjacent node. The adjacent node means a wireless ad hoc terminal other than the own terminal located in a range where wireless communication with the own terminal is possible, and the co-adjacent node is an adjacent node in one wireless ad hoc terminal is another When the wireless ad hoc terminal is also an adjacent node, it means the common adjacent node.

(Operation of wireless ad hoc terminal)
Next, with respect to the operation of the wireless ad hoc terminal 101 in the above-described ad hoc network system, the case where the wireless ad hoc terminal 101-d performs failure diagnosis of the wireless ad hoc terminal 101-a is taken as an example. Will be described with reference to FIG. FIG. 3 is a diagram illustrating a processing sequence when the wireless ad hoc terminal 101-d performs failure diagnosis of the wireless ad hoc terminal 101-a. FIG. 4 is a diagram showing a format example of a presence notification message for notifying other terminals that the own terminal exists in the system, and FIG. 5 shows holding of an adjacent node list of the wireless ad hoc terminal 101-d. 6 is a diagram illustrating an example of an adjacent node list stored in the unit 14, and FIG. 6 is a diagram illustrating an example of a co-adjacent node table stored in the co-adjacent node table holding unit 16 of the wireless ad hoc terminal 101-d. 7 is a diagram showing a format example of a failure diagnosis message transmitted from the wireless ad hoc terminal that performs the first and second failure diagnosis to the wireless ad hoc terminal that is a failure diagnosis target, and FIG. 8 is a wireless that performs the failure diagnosis. It is a figure which shows the example of a format of the failure diagnosis request message output when an ad hoc terminal requests failure diagnosis to the wireless ad hoc terminal of a co-adjacent node. Is a diagram showing a format example of a diagnostic result message is output when the wireless ad-hoc terminal in failure diagnosis request destination is notified of the failure diagnosis result in the failure diagnosis request source wireless ad hoc terminals.

  In FIG. 3, the wireless ad hoc terminal 101-y continues the periodic inquiry based on SNMP to the wireless ad hoc terminals 101-d and 101-a that have already entered the ad hoc network system (step S501). , Sequence SQ601). For example, when the wireless ad hoc terminal 101-e newly enters this ad hoc network system (step S502), the wireless ad hoc terminal 101-y is notified of the subscription (sequence SQ602), and the wireless ad hoc terminal 101-y. Starts a periodic inquiry based on SNMP to the wireless ad hoc terminal 101-e (step S503, sequence SQ603).

  Also, each of the wireless ad hoc terminals 101-a, 101-d, and 101-e participating in the ad hoc network system transmits the presence notification message shown in FIG. 4 to the adjacent node (steps S504 and S505). , S508, S509, S512, S513, sequences SQ604 to SQ609). Here, the presence notification message 201 illustrated in FIG. 4 indicates a presence notification message transmitted from the wireless ad hoc terminal 101-a to the wireless ad hoc terminals 101-d and 101-e that are adjacent nodes. That is, in the figure, the presence notification message 201 includes fields of a sender mode identifier, a lifetime, a response request flag, and a list of adjacent wireless ad hoc terminals, and the sender mode identifier includes a wireless ad hoc terminal 101-. The identifier of a is a predetermined time indicating the lifetime of this message in the lifetime, “NO_ACK” indicating that no response is required in the response request flag, and the list field of the adjacent wireless ad hoc terminal includes the wireless ad hoc The identifiers of the wireless ad hoc terminals 101-b to 101-g, which are adjacent nodes viewed from the terminal 101-a, are embedded. In addition, from the viewpoint of notifying the state of the terminal itself (“lively dead”) as the presence notification message, the list information of the adjacent wireless ad hoc terminal is not an essential requirement. However, the list information of adjacent wireless ad hoc terminals is information required when creating a co-adjacent node table described later, and it is effective in terms of suppressing traffic increase to transmit together with the presence notification message. is there.

  Returning to the sequence of FIG. 3, each of the wireless ad hoc terminals 101-a, 101-d, and 101-e is shown in FIG. 5 based on the information of the adjacent wireless ad hoc terminals included in the mutually notified presence notification message. 6 is created or updated (steps S506, S510, and S514), and the co-adjacent node table shown in FIG. 6 is created or updated based on the information of the neighboring node list in its own terminal (steps S507 and S514). S511, S515). The adjacent node list 250 shown in FIG. 5 shows an example of the adjacent node list held in the adjacent node list holding unit 14 of the wireless ad hoc terminal 101-d, and the ad hoc network system shown in FIG. According to the configuration, the information of each identifier of the wireless ad hoc terminals 101-a, 101-c, 101-e, 101-h, and 101-i is held. The co-adjacent node table 300 shown in FIG. 6 is an example of the co-adjacent node table held in the co-adjacent node table holding unit 16 of the wireless ad hoc terminal 101-d. According to the configuration of the network system, information on the identifier of the co-adjacent wireless ad hoc terminal for each identifier of the adjacent wireless ad hoc terminal is retained. For example, in the field row of the adjacent wireless ad hoc terminal 101-a, each of the wireless ad hoc terminals 101-c and 101-e, which are co-adjacent nodes between the wireless ad hoc terminal 101-d and the wireless ad hoc terminal 101-a, is displayed. Identifier information is retained.

  Next, in the wireless ad hoc terminal 101-d in which the adjacent node list as shown in FIG. 5 and the co-adjacent node table as shown in FIG. 6 are held, a terminal having a possibility of failure (hereinafter referred to as “failure possibility terminal”). Is detected). Here, the detection of the failure possibility terminal is performed based on whether or not the above-described presence notification message has been received, and for example, a wireless link based on information on the wireless interface between the own terminal and the detection target terminal. A terminal that can be disconnected may be detected as a terminal with a possibility of failure. In the following sequence, a case where failure diagnosis including detection of a failure possibility terminal is performed based on the presence notification message shown here or other messages shown below will be described as an example. In addition to the transmission / reception of the message, it may be performed based on the information related to the wireless interface exemplified here.

  Returning to the sequence of FIG. 3, when the presence notification message from the wireless ad hoc terminal 101-e can be received (step S516, sequence SQ610), the possibility of failure of the wireless ad hoc terminal 101-e is denied. On the other hand, when the presence notification message from the wireless ad hoc terminal 101-a cannot be received within the predetermined lifetime (sequence SQ611), the wireless ad hoc terminal 101-a is detected as a failure possibility terminal (step S517), 7 is transmitted from the wireless ad hoc terminal 101-d to the wireless ad hoc terminal 101-a (step S518, sequence SQ612). Note that the failure diagnosis message transmitted at this time is performed as the first failure diagnosis, and in order to distinguish it from the failure diagnosis message transmitted during the second failure diagnosis described later, This is called a failure diagnosis message.

  Here, when the first failure diagnosis message is received by the wireless ad hoc terminal 101-a, a presence notification message is transmitted from the wireless ad hoc terminal 101-a to the wireless ad hoc terminal 101-d (step S519). , Sequence SQ613). The possibility of failure of the wireless ad hoc terminal 101-a is denied by this presence notification message. On the other hand, for example, when the wireless ad hoc terminal 101-a cannot receive the first failure diagnosis message, or when the presence notification message from the wireless ad hoc terminal 101-a is not received by the wireless ad hoc terminal 101-d, for example, due to a malfunction of the wireless link. (Sequence SQ 614) The wireless ad hoc terminal 101-d that has performed the first failure diagnosis transmits a failure diagnosis request message 205 illustrated in FIG. 8 to the wireless ad hoc terminal 101-e that is one of the co-adjacent nodes. (Step S520, sequence SQ615).

  The wireless ad hoc terminal 101-e that has received the failure diagnosis request message 205 serves as a second failure diagnosis terminal for the failure diagnosis message 203 (first failure diagnosis of FIG. 7) to the wireless ad hoc terminal 101-a. In order to distinguish it from the failure diagnosis message output at this time, a second failure diagnosis message is referred to for convenience (step S521, sequence SQ616).

  Here, when the second failure diagnosis message is received by the wireless ad hoc terminal 101-a, the presence notification message illustrated in FIG. 4 is transmitted from the wireless ad hoc terminal 101-a to the wireless ad hoc terminal 101-e. (Step S522, Sequence SQ617), the wireless ad hoc terminal 101-e diagnoses the wireless ad hoc terminal 101-a as non-failure based on the presence notification message from the wireless ad hoc terminal 101-a, and the diagnosis result (non-failure) Is embedded in the diagnosis result message 207 shown in FIG. 9 and transmitted to the wireless ad hoc terminal 101-d (step S523, sequence SQ618). As in the case of the first failure diagnosis, the possibility of failure of the wireless ad hoc terminal 101-a is denied by this presence notification message.

  On the other hand, when the presence notification message from the wireless ad hoc terminal 101-a cannot be received within the predetermined lifetime (sequence SQ619), the wireless ad hoc terminal 101-a is diagnosed as a failure, and the diagnosis result (failure) is shown. 9 is embedded in the diagnosis result message 207 shown in FIG. 9 and transmitted to the wireless ad hoc terminal 101-d that is the request source of the failure diagnosis (step S524, sequence SQ620). The wireless ad hoc terminal 101-d that has received the determination result (failure) notifies the wireless ad hoc terminal 101-y, which is a manager, of the wireless ad hoc terminal 101-a as a failed terminal (step S525, sequence SQ621).

  Next, some supplementary explanation will be added to some of the messages used in the above sequence. First, each of the first and second failure diagnosis messages can use the same format shown in FIG. 7 as the presence notification message shown in FIG. However, “ACK_REQUIRED” indicating that a response is required is attached to the response request flag. Further, similar to the presence notification message, the list information of adjacent wireless ad hoc terminals is not an essential requirement. However, it is preferable to transmit the list information of the adjacent wireless ad hoc terminals together because the latest information at that time is transmitted to prevent the generation of unnecessary traffic. Furthermore, by making each of the first and second failure diagnosis messages and presence notification messages have a common format as shown in FIG. 4 and FIG. 7, processing relating to message generation is simplified and simplified, and the wireless ad hoc terminal The influence on the resources can be suppressed.

  Further, the failure diagnosis request message transmitted from the failure diagnosis request source wireless ad hoc terminal can use the format shown in FIG. 8, and similarly, the diagnosis transmitted from the failure diagnosis request destination wireless ad hoc terminal. The result message can use the format shown in FIG. Note that the format shown in FIG. 8 and the format shown in FIG. 9 are the same, and the diagnostic result may be embedded in the “other information” field in the format of FIG.

  In the above-described processing of step S523 (sequence SQ618) and step S524 (sequence SQ620), the failure diagnosis request destination wireless ad hoc terminal 101-e sends a failure diagnosis result to the failure diagnosis request source wireless ad hoc terminal 101-d. However, it is not always necessary to transmit a failure diagnosis result, and it may be determined that a failure has occurred when the wireless ad hoc terminal 101-d as the failure diagnosis request source cannot receive within a predetermined time. With such processing, traffic in the ad hoc network system can be limited.

  In the first and second failure diagnosis described above, the first and second failure diagnosis messages have been described as an example in the case of unicast communication that specifies individual wireless ad hoc terminals when transmitting the first and second failure diagnosis messages, respectively. It is also possible to transmit using broadcast or other communication methods. In the case of performing such broadcast communication, the adjacent node list shown in FIG. 5 and the co-adjacent node table shown in FIG. 6 can be omitted. Can be suppressed. Further, in the case of a form having only the adjacent node list without having the co-adjacent node table, unicast communication may be performed for the wireless ad hoc terminals held in the adjacent node list.

  In the above description, the case where the ad hoc network system component is a wireless ad hoc terminal has been described as an example. However, the wireless ad hoc terminal may be a sensor node or a wireless device. .

  As described above, in this embodiment, in addition to the management method based on SNMP, each wireless ad hoc terminal autonomously detects a failure of an adjacent wireless ad hoc terminal in the ad hoc network system. As a result, a wireless ad hoc terminal that has left the system due to a failure or the like can be quickly detected without depending on the inquiry cycle from the manager.

  In the above embodiment, a single ad hoc network system as shown in FIG. 1 has been described as an example. For example, FIG. 1 is a diagram configured by a plurality of sub ad hoc network systems 901 to 905. The present invention can also be applied to an ad hoc network system 900 as shown in FIG. In the figure, for example, in a sub ad hoc network system 901, a sub manager 911 functions as the wireless ad hoc terminal 101-y in FIG. 1 and manages the sub ad hoc network system 901. The same applies to the other sub-ad hoc network systems 902 to 905, and management information from the sub-managers 911 to 915 that manage these sub-ad hoc network systems is transmitted to the manager 910. The entire ad hoc network system 900 can be managed.

  As described above, the wireless ad hoc terminal according to the present invention is useful for an ad hoc network in which a plurality of wireless ad hoc terminals autonomously form a network.

It is a figure which shows the structure of the ad hoc network system comprised by the some aggregate | assembly of the radio | wireless ad hoc terminal concerning this invention. 2 is a block diagram showing a functional configuration of a wireless ad hoc terminal 101. FIG. It is a figure which shows the process sequence in case the wireless ad hoc terminal 101-d diagnoses failure of the wireless ad hoc terminal 101-a. It is a figure which shows the example of a format of the presence notification message for notifying other terminals that the own terminal exists in a system. It is a figure which shows an example of the adjacent node list stored in the adjacent node list holding | maintenance part of wireless ad hoc terminal 101-d. It is a figure which shows an example of the Hello message as a message which shows presence. It is a chart which shows an example of a co-adjacent radio | wireless ad hoc terminal table. It is a figure which shows an example of the co-adjacent node table stored in the co-adjacent node table holding | maintenance part of wireless ad hoc terminal 101-d. It is a figure which shows the example of a format of the failure diagnosis message which the radio | wireless ad hoc terminal which performs the 1st, 2nd failure diagnosis transmits to the wireless ad hoc terminal of failure diagnosis object. It is a figure which shows the example of a format of the failure diagnosis request message output when the radio | wireless ad hoc terminal which performs a failure diagnosis requests | requires a failure diagnosis to the wireless ad hoc terminal of a co-adjacent node. It is a figure which shows the example of a format of the diagnostic result message output when the radio | wireless ad hoc terminal of a failure diagnosis request destination notifies a failure diagnosis result to the wireless ad hoc terminal of a failure diagnosis request source. It is a figure which shows the structure of the ad hoc network system comprised from a some sub ad hoc network system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Transmission / reception part 12 Message processing part 14 Adjacent node list holding | maintenance part 16 Co-adjacent node table holding | maintenance part 101,101-ai Wireless ad hoc terminal 102,902 Wireless link 201 Presence notification message 203 Failure diagnosis message 205 Failure diagnosis request message 207 Diagnosis Result message 250 Adjacent node list 300 Co-adjacent node table 900 Ad hoc network system 901 to 905 Sub ad hoc network system 910 Manager 911 to 915 Sub manager

Claims (9)

In a wireless ad hoc terminal that forms an ad hoc network system and communicates with other terminals through a wireless interface,
Means for generating a presence notification message for notifying the presence of the terminal;
Means for generating a first failure diagnosis message for performing a first failure diagnosis;
Means for generating a failure diagnosis request message for requesting failure diagnosis;
Means for generating a second failure diagnosis message for performing a second failure diagnosis;
Means for generating a diagnostic result message with a diagnostic result for a wireless ad hoc terminal subject to failure diagnosis;
With
A wireless ad hoc terminal that has not received the presence notification message within a predetermined time or a wireless ad hoc terminal that has detected the possibility of wireless link disconnection based on information about a wireless interface is a wireless ad hoc terminal that performs a first failure diagnosis. Transmitting the first failure diagnosis message that obligates a response to the wireless ad hoc terminal targeted for failure diagnosis;
The wireless ad hoc terminal that performs the first failure diagnosis transmits the failure diagnosis request message when there is no response to the first failure diagnosis message,
The wireless ad hoc terminal that has received the failure diagnosis request message transmits the second failure diagnosis message that obliges a response to the wireless ad hoc terminal targeted for failure diagnosis included in the failure diagnosis request message,
The wireless ad hoc terminal that performs the second failure diagnosis transmits the diagnosis result message to the wireless ad hoc terminal that has performed the first failure diagnosis based on whether or not there is a response to the second failure diagnosis message. Features wireless ad hoc terminal. A wireless ad hoc terminal other than the own terminal located in a range where wireless communication with the own terminal can be performed as an adjacent node, further comprising an adjacent node list that holds an identifier of the adjacent node;
The failure diagnosis request message transmitted from the wireless ad hoc terminal performing the first failure diagnosis is transmitted to the adjacent wireless ad hoc terminal held in the adjacent node list of the wireless ad hoc terminal performing the first failure diagnosis. The wireless ad hoc terminal according to claim 1, wherein: A wireless ad hoc terminal other than the local terminal located in a range where wireless communication with the local terminal can be performed as an adjacent node, and an adjacent node list that holds an identifier of the adjacent node;
A wireless ad hoc terminal having the same identifier of the wireless ad hoc terminal held in the adjacent node list and the identifier of the wireless ad hoc terminal included in the presence notification message addressed to the own terminal is defined as a co-adjacent node, and A co-adjacent node table holding identifiers of co-adjacent nodes;
Further comprising
The failure diagnosis request message transmitted from the wireless ad hoc terminal that performs the first failure diagnosis is sent to the co-adjacent wireless ad hoc terminal held in the co-adjacent node table of the wireless ad hoc terminal that performs the first failure diagnosis. The wireless ad hoc terminal according to claim 1, wherein the wireless ad hoc terminal is transmitted.   The wireless ad hoc terminal according to any one of claims 1 to 3, wherein the first failure diagnosis message and the second failure diagnosis message share the same message format.   The wireless ad hoc terminal according to any one of claims 1 to 4, wherein the failure diagnosis request message and the diagnosis result message share the same message format. A failure detection method in a wireless ad hoc terminal that forms an ad hoc network system and communicates with other terminals through a wireless interface,
The wireless ad hoc terminal is
Generating a presence notification message for notifying the presence of the terminal;
Generating a first fault diagnosis message for performing a first fault diagnosis;
Generating a fault diagnosis request message for requesting fault diagnosis;
Generating a second fault diagnosis message for performing a second fault diagnosis;
Generating a diagnostic result message with a diagnostic result for a wireless ad hoc terminal subject to failure diagnosis;
Including
A wireless ad hoc terminal that has not received the presence notification message within a predetermined time or a wireless ad hoc terminal that has detected the possibility of wireless link disconnection based on information about a wireless interface is a wireless ad hoc terminal that performs a first failure diagnosis. Transmitting the first failure diagnosis message that obligates a response to the wireless ad hoc terminal targeted for failure diagnosis;
The wireless ad hoc terminal that performs the first failure diagnosis is a wireless ad hoc terminal other than the own terminal that is located in a range where wireless communication with the own terminal is possible when there is no response to the first failure diagnosis message. Sending the failure diagnosis request message to a neighboring wireless ad hoc terminal;
The wireless ad hoc terminal that has received the failure diagnosis request message transmits the second failure diagnosis message that obliges a response to the wireless ad hoc terminal targeted for failure diagnosis included in the failure diagnosis request message,
The wireless ad hoc terminal that performs the second failure diagnosis transmits the diagnosis result message to the wireless ad hoc terminal that has performed the first failure diagnosis based on whether or not there is a response to the second failure diagnosis message. A failure detection method for a wireless ad hoc terminal. A failure detection method in a wireless ad hoc terminal that forms an ad hoc network system and communicates with other terminals through a wireless interface,
The wireless ad hoc terminal is
Generating a presence notification message for notifying the presence of the terminal;
Generating a first fault diagnosis message for performing a first fault diagnosis;
Generating a fault diagnosis request message for requesting fault diagnosis;
Generating a second fault diagnosis message for performing a second fault diagnosis;
Generating a diagnostic result message with a diagnostic result for a wireless ad hoc terminal subject to failure diagnosis;
Including
A wireless ad hoc terminal that has not received the presence notification message within a predetermined time or a wireless ad hoc terminal that has detected the possibility of wireless link disconnection based on information about a wireless interface is a wireless ad hoc terminal that performs a first failure diagnosis. Transmitting the first failure diagnosis message that obligates a response to the wireless ad hoc terminal targeted for failure diagnosis;
The wireless ad hoc terminal that performs the first failure diagnosis is a wireless ad hoc terminal other than the own terminal that is located in a range where wireless communication with the own terminal is possible when there is no response to the first failure diagnosis message. Transmitting the failure diagnosis request message to a co-adjacent wireless ad hoc terminal that is the same wireless ad hoc terminal as the identifier of a certain adjacent wireless ad hoc terminal and the wireless ad hoc terminal identifier included in the presence notification message addressed to the own terminal;
The wireless ad hoc terminal that has received the failure diagnosis request message transmits the second failure diagnosis message that obliges a response to the wireless ad hoc terminal targeted for failure diagnosis included in the failure diagnosis request message,
The wireless ad hoc terminal that performs the second failure diagnosis transmits the diagnosis result message to the wireless ad hoc terminal that has performed the first failure diagnosis based on whether or not there is a response to the second failure diagnosis message. A failure detection method for a wireless ad hoc terminal. In an ad hoc network system in which a plurality of wireless ad hoc terminals each having a wireless interface form an autonomous network,
The wireless ad hoc terminal is
Means for generating a presence notification message for notifying the presence of the terminal;
A wireless ad hoc terminal other than the local terminal located in a range where wireless communication with the local terminal can be performed as an adjacent node, and an adjacent node list that holds an identifier of the adjacent node;
A wireless ad hoc terminal having the same identifier of the wireless ad hoc terminal held in the adjacent node list and the identifier of the wireless ad hoc terminal included in the presence notification message addressed to the own terminal is defined as a co-adjacent node, and A co-adjacent node table holding identifiers of co-adjacent nodes;
Means for generating a first failure diagnosis message for performing a first failure diagnosis;
Means for generating a failure diagnosis request message for requesting failure diagnosis;
Means for generating a second failure diagnosis message for performing a second failure diagnosis;
Means for generating a diagnostic result message with a diagnostic result for a wireless ad hoc terminal subject to failure diagnosis;
With
A wireless ad hoc terminal that has not received the presence notification message within a predetermined time or a wireless ad hoc terminal that has detected the possibility of wireless link disconnection based on information about a wireless interface is a wireless ad hoc terminal that performs a first failure diagnosis. Transmitting the first failure diagnosis message that obligates a response to the wireless ad hoc terminal targeted for failure diagnosis;
When there is no response to the first failure diagnosis message, the wireless ad hoc terminal performing the first failure diagnosis sends the failure diagnosis request message to the co-adjacent wireless ad hoc terminal held in the co-adjacent node table of the own terminal. Send
The wireless ad hoc terminal that has received the failure diagnosis request message transmits the second failure diagnosis message that obliges a response to the wireless ad hoc terminal targeted for failure diagnosis included in the failure diagnosis request message,
The wireless ad hoc terminal that performs the second failure diagnosis transmits the diagnosis result message to the wireless ad hoc terminal that has performed the first failure diagnosis based on whether or not there is a response to the second failure diagnosis message. A featured ad hoc network system. A specific wireless ad hoc terminal among the plurality of wireless ad hoc terminals functions as a management terminal that manages the plurality of wireless ad hoc terminals;
The wireless ad hoc terminal that has performed the first failure diagnosis transmits, when the content of the diagnosis result message is a failure, predetermined information regarding the wireless ad hoc terminal diagnosed as the failure to the management terminal. The ad hoc network system according to claim 8.

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