JP4896751B2 - Wireless ad hoc terminal - Google Patents

Description

  The present invention relates to a wireless ad hoc terminal that constructs an ad hoc network system, and more particularly to a wireless ad hoc terminal that efficiently detects a failure.

  In recent years, there has been an increasing interest in ad hoc network systems that enable communication between communication devices without using existing network infrastructure. This ad hoc network system is different from a conventional fixed infrastructure type network (for example, a network system configured to communicate via an access point), and is based on a large number of objects and devices. An autonomous network can be constructed. It is also possible to construct a network that does not depend on existing communication infrastructure. In the future, in order for ad hoc network systems to become widespread, state management (network management) of devices constituting the system is necessary.

  In a conventional infrastructure type IP network system, a faulty terminal is generally identified by applying a management method based on SNMP (Simple Network Management Protocol). 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, managers query individual agents at 15 minute intervals by default to see if an agent is alive or dead. However, 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 or leave the system, and so on frequently. 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 terminals changes due to temporary factors such as interference, so that it is not possible to determine the failure of the adjacent terminal based on only the information on the wireless state change. there were.

  On the other hand, in the prior application (Japanese Patent Application No. 2005-311732) of the present applicant, in order to solve the above-described problems and achieve the object, an ad hoc network system is formed, and a wireless interface is used to communicate with other terminals. A wireless ad hoc terminal that performs communication between the means for generating a presence notification message for notifying the presence of the own terminal, a means for generating a first failure diagnosis message for performing a first failure diagnosis, and a failure Means for generating a failure diagnosis request message for requesting diagnosis, means for generating a second failure diagnosis message for performing second failure diagnosis, and a diagnosis result for the wireless ad hoc terminal to be diagnosed Means for generating a diagnostic result message, and a wireless ad hoc terminal that has not received a presence notification message within a predetermined time period or The wireless ad hoc terminal that has detected the possibility of disconnection of the wireless link based on the information related to the wireless interface is a wireless ad hoc terminal that performs the first failure diagnosis. The wireless ad hoc terminal that transmits the message and performs the first failure diagnosis transmits the failure diagnosis request message when there is no response to the first failure diagnosis 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 obliged to respond to the wireless ad hoc terminal targeted for failure diagnosis included in the failure diagnosis request message. A wireless ad hoc terminal that has made a first failure diagnosis based on whether there is a response to And transmitting the diagnostic result message, a specific method of fault terminal are described.

  The failure terminal identification method of the above-mentioned prior application, when generating the neighboring terminal list, only the unique information (information that can identify the terminal) sent indiscriminately from neighboring neighboring terminals. Since it is a mechanism to receive as it is, when trying to request a terminal that is suspected of malfunctioning to an adjacent terminal, it may take a long time to obtain a determination result, and it may not be possible to make a correct determination There was a problem of high nature.

  In reality, it is impossible to limit the size of the adjacent terminal list and it is necessary to add a limit. When generating the adjacent terminal list, which of the adjacent terminals is generated. Since there is no means for determining whether the terminal should be left in the list, there is also a problem that there is a high possibility that a faulty terminal cannot be correctly identified (that is, a useless) adjacent terminal list is created.

  For example, when there are terminals B, C, D, E, F, G, H, I, J, and K around a certain terminal A, the terminal A has ten adjacent terminal tables. Further, for each item of the adjacent terminal table held by the terminal A (that is, terminals B, C, D, E, F, G, H, I, J, K), a table of terminals adjacent to each other, It has a common adjacent terminal table as used in the prior application. In this case, when there are terminals E, F, G, H, I, J, K, L, and M in the adjacent table of the terminal D in the adjacent terminal list of the terminal A in this case, If terminal D is suspected of malfunctioning (because terminal A tried to communicate with terminal D but did not respond), terminal E, F, G, H, I, J, K Request (from terminal A) the identification of the faulty terminal.

  At this time, the situation of radio waves changes due to disturbances such as obstacles, so that the communication situation becomes worse, and communication from terminal E, F, G, H, I, J to terminal D is not possible. When communication with the terminal D can be performed (as an example in which such a situation is easy to understand, the terminals A, D, and K are installed at positions close to each other, and the terminals E, F, G, H, I, and J are In the failure terminal identification method of the prior application, a failure terminal identification request is issued to each of the terminals E, F, G, H, I, and J that cannot communicate with each other. Only when a request is made to the terminal K, the result that the terminal D is not broken is obtained. The larger the neighboring terminal list, the longer the overhead time until a failure determination result is obtained.

  In order to avoid this, it is conceivable to limit the size of the neighboring terminal list, but the prior application does not describe a method for determining which neighboring terminal information is to be left and which neighboring terminal information is to be discarded. It becomes the state that is equal to having been elected at random. In this case, an adjacent terminal that is most likely to be able to communicate with a terminal suspected of being out of order is not selected, and as a result, it is determined that the terminal is in error.

  The present invention has been made to solve the above-described problems. The purpose of the present invention is to efficiently determine whether or not a terminal is really out of order when a terminal suspected of being out of order is discovered. A wireless ad hoc terminal capable of being obtained is obtained.

  A wireless ad hoc terminal according to the present invention is a wireless ad hoc terminal that constructs an ad hoc network system, and includes a position information recording unit that records position information where the wireless ad hoc terminal is located, and the wireless ad hoc terminal. An adjacent terminal list holding unit for holding an adjacent terminal list configured from an identifier and position information of a second wireless ad hoc terminal located in a communicable range, and created based on the adjacent terminal list, and adjacent in the wireless ad hoc terminal When the terminal is also an adjacent terminal in the third wireless ad hoc terminal, a common adjacent terminal table holding unit that holds a common adjacent terminal table related to the adjacent terminal, an identifier of the wireless ad hoc terminal, and the position information recording unit The obtained location information of the wireless ad hoc terminal and the adjacent terminal list Based on the neighboring terminal list held by the holding unit, a first presence notification message is generated and transmitted to the second wireless ad hoc terminal, and from the second wireless ad hoc terminal to the first presence notification message. When the corresponding second presence notification message is received, the neighboring terminal list is updated when the possibility of communication is high based on the location information of the second wireless ad hoc terminal that has sent the second presence notification message And a message processing unit for updating the common adjacent terminal table.

  The wireless ad hoc terminal according to the present invention has an effect that when a terminal suspected of malfunctioning is found, it can be efficiently determined whether or not the terminal is truly malfunctioning. That is, when a terminal that is suspected of malfunctioning is detected and an inquiry is made to an adjacent terminal to check whether the terminal is really malfunctioning, priority is given to the terminal that is most likely to communicate with the suspected malfunctioning terminal from the list of adjacent terminals Thus, it is possible to issue a request for specifying a faulty terminal, and it is possible to leave a terminal that is most suitable for communication when information is embedded in an adjacent terminal list having a size restriction.

Embodiment 1 FIG.
An ad hoc network system according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a configuration of an ad hoc network system according to Embodiment 1 of the present invention. In the following, in each figure, the same reference numerals indicate the same or corresponding parts.

  In FIG. 1, the ad hoc network system according to the first embodiment is provided with a plurality of wireless ad hoc terminals 101 connected by a wireless link 102. In the figure, wireless ad hoc terminals 101-a to 101-i and 101-y are illustrated.

  In the ad hoc network system shown in FIG. 1, a specific wireless ad hoc terminal operates as a manager of a management method using SNMP (Simple Network Management Protocol), and other wireless ad hoc terminals operate as agents. Periodic inquiries have been made to individual agents to confirm “dead or alive”. In the following description, it is assumed that “wireless ad hoc terminal 101-y” is handled as a manager.

  FIG. 2 is a block diagram showing a configuration of the wireless ad hoc terminal according to Embodiment 1 of the present invention.

  In FIG. 2, the wireless ad hoc terminal 101 includes a transmission / reception unit 10, a message processing unit 12, an adjacent terminal list holding unit 14, a common adjacent terminal table holding unit 16, an adjacent terminal selection unit 18, and a recursive diagnosis checking unit 22. In addition, a recursive diagnosis request unit 24 and a position information recording unit 26 are provided.

  The transmission / reception unit 10 transmits a predetermined message to another wireless ad hoc terminal and receives the predetermined message from the other wireless ad hoc terminal. The message processing unit 12 generates various messages defined in this embodiment, grasps the contents of messages transmitted from other wireless ad hoc terminals, and creates and updates an adjacent terminal list and a common adjacent terminal table To do. The neighboring terminal list holding unit 14 holds a neighboring terminal list composed of identifiers and position information of wireless ad hoc terminals called neighboring terminals. Moreover, the common adjacent terminal table holding | maintenance part 16 hold | maintains the common adjacent terminal table comprised from the identifier and position information of the radio | wireless ad hoc terminal called a common adjacent terminal for every adjacent terminal.

  Note that “adjacent terminal” means a wireless ad hoc terminal other than the own terminal located in a range where wireless communication can be performed with the own terminal, and “common adjacent terminal” means an adjacent in one wireless ad hoc terminal. When the terminal is also an adjacent terminal in another wireless ad hoc terminal, it means the common adjacent terminal.

  The adjacent terminal selection unit 18 selects a terminal having the highest possibility of communication from the common adjacent terminal table when issuing a failure terminal specification request. The recursive diagnosis checking unit 22 determines whether the received failure diagnosis request is recursive. The recursive diagnosis requesting unit 24 is the recursive diagnosis checking unit 22 described above, and the received fault diagnosis request is a recursive request, and the result of the fault diagnosis performed by itself is a fault and recursively confirms. When the number of depths to be performed (for example, the case where it is set up to three levels and is still in the second level) has not yet been reached, a failure diagnosis request is issued recursively (further starting from itself). The location information recording unit 26 records location information where the terminal is located.

  In addition, as a specific realization method for acquiring the position information recorded by the position information recording unit 26, for example, it may be acquired by a function such as GPS, or coordinate axis data input in advance by a user to be arranged. In addition, the radio wave intensity (between terminals) obtained as a result of communication with other terminals, the error rate during communication, or the like may be used or combined.

  FIG. 3 is a diagram showing a configuration of an adjacent terminal list stored in the adjacent terminal list holding unit of the wireless ad hoc terminal according to Embodiment 1 of the present invention.

  FIG. 3 shows an example of an adjacent terminal list stored in the adjacent terminal list holding unit 14 of the wireless ad hoc terminal 101-d. The adjacent terminal list 250 holds identifiers (251a to 251e) of the wireless ad hoc terminals 101-a, 101-c, 101-e, 101-h, and 101-i, and position information (252a to 252e). In this case, the position information is filled with coordinate axis information as an example.

  FIG. 4 is a diagram showing a configuration of a common adjacent terminal table stored in the common adjacent terminal table holding unit of the wireless ad hoc terminal according to Embodiment 1 of the present invention.

  FIG. 4 shows an example of the common adjacent terminal table stored in the common adjacent terminal table holding unit 16 of the wireless ad hoc terminal 101-d. The common adjacent terminal table 300 holds the identifier of the common adjacent wireless ad hoc terminal and the position information for each identifier of the adjacent wireless ad hoc terminal. That is, the field row 310 of the adjacent wireless ad hoc terminal 101-a (the information of the wireless ad hoc terminal 101-a is entered in the area 311) is between the wireless ad hoc terminal 101-d and the wireless ad hoc terminal 101-a. The respective identifiers (312a to 312d) and position information (313a to 313d) of the wireless ad hoc terminals 101-c, 101-e, 101-h, and 101-i, which are common adjacent terminals, are retained, and the failure diagnosis is performed recursively. As a result of performing the above, if it is confirmed that there is no failure via another terminal that is not visible to the wireless ad hoc terminal 101-d (that is, a terminal that does not appear in the common adjacent terminal table), the terminal information Is stored in the route tables 314, 324, and 334, and other information is stored in the areas 315, 325, and 335. In this case, the position information is filled with coordinate axis information as an example.

  FIG. 5 is a diagram showing the configuration of the presence notification message of the ad hoc network system according to Embodiment 1 of the present invention.

  FIG. 5 shows a format example of a presence notification message 201 for notifying other terminals that the own terminal exists in the system. In the figure, a presence notification message 201 includes fields 201e of an identifier 201a of a transmission source terminal, location information 201b of the transmission source terminal, a lifetime 201c, a response request flag 201d, and an identifier of a list of adjacent wireless ad hoc terminals. , 201g, 201i, 201k, 201m, 201o and fields 201f, 201h, 201j, 201l, 201n, 201p of position information of the list of adjacent wireless ad hoc terminals.

  FIG. 6 is a diagram showing a configuration of a failure diagnosis message of the ad hoc network system according to Embodiment 1 of the present invention.

  FIG. 6 shows a format example of a failure diagnosis message transmitted from the wireless ad hoc terminal performing the first and second failure diagnosis to the wireless ad hoc terminal targeted for failure diagnosis. In the figure, a failure diagnosis message 203 includes an identifier 203a of a transmission source terminal, a lifetime 203b, a response request flag 203c, a recursive failure diagnosis designation flag 203d, and an identifier and location information 203e of an adjacent wireless ad hoc terminal. . “ACK_REQUIRED” indicating that a response is required is attached to the response request flag 203c.

  FIG. 7 is a diagram showing a configuration of a failure diagnosis request message of the ad hoc network system according to the first embodiment of the present invention.

  FIG. 7 shows a format example of a failure diagnosis request message that is output when a wireless ad hoc terminal that performs failure diagnosis requests a wireless ad hoc terminal that is a common adjacent terminal to perform failure diagnosis. In the figure, a failure diagnosis request message 205 includes an identifier 205a of a transmission source terminal, an identifier 205b of a failure diagnosis target terminal, a recursive failure diagnosis designation flag 205c, and other information 205d. The recursive failure diagnosis designation flag 205c is used to specify that the failure diagnosis is performed recursively (in this case, “numerical value 1” or “numerical value 0” that is not performed), and a method of specifying the number of times is also possible. (Do not do “value 0”, do N times “value N”).

  FIG. 8 is a diagram showing a structure of a diagnostic result message of the ad hoc network system according to the first embodiment of the present invention.

  FIG. 8 shows a format example of a diagnosis result message that is output when the failure diagnosis request destination wireless ad hoc terminal notifies the failure diagnosis request source wireless ad hoc terminal of the failure diagnosis result. In the figure, a diagnosis result message 207 includes an identifier 207a of a transmission source terminal, an identifier 207b of a failure diagnosis target terminal, a recursive failure diagnosis designation flag 207c, and other information 207d. The recursive failure diagnosis designation flag 207c is used to substitute the result of how far recursive failure diagnosis has been performed.

  Next, the operation of the wireless ad hoc terminal of the ad hoc network system according to the first embodiment will be described with reference to the drawings.

  A case where the wireless ad hoc terminal 101-d performs failure diagnosis of the wireless ad hoc terminal 101-a will be described as an example.

  FIG. 9 is a diagram showing an operation sequence of the ad hoc network system according to the first embodiment of the present invention.

  FIG. 9 shows a case where the wireless ad hoc terminal 101-e has not yet entered the network in which the wireless ad hoc terminals 101-d, 101-a, 101-g, 101-e, and the manager 101-y exist. The periodic inquiry from the wireless ad hoc terminal 101-y and processing when the wireless ad hoc terminal 101-e enters the network from the middle are shown.

  In FIG. 9, the wireless ad hoc terminal 101-y continues to make periodic inquiries based on SNMP to the wireless ad hoc terminals 101-d, 101-a, and 101-g that have already entered the ad hoc network system. (Step S501, Sequence SQ601). That is, transmission of hello packets is periodically activated.

  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).

  FIG. 10 is a diagram showing an operation sequence of the ad hoc network system according to the first embodiment of the present invention.

  10 includes the same wireless ad hoc terminals 101-d, 101-a, 101-g, 101-e, and 101-y as FIG. 9, and the wireless ad hoc terminals 101-d, 101-a, and 101-y. g and 101-e each show an operation sequence when the presence notification message 201 is received from each neighboring neighboring terminal, and the neighboring terminal list 250 is created / updated and the common neighboring terminal table 300 is created / updated.

  In FIG. 10, the message processing units 12 of the wireless ad hoc terminals 101-d, 101-a, 101-e, and 101-g that have entered the ad hoc network system generate the presence notification message 201 shown in FIG. And transmitted to the adjacent terminals (steps S504, S505, S701, S508, S509, S702, S703, S512, S513, S704, S705, S706, sequences SQ604 to SQ609, SQ801 to SQ806). That is, each wireless ad hoc terminal transmits “survival information” that it is here.

  In FIG. 10A, the wireless ad hoc terminal 101-d receives the presence notification message 201 from the wireless ad hoc terminals 101-a and 101-e. The wireless ad hoc terminal 101-d cannot be received from the wireless ad hoc terminal 101-g.

  In FIG. 10B, the wireless ad hoc terminal 101-e receives the presence notification message 201 from the wireless ad hoc terminals 101-a, 101-d, and 101-g.

  In FIG. 10C, the wireless ad hoc terminal 101-a receives the presence notification message 201 from the wireless ad hoc terminals 101-g, 101-d, and 101-e.

  In FIG. 10D, the wireless ad hoc terminal 101-g receives the presence notification message 201 from the wireless ad hoc terminals 101-a, 101-e, and 101-d.

  Here, in describing the details of FIG. 5, the wireless ad hoc terminal 101-a is taken as an example. FIG. 5 shows a presence notification message transmitted from the wireless ad hoc terminal 101-a to the adjacent wireless ad hoc terminals 101-b, 101-c, 101-d, 101-e, 101-f, and 101-g. 201 is shown.

  That is, in the figure, as described above, the presence notification message 201 includes the identifier 201a of the transmission source terminal, the location information 201b of the transmission source terminal, the lifetime 201c, the response request flag 201d, and the adjacent wireless ad hoc terminal. Each field 201e, 201g, 201i, 201k, 201m, and 201o of the list identifier and each field 201f, 201h, 201j, 201l, 201n, and 201p of the position information of the list of adjacent wireless ad hoc terminals are included.

  The identifier 201a of the transmission source terminal indicates the identifier of the wireless ad hoc terminal 101-a, the lifetime 201c indicates a predetermined time indicating the lifetime of the message, and the response request flag 201d indicates that no response is required. “NO_ACK” indicates that each of the wireless ad hoc terminals 101-b to 101-g is an adjacent terminal viewed from the wireless ad hoc terminal 101-a in the list fields 201e, 201g, 201i, 201k, 201m, and 201o of the adjacent wireless ad hoc terminals. In the list fields 201f, 201h, 201j, 201l, 201n, and 201p of the adjacent wireless ad hoc terminals, the location information of the wireless ad hoc terminals 101-b to 101g that are adjacent terminals viewed from the wireless ad hoc terminal 101-a Are embedded.

  The position information recording unit 26 shown in FIG. 2 is used for the position information of the terminal itself. In addition, the list of adjacent wireless ad hoc terminals is sequentially filled with the presence notification messages 201 from neighboring adjacent terminals. FIG. 5 shows a state where the wireless ad hoc terminal has received the presence notification message 201 from neighboring terminals to some extent.

  Note that the list information 201e to 201p of the adjacent wireless ad hoc terminals is not an indispensable requirement from the viewpoint of notifying the presence terminal message 201 of the state of only the terminal itself (“dead and alive”). However, the list information of adjacent wireless ad hoc terminals is information required when creating the common adjacent terminal table 300 described later, and it is possible to transmit the information together with the presence notification message 201 from the viewpoint of suppressing an increase in traffic. It is effective.

  Returning to the operation sequence of FIG. 10, as the operation on the side that has received the “survival information”, the wireless ad hoc terminals 101-d, 101-a, 101-g, and 101-e notify each other the presence notification message 201. 3 is created or updated based on the information on the adjacent wireless ad hoc terminals included in (steps S506, S510, S514, S707), and further, based on the information on the adjacent terminal list 250 in the own terminal Thus, the common adjacent terminal table 300 shown in FIG. 4 is created or updated (steps S507, S511, S515, and S708).

  Here, creation or updating of the adjacent terminal list 250 and the common adjacent terminal table 300 will be described with reference to FIG. FIG. 11 is a flowchart showing operations for creating and updating the neighboring terminal list and the common neighboring terminal table of the message processing unit of the wireless ad hoc terminal according to the first embodiment of the present invention.

  When the message processing unit 12 of the wireless ad hoc terminal receives the presence notification message 201 from the neighboring terminal (step 1100), the message processing unit 12 first checks whether there is a vacancy (NULL) in the neighboring terminal list 250 (step 1101). If there is a vacancy, it is confirmed whether the terminal that sent the presence notification message 201 is already in the adjacent terminal list 250 (step 1102). If there is, it is checked whether the shared adjacent terminal information that has been passed matches the common adjacent terminal table 300 (step 1105), and if they match, no processing is performed (step 1199).

  Returning to step 1105, if it does not match the common adjacent terminal table 300, the passed common adjacent terminal information is added to the common adjacent terminal table 300 and updated (step 1106), and the process ends (step 1199). .

  Returning to step 1102, if the terminal that sent the presence notification message 201 does not exist in the neighboring terminal list 250, the sent neighboring terminal identifier is substituted into an empty part of the neighboring terminal list 250 (step 1103). Also, the passed common adjacent terminal information is substituted into the common adjacent terminal table 300 (step 1106), and the process ends (step 1199).

  Returning to step 1101, if there is no space in the adjacent terminal list 250, the location information of the adjacent terminal that has sent the presence notification message 201 is compared with the adjacent terminal list 250 and replaced with the terminal with the lowest possibility of communication ( Step 1104). In some cases, the adjacent terminal itself that sent the presence notification message 201 has the lowest possibility of communication, and it is determined whether or not the adjacent terminal list 250 has been replaced (step 1107). Then, the common adjacent terminal information passed is substituted into the common adjacent terminal table 300 (step 1106), and the process ends (1199). If there is no replacement, the process ends as it is (1199).

  This is a method for determining the possibility of communication between the own terminal and the adjacent terminal. First, the determination may be made based on the distance between the terminals calculated from the position information, or the presence notification message 201 is received. The determination may be made including the radio field intensity at the time, or the determination may be made so that a terminal having more neighboring terminals is given priority.

  3 shows an example of the adjacent terminal list held in the adjacent terminal list holding unit 14 of the wireless ad hoc terminal 101-d, and the ad hoc network system shown in FIG. As described above, the identifiers (251a to 251e) and the position information (252a to 252e) of the wireless ad hoc terminals 101-a, 101-c, 101-e, 101-h, and 101-i are held according to the configuration of The In this case, the position information is filled with coordinate axis information as an example.

  4 shows an example of the common adjacent terminal table held in the common adjacent terminal table holding unit 16 of the wireless ad hoc terminal 101-d. The common adjacent terminal table 300 shown in FIG. According to the configuration of the network system, as described above, the identifier and position information of the common adjacent wireless ad hoc terminal for each identifier of the adjacent wireless ad hoc terminal are retained. That is, the field row 310 of the adjacent wireless ad hoc terminal 101-a (the information of the wireless ad hoc terminal 101-a is entered in the area 311) is between the wireless ad hoc terminal 101-d and the wireless ad hoc terminal 101-a. The respective identifiers (312a to 312d) and position information (313a to 313d) of the wireless ad hoc terminals 101-c, 101-e, 101-h, and 101-i, which are common adjacent terminals, are retained, and the failure diagnosis is performed recursively. As a result of performing the above, if it is confirmed that there is no failure via another terminal that is not visible to the wireless ad hoc terminal 101-d (that is, a terminal that does not appear in the common adjacent terminal table), the terminal information Are stored in the areas 314, 324, and 334, and other information is stored in the areas 315, 325, and 335. In this case, the position information is filled with coordinate axis information as an example.

  Next, in the wireless ad hoc terminal 101-d holding the adjacent terminal list 250 as shown in FIG. 3 and the common adjacent terminal table 300 as shown in FIG. The process in which the detection is performed with reference to FIG. 12, FIG. 13, FIG. 14, and FIG.

  Here, the detection of the failure possibility terminal is performed based on whether the above-described presence notification message 201 has been received or not, for example, based on information on the wireless interface between the own terminal and the detection target terminal. You may detect a terminal with a possibility of a link disconnection as a failure possibility terminal. In the following operation sequence, a case in which failure diagnosis including detection of a failure possibility terminal is performed based on the presence notification message 201 shown here and other messages shown below will be described as an example. In addition to the transmission / reception of these messages, it may be performed based on the information related to the wireless interface exemplified here.

  A case where a terminal having a possibility of failure is detected and the presence notification message 201 is returned when the failure diagnosis is performed will be described with reference to FIG.

  FIG. 12 is a diagram showing an operation sequence of the ad hoc network system according to the first embodiment of the present invention.

  FIG. 12 includes the same wireless ad hoc terminals 101-d, 101-a, 101-g, 101-e, and 101-y as FIG. 9, and as shown in FIG. -A, 101-g, and 101-e create / update the neighboring terminal list 250 and create / update the common neighboring terminal table 300, respectively, the wireless ad hoc terminal 101-d is the wireless ad hoc terminal 101-a. As a result of detecting the possibility of failure and diagnosing the failure, the presence notification message 201 is returned, so that the operation sequence when it is determined that there is no failure is shown.

  Before that, since the wireless ad hoc terminal 101-d is set as described above (FIG. 10), the wireless ad hoc terminal 101-a (S504) and the wireless ad hoc terminal 101-e (S505) are regularly connected. Only the presence notification message 201 (SQ604, SQ605) is received, and the presence notification message 201 (SQ801) from the wireless ad hoc terminal 101-g (S701) cannot be received. That is, when the presence notification message 201 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.

  Under such setting, as shown in FIG. 12, the wireless ad hoc terminal 101-d receives the transmission of the presence notification message 201 sent by the wireless ad hoc terminal 101-e (S516, SQ610), but the wireless ad hoc terminal 101. When the presence notification message 201 from -a cannot be received within a predetermined lifetime (S710, SQ611), the wireless ad hoc terminal 101-a is detected as a failure possibility terminal (S517), and the message processing unit 12 performs FIG. Is generated and transmitted from the wireless ad hoc terminal 101-d to the wireless ad hoc terminal 101-a (S518, SQ612).

  Note that the wireless ad hoc terminal 101-d cannot receive the presence notification message 201 from the wireless ad hoc terminal 101-g (S709, SQ807). Not recognized. The failure diagnosis message 203 transmitted from the wireless ad hoc terminal 101-d to the wireless ad hoc terminal 101-a is performed as a first failure diagnosis, and is transmitted during a second failure diagnosis described later. In order to distinguish from the failure diagnosis message 203, it is called a first failure diagnosis message for convenience.

  Here, when the first failure diagnosis message is received by the wireless ad hoc terminal 101-a, the presence notification message 201 shown in FIG. 5 is transmitted from the wireless ad hoc terminal 101-a to the wireless ad hoc terminal 101-d. (S519, SQ613). The presence notification message 201 denies the possibility of failure of the wireless ad hoc terminal 101-a.

  On the other hand, for example, when the wireless ad hoc terminal 101-a cannot receive the first failure diagnosis message, or the presence notification message 201 from the wireless ad hoc terminal 101-a is not received by the wireless ad hoc terminal 101-d due to, for example, a malfunction of the wireless link. The case will be described with reference to FIG.

  FIG. 13 is a diagram showing an operation sequence of the ad hoc network system according to the first embodiment of the present invention.

  FIG. 13 is the same as FIG. 12 until the wireless ad hoc terminal 101-d detects the possibility of failure of the wireless ad hoc terminal 101-a and performs failure diagnosis. Since there is no response, the failure diagnosis is requested to the wireless ad hoc terminal 101-e, and as a result, an operation sequence when there is a response from the wireless ad hoc terminal 101-a and when there is no response is shown.

  FIG. 13 is the same as FIG. 12 described above until the operation (S518, SQ612) in which the wireless ad hoc terminal 101-d transmits the first failure diagnosis message. On the other hand, when the presence notification message 201 does not return from the wireless ad hoc terminal 101-a (S711, SQ614), the wireless ad hoc terminal 101-d that has performed the first failure diagnosis receives the adjacent terminal selection unit 18 By referring to the common adjacent terminal table 300, the wireless ad hoc terminal 101-e that is one of the common adjacent terminals with the highest possibility of communication is selected from the position information. The wireless ad hoc terminal 101-e transmits a failure diagnosis request message 205 shown in FIG. 7 to the wireless ad hoc terminal 101-e (step S520, sequence SQ615).

  At this time, in the case where the route table 314 exists (that is, the wireless ad hoc terminal 101-d has performed a failure diagnosis of the wireless ad hoc terminal 101-a in the past. As a result of the request, a method of recursively requesting failure diagnosis, which will be described later, results in being invisible directly to the wireless ad hoc terminal 101-d (that is, listed in the common adjacent terminal table 300 of the wireless ad hoc terminal 101-a). (If there has been a non-fault diagnosis result via a wireless ad hoc terminal (101-g in this example to be described later)), a fault diagnosis request message 205 is transmitted to the terminal in this route table. That's fine.

  At that time, the name of the terminal to which the other information 205d should be recursively requested for failure diagnosis (that is, the wireless ad hoc terminal 101-a that cannot be seen by the wireless ad hoc terminal 101-d but is suspected of being broken) In this case where communication is possible, the wireless ad hoc terminal 101-g) may be substituted. Of course, the receiving side can check other information, and if something is entered (without performing fault diagnosis for a terminal that is suspected of being faulty), it can recursively request a fault diagnosis from the next terminal. This makes it possible to check failures efficiently.

  When a terminal having no via table and having the highest possibility of communication is selected from the position information, and a failure diagnosis request message 205 is sent to the terminal, the story is returned.

  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. 6) shown in FIG. In order to distinguish from the failure diagnosis message output at this time, the 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 201 illustrated in FIG. 5 is transmitted from the wireless ad hoc terminal 101-a to the wireless ad hoc terminal 101-e. Is transmitted (step S522, sequence SQ617), the wireless ad hoc terminal 101-e diagnoses the wireless ad hoc terminal 101-a as non-failed based on the presence notification message 201 from the wireless ad hoc terminal 101-a. The failure is embedded in the diagnosis result message 207 shown in FIG. 8 and transmitted to the wireless ad hoc terminal 101-d (step S523, sequence SQ618). Similar to the first failure diagnosis, the presence notification message 201 denies the possibility of failure of the wireless ad hoc terminal 101-a.

  On the other hand, the case where the wireless ad hoc terminal 101-a cannot receive the presence notification message 201 from the wireless ad hoc terminal 101-a within the predetermined lifetime 203b and the recursive failure diagnosis designation flag is not designated will be described.

  After performing the same steps until the wireless ad hoc terminal 101-e transmits the second failure diagnosis message to the wireless ad hoc terminal 101-a (S521, SQ616), the presence notification message 201 from the wireless ad hoc terminal 101-a is transmitted. Is not received within the predetermined lifetime 203b (S712, sequence SQ619), the wireless ad hoc terminal 101-a is diagnosed as a failure, and the diagnosis result (failure) is shown in FIG. It is embedded in the result message 207 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).

  FIG. 14 shows a case where the presence notification message 201 from the wireless ad hoc terminal 101-a cannot be received by the wireless ad hoc terminal 101-e within the predetermined lifetime 203b and the recursive failure diagnosis designation flag is designated. The description will be given with reference.

  FIG. 14 is a diagram showing an operation sequence of the ad hoc network system according to the first embodiment of the present invention.

  In FIG. 14, a failure diagnosis request is issued to the wireless ad hoc terminal 101-e, and the recursive failure diagnosis designation flag is set together with FIG. 13 until there is no response. The operation sequence when a response is returned from is shown.

  In FIG. 14, the above-described wireless ad hoc terminal 101-e transmits the second failure diagnosis message to the wireless ad hoc terminal 101-a (S521, SQ616), but the presence notification message 201 is received from the wireless ad hoc terminal 101-a. This is the same as before (S712, SQ619). The recursive diagnosis confirmation unit 22 of the wireless ad hoc terminal 101-e confirms whether or not the recursive failure diagnosis designation flag 205c is set in the failure diagnosis request message 205 received from the wireless ad hoc terminal 101-d. If it is set, the wireless ad hoc terminal 101-e that has performed the second failure diagnosis uses the adjacent terminal selection unit 18 to store the common adjacent terminal table 300 (of the wireless ad hoc terminal 101-e). The wireless ad hoc terminal 101-g that is one of the common adjacent terminals with the highest possibility of communication is selected from the position information. The recursive diagnosis request unit 24 issues a failure diagnosis request message 205 shown in FIG. 7 to the wireless ad hoc terminal 101-g, and the transmission / reception unit 10 transmits it (step S713, sequence SQ808).

  At this time, the recursive failure diagnosis designation flag 205c is set to 0 for transmission. In addition, when a numerical value is assigned to the recursive failure diagnosis designation flag 205c, and a failure diagnosis request is to be performed recursively by the number of times, a value obtained by subtracting 1 is used. In this example, a failure diagnosis request is recursively issued only once. The wireless ad hoc terminal 101-g that has received the failure diagnosis request transmits a second failure diagnosis message to the wireless ad hoc terminal 101-a in the same manner as the wireless ad hoc terminal 101-e (S714, SQ809). When the presence notification message 201 is received from the terminal 101-a (S715, SQ810), the wireless ad hoc terminal 101-g transmits a diagnosis result message 207 indicating a non-failure to the wireless ad hoc terminal 101-e (S716, SQ811). Receiving this, the wireless ad hoc terminal 101-e similarly transmits a diagnosis result message 207 indicating a non-failure to the wireless ad hoc terminal 101-d (S717, SQ812).

  On the other hand, the case where the wireless ad hoc terminal 101-g that has recursively received a failure diagnosis request transmits the second failure diagnosis message (recursively), but there is no response from the wireless ad hoc terminal 101-a. Will be described with reference to FIG.

  FIG. 15 is a diagram showing an operation sequence of the ad hoc network system according to the first embodiment of the present invention.

  FIG. 15 shows an operation sequence when there is no response from the recursively requested destination in FIG. 14 and it is finally found that there is a failure.

  FIG. 15 is the same until the wireless ad hoc terminal 101-g recursively receiving a failure diagnosis request from the above-described wireless ad hoc terminal 101-e transmits (recursively) a second failure diagnosis message (S714, SQ809). It is. If the wireless ad hoc terminal 101-g cannot receive the presence notification message 201 from the wireless ad hoc terminal 101-a within the predetermined lifetime 203b (S718, SQ813), a failure diagnosis result message to the wireless ad hoc terminal 101-e 207 is transmitted (S719, SQ814). Of course, when the wireless ad hoc terminal 101-g receives a failure diagnosis request, if the value of the recursive failure diagnosis flag is not 0, the failure diagnosis is performed recursively. Therefore, the wireless ad hoc terminal 101-g does not recursively diagnose a failure and returns a failure diagnosis result message 207. The wireless ad hoc terminal 101-e that has received it also transmits a failure diagnosis result message 207 to the wireless ad hoc terminal 101-d (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. 6 as the presence notification message 201 shown in FIG. However, “ACK_REQUIRED” indicating that a response is required is attached to the response request flag. As with the presence notification message 201, 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. Further, by making the first and second failure diagnosis messages and presence notification messages have a common format as shown in FIG. 5 and FIG. 6, processing relating to message generation is simplified and simplified, and the wireless ad hoc terminal The influence on the resources can be suppressed.

  The failure diagnosis request message 205 transmitted from the failure diagnosis request source wireless ad hoc terminal can use the format shown in FIG. 7, and is similarly transmitted from the failure diagnosis request destination wireless ad hoc terminal. The diagnosis result message 207 can use a format as shown in FIG. The format shown in FIG. 7 is the same as the format shown in FIG. 8, and the identifiers 205a and 207a of the transmission source terminal, the identifiers 205b and 207b of the fault diagnosis target terminal, the recursive fault diagnosis designation flags 205c and 207c, and other It consists of information 205d and 207d. The recursive failure diagnosis designation flag 205c is used to specify that the failure diagnosis is performed recursively (in this case, “numerical value 1” or “numerical value 0” that is not performed), and a method of specifying the number of times is also possible. (Do not do “value 0”, do N times “value N”). One recursive fault diagnosis designation flag 207c is used to substitute the result of how far recursive fault diagnosis has been performed.

  The terminal that first evoked the second failure diagnosis message recursively diagnoses the failure to what depth by referring to the recursive failure diagnosis designation flag 207c in the diagnosis result message 207 returned to its own hand. You can see what went on. Further, the other information 207d shown in FIG. 8 may be embedded in the diagnosis result field of “other information 205d” in the failure diagnosis request message 205 shown in FIG.

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

  In addition, in the above description, the processing when a failure diagnosis request is accepted will be supplementarily described with reference to FIG.

  FIG. 16 is a flowchart showing an operation when the wireless ad hoc terminal according to Embodiment 1 of the present invention receives a failure diagnosis request from another terminal.

  First, a wireless ad hoc terminal that has received a failure diagnosis request (step 1200) has received a request from another wireless ad hoc terminal. 2 "is sent for confirmation (step 1201). As a result (step 1202), if there is a response, a non-failure diagnosis result is returned (step 1203).

  On the other hand, if there is no response, the recursive failure diagnosis designation flag is checked, and it is determined whether or not a failure diagnosis instruction is recursively issued (step 1204). If the recursive failure diagnosis designation flag is 0, the failure diagnosis result is returned to the transmission source terminal (step 1205).

  When the recursive fault diagnosis designation flag is designated or a value greater than or equal to 0 is entered, the optimum terminal is selected by referring to the common adjacent terminal table 300 (stored together in the selection judgment) The failure diagnosis request is recursively transmitted. At this time, if the recursive failure diagnosis designation flag is set to 0 or a value other than 0 is entered, a value obtained by subtracting 1 is used for the failure diagnosis request message 205 (step 1206). As a result (step 1207), if there is a response, it returns to the transmission source that it was not a failure (step 1208), and if there was no response or a notification of failure, the transmission source (Step 1209).

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

  As described above, in the first 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, it is possible to quickly detect a wireless ad hoc terminal that has left the system due to a failure or the like without depending on the inquiry cycle from the manager.

  In addition, when requesting confirmation of a failure to an adjacent terminal, it is possible to access from the terminal with the highest possibility of communication by using location information, so it is possible to determine failure / non-failure efficiently. Yes. In addition, by referring to the route table when it exists, it is possible to request failure detection to a terminal that can communicate without making a useless failure check for each route-routed terminal.

  FIG. 17 is a diagram showing another configuration of the ad hoc network system according to Embodiment 1 of the present invention.

  FIG. 17 shows a configuration of an ad hoc network system including a plurality of sub ad hoc network systems.

  In FIG. 1, a single ad hoc network system has been described as an example. For example, an ad hoc network system 900 shown in FIG. 17 configured by a plurality of sub ad hoc network systems 901 to 905 is used. It can also be applied. 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 901 to 905 is transmitted to the manager 910. As a result, the entire ad hoc network system 900 can be managed.

It is a figure which shows the structure of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a block diagram which shows the structure of the radio | wireless ad hoc terminal which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the adjacent terminal list stored in the adjacent terminal list holding | maintenance part of the radio | wireless ad hoc terminal which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the common adjacent terminal table stored in the common adjacent terminal table holding | maintenance part of the radio | wireless ad hoc terminal which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the presence notification message of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the failure diagnosis message of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the failure diagnosis request message of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the diagnostic result message of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the operation | movement sequence of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the operation | movement sequence of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a flowchart which shows the preparation and update operation | movement of the adjacent terminal list | wrist of the message processing part of the radio | wireless ad hoc terminal which concerns on Embodiment 1 of this invention, and a common adjacent terminal table. It is a figure which shows the operation | movement sequence of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the operation | movement sequence of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the operation | movement sequence of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a figure which shows the operation | movement sequence of the ad hoc network system which concerns on Embodiment 1 of this invention. It is a flowchart which shows operation | movement when the radio | wireless ad hoc terminal which concerns on Embodiment 1 of this invention receives a failure diagnosis request from another terminal. It is a figure which shows another structure of the ad hoc network system which concerns on Embodiment 1 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Transmission / reception part, 12 Message processing part, 14 Neighboring terminal list holding part, 16 Common adjacent terminal table holding part, 18 Neighboring terminal selection part, 22 Recursive diagnosis confirmation part, 24 Recursive diagnosis request part, 26 Location information recording part, 101 Wireless Ad hoc terminal, 102 wireless link, 900 ad hoc network system, 901 sub ad hoc network system, 910 manager, 911 sub manager.

Claims (5)

A wireless ad hoc terminal for building an ad hoc network system,
A location information recording unit for recording location information where the wireless ad hoc terminal is located;
An adjacent terminal list holding unit that holds an adjacent terminal list composed of an identifier and position information of a second wireless ad hoc terminal located in a range in which communication with the wireless ad hoc terminal is possible;
A common adjacent terminal table holding unit that is created based on the adjacent terminal list and holds a common adjacent terminal table related to the adjacent terminal when the adjacent terminal in the wireless ad hoc terminal is also an adjacent terminal in the third wireless ad hoc terminal When,
A first presence notification message is generated based on the identifier of the wireless ad hoc terminal, the position information of the wireless ad hoc terminal obtained from the position information recording unit, and the neighboring terminal list held by the neighboring terminal list holding unit. When the second presence notification message corresponding to the first presence notification message is received from the second wireless ad hoc terminal, the second presence notification message is transmitted. A message processing unit for updating the adjacent terminal list and updating the common adjacent terminal table when communication possibility is high based on the position information of the second wireless ad hoc terminal. A wireless ad hoc terminal. When a possible failure terminal is detected, a failure diagnosis message is transmitted to the failure possibility terminal, and a presence notification message corresponding to the failure diagnosis message is not returned. The reference terminal according to claim 1, further comprising: an adjacent terminal selection unit that refers to the common adjacent terminal table and selects a common adjacent terminal having a high possibility of communication from position information regarding the failure possibility terminal. Wireless ad hoc terminal. When the message processing unit receives the second presence notification message from the second wireless ad hoc terminal, the message processing unit adds the second wireless ad hoc terminal to the free space when the adjacent terminal list has a free space. When the neighboring terminal list is updated and there is no space in the neighboring terminal list, the position information of the second wireless ad hoc terminal that has sent the second presence notification message is used as the position information of the neighboring terminal list. The wireless ad hoc terminal according to claim 2, wherein the reference is compared and replaced with a terminal having the lowest possibility of communication to update the adjacent terminal list and to update the common adjacent terminal table. In the received failure diagnosis request message, a recursive diagnosis confirmation unit for confirming whether or not a recursive failure diagnosis designation flag for specifying recursive diagnosis is set,
If it is confirmed by the recursive diagnosis confirmation unit that the recursive failure diagnosis designation flag is set, a failure diagnosis is performed on the common adjacent terminal selected by the adjacent terminal selection unit and having the highest possibility of communication. The wireless ad hoc terminal according to claim 1, further comprising a recursive diagnosis requesting unit that transmits a request message. When the common adjacent terminal table recursively requests failure diagnosis, as a result of having confirmed that it is not a failure, the common adjacent terminal table has a route table that stores information of the terminal that passed,
The message processing unit transmits a failure diagnosis request message to a terminal stored in the route table instead of the terminal selected by the adjacent terminal selection unit. 3. A wireless ad hoc terminal according to 3.

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