JP2010141404A - System and method for detecting unauthorized device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for detecting an unauthorized device capable of detecting presence of an unauthorized roadside machine Z even when the unauthorized roadside machine Z is about to intrude into a communication system. <P>SOLUTION: This system for detecting an unauthorized device includes a storage part 14 for storing identification information allocated to each of normal roadside machines 1. The system further includes a detection part 15 for detecting identification information included in a signal transmitted by the roadside machine, and checking the detected identification information against normal identification information stored in the storage part 14 to predict that the roadside machine being a transmission source of the signal including the detected identification information is an unauthorized roadside machine Z when the detected identification information is not coincident with the normal identification information. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an unauthorized device detection system that detects the presence of an unauthorized communication device that attempts to intrude into a communication system and a detection method thereof.

In recent years, for the purpose of promoting traffic safety and preventing traffic accidents, an intelligent road traffic system (ITS) that receives information from infrastructure devices installed on the road and uses this information to improve vehicle safety. (Intelligent Transport System) has been studied (for example, see Patent Document 1).
This traffic system is mainly realized by a plurality of roadside communication devices as communication devices on the infrastructure side and an in-vehicle communication device (mobile terminal) that is a communication device mounted on each vehicle. Communication combinations include road-to-road communication between roadside communication devices, road-to-vehicle (or vehicle-road) communication between roadside communication devices and in-vehicle communication devices, and vehicle-to-vehicle communication between in-vehicle communication devices. .

Japanese Patent No. 2806801

The roadside communication device is installed at each intersection of the road, for example, and other roadside communication devices installed in the neighborhood or the same intersection receive information transmitted from the roadside communication device installed at a certain intersection Can do. Such road-to-road communication is performed, and road-to-vehicle communication is performed between the roadside communication device and the vehicle-mounted communication device of the vehicle traveling around the roadside communication device. It becomes possible to notify the information of the part which is a blind spot beforehand, and the traffic accident in an intersection can be prevented beforehand.
However, if an unauthorized communication device intrudes into such a system, in addition to intercepting information related to traffic control, the unauthorized communication device will transmit false information to surrounding in-vehicle communication devices. There is a risk of deteriorating the function of the system.

  Accordingly, an object of the present invention is to provide an unauthorized device detection system and a detection method thereof that can detect the presence of an unauthorized communication device even if an unauthorized communication device attempts to enter the communication system.

  (1) The present invention is an unauthorized device detection system for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of authorized roadside communication devices, and identification information assigned to each of the authorized roadside communication devices. And the identification information included in the signal transmitted by the roadside communication device is detected, the detected identification information is compared with the regular identification information stored in the storage unit, and the mismatch is detected. In this case, the roadside communication device that is a transmission source of the signal including the detected identification information includes a detection unit that estimates that the roadside communication device is an unauthorized roadside communication device.

According to the present invention, the detection unit detects the identification information included in the signal transmitted by the roadside communication device, and collates the detected identification information with the regular identification information stored in the storage unit, If there is a mismatch, the roadside communication device that is the source of the signal including the detected identification information is estimated to be an unauthorized roadside communication device, so even if an unauthorized roadside communication device attempts to enter the communication system This unauthorized roadside communication device can be detected.
In addition, it can be said that it is inconsistent when the identification information included in the signal transmitted by the roadside communication device is different from any of the plurality of identification information stored in the storage unit.

(2) Further, the detection unit collates the detected identification information with the regular identification information stored in the storage unit, determines that there is a mismatch, and the detected identification information. When the strength of the signal including the identification information is determined and the strength is equal to or greater than the threshold, it is estimated that the roadside communication device that is the transmission source of the signal including the detected identification information is an unauthorized roadside communication device. preferable.
In this case, the detection unit can happen to detect the identification information included in the signal transmitted by the distant regular roadside communication device that is not scheduled to communicate, and the identification information included in the signal is stored in the storage unit. Even if not, the signal that can be received from the legitimate roadside communication device existing in the distance is weak. Therefore, according to the detection unit of the present invention, the far roadside communication device is It can be prevented from being regarded as a communication device.

  (3) Further, the present invention is an unauthorized device detection system for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of authorized roadside communication devices that perform radio communication by time division multiplexing, A storage unit that stores slot information related to the timing of the time slot assigned to each of the roadside communication devices, a timing of a signal transmitted by the roadside communication device, and a timing that is detected and stored by the storage unit The roadside communication device that is the source of the signal that has detected the timing is provided with a detection unit that estimates that the slot information is an unauthorized roadside communication device when the slot information is compared and is not compatible. Features.

  According to the present invention, when the detection unit detects the timing of the signal transmitted by the roadside communication device, and compares the detected timing with the slot information stored in the storage unit, and when it does not match The roadside communication device that is the transmission source of the signal whose timing has been detected is estimated to be an unauthorized roadside communication device. Therefore, even if an unauthorized roadside communication device attempts to enter the communication system, the unauthorized roadside communication device Can be detected.

(4) In addition, the detection unit compares the detected timing with the slot information stored in the storage unit, determines that they are not compatible, and determines the strength of the signal from which the timing is detected. When the strength is equal to or greater than the threshold value, it is preferable to estimate that the roadside communication device that is the source of the signal that has detected the timing is an unauthorized roadside communication device.
In this case, it is possible for the detection unit to detect the timing of a signal transmitted by a distant regular roadside communication device that is not scheduled for communication, and the slot information includes the time slot of the distant regular roadside communication device. Even if not, the signal that can be received from the regular roadside communication device existing in the distance is weak, so according to the detection unit of the present invention, the far regular roadside communication device is illegally communicated. It can be prevented that the device is regarded as a device.

  (5) Further, the present invention is an unauthorized device detection system for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of authorized roadside communication devices that perform radio communication by time division multiplexing, A storage unit that stores slot information regarding the timing of the time slot assigned to each of the roadside communication devices, a timing of a signal transmitted by a certain communication device, and a timing that is detected and stored by the storage unit A first determination unit that determines whether or not the slot information is matched, and whether the communication device that is the source of the signal for which the first determination unit has detected timing is a roadside communication device A second determination unit that determines whether or not the first determination unit is not compatible, and the second determination unit is a communication source of the signal If the location is determined to be a roadside communication apparatus, the communication device is a source of the signal is characterized by comprising a detecting section that estimates that an illegal roadside communication device.

  According to the present invention, the first detection unit determines that the timing detected from the signal and the slot information stored in the storage unit do not match, and the communication device that is the source of the signal is on the roadside When the second determination unit determines that the communication device is a communication device, the detection unit estimates that the communication device that is the transmission source of the signal is an unauthorized roadside communication device. Even if the communication device is about to enter, this unauthorized roadside communication device can be detected.

  (6) Further, the present invention is a method for detecting an unauthorized device for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices, and is included in a signal transmitted by the roadside communication device. The identification information is detected, and the detected identification information is compared with the identification information assigned to each of the regular roadside communication devices, and if they do not match, the signal transmission source including the detected identification information The roadside communication device is estimated to be an unauthorized roadside communication device.

  According to the present invention, the identification information included in the signal transmitted by the roadside communication device is detected, the detected identification information is compared with the identification information assigned to each of the regular roadside communication devices, and the mismatch is detected. When the roadside communication device that is the source of the signal including the detected identification information is estimated to be an unauthorized roadside communication device, even if an unauthorized roadside communication device attempts to enter the communication system, This unauthorized roadside communication device can be detected.

  (7) Furthermore, the present invention is a method for detecting an unauthorized device for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices that perform wireless communication by time division multiplexing. When the timing of the signal transmitted by the communication device is detected and the detected timing is compared with the slot information related to the timing of the time slot assigned to each of the regular roadside communication devices, and when it does not fit, The roadside communication device that is the source of the signal whose timing is detected is estimated to be an unauthorized roadside communication device.

  According to the present invention, the timing of the signal transmitted by the roadside communication device is detected, and the detected timing is compared with the slot information related to the timing of the time slot assigned to each of the regular roadside communication devices, If the roadside communication device that is the source of the signal that has detected the timing is presumed to be an unauthorized roadside communication device when it is not compatible, even if an unauthorized roadside communication device tries to enter the communication system, This unauthorized roadside communication device can be detected.

  (8) Further, the present invention is an unauthorized device detection method for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices that perform wireless communication by time division multiplexing. The timing of the signal transmitted by the communication device is detected, and the detected timing is compared with the slot information related to the timing of the time slot assigned to each of the regular roadside communication devices to determine whether or not they are compatible. A first determination to be performed, and a second determination to determine whether or not the communication device that is the transmission source of the signal whose timing is detected by the first determination is a roadside communication device. When it is determined that the communication device is not suitable and the communication device that is the source of the signal is determined to be a roadside communication device by the second determination. The communication device is a source of the signal and estimates that the illegal roadside communication device.

  According to the present invention, it is determined that the timing detected from the signal does not match the slot information (first determination), and the communication device that is the source of the signal is determined to be a roadside communication device. (Second determination), it is estimated that the communication device that is the source of the signal is an unauthorized roadside communication device. Therefore, even if an unauthorized roadside communication device attempts to enter the communication system, A simple roadside communication device can be detected.

  According to the present invention, even if an unauthorized roadside communication device attempts to enter the communication system, it is possible to detect this unauthorized roadside communication device and prevent further intrusion.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram of a road where a communication system is provided, and FIG. 2 is an explanatory diagram illustrating a part of FIG. 1 (a part surrounded by a two-dot chain line) in an enlarged manner.
The communication system includes a plurality of roadside communication devices (hereinafter referred to as “roadside machines”) 1. In FIG. 1, roadside machines 1 </ b> A to 1 </ b> I and 1 </ b> Q are shown as roadside machines 1. In addition, the communication system includes a central control device 4 of a traffic control center that supervises a plurality of regular roadside devices 1. These roadside devices 1 are connected to the central control device 4 of the traffic control center, and the central control device 4 and each roadside device 1 can communicate with each other by wire or wirelessly.
The control of the plurality of regular roadside devices 1 is not the central control device 4 of the traffic control center, but a centralized monitoring device (communication control device) installed on the roadside (not shown) separately from the traffic control center (not shown). ) May do.

The roadside device 1 is installed at an intersection (including the vicinity of the intersection) J, and communicates with an in-vehicle communication device (hereinafter referred to as “in-vehicle device”) 2 mounted on a vehicle 5 (see FIG. 2). Is possible. Communication between the roadside device 1 and the vehicle-mounted device 2 is referred to as “road-to-vehicle communication”.
The roadside machine 1 (for example, the roadside machine 1A) can also communicate with other roadside machines (roadside machines 1B, 1C, 1D, 1E), and can exchange information between the roadside machines 1. It is. Communication between the roadside devices 1 is referred to as “roadside communication”.
The frequency used by the communication system is, for example, the 720 MHz band.

In the present embodiment, as an example of the road structure, a grid structure in which a plurality of roads in the north-south direction and a plurality of roads in the east-west direction intersect is assumed. Accordingly, four roads RE, RW, RN, and RS are connected to one intersection J from four directions of east, west, north, and south.
In FIG. 2, at each intersection J, four (plural) traffic signal lamps 20a, 20b, 20c, and 20d are installed for each of four roads RE, RW, RN, and RS.
In addition, there are obstacles such as buildings at the corners of each intersection. The road structure is not limited to the above.

  As shown in the block diagram of FIG. 3, each roadside machine 1 includes a communication device body 10 and an antenna unit 11 connected to the communication device body 10. The communication device main body 10 can communicate with the central control device 4 of the traffic control center that controls the communication system. The communication device body 10 includes a wireless unit (transmission / reception unit) 12 and a control unit 13 that performs control related to communication. The control part 13 consists of a microcomputer etc. which have CPU, and can perform various processes with the memorize | stored program.

In addition, the roadside device 1 can perform communication by the time division multiplexing method. For this purpose, the control unit 13 manages time division slots. The slot management may be performed by the wireless unit 12.
The roadside device 1 can perform broadcast communication (one-to-many communication) with respect to the in-vehicle device 2 and can simultaneously transmit traffic information and the like to the in-vehicle devices 2 existing around.

  As shown in FIG. 2, the antenna unit 11 of the present embodiment includes a plurality (four) of directional antennas 11 a corresponding to the number of roads RE, RW, RN, RS connected to the intersection J. ing. The directional antenna 11a is provided in each of the four traffic signal lamps 20a, 20b, 20c, and 20d installed at the intersection J.

  The antenna unit 11 is used not only for road-to-vehicle communication but also for road-to-road communication. In the road-to-road communication, since the roadside device 1 that is a communication partner is specified and communication (referred to as individual communication or fixed communication) is performed, the antenna unit 11 has directivity. In the present embodiment, road-to-vehicle communication is performed by the directional antenna 11a, and the direction in which the directional antenna 11a is directed is the direction of the position where the other roadside device 1 is installed.

  The directivity of the antenna unit 11 will be specifically described. For example, the antenna unit 11 of the roadside machine 1A has directivity in the direction of the roadside machine 1B, the direction of the roadside machine 1C, the direction of the roadside machine 1D, and the direction of the roadside machine 1E. Furthermore, this directivity matches the direction of the road (lighting direction of the lamp) that the traffic signal lamps 20a, 20b, 20c, and 20d are directed to signal. Thereby, the antenna unit 11 having the directional antennas 11a, 11a, 11a, 11a is connected to the intersection J and has directivity along the road directions of the plurality of roads RE, RW, RN, RS on which the vehicle 5 is traveling. have.

  In FIG. 3, the vehicle-mounted device 2 includes a communication device main body 20 and an omnidirectional antenna 21 connected to the communication device main body 20. The communication device main body 20 includes a wireless unit 22 and a control unit 23, similarly to the communication device main body 10 of the roadside device 1. The in-vehicle device 2 can communicate with the in-vehicle devices (inter-vehicle communication) in addition to the communication with the roadside device 1. Since the antenna 21 of the in-vehicle device 2 is omnidirectional, it can receive radio waves regardless of the direction of the roadside device 1 or another in-vehicle device 2.

In the communication system of the communication system configured as described above, the TDMA system and the CSMA / CA system are combined in the MAC layer. That is, as shown in FIG. 4, a time zone (first time zone) for the roadside device 1 to transmit a signal is secured, and the slots of the plurality of roadside devices 1 in the first time zone are further secured. The TDMA method is adopted for the allocation.
The remaining second time zone other than the first time zone is a time during which the vehicle-mounted device 2 can transmit a signal, and vehicle-to-vehicle communication using, for example, the CSMA / CA method is performed in the second time zone. .

Thereby, in the first time zone, road-to-road communication between the roadside devices 1 and road-to-vehicle communication in which a signal is sent from the roadside device 1 to the vehicle-mounted device 2 are performed. In the second time zone, road-to-vehicle communication in which a signal is sent from the vehicle-mounted device 2 to the roadside device 1 and vehicle-to-vehicle communication between the vehicle-mounted devices 2 are performed. In the first time zone, the in-vehicle device 2 is prohibited from transmitting signals.
Thus, the quality of the signal transmitted from the roadside device 1 is ensured by giving the time (first time zone) during which the roadside device 1 transmits the signal preferentially.

Further, all the roadside devices 1 have a function of synchronizing the time in order to control the timing of signal transmission. And each roadside machine 1 can obtain the information (allocation information) regarding the time allocation of the first time zone (and the second time zone) by communication from the central control device 4 of the traffic control center.
And each roadside machine 1 synchronizes time, and transmits the said allocation information in communication area (to vehicle equipment 2 in a communication area). The allocation information includes slot information described later.

Accordingly, each roadside device 1 sharing the allocation information can perform one or both of road-to-road communication and road-to-vehicle communication in a designated slot in the first time zone.
On the other hand, the in-vehicle device 2 obtained by receiving the allocation information includes a time zone (first time zone) in which the roadside device 1 transmits a signal and a communicable time in which the in-vehicle device 2 can transmit the signal. You can know the zone (second time zone). Thereby, the onboard equipment 2 can perform one or both of the inter-road communication and the inter-vehicle communication in the second time zone.

The slot information will be further described with reference to FIG.
The slot information is information regarding the timing of a time slot (hereinafter also referred to as a slot) assigned to each roadside device 1. For example, the slot from which each roadside device 1 transmits a signal based on the start of the first time zone. The information regarding the timing (time) of is included. In the embodiment of FIG. 4, the roadside machine 1A, the roadside machine 1B, the roadside machine 1C, the roadside machine 1D, and the roadside machine 1E each transmit a signal at a specified time-division timing based on the start of the first time zone. Slots are defined to do this. With this slot information, it is possible to determine which roadside device 1 transmits a signal at which timing from the start of the first time slot.

  As described above, even when other roadside devices 1B to 1E are present in the antenna pointing direction of the roadside device 1A, the time division is performed as in the slot information, so that it is close (in the communication area). Interference can be prevented between installed roadside units. In the first time zone, there is a blank part (blank slot) that is not assigned to any roadside machine 1, or other roadside machines 1Q other than the group of neighboring roadside machines 1A to 1I (see FIG. 1). There is an allocation slot for (time zone M).

  For example, in the inter-road communication, an unauthorized device detection system is provided in the communication system in order to appropriately execute the individual communication. The unauthorized device detection system has a function of detecting the presence of an unauthorized roadside communication device (hereinafter referred to as an unauthorized communication device) that attempts to illegally enter the communication system.

For this purpose, the unauthorized device detection system includes a storage unit 14 and a detection unit 15 as shown in FIG.
The storage unit 14 includes a storage device such as a ROM or a RAM that stores various types of information and computer programs. The detection unit 15 includes a microcomputer having a CPU, and includes an acquisition unit 15a, a collation unit 15b, and a level determination unit 15c as functional units that execute various processes according to the computer program. These functional units will be described later.
In the present embodiment, the communication device body 10 of each roadside device 1 includes a storage unit 14 and a detection unit 15. Further, the control unit 13 of the communication apparatus main body 10 may have the function of the detection unit 15.

  Further, the detection unit 15 determines the direction of the transmission source of the received signal by knowing which directional antenna 11a among the plurality of directional antennas 11a of the antenna unit 11 has received the signal. It also has a function as the route determination unit 15d.

A function for detecting the presence of an unauthorized communication device executed by the unauthorized device detection system will be described.
In FIG. 1, roadside machines 1A to 1I, 1Q are regular roadside machines 1 managed by a traffic control center, and a communication apparatus (hereinafter referred to as an unauthorized communication apparatus) in which the communication apparatus Z is attempting to illegally enter the communication system. Z).
The unauthorized communication device Z is present between the roadside machine 1A and the roadside machine 1E, and can transmit and receive signals to and from the roadside machines 1A and 1E and the surrounding vehicle-mounted device 2.

[Function for detecting presence of unauthorized communication device (first embodiment)]
A method for detecting the unauthorized communication device Z by the unauthorized device detection system provided in the roadside machine 1A will be described.

In the first embodiment, identification information is assigned in advance to each regular roadside device 1, and the storage unit 14 in each roadside device 1 stores its own identification information (ID information). The identification information of other regular roadside machines 1 is also stored. In addition, the memory | storage part 14 in each roadside machine 1 should just memorize | store at least the identification information of the other regular roadside machine 1 which exists in an own communication area. That is, it is only necessary to store the identification information of the roadside device 1 that is a partner with which individual communication is performed. Specifically, the storage unit 14 of the roadside machine 1A only needs to store identification information of the roadside machines 1B to 1E installed at the ends of roads extending in four directions, and may be a communication partner. The identification information of no roadside devices 1F to 1I and 1Q may not be stored.
Each roadside device 1 can transmit a signal by including its own identification information in the transmission signal from the antenna unit 11.

  As described above, the storage unit 14 of the roadside machine 1A stores identification information for the roadside machines 1B to 1E. According to the slot information of FIG. 4, the roadside device 1A receives signals from other regular roadside devices 1B to 1E after transmitting a signal in the first time zone. Since each received signal includes the identification information of the roadside device 1 that has transmitted the signal, the detection unit 15 of the roadside device 1A performs a verification process of the identification information included in each received signal. To do.

  That is, a signal transmitted by another roadside device is received, and the identification information included in the signal is detected by the acquisition unit 15a of the detection unit 15. The collation unit 15b collates the detected identification information with the regular identification information stored in the storage unit 14. As a result, when there is a mismatch, a process for estimating that the roadside device that is the transmission source of the signal including the detected identification information is the unauthorized communication device Z is executed.

  More specifically, the storage unit 14 in the roadside machine 1A stores identification information of the roadside machines 1B to 1E as regular identification information. Although the identification information included in the signal that should be received by the roadside device 1A is the identification information given to the roadside devices 1B to 1E, the identification information included in the received signal is In other words, when the identification information included in the received signal is different from any of the identification information of the roadside devices 1B to 1E stored in the storage unit 14, it becomes the source of the received signal. The detection unit 15 can estimate that the roadside device is the unauthorized communication device Z.

FIG. 5 is a flowchart for explaining a more preferable detection method of the unauthorized communication device Z.
The detection unit 15 in the roadside machine 1A receives a signal transmitted from another roadside machine, and the acquisition unit 15a detects the identification information included in the signal (step S11). Then, the collation unit 15b collates the detected identification information with the regular identification information stored in the storage unit 14 (step S12). As a result, when the identification information included in the received signal is different from any of the plurality of regular identification information stored in the storage unit 14, it is determined that there is a mismatch, and in this case ("mismatch" in step S12). ”), The second determination is performed by the level determination unit 15c.

  That is, as the second determination, the level determination unit 15c determines the strength (signal level) of the signal including the identification information detected by the acquisition unit 15a (step S13), and the strength is equal to or greater than the threshold value. In the case (Yes in step S12), it is estimated that the roadside device that is the transmission source of the signal including the detected identification information is the unauthorized communication device Z (step S14).

  This is a case where the storage unit 14 of the roadside machine 1A stores only identification information about the other roadside machines 1B to 1E that are present in the vicinity and are to perform individual communication. As shown in FIG. 1, when a roadside machine 1A happens to receive a signal from another regular roadside machine 1Q located far away from the regular roadside machine 1A, the roadside machine 1Q This is because the storage unit 14 of the roadside machine 1A does not store the identification number of the roadside machine 1A, so that it is possible to prevent the other regular roadside machine 1Q far away from being regarded as an unauthorized communication device.

That is, when there is an unauthorized communication device Z in the vicinity of the roadside device 1A, the signal from the unauthorized communication device Z received by the roadside device 1A is considered to be strong, so the strength of the received signal is determined, When the strength is greater than or equal to the threshold, the communication device that is the source of the received signal can be estimated as an unauthorized communication device. However, since the strength of the signal from the regular roadside machine 1Q far away is considered to be weak (smaller than the threshold value), the regular roadside machine 1Q existing in this distance is estimated as an unauthorized communication device. It is possible to configure so that it does not occur. Then, the legitimate roadside device 1 existing near the unauthorized communication device Z can detect the unauthorized communication device Z.
Accordingly, it is sufficient that the storage unit 14 in a certain roadside device 1 stores identification information about other roadside devices 1 that exist around the roadside device 1 and perform individual communication.

In the collation process in step S12 in FIG. 5, if it is determined as “match”, the roadside machine that is the source of the signal including the detected identification information is authenticated as the legitimate roadside machine 1 (step S15). ).
If the level of the received signal is less than the threshold value (No) in the determination in step S13, the received signal is ignored and the detection process of the unauthorized communication device Z is temporarily terminated.

  Further, in the roadside device 1A, it is possible to determine that the unauthorized communication device Z is present in the direction of the roadside device 1E by the function of the route determination unit 15d included in the detection unit 15. Therefore, when the unauthorized communication device Z is detected by the detection unit 15 of the roadside device 1A, information indicating that the unauthorized communication device Z is present near the roadside device 1A and information regarding the direction in which the unauthorized communication device Z is present are: It is transmitted to the central control unit 4 of the traffic control center. Thereby, the central control unit 4 can know that the unauthorized communication device Z exists between the roadside machine 1A and the roadside machine 1E, and sends an alarm signal to each roadside machine 1 as information to that effect. Send.

In addition, this unauthorized device detection system executes an authentication process that the one roadside device 1 is a legitimate roadside device when the other roadside device 1 receives a signal transmitted from one roadside device 1. You can also
As described above, each of the roadside devices 1B, 1C, 1D, and 1E receives the signal transmitted from the roadside device 1A. The signal transmitted from the roadside machine 1A includes identification information of the roadside machine 1A. The storage units 14 of the roadside devices 1B, 1C, 1D, and 1E store the identification information of the roadside device 1A in association with the roadside device 1A.

For this reason, each detection part 15 of roadside machine 1B, 1C, 1D, 1E collates the identification information contained in the actually received signal, and the identification information which the memory | storage part 14 has memorize | stored. That is, the detection unit 15 determines that the identification information included in the received signal matches any one of the plurality of identification information stored in the storage unit 14, so that the normal roadside device 1A authentication processing is executed. When the detection unit 15 of each of the roadside devices 1B, 1C, 1D, and 1E authenticates that the roadside device 1A is authentic, information to that effect is transmitted to the central control unit 4 of the traffic control center. .
The roadside machine 1A that is recognized as being legitimate by the roadside machines 1B, 1C, 1D, and 1E is also recognized as being legitimate by the central control unit 4.

[Function for detecting presence of unauthorized communication device (second embodiment)]
As in the first embodiment, in FIG. 1, the roadside machines 1A to 1I, 1Q are regular roadside machines 1 managed by the traffic control center, and the communication device Z attempts to illegally enter the communication system. Roadside communication device (hereinafter referred to as unauthorized communication device Z). The unauthorized communication device Z is present between the roadside machine 1A and the roadside machine 1E, and can transmit and receive signals to and from the roadside machines 1A and 1E and the surrounding vehicle-mounted device 2.

As shown in FIG. 4, in this communication system, a plurality of regular roadside devices 1A to 1E are set so that wireless communication is performed by time division multiplexing.
Therefore, the storage unit 14 provided in the communication device main body 10 of the roadside machine 1A stores the slot information related to the timing of the time slot assigned to each of the regular roadside machines 1A to 1E.

According to the slot information of FIG. 4, the roadside machine 1 </ b> A transmits signals from the other regular roadside machines 1 </ b> B to 1 </ b> E after the roadside machine 1 </ b> A (self) transmits a signal simultaneously with the start of the first time period. Should receive. That is, the time zone in which the roadside device 1A actually receives signals from the other regular roadside devices 1B to 1E on the basis of the start of the first time zone is a specified time indicated by the slot information stored in the storage unit 14. It should be included in band T. The prescribed time zone T includes a time zone in which the roadside device 1A transmits a signal.
Therefore, the detection unit 15 performs a verification process based on the slot information to determine whether the actually received signal is received within the specified time period T indicated by the slot information.

  That is, the roadside machine 1A receives a signal transmitted from another roadside machine, and the acquisition unit 15a of the detection unit 15 in the roadside machine 1A determines the reception timing of the signal with reference to the start of the first time zone. To detect. The collation unit 15b collates the detected reception timing with the slot information stored in the storage unit 14. As a result, when it does not conform, that is, when the detected reception timing is other than the specified time zone T indicated by the slot information, the roadside device that is the transmission source of the signal that has detected the reception timing Performs a process of estimating that the communication device Z is an unauthorized communication device Z.

FIG. 6 is a flowchart for explaining a more preferable detection method of the unauthorized communication device Z.
In FIG. 6, the detection unit 15 in the roadside machine 1A receives a signal transmitted by another roadside machine, and the acquisition unit 15a detects the reception timing of the received signal (step S11). The collation unit 15b collates the detected reception timing with the slot information stored in the storage unit 14 (step S12).

Steps S11 and S12 will be specifically described. According to the slot information (see FIG. 7A), the roadside devices 1A, 1B, 1C, 1D, and 1E transmit signals within the specified time zone T indicated by the slot information.
Therefore, when the roadside device 1A receives a signal from another roadside device, the acquisition unit 15a detects the reception timing of each reception signal, and the collation unit 15b determines that the reception timing is within the first time zone. If it is within the time zone T, it is determined that this reception timing is compatible with the slot information stored in the storage unit 14.
Therefore, in the case of FIG. 7B, the roadside machine 1A can receive the signals (B to E) from the roadside machines 1B, 1C, 1D, and 1E within the specified time zone T. Therefore, the collation unit 15b in the roadside device 1A can determine that the reception timing of each reception signal is within the specified time zone T, and is suitable for the slot information stored in the storage unit 14. Judgment is made (“fit” in step S12 of FIG. 6).

However, in the case of FIG. 7C, when the unauthorized communication device Z transmits a signal in a time zone M other than the specified time zone T in the first time zone, the roadside device 1A The signal Z of the unauthorized communication device Z is received in the time zone M other than the time zone T.
In this case, the matching unit 15b in the roadside device 1A can determine that the reception timing of the received signal is other than the specified time zone T, and does not conform to the slot information stored in the storage unit 14. Determination is made (“nonconformity” in step S12 in FIG. 6).
Thus, in the case of “nonconformity”, the level determination unit 15c performs the second determination.

  That is, as a second determination, the level determination unit 15c determines the strength (signal level) of the signal whose reception timing is detected by the acquisition unit 15a (step S13), and the strength is equal to or greater than the threshold (step S13). In the case of S12 (Yes), it is estimated that the roadside communication device that is the transmission source of the signal that has detected the reception timing is an unauthorized roadside communication device (step S14).

  This is because the slot information stored in the storage unit 14 of the roadside machine 1A includes only the time slots for the other roadside machines 1B to 1E that are present in the vicinity and are to perform individual communication. 1, as shown in FIG. 1, a signal from another regular roadside machine 1 </ b> Q that is located far from the regular roadside machine 1 </ b> A is sent to other than the specified time zone T. This is to prevent the other regular roadside machine 1Q that is far away from being regarded as an unauthorized communication device when the roadside machine 1A happens to be received in the time zone M.

That is, when there is an unauthorized communication device Z in the vicinity of the roadside device 1A, the signal from the unauthorized communication device Z received by the roadside device 1A is considered to be strong, so the strength of the received signal is determined, When the strength is greater than or equal to the threshold, the communication device that is the source of the received signal can be estimated as an unauthorized communication device. However, since the strength of the signal from the regular roadside machine 1Q far away is considered to be weak (smaller than the threshold value), the regular roadside machine 1Q existing in this distance is estimated as an unauthorized communication device. It is possible to configure so that it does not occur. Then, the legitimate roadside device 1 existing near the unauthorized communication device Z can detect the unauthorized communication device Z.
Accordingly, if the storage unit 14 in a certain roadside device 1 stores slot information about the slots of other roadside devices 1 that exist around the roadside device 1 and are to perform individual communication. It ’s enough.

In addition, in the collation process of step S12 of FIG. 6, if it determines with "conformity", the roadside machine which is a transmission source of the signal which detected the timing will be authenticated as the regular roadside machine 1 (step S15).
If the level of the received signal is less than the threshold value (No) in the determination in step S13, the received signal is ignored and the detection process of the unauthorized communication device Z is temporarily terminated.

  Further, in the roadside machine 1A, it is possible to determine that the unauthorized communication device Z exists in the direction of the roadside machine 1E by the function of the route determination unit 15d included in the detection unit 15. Therefore, when the unauthorized communication device Z is detected by the detection unit 15 of the roadside device 1A, information indicating that the unauthorized communication device Z is present near the roadside device 1A and information regarding the direction in which the unauthorized communication device Z is present are: It is transmitted to the central control unit 4 of the traffic control center. Thereby, the central control unit 4 can know that the unauthorized communication device Z exists between the roadside machine 1A and the roadside machine 1E, and sends an alarm signal to each roadside machine 1 as information to that effect. Send.

  In the fraudulent device detection system according to the second embodiment, one roadside machine 1 (roadside machine 1A) and other roadside machines 1 (roadside machines 1B to 1E) in communication with each other transmit signals. When the unauthorized communication device Z transmits a signal out of timing (see FIG. 7C), the unauthorized communication device Z can be detected.

In addition, in the second embodiment, in addition to performing the estimation of the unauthorized communication device Z when the slot information is not suitable as described above (this determination process is referred to as slot determination), the first embodiment As described above, the storage unit 14 stores the identification information assigned to each regular roadside device 1, and the storage unit 14 stores the identification information included in the signal transmitted by a certain communication device. The communication device that is a transmission source of the signal including the detected identification information is an illegal roadside communication device Z when there is a mismatch with the regular identification information that is present (this determination processing is called identification information determination). May be estimated.
That is, the unauthorized communication device Z may be estimated by satisfying one or both of the slot determination and the identification information determination.

In this case, when receiving the signal, the roadside device 1A detects the identification information included in the signal, and the detected identification information matches the regular identification information stored in the storage unit 14. It is determined whether or not the reception timing of the signal is within the specified time zone T indicated by the slot information.
As shown in FIG. 8A, according to the slot information, signals are transmitted in the order of the roadside devices 1A, 1B, 1C, 1D, and 1E in the specified time zone T of the first time zone. It has become. For this reason, the roadside machine 1A having the slot information and the identification information of the regular roadside machine has the roadside machines 1B and 1C within the specified time zone T as shown in FIG. , 1D, 1E in this order can be confirmed. In this case, in both the slot determination and the identification information determination, it can be estimated that the communication device that is the transmission source of the received signal is a regular roadside device.

However, as shown in FIG. 8 (c), after receiving the signals in the order of the roadside devices 1B, 1C, 1D, and 1E within the specified time zone T, the signals are received outside the specified time zone T. Therefore, in this case, the slot determination makes it possible to estimate that the communication device that is the source of signals received outside the specified time zone T is the unauthorized communication device Z.
Further, as shown in FIG. 8D, the received signal is within the specified time zone T, but the detected identification information is identical to the identification information of the legitimate roadside machine stored in the storage unit 14. If not, it can be estimated by the identification information determination that the communication device that is the source of the signal whose identification information does not match is the unauthorized communication device Z.

In each of the above embodiments, when the unauthorized communication device Z transmits a signal also to the roadside device 1E, the detection of the unauthorized communication device similar to the above is performed also in the roadside device 1E.
Furthermore, since the detection unit 15 performs the detection process of the unauthorized communication device Z during the first time period, the in-vehicle device 2 should not transmit a signal during the first time period. Therefore, the in-vehicle device 2 is not detected as the unauthorized communication device Z.

[Function for detecting presence of unauthorized communication device (third embodiment)]
As in the first and second embodiments, in FIG. 1, the roadside machines 1A to 1I, 1Q are regular roadside machines 1 managed by the traffic control center, and the communication device Z is illegally connected to the communication system. It is a roadside machine (hereinafter referred to as an unauthorized communication device Z) that is about to enter. The unauthorized communication device Z is present between the roadside machine 1A and the roadside machine 1E, and can transmit and receive signals to and from the roadside machines 1A and 1E and the surrounding vehicle-mounted device 2.

  In the third embodiment, as shown in FIG. 9, the communication device body 10 of the roadside machine 1 has a function of an unauthorized device detection system, and the unauthorized device detection system includes a microcomputer having a CPU, etc. The microcomputer (computer program) includes a first determination unit 15e, a second determination unit 15f, a detection unit 15g, a level determination unit 15c, and a route determination unit 15d as functional units that execute various processes. Yes. Although these functional units will be described later, the level determination unit 15c and the route determination unit 15d are the same as those in the above embodiment.

  Further, as in the second embodiment, in this communication system, the plurality of regular roadside devices 1A to 1E are set so that wireless communication is performed by time division multiplexing (see FIG. 4). In the storage unit 14 provided in the communication apparatus main body 10 of 1A, the slot information related to the timing of the time slot assigned to each of the regular roadside devices 1A to 1E is stored.

According to the slot information of FIG. 4, the storage unit 14 stores the time zone in which the roadside device 1A actually receives signals from the other regular roadside devices 1B to 1E with reference to the start of the first time zone. It should be included in the specified time zone T indicated by the slot information.
Therefore, the first determination unit 15e of the unauthorized device detection system in the roadside machine 1A performs a verification process as to whether or not an actually received signal is received within the specified time zone T indicated by the slot information. Run based on information.

That is, when the roadside device 1A receives a signal transmitted from another communication device (roadside device), the first determination unit 15e in the roadside device 1A receives the signal on the basis of the start of the first time zone. Is detected. Furthermore, the first determination unit 15e compares the detected reception timing with the slot information stored in the storage unit 14, and determines whether or not the matching is achieved.
In other words, when the detected reception timing is other than the specified time period T indicated by the slot information, the first determination unit 15e determines that it is not compatible. For example, when the roadside device 1A actually receives a signal from the in-vehicle device 2 or the unauthorized communication device Z in the second time zone (see FIG. 4) in which the in-vehicle device 2 can transmit a signal, The first determination unit 15e determines that they are not compatible.

  Similarly to the first embodiment, each legitimate roadside machine 1 is assigned identification information in advance, and the storage unit 14 in the roadside machine 1 stores its own identification information (ID information). In addition, identification information of other legitimate roadside devices 1 (identification information of the roadside device 1 that is an opponent for individual communication) is also stored. Each roadside device 1 transmits the signal by including its own identification information in the transmission signal from the antenna unit 11.

Therefore, the second determination unit 15f of the unauthorized device detection system in the roadside machine 1A detects the identification information included in the signal from which the first determination unit 15e has detected the reception timing. Further, the second determination unit 15f collates the detected identification information with the regular identification information stored in the storage unit 14, thereby the source of the signal from which the first determination unit 15e has detected the reception timing. It is determined whether or not the communication device is a roadside device.
As a case where the second determination unit 15f determines that the communication device that is a signal transmission source is not a roadside device, the identification information included in the signal is stored in the storage unit 14 in the roadside device 1B. This is a case different from any of the identification information of ˜1E.

  The second determination unit 15f may determine whether or not the communication device that is a signal transmission source is a roadside device by other means. For this purpose, the communication apparatus transmits a signal including information indicating the attribute of the transmission source (self). For example, when information (attribute information) indicating an attribute is included in a header of a signal to be transmitted and the attribute information is “0”, the transmission source means a roadside device, and when the transmission information is “1” Original means in-vehicle device. Therefore, when the second determination unit 15f detects that the attribute information included in the received signal is “0”, the second determination unit 15f determines that the signal transmission source is the roadside device.

  Still another means will be described. The communication device transmits a signal including information indicating attributes of a transmission source and a transmission destination. For example, when information (attribute information) indicating an attribute is included in a header or the like of transmission data and the attribute information is “0”, the transmission source is a roadside device, the transmission destination is an in-vehicle device, and “1”. , The transmission source is a roadside machine, the transmission destination is a roadside machine, and “2”, the transmission source is an in-vehicle device, the transmission destination is a roadside machine, and “3”, the transmission source Is an in-vehicle device and the transmission destination is an in-vehicle device and is “4”, the transmission source is a roadside device, the transmission destination is another roadside device and the in-vehicle device, and the transmission source is “5”, the transmission source is It is an in-vehicle device and the transmission destination is a roadside device and another in-vehicle device. Therefore, when the second determination unit 15f detects that the attribute information included in the received signal is “0”, “1”, or “4”, the second determination unit 15f determines that the signal transmission source is the roadside device. .

  When the first determination unit 15e determines that the reception timing is not suitable, and the second determination unit 15f determines that the communication device that is the transmission source of the signal is a roadside device, The detection unit 15g performs a process of estimating that the roadside device that is the transmission source of the signal is the unauthorized communication device Z.

FIG. 10 is a flowchart for explaining a detection method of the unauthorized communication device Z in the third embodiment.
In FIG. 10, the roadside device 1A receives a signal transmitted by another communication device (roadside device or in-vehicle device), and the received signal is received by the first determination unit 15e of the unauthorized device detection system in the roadside device 1A. Is received (step S21). Further, the first determination unit 15e collates the detected reception timing with the slot information stored in the storage unit 14 (step S22).

Steps S21 and S22 will be specifically described. In FIG. 4, when the unauthorized communication device Z transmits a signal in a second time zone that is a time zone other than the specified time zone T in the first time zone, the roadside device 1A The signal of the unauthorized communication device Z is received in the second time zone other than the time zone T.
In this case, the first determination unit 15e in the roadside device 1A can determine that the reception timing of the received signal is other than the specified time zone T, and is suitable for the slot information stored in the storage unit 14. ("Nonconformity" in step S22 in FIG. 10).

In this case, the second determination unit 15f detects the identification information included in the signal used for the determination by the first determination unit 15e (step S23). Then, the second determination unit 15f collates the detected identification information with the regular identification information stored in the storage unit 14 (step S24). As a result, when the identification information included in the received signal is different from any of a plurality of regular identification information stored in the storage unit 14, it is determined that they do not match.
Here, although the transmission source of the signal is the unauthorized communication device Z, the unauthorized communication device Z has identification information indicating that the unauthorized communication device Z is a roadside device, or identification information of the regular roadside devices 1A to 1I. Is illegally acquired and a signal including the identification information is transmitted, it is determined as “match” in the collation processing in step S24 by the second determination unit 15f.
Or the 2nd determination part 15f is based on the said attribute information contained in the said signal which the 1st determination part 15e used for determination, whether the communication apparatus which is a transmission source of a signal is a roadside machine. It may be determined. In this case, if the unauthorized communication device Z transmits a signal including attribute information indicating that it is a roadside device, the second determination unit 15f determines that the communication device that is the source of the signal is a roadside device. (This determination result corresponds to the “match”).

  However, even in this case, according to the detection unit 15g, the second determination unit 15f not only determines that the communication device that is the transmission source of the signal is a roadside device, but also the first determination unit. It is determined that 15e is not compatible (“non-conformity” in step S22) as a condition for estimating that the communication device Z is an unauthorized communication device Z. Even if it has identification information (attribute information) indicating that it is a roadside machine (even if identification information of the legitimate roadside machines 1A to 1I is illegally acquired), the presence of the unauthorized communication device Z is detected. be able to.

  Since the second time zone (see FIG. 4) is a time zone in which the vehicle-mounted device 2 can transmit signals, the roadside device 1A receives a signal from the vehicle-mounted device 2 during this second time zone. However, since it is determined as “mismatch” in step S24, the in-vehicle device 2 is not erroneously determined to be the unauthorized communication device Z.

  Also in this embodiment, as a further determination (step S25), the level determination unit 15c determines the signal strength (signal level) used for the determination by the first determination unit 15e and the second determination unit 15f, When the strength is greater than or equal to the threshold, the roadside communication device that is the source of the signal that has detected the reception timing may be estimated to be an unauthorized roadside communication device.

  According to each of the embodiments described above, even if an unauthorized communication device Z is about to enter the communication system, the unauthorized communication device Z is detected, and the traffic control center transmits a warning to each roadside device 1. Each roadside device 1 can start processing for preventing further intrusion. Thereby, the security of a communication system can be improved. As a process for preventing the intrusion, there is a process of ignoring all signals (information) including the detected identification information of the unauthorized communication device Z thereafter.

In addition, with respect to the present invention, the embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not intended to include the above-described meanings, but is intended to include meanings equivalent to the claims and all modifications within the scope.
For example, in the above-described embodiment, the case where the unauthorized device detection system (the storage unit 14 and the detection unit 15) is provided in each roadside device 1 has been described, but otherwise, the unauthorized device detection system is provided in the traffic control center. Also good. In this case, the traffic control center receives a signal received by each roadside device 1 and detects an unauthorized communication device based on this signal.
Or although the detection part 15 is provided in each roadside machine 1, you may provide the memory | storage part 14 in a traffic control center. In this case, the detection part 15 of each roadside machine 1 receives the information memorize | stored in the memory | storage part 14 of a traffic control center by communication, and detects an unauthorized communication apparatus.

It is a schematic diagram of the road where the communication system is provided. It is explanatory drawing which expands and demonstrates a part of FIG. It is a block diagram of a traffic control center, a roadside machine, and an in-vehicle machine. It is explanatory drawing of slot information. It is a flowchart explaining the detection method of an unauthorized communication apparatus. It is a flowchart explaining the detection method of an unauthorized communication apparatus. It is explanatory drawing of an unauthorized device detection method. It is explanatory drawing of an unauthorized device detection method. It is a block diagram of the traffic control center, roadside machine, and vehicle equipment which concern on other embodiment. It is a flowchart explaining the detection method of an unauthorized communication apparatus.

Explanation of symbols

1 Roadside machine (roadside communication device)
14 storage unit 15 detection unit 15e first determination unit 15f second determination unit 15g detection unit Z unauthorized communication device

Claims (8)

An unauthorized device detection system for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices,
A storage unit for storing identification information assigned to each of the regular roadside communication devices;
The identification information included in the signal transmitted by the roadside communication device is detected, and the detected identification information is compared with the regular identification information stored in the storage unit. And a detection unit that estimates that the roadside communication device, which is a transmission source of the signal including the identification information, is an unauthorized roadside communication device.   The detection unit compares the detected identification information with the regular identification information stored in the storage unit, determines that there is a mismatch, and the strength of the signal including the detected identification information The unauthorized device according to claim 1, wherein when the strength is equal to or greater than a threshold value, the roadside communication device that is a transmission source of the signal including the detected identification information is estimated to be an unauthorized roadside communication device. Detection system. An unauthorized device detection system for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices that perform wireless communication by time division multiplexing,
A storage unit that stores slot information related to timing of time slots assigned to each of the regular roadside communication devices;
The timing of the signal transmitted by the roadside communication device is detected, and the detected timing is compared with the slot information stored in the storage unit. A fraudulent device detection system comprising: a detection unit that estimates that a roadside communication device as a transmission source is an unauthorized roadside communication device.   The detection unit collates the detected timing with the slot information stored in the storage unit, determines that the timing does not match, and determines the strength of the signal at which the timing is detected, The unauthorized device detection system according to claim 3, wherein when the strength is equal to or greater than a threshold value, the roadside communication device that is a transmission source of the signal that has detected the timing is estimated to be an unauthorized roadside communication device. An unauthorized device detection system for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices that perform wireless communication by time division multiplexing,
A storage unit that stores slot information related to timing of time slots assigned to each of the regular roadside communication devices;
A first determination unit that detects a timing of a signal transmitted by a certain communication device, and compares the detected timing with the slot information stored in the storage unit to determine whether or not it is compatible; ,
A second determination unit that determines whether or not the communication device that is the source of the signal whose timing is detected by the first determination unit is a roadside communication device;
When it is determined that the first determination unit is not compatible, and the second determination unit determines that the communication device that is the transmission source of the signal is a roadside communication device, it is the transmission source of the signal An unauthorized device detection system comprising: a detection unit that estimates that the communication device is an unauthorized roadside communication device. An unauthorized device detection method for detecting the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices,
When the identification information included in the signal transmitted by the roadside communication device is detected, the detected identification information is compared with the identification information assigned to each of the regular roadside communication devices. A method of detecting a fraudulent device, characterized in that a roadside communication device that is a transmission source of a signal including detected identification information is estimated to be an unauthorized roadside communication device. A method of detecting an unauthorized device that detects the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices that perform wireless communication by time division multiplexing,
When the timing of the signal transmitted by the roadside communication device is detected, and the detected timing is compared with the slot information related to the timing of the time slot assigned to each of the regular roadside communication devices. A method of detecting an unauthorized device, wherein the roadside communication device that is a transmission source of the signal that has detected the timing is estimated to be an unauthorized roadside communication device. A method of detecting an unauthorized device that detects the presence of an unauthorized roadside communication device in a communication system including a plurality of regular roadside communication devices that perform wireless communication by time division multiplexing,
Whether the timing of the signal transmitted by a certain communication device is detected, and the detected timing is compared with the slot information related to the timing of the time slot allocated to each of the regular roadside communication devices, and whether or not they match A first determination for determining
Performing a second determination to determine whether or not the communication device that is the source of the signal whose timing has been detected by the first determination is a roadside communication device,
If it is determined by the first determination that the communication device is not adapted, and the second determination determines that the communication device that is the transmission source of the signal is a roadside communication device, the signal that is the transmission source of the signal A method for detecting an unauthorized device, wherein the communication device is estimated to be an unauthorized roadside communication device.

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