JP6273533B2 - Wireless communication detection device, wireless communication detection method, and program - Google Patents

Description

  The present invention relates to a wireless communication detection device that detects wireless communication using a spectrogram acquired from a received signal.

  Conventionally, from a spectrogram obtained in an environment where a plurality of radio signal transmission sources exist, a difference in average received power value for each transmission signal source is identified by a statistical method, and an appropriate separation threshold is automatically derived. A method of separating a radio signal for each transmission signal source is known (for example, see Non-Patent Document 1).

  Also known is a method of performing analysis (pulse timing signature analysis) related to frequency hopping such as Bluetooth (registered trademark) (see, for example, Patent Document 1).

JP 2005-523616 A

Akihiro Miyasaka, Masahiro Uno, Seiji Tsukamoto, Hiroki Oshima, Hitoshi Yano, Kiyoshi Kobayashi, "Separation Method of Multiple Source Radio Signals Using Statistical Techniques", 2013 IEICE General Conference, B-17-7, p. 651, March 2013

By using the method of Non-Patent Document 1, for example, a wireless signal based on a wireless LAN and a wireless signal based on Bluetooth (registered trademark) can be separated. On the other hand, there is a problem that it is not easy to identify each wireless system for wireless communication having similar frequency bandwidths such as Bluetooth (registered trademark) and ZigBee.
Generally speaking, there has been a desire to appropriately distinguish and detect wireless communications having similar frequency bandwidths.

  The present invention has been made in accordance with the above circumstances, and an object thereof is to provide a wireless communication detection device and the like that can appropriately distinguish and detect wireless communication having similar frequency bandwidths.

In order to achieve the above object, a wireless communication detection apparatus according to the present invention is obtained by a receiving unit that receives a received signal by wireless communication, a spectrogram acquiring unit that acquires a spectrogram related to the received signal received by the receiving unit, and a spectrogram acquiring unit In the spectrogram, a value corresponding to the remainder obtained by dividing the transmission start time by the transmission interval of the radio signal for each set of signals, a specific unit that identifies a set of signals that are continuous in at least one of the frequency direction and the time direction And a detection unit that detects wireless communication performed at a transmission interval corresponding to a value corresponding to the residue when a value corresponding to the residue acquired by the residue acquisition unit is localized, And an output unit that outputs a detection result by the detection unit.
With such a configuration, by using a value corresponding to the acquired remainder, it becomes possible to appropriately distinguish and detect wireless communication having a similar frequency bandwidth. For example, even when both wireless communication by Bluetooth (registered trademark) and wireless communication by ZigBee are mixed, wireless communication by Bluetooth (registered trademark) having the same transmission interval is appropriately detected. Will be able to.

The wireless communication detection apparatus according to the present invention further includes a feature amount acquisition unit that acquires a feature amount including a transmission start time for each set of signals, and the remainder acquisition unit performs transmission start time included in the feature amount. You may calculate the remainder by the transmission interval of a radio signal.
With such a configuration, the remainder itself can be calculated as a value corresponding to the remainder. Then, it becomes possible to appropriately distinguish and detect wireless communication having a similar frequency bandwidth by using the calculated remainder.

Further, in the wireless communication detection device according to the present invention, the feature amount acquisition unit acquires a feature amount including the center frequency for each set of signals, and the detection unit localizes the center frequency included in the feature amount. If so, wireless communication performed at the center frequency may be detected.
With such a configuration, when the center frequency is localized, wireless communication according to the center frequency can be detected.

In the wireless communication detection device according to the present invention, the feature amount acquisition unit acquires a feature amount including a frequency bandwidth for each set of signals, and the detection unit has a predetermined frequency bandwidth included in the feature amount. When the condition is satisfied, wireless communication performed with a frequency bandwidth corresponding to the condition may be detected.
With such a configuration, when the frequency bandwidth satisfies a predetermined condition, wireless communication according to the predetermined condition can be detected.

Further, in the wireless communication detection device according to the present invention, the time direction of the spectrogram is associated with a counter value that is reset according to the transmission interval of the wireless signal, and the remainder acquisition unit performs the remainder for each set of signals. As a corresponding value, a counter value corresponding to the transmission start time may be acquired.
With such a configuration, it is possible to detect a radio signal at a constant transmission interval using a counter value that is a value corresponding to the remainder without calculating the remainder.

  According to the wireless communication detection device and the like according to the present invention, it is possible to appropriately distinguish and detect wireless communication having similar frequency bandwidths.

1 is a block diagram showing a configuration of a wireless communication detection device according to Embodiment 1 of the present invention. The block diagram which shows the structure of the receiving part in the embodiment The flowchart which shows operation | movement of the radio | wireless communication detection apparatus by the embodiment The flowchart which shows operation | movement of the radio | wireless communication detection apparatus by the embodiment The figure which shows an example of the spectrogram in the same embodiment The figure which shows the signal more than the threshold value of the spectrogram in the same embodiment The figure which shows an example of the number of packets for every frequency bandwidth in the embodiment The figure which shows an example of the spectrogram by the embodiment The figure which shows the signal more than the threshold value of the spectrogram in the same embodiment The figure which shows an example of the number of packets for every frequency bandwidth in the embodiment The figure which shows an example of the relationship between the center frequency and the time remainder in the same embodiment The figure which shows an example of the packet number for every time remainder in the embodiment Schematic diagram showing an example of the appearance of the computer system in the embodiment The figure which shows an example of a structure of the computer system in the embodiment

  Hereinafter, a wireless communication detection apparatus according to the present invention will be described using embodiments. In the following embodiments, components and steps denoted by the same reference numerals are the same or equivalent, and repetitive description may be omitted.

(Embodiment 1)
A wireless communication detection apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. The wireless communication detection apparatus according to the present embodiment detects wireless communication using a time residue in a spectrogram.

  FIG. 1 is a block diagram illustrating a configuration of a wireless communication detection device 1 according to the present embodiment. The wireless communication detection device 1 according to the present embodiment includes a reception unit 11, a spectrogram acquisition unit 12, a specification unit 13, a feature amount acquisition unit 14, a remainder acquisition unit 15, a detection unit 16, and an output unit 17. Is provided. The wireless communication detection device 1 may be, for example, a terminal device such as a station or a mobile node, or may be a wireless base station such as an access point that performs wireless communication with one or more terminal devices. It may be another device for receiving. Further, the wireless communication detection device 1 may or may not be a device that performs wireless communication in an autonomous distributed wireless network. In addition, the wireless network may be an environment in which other wireless systems are mixed. That is, many wireless communication devices may share the same frequency band.

  The receiving unit 11 receives a reception signal by wireless communication. The receiving unit 11 may receive a radio signal by a plurality of radio communications. That is, the receiving unit 11 may receive radio signals from a plurality of radio signal sources. The radio signal may be any signal that propagates by radio. The radio signal may be, for example, a radio signal of a wireless LAN (wireless communication according to the IEEE 802.11 standard), a Bluetooth (registered trademark) radio signal, or ZigBee (IEEE 802.15.4). The wireless signal may be a wireless signal according to a standard, or may be a wireless signal according to another method. Moreover, the frequency of the radio signal does not matter. The frequency of the radio signal may be, for example, the ISM band or another frequency. For example, as illustrated in FIG. 2, the reception unit 11 that receives a radio signal includes a low noise amplification unit 21, a frequency conversion unit 22, a local oscillation unit 23, a filter unit 24, and an AD conversion unit 25. You may prepare. The low noise amplifying unit 21 receives an analog reception signal via an antenna and amplifies the received signal. The frequency converter 22 uses the signal generated by the local oscillator 23 to frequency-convert the amplified received signal and convert it to an equivalent baseband received signal that can be converted by the AD converter 25. The local oscillator 23 generates a signal for frequency conversion by the frequency converter 22. The filter unit 24 is a filter that passes only a predetermined frequency band. For example, the frequency band may be set to a frequency band corresponding to wireless communication that is to be detected by the detection unit 16. The filter unit 24 may be, for example, a low pass filter, a high pass filter, or a band pass filter. The AD conversion unit 25 converts an analog signal that is an equivalent baseband received signal into a digital signal. The digital signal after AD conversion is also referred to as a received signal. The configuration of the receiving unit 11 is an example, and the receiving unit 11 may have a configuration other than this.

  The spectrogram acquisition unit 12 acquires a spectrogram related to the reception signal received by the reception unit 11. The spectrogram shows the power related to the received signal received in the frequency domain and the time domain. Therefore, it can also be said that the spectrogram is a frequency power spectrogram. The spectrogram acquisition unit 12 may acquire the spectrogram, for example, by performing Fourier transform on the received signal received at predetermined time intervals. The Fourier transform may be, for example, a discrete Fourier transform (DFT) or a fast Fourier transform (FFT). Further, the acquired spectrogram may be stored in a recording medium (not shown).

  The specifying unit 13 specifies a set of signals (power values) that are continuous in at least one of the frequency direction and the time direction in the spectrogram acquired by the spectrogram acquisition unit 12. The set of signals usually corresponds to one packet (radio signal). Therefore, it can be considered that the specifying unit 13 specifies a radio signal or a packet in the spectrogram. The specifying unit 13 may perform the above-described processing using a signal that is equal to or greater than a threshold value in the spectrogram. The threshold value may be a predetermined value or may be a threshold value for separating the background noise and the signal specified by the method according to Non-Patent Document 1 or the like. The specifying unit 13 is, for example, when the interval between the two signals in the frequency direction is smaller than a predetermined threshold and the interval between the two signals in the time direction is smaller than a predetermined threshold. It may be determined that the two signals are continuous in the frequency direction or the time direction. In that case, the two signals are specified as signals belonging to the same set. In specifying the set of signals, the specifying unit 13 may specify continuous signals using, for example, a nearest neighbor method. Further, the threshold value in the frequency direction and the threshold value in the time direction used by the specifying unit 13 are set so that a series of signals corresponding to a single transmission packet transmitted from the same transmission source is included in one set. Is preferable. In addition, the specifying unit 13 may specify a set as, for example, a nearby point that can be connected to the closest point in the frequency direction and the second adjacent point in the time axis direction in the spectrogram. Further, the specifying unit 13 may determine only a set having a predetermined number (for example, 3) or more of signals as a final set as a result of specifying the set. This is for removing noise. Note that information on the sets specified by the specifying unit 13, for example, information on which signals are included in each set may be stored in a recording medium (not shown).

  The feature amount acquisition unit 14 acquires a feature amount for each set of signals specified by the specification unit 13. The feature amount may include a transmission start time, may include a center frequency, and may include a frequency bandwidth. In the present embodiment, a case where the feature amount includes a transmission start time, a center frequency, and a frequency bandwidth will be mainly described. The transmission start time is the transmission time of the packet corresponding to the set of signals, and may be the earliest time among the times corresponding to the signals included in the set. The center frequency is the center frequency of packets corresponding to a set of signals, and may be an average value or an intermediate value of frequencies corresponding to each signal included in the set. Further, the center frequency may be a frequency corresponding to the center of gravity with the estimated power value of each signal included in the set of signals as a weight. The frequency bandwidth is a frequency bandwidth of a packet corresponding to a set of signals, and may be a value obtained by subtracting a minimum value from the maximum value of the frequency corresponding to each signal included in the set. The feature amount acquisition unit 14 performs processing for acquiring the feature amount for each set specified by the specification unit 13. The feature amount acquired in this way may be stored in a recording medium (not shown).

  The remainder acquisition unit 15 calculates a remainder based on the transmission interval of the radio signal for the transmission start time included in the feature quantity acquired by the feature quantity acquisition unit 14. The remainder may be a minimum non-negative remainder. The transmission interval used in the calculation of the remainder is a transmission interval of wireless communication performed at equal transmission intervals. Examples of such wireless communication include Bluetooth (registered trademark) and wireless communication using time division multiple access (TDMA). Examples of wireless communication using time division multiple access include DECT (Digital Enhanced Cordless Communications), which is a digital cordless telephone standard. Note that the wireless communication may or may not have frequency hopping. For example, the transmission interval (slot length) of Bluetooth (registered trademark) is 625 (μs). Therefore, when the detection unit 16 detects Bluetooth (registered trademark), the residue acquisition unit 15 may calculate a residue of 625 (μs) for the transmission start time included in each feature quantity. That is, for each transmission start time, a remainder obtained by dividing by 625 (μs) may be calculated. Note that, for wireless communication in which wireless signals are transmitted at a constant transmission interval, this remainder has the same value. Therefore, it becomes possible to identify wireless communication using this fact.

  The detection unit 16 detects wireless communication performed at a transmission interval corresponding to the remainder when the remainder calculated by the remainder acquisition unit 15 is localized. As described above, the remainder calculated by the remainder acquisition unit 15 is a remainder due to a certain wireless communication transmission interval. Therefore, when the remainder is localized, it can be detected that wireless communication is performed to transmit a radio signal corresponding to the transmission interval used in the calculation of the remainder. In addition, that the remainder is localized means that the remainder is concentrated within a predetermined width range. For example, the detection unit 16 may determine that the remainder is localized when there is a remainder equal to or larger than the threshold number in a predetermined time width. The threshold value may be determined in advance or may be determined according to the number of sets (packets) specified by the specifying unit 13. In the latter case, for example, a value obtained by multiplying the total number of sets specified by the specifying unit 13 by a positive real number smaller than 1 (for example, 0.5 or 0.3) may be used as the threshold value. By this detection, for example, since frequency hopping is performed, wireless communication such as Bluetooth (registered trademark) with a constant transmission interval can be detected although the center frequency is not determined. Note that the detection of wireless communication may be considered as specifying what kind of wireless communication is being performed, that is, specifying a wireless communication transmission source.

  In addition, when the center frequency included in the feature quantity is localized, the detection unit 16 detects wireless communication performed at the center frequency. For example, there is wireless communication in which the center frequency is determined, such as ZigBee. Therefore, when the center frequency is localized, it can be detected that wireless communication corresponding to the center frequency is performed. For example, the detection unit 16 may determine that the center frequency is localized when there are center frequencies equal to or greater than the threshold number in a predetermined frequency width. The threshold value may be determined in advance or may be determined according to the number of sets specified by the specifying unit 13 as in the case of detection using a remainder.

  Moreover, the detection part 16 detects the radio | wireless communication performed with the frequency bandwidth according to conditions, when the frequency bandwidth contained in a feature-value satisfy | fills predetermined conditions. For example, there are wireless communication performed with a frequency bandwidth equal to or greater than a certain threshold, and wireless communication performed with a frequency bandwidth equal to or less than a certain threshold. Therefore, for example, wireless communication can be detected according to the comparison result between the frequency bandwidth included in the feature amount and the threshold value. Therefore, the above-mentioned predetermined condition may be that the frequency bandwidth is larger than the lower threshold, the frequency bandwidth may be smaller than the upper threshold, or the frequency bandwidth is It may be larger than the lower threshold and smaller than the upper threshold. Specifically, since the required bandwidth of the wireless LAN (IEEE802.11b and IEEE802.11g standards) is about 20 MHz, when there is a set of frequency bandwidths of 15 MHz or more, the detection unit 16 is based on the wireless LAN. Wireless communication may be detected. In addition, since the bandwidth of one channel of Bluetooth (registered trademark) is 1 MHz and the bandwidth of one channel of ZigBee is 2 MHz, when a set of frequency bandwidths of 3 MHz or less exists, the detection unit 16 For example, Bluetooth (registered trademark) or ZigBee may be detected. In addition, since the frequency bandwidth of Bluetooth (registered trademark) and ZigBee is approximate, it is difficult to identify both using only the frequency bandwidth. The detection unit 16 may determine that the frequency bandwidth satisfies the predetermined condition when there are more sets (packets) having the frequency bandwidth satisfying the predetermined condition than the threshold number. The number of threshold values is the same as that in the case of detection using a remainder or center frequency.

  The output unit 17 outputs the detection result by the detection unit 16. The detection result may be information indicating what kind of wireless communication is detected in the wireless communication according to the spectrogram acquired by the spectrogram acquisition unit 12. The detection result may be information indicating a detected wireless system (for example, wireless LAN, Bluetooth (registered trademark), ZigBee, etc.), for example. Here, the output may be, for example, display on a display device (for example, a CRT or a liquid crystal display), transmission via a communication line to a predetermined device, printing by a printer, or audio output by a speaker. Alternatively, it may be stored in a recording medium or delivered to another component. The output unit 17 may or may not include an output device (for example, a display device or a printer). The output unit 17 may be realized by hardware, or may be realized by software such as a driver that drives these devices.

Next, the operation of the wireless communication detection apparatus 1 will be described using the flowchart of FIG. 3A.
(Step S101) The receiving unit 11 receives a received signal. In addition, when the length of the time domain of the spectrogram to be acquired is determined, the reception unit 11 may perform reception according to the length. Further, the received signal received may be stored in a recording medium (not shown). For example, the received signal after AD conversion by the AD conversion unit 25 may be stored in a recording medium (not shown).

  (Step S102) The spectrogram acquisition unit 12 acquires a spectrogram related to the received signal. The acquired spectrogram may be stored in a recording medium (not shown).

  (Step S103) The specifying unit 13 specifies a set of signals in the acquired spectrogram. The set of signals corresponds to, for example, a packet.

  (Step S104) The feature amount acquisition unit 14 acquires a feature amount for each specified set of signals. The feature amount may include a transmission start time, a center frequency, and a frequency bandwidth. Note that the acquired feature amount may be stored in a recording medium (not shown).

  (Step S105) The remainder acquisition unit 15 calculates a remainder by a transmission interval corresponding to a predetermined wireless communication for each transmission start time included in the feature amount. In addition, when there are two or more wireless communications that transmit at equal intervals, the remainder acquisition unit 15 may calculate the remainder for each wireless communication. Further, the calculated remainder may be stored on a recording medium (not shown).

  (Step S106) The detection unit 16 detects wireless communication that is transmitting a wireless signal, using the feature amount and the calculation result. This detection process will be described later with reference to the flowchart of FIG. 3B.

(Step S107) The output part 17 outputs the detection result by the detection part 16. In this way, a series of processes for detecting the wireless communication being performed is completed.
Note that the processing in the flowchart of FIG. 3A may be repeated periodically, for example.

FIG. 3B is a flowchart showing details of the wireless communication detection process (step S106) in the flowchart of FIG. 3A.
(Step S201) The detection unit 16 determines whether the frequency bandwidth included in the feature amount satisfies a predetermined condition. If the predetermined condition is satisfied, the process proceeds to step S202. If not, the process proceeds to step S203.

  (Step S202) The detector 16 determines that wireless communication according to a predetermined condition is being performed. When there are two or more frequency bandwidths that satisfy two or more conditions, the detection unit 16 determines that two or more wireless communications respectively corresponding to the two or more conditions are performed. Also good.

  (Step S203) The detection unit 16 determines whether the center frequency included in the feature amount is localized. If it is localized, the process proceeds to step S204. If not, the process proceeds to step S205.

  (Step S204) The detection unit 16 determines that wireless communication corresponding to the localized center frequency is being performed. When there are two or more localized center frequencies, the detection unit 16 may determine that two or more wireless communications respectively corresponding to the two or more center frequencies are being performed. .

  (Step S205) The detection unit 16 determines whether the residue calculated by the residue acquisition unit 15 is localized. If it is localized, the process proceeds to step S206, and if not, the process returns to the flowchart of FIG. 3A. When the remainder according to two or more transmission intervals is calculated by the remainder acquisition unit 15, the detection unit 16 determines whether there is a localized residue for each calculation result. May be.

  (Step S206) The detection unit 16 determines that wireless communication according to the transmission interval used in the calculation of the localized residue is being performed. When two or more residues are calculated and there are two or more localized residues, the detection unit 16 performs two or more wireless communications corresponding to transmission intervals corresponding to the two or more residues, respectively. It may be determined that is being performed. And it returns to the flowchart of FIG. 3A.

  The detection of the wireless communication by the detection unit 16 may be to store information for identifying the wireless communication (for example, a name of the wireless communication) in a recording medium (not shown), and identify the wireless communication. Information such as a flag may be set in association with the information.

  Next, the operation of the wireless communication detection device 1 according to the present embodiment will be described using a specific example. In this specific example, the time residue is calculated by dividing the transmission start time by 625 (μs) which is the slot length of Bluetooth (registered trademark). It is assumed that wireless communication by the IEEE 802.11 wireless LAN is detected when a frequency bandwidth of 5 MHz or more exists. In addition, it is assumed that wireless communication by Bluetooth (registered trademark) is detected when there is a localization of 10 (μs) or less with respect to the time residue. Further, it is assumed that ZigBee wireless communication is detected when the center frequency is localized for a set of signals that do not have a frequency bandwidth of 5 MHz or more.

  First, specific example 1 will be described. In this specific example 1, it is assumed that wireless communication between the wireless LAN and ZigBee is performed. Assume that the receiving unit 11 receives radio waves from those wireless systems (step S101), and the spectrogram acquisition unit 12 acquires the spectrogram shown in FIG. 4A (step S102). The spectrogram was obtained by periodogram processing with an FFT of 1600 points in length and an overlap ratio of 1/2 based on 200 Msps sampling data obtained in a 200 ms band measurement experiment (100 MHz width) in an anechoic chamber. It is an actual measurement spectrogram having a frequency resolution of 1 MHz and a time resolution of 4 μs obtained by dividing and averaging the obtained frequency power spectrogram by 8 points in the frequency direction. In the spectrogram of FIG. 4A, a signal extending long in the frequency direction is a wireless LAN signal, and the other signals are ZigBee signals. In the spectrogram, the specifying unit 13 specifies a set of signals corresponding to the packet by using signals that are equal to or higher than the threshold (step S103). FIG. 4B is a diagram illustrating a signal that is equal to or greater than a threshold in the spectrogram. In FIG. 4B, a white area corresponds to a set of signals. Thereafter, the feature amount acquisition unit 14 acquires a transmission start time, a center frequency, and a frequency bandwidth for each packet (step S104). In addition, the remainder acquisition unit 15 calculates a remainder obtained by dividing the transmission start time corresponding to each set by the slot length of Bluetooth (registered trademark) (step S105).

  Thereafter, the detection unit 16 detects wireless communication using the frequency bandwidth or the like (step S106). Specifically, the detection unit 16 determines whether there is a packet having a frequency bandwidth of 5 MHz or more (step S201). In this case, since it exists, the detection unit 16 detects that wireless communication by the wireless LAN is being performed (step S202). In addition, the detection unit 16 determines whether there is a packet having a frequency bandwidth of less than 5 MHz and having a center frequency localized (step S203). Since it exists in this case, the detection unit 16 detects that wireless communication by ZigBee is being performed (step S204). FIG. 4C is a diagram illustrating the number of packets for each frequency bandwidth. As can be seen from FIG. 4C, since a packet having a frequency bandwidth near 20 MHz is detected, it can be seen that wireless communication is performed by wireless LAN (WLAN). Also, ZigBee packets with a frequency bandwidth of around 3 MHz have been detected. However, ZigBee and Bluetooth (registered trademark) cannot be properly distinguished only with this frequency bandwidth, so the center frequency is also used. , Will distinguish between the two. Further, the detection unit 16 determines whether or not the time residue is localized (step S205). In this case, since there is no time residue localization, the detection unit 16 does not detect wireless communication using Bluetooth (registered trademark). As a result, the detection unit 16 can detect that wireless communication between the wireless LAN and ZigBee is being performed, and the output unit 17 outputs the fact (step S107). By referring to the output result, the user of the wireless communication detection device 1 can know that communication by wireless LAN and communication by ZigBee are being performed.

  Next, specific example 2 will be described. In this specific example 2, it is assumed that wireless communication between ZigBee and Bluetooth (registered trademark) is performed. Until radio waves of those wireless systems are received, a spectrogram is acquired, a packet corresponding to the packet is specified, a feature amount such as a transmission start time is acquired, and a time residue according to Bluetooth (registered trademark) is calculated These processes (steps S101 to S105) are the same as in the first specific example. FIG. 5A is a diagram illustrating the acquired spectrogram, and FIG. 5B is a diagram illustrating a signal that is equal to or greater than a threshold value in the spectrogram. The spectrogram is also an actual spectrogram acquired in the same manner as the spectrogram of FIG. 4A. In addition, ZigBee and Bluetooth (registered trademark) are configured by one terminal for transmission and one for reception, and full buffer traffic is applied.

  Thereafter, the detection unit 16 detects wireless communication using the frequency bandwidth or the like (step S106). Specifically, the detection unit 16 determines whether there is a packet having a frequency bandwidth of 5 MHz or more (step S201). In this case, as can be seen from the figure showing the number of packets for each frequency bandwidth in FIG. 5C, the wireless LAN is not detected because there is no packet having a frequency bandwidth of 5 MHz or more. In addition, the detection unit 16 determines whether there is a packet having a frequency bandwidth of less than 5 MHz and having a center frequency localized (step S203). Since it exists in this case, the detection unit 16 detects that wireless communication by ZigBee is being performed (step S204). Further, the detection unit 16 determines whether or not the time residue is localized (step S205). In this case, since the time residue is localized, the detection unit 16 detects wireless communication using Bluetooth (registered trademark) (step S206). FIG. 5D is a diagram showing the correspondence between the center frequency and the time residue, and FIG. 5E is a diagram showing the number of packets for each time residue. As shown in FIG. 5D, it can be seen that wireless communication by ZigBee is performed according to the localization of the center frequency. Further, as shown in FIGS. 5D and 5E, it can be seen that wireless communication by Bluetooth (registered trademark) is performed according to the localization of the time residue. In this way, the detection unit 16 can detect that wireless communication between ZigBee and Bluetooth (registered trademark) is being performed, and the output unit 17 outputs that (step S107). By referring to the output result, the user of the wireless communication detection device 1 can know that communication using ZigBee and communication using Bluetooth (registered trademark) are being performed. In FIG. 5E, there is a large localization in a region of 270 to 280 μs and a width of 10 μs. Since the average regarding the frequency (number of packets) of each bin in the histogram of FIG. 5E is 1.184, and the standard deviation (σ) is 7.293, packets of bins exceeding 1σ are Bluetooth (registered trademark) packets. As a result, it is possible to detect Bluetooth (registered trademark) wireless communication. Therefore, when more than the number of packets corresponding to 1σ are localized in an area having a width of 10 μs or less in the time residue, the detection unit 16 may detect wireless communication by Bluetooth (registered trademark).

  As described above, according to the wireless communication detection device 1 according to the present embodiment, it is possible to appropriately distinguish and detect wireless communication having a similar frequency bandwidth or the like by using the time residue. For example, the communication by ZigBee and the communication by Bluetooth (registered trademark) are similar in frequency bandwidth, so it is difficult to distinguish both communication by frequency bandwidth and center frequency. Also, if the packet transmission interval is calculated in a situation where both communications are mixed, there is a possibility of acquiring the transmission interval between the ZigBee packet and the Bluetooth (registered trademark) packet. In this case, an appropriate transmission interval cannot be acquired, and as a result, the transmission interval such as Bluetooth (registered trademark) is constant, and wireless communication that performs frequency hopping cannot be detected. On the other hand, by detecting whether or not the time residue is localized, wireless communication is detected, so that ZigBee communication and Bluetooth (registered trademark) communication are mixed, as in specific example 2. Even if it exists, both can be distinguished and detected appropriately. Further, even when two or more radio communications performing frequency hopping are mixed by radio communication detection apparatus 1 according to the present embodiment, when the transmission interval (transmission slot time length) of each radio communication is different. Will be able to detect them.

  In the present embodiment, the case where the center frequency and the frequency bandwidth are included in the feature amount has been described, but this need not be the case. The feature amount may not include at least one of the center frequency and the frequency bandwidth. When the center frequency or the like is not included in the feature quantity, the feature quantity acquisition unit 14 does not need to perform acquisition processing of what is not included in the feature quantity, and the detection unit 16 does not include the feature quantity. It is not necessary to perform the process of detecting wireless communication using the one not included.

  In addition, by using the detection result of the wireless communication detection device 1, it is possible to specify which wireless communication is used to transmit each packet. For example, a packet having a frequency bandwidth greater than or equal to a threshold (for example, 5 MHz) may be determined to be a wireless LAN packet. A packet having a frequency bandwidth smaller than the threshold and having a localized center frequency may be determined to be a ZigBee packet. Further, a packet having a frequency bandwidth smaller than the threshold and having a localized time residue may be determined to be a Bluetooth (registered trademark) packet. As shown in FIG. 5D, which packet is the packet included in the common part of the set of packets in which the center frequency is localized and the set of packets in which the time residue is localized is determined. You may judge by another method.

  In the above description, the case has been described in which the remainder acquisition unit 15 calculates a remainder obtained by dividing the transmission start time included in the feature amount by the transmission interval of the wireless signal, but this need not be the case. For example, the time direction of the spectrogram may be associated with a counter value that is reset according to the transmission interval of the radio signal. The counter value is a value associated with each data point of received sampling data or spectrogram data that is time-series data. Note that, since the spectrogram is calculated using the received sampling data, it can be considered that the counter value associated with the received sampling data is also associated with the time direction of the spectrogram as a result. The counter value is a value that increases or decreases with the passage of time from the beginning of the time series data. The increase / decrease is proportional to the passage of time. Therefore, the range of increase / decrease of the counter value associated with each data point of the time series data is the same. Further, the counter value is reset to 0 when the transmission interval (transmission slot time length) of the wireless communication to be detected is reached. That is, the counter value is reset according to the transmission interval of the radio signal transmitted at a constant interval. Therefore, the counter value is a value corresponding to the above-described remainder itself. Note that the spectrogram time direction being associated with the counter value may mean that the spectrogram time itself is the counter value, or the counter value corresponding to the spectrogram time is It may be held separately from the time. Further, since the counter value is a value corresponding to the remainder itself, when the counter value corresponding to the transmission start time of each packet is localized, wireless communication performed at a transmission interval corresponding to the counter value Can be detected. That is, in the wireless communication detection device 1, the spectrogram may be associated with a counter value that is reset according to the transmission interval of the wireless signal (for example, 625 μs described above). Then, the remainder acquisition unit 15 may acquire a counter value corresponding to the transmission start time for each set of signals. Specifically, the remainder acquisition unit 15 may acquire a counter value corresponding to the earliest time among the times corresponding to the signals included in the signal set. Further, when the counter value acquired by the remainder acquisition unit 15 is localized, the detection unit 16 may detect wireless communication performed at a transmission interval corresponding to the counter value. For example, the counter value may be set by the spectrogram acquisition unit 12, may be set by the reception unit 11, or may be set by other components. As a result, if a counter value corresponding to an arbitrary time in the spectrogram can be specified, the counter value setting target may be, for example, a spectrogram or reception sampling data.

  Thus, the remainder acquisition part 15 may calculate the remainder itself, or may acquire a counter value. That is, the remainder acquisition unit 15 may acquire a value corresponding to a remainder obtained by dividing the transmission start time by the transmission interval of the radio signal for each set of signals. The value corresponding to the remainder may be, for example, the remainder itself or a counter value corresponding to the transmission start time. Moreover, the detection part 16 may detect the radio | wireless communication performed by the transmission interval corresponding to the value according to the value when the value according to the remainder which the remainder acquisition part 15 acquired is localized. . In addition, when the remainder acquisition part 15 acquires the counter value which is a value according to the remainder, and the detection part 16 does not detect the wireless communication using the center frequency or the frequency bandwidth, The wireless communication detection device 1 may not include the feature amount acquisition unit 14.

  Further, in the present embodiment, the case where the reception unit 11 receives a radio signal for detection of wireless communication has been described. However, the reception unit 11 receives a radio signal for other purposes as well. Also good. Further, the wireless communication detection device 1 may transmit a wireless signal.

  In the above embodiment, each process or each function may be realized by centralized processing by a single device or a single system, or may be distributedly processed by a plurality of devices or a plurality of systems. It may be realized by doing.

  In the above embodiment, the information exchange between the components is performed by one component when, for example, the two components that exchange the information are physically different from each other. It may be performed by outputting information and receiving information by the other component, or when two components that exchange information are physically the same, one component May be performed by moving from the phase of the process corresponding to to the phase of the process corresponding to the other component.

  In the above embodiment, information related to processing executed by each component, for example, information received, acquired, selected, generated, transmitted, or received by each component In addition, information such as threshold values, mathematical formulas, addresses, and the like used by each component in processing may be temporarily or for a long time held in a recording medium (not shown), even if not specified in the above description. Further, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Further, reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

  In the above embodiment, when information used by each component, for example, information such as a threshold value, an address, and various setting values used by each component may be changed by the user, Even if it is not specified in the description, the user may be able to change the information as appropriate, or may not be so. If the information can be changed by the user, the change is realized by, for example, a not-shown receiving unit that receives a change instruction from the user and a changing unit (not shown) that changes the information in accordance with the change instruction. May be. The change instruction received by the receiving unit (not shown) may be received from an input device, information received via a communication line, or information read from a predetermined recording medium, for example. .

  In the above embodiment, when two or more components included in the wireless communication detection apparatus 1 include a communication device, an input device, etc., the two or more components have a physically single device. Or may have separate devices.

  In the above embodiment, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component can be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory. At the time of execution, the program execution unit may execute the program while accessing the storage unit or the recording medium. In addition, the software which implement | achieves the wireless communication detection apparatus 1 in the said embodiment is the following programs. That is, this program specifies a set of signals that are continuous in at least one of the frequency direction and the time direction in a spectrogram acquisition unit that acquires a spectrogram related to a received received signal and a spectrogram acquired by the spectrogram acquisition unit. For each set of signals, the signal acquisition unit obtains a value corresponding to the remainder obtained by dividing the transmission start time by the radio signal transmission interval, and a value corresponding to the remainder obtained by the remainder obtaining unit is localized. A program for functioning as a detection unit for detecting wireless communication performed at a transmission interval corresponding to a value corresponding to a remainder and an output unit for outputting a detection result by the detection unit.

  In the program, the functions realized by the program do not include functions that can be realized only by hardware. For example, functions that can be realized only by hardware such as a modem or an interface card in an acquisition unit that acquires information, an output unit that outputs information, and the like are not included in at least the functions realized by the program.

  Further, this program may be executed by being downloaded from a server or the like, and a program recorded on a predetermined recording medium (for example, an optical disk such as a CD-ROM, a magnetic disk, a semiconductor memory, or the like) is read out. May be executed by Further, this program may be used as a program constituting a program product.

  Further, the computer that executes this program may be singular or plural. That is, centralized processing may be performed, or distributed processing may be performed.

  FIG. 6 is a schematic diagram showing an example of the appearance of a computer that executes the program and realizes the wireless communication detection apparatus 1 according to the embodiment. The above-described embodiment can be realized by computer hardware and a computer program executed on the computer hardware.

  In FIG. 6, the computer system 900 includes a computer 901 including a CD-ROM drive 905, a keyboard 902, a mouse 903, and a monitor 904.

  FIG. 7 is a diagram showing an internal configuration of the computer system 900. In FIG. 7, in addition to the CD-ROM drive 905, a computer 901 is connected to an MPU (Micro Processing Unit) 911, a ROM 912 for storing a program such as a boot-up program, and the MPU 911. A RAM 913 that temporarily stores and provides a temporary storage space, a hard disk 914 that stores application programs, system programs, and data, and a bus 915 that interconnects the MPU 911, the ROM 912, and the like are provided. The computer 901 may include a network card (not shown) that provides connection to a LAN, WAN, or the like.

  A program that causes the computer system 900 to execute the function of the wireless communication detection device 1 according to the above-described embodiment may be stored in the CD-ROM 921, inserted into the CD-ROM drive 905, and transferred to the hard disk 914. Instead, the program may be transmitted to the computer 901 via a network (not shown) and stored in the hard disk 914. The program is loaded into the RAM 913 when executed. The program may be loaded directly from the CD-ROM 921 or the network. Further, the program may be read into the computer system 900 via another recording medium (for example, a DVD) instead of the CD-ROM 921.

  The program does not necessarily include an operating system (OS) or a third party program that causes the computer 901 to execute the function of the wireless communication detection apparatus 1 according to the above-described embodiment. The program may include only a part of an instruction that calls an appropriate function or module in a controlled manner and obtains a desired result. How the computer system 900 operates is well known and will not be described in detail.

  Further, the present invention is not limited to the above-described embodiment, and various modifications are possible, and it goes without saying that these are also included in the scope of the present invention.

  As described above, according to the wireless communication detection device and the like according to the present invention, an effect that the wireless communication can be appropriately distinguished and detected is obtained. For example, a device that detects what kind of wireless communication is performed. Useful as such.

DESCRIPTION OF SYMBOLS 1 Wireless communication detection apparatus 11 Receiving part 12 Spectrogram acquisition part 13 Specification part 14 Feature-value acquisition part 15 Remainder acquisition part 16 Detection part 17 Output part

Claims (7)

A receiving unit for receiving a reception signal by wireless communication;
A spectrogram acquisition unit that acquires a spectrogram related to a received signal received by the reception unit;
In the spectrogram acquired by the spectrogram acquisition unit, a specifying unit that specifies a set of signals that are continuous in at least one of the frequency direction and the time direction;
For each set of signals, a residue acquisition unit that acquires a value corresponding to a residue obtained by dividing a transmission start time by a transmission interval of a radio signal;
A detection unit that detects wireless communication performed at a transmission interval corresponding to a value corresponding to the residue when a value corresponding to the residue acquired by the residue acquisition unit is localized;
A wireless communication detection apparatus comprising: an output unit that outputs a detection result by the detection unit. A feature amount acquisition unit that acquires a feature amount including a transmission start time for each set of signals,
The wireless communication detection apparatus according to claim 1, wherein the remainder acquisition unit calculates a remainder based on a transmission interval of wireless signals for a transmission start time included in the feature amount. The feature amount acquisition unit acquires a feature amount including a center frequency for each set of the signals,
The wireless communication detection device according to claim 2, wherein the detection unit detects wireless communication performed at the center frequency when the center frequency included in the feature amount is localized. The feature amount acquisition unit acquires a feature amount including a frequency bandwidth for each set of signals,
4. The radio according to claim 2, wherein when the frequency bandwidth included in the feature amount satisfies a predetermined condition, the detection unit detects radio communication performed with a frequency bandwidth according to the condition. Communication detection device. The time direction of the spectrogram is associated with a counter value that is reset according to the transmission interval of the radio signal,
The wireless communication detection apparatus according to claim 1, wherein the remainder acquisition unit acquires a counter value corresponding to a transmission start time as a value corresponding to the remainder for each set of signals. A reception step of receiving a reception signal by wireless communication;
A spectrogram acquisition step of acquiring a spectrogram related to the received signal received in the reception step;
In the spectrogram acquired in the spectrogram acquisition step, a specifying step of specifying a set of signals continuous in at least one of the frequency direction and the time direction;
For each set of signals, a residue acquisition step of acquiring a value corresponding to a residue obtained by dividing the transmission start time by the transmission interval of the radio signal;
A detection step of detecting wireless communication performed at a transmission interval corresponding to a value corresponding to the residue when a value corresponding to the residue acquired in the residue acquisition step is localized;
An output step of outputting a detection result of the detection step. Computer
A spectrogram acquisition unit for acquiring a spectrogram relating to a received signal received;
In the spectrogram acquired by the spectrogram acquisition unit, a specifying unit that specifies a set of signals that are continuous in at least one of the frequency direction and the time direction,
For each set of signals, a residue acquisition unit that acquires a value corresponding to a residue obtained by dividing the transmission start time by the transmission interval of the radio signal,
A detection unit for detecting wireless communication performed at a transmission interval corresponding to a value corresponding to the residue when a value corresponding to the residue acquired by the residue acquisition unit is localized;
A program for functioning as an output unit for outputting a detection result by the detection unit.