WO2007091655A1 - Externally-acquired information power line communication system, data transmission device, data reception device, power line communication method, and power line communication program - Google Patents

Abstract

Provided are an externally-acquired information power line communication system, a data transmission device, a data reception device, a power line communication method, and a power line communication program capable of transmitting/receiving data acquired by a camera or the like with a preferable communication quality. The power line communication system includes a camera (CA), a data transmission device (102) for transmitting video captured by the camera (CA) as acquired data via a power line (101); a data reception device (103) for receiving the transmitted acquired data via the power line (101); and a monitor device (104) for reproducing/displaying the acquired data received by the data reception device (103). According to the reception state of the signal transmitted from the data transmission device (102), the data reception device (103) detects a notch existing in a frequency band used for the power line communication and selects arrangement of a plurality of channels for performing transmission/reception of the acquired data while avoiding the frequency band having the notch. The data transmission device (102) transmits the acquired data according to the arrangement of the selected channels. The data reception device (103) receives the acquired data according to the arrangement of the selected channels.

Description

 Power line communication system, data transmission apparatus, data reception apparatus, power line communication method and power line communication program for externally acquired information

 Technical field

 The present invention relates to an externally acquired information power line communication system for transmitting and receiving real time information such as video acquired by an external information acquiring apparatus such as a camera for monitoring via a power line, a master unit and a plurality of nodes. This application relates to a power line communication system, a data transmission apparatus, a data reception apparatus, a power line communication method, and a power line communication program for performing data communication between power lines between Japanese Patent Application No. 2006- filed in Japan on February 9, 2006. We claim priority based on 33135 and Japanese Patent Application No. 2006-186708 filed in Japan on July 6, 2006, the contents of which are incorporated herein.

 Background art

 [0002] Conventionally, a system in which one or a plurality of cameras are installed for the purpose of monitoring or the like and a captured image is monitored at a place away from the camera power is used. When transmitting the acquired data of this camera to a remote location, the power used by a dedicated communication line such as a coaxial cable, etc. It was necessary to install this communication line. In addition, the acquired data is transmitted wirelessly, but the acquired data cannot be received well in places where there are many obstructions to radio waves such as walls or where the wireless does not reach. There is a problem.

 [0003] For this reason, Patent Document 1 proposes a video monitor system using a power line in an information transmission path. Further, Patent Document 2 proposes a power line communication type IP surveillance camera that converts a manufacturing signal of a monitoring image taken by a camera unit into IP and transmits the signal superimposed on a power line by a power line communication modem! .

 Disclosure of the invention

 Problems to be solved by the invention

[0004] The following problems remain in the conventional technology.

In other words, when images captured by a camera are transmitted and received as acquired data via a power line. In some cases, the state of the propagation path differs depending on the camera installation environment, and notches and noise may exist in some of the frequencies used for communication, resulting in the inconvenience that communication quality deteriorates. As a countermeasure, there is a method to increase the transmission power in order to increase the SN ratio (signal-to-noise ratio) of the channel to be used. However, if the transmission power is increased, the leakage field will increase. There was a problem.

[0005] The present invention has been made in view of the above-described problems, and a power line communication system for externally acquired information capable of transmitting and receiving acquired data by an external information acquiring device such as a camera with good communication quality, An object is to provide a data transmission device, a data reception device, a power line communication method, and a power line communication program.

 [0006] In recent years, power line communication (PLC) that performs data communication between communication devices via power lines wired in buildings, vehicles, and the like has been studied. In this power line communication, when multiple electronic devices and electrical devices are connected and other electronic devices are operating, the impedance and noise of the power line change from moment to moment, eliminating the effects of noise and reducing signal attenuation. Various improvements have been proposed because it is difficult to carry out this effectively.

 [0007] For example, in Patent Document 3, a packet is transmitted from a first node to a second node through multiple channels at a predetermined transmission rate, and the presence or absence of a packet misdiagnosis at that time is searched by the second node. By transmitting the result to the first node, the procedure for transmitting packets to the second node at different transmission speeds is periodically performed based on the information on the successful transmission of the packet at the first node. An adaptive multi-channel packet transmission method has been proposed. In other words, this communication technology is a technology for periodically transmitting packets between nodes and selecting the transmission rate for the packet transmission result at the next communication. As a result, stable packet transmission is performed at an optimum speed suitable for the multi-channel environment between nodes of the power line communication system.

 Patent Document 1: Japanese Patent Laid-Open No. 2000-91962

 Patent Document 2: Japanese Patent Laid-Open No. 2003-8962

 Patent Document 3: Japanese Unexamined Patent Publication No. 2003-18050

[0008] The following problems remain in the above conventional technique. [0009] As described above, the transmission characteristics of a power line, which is a transmission path in power line communication, change from moment to moment for each node transmission path in a short cycle due to the connection of electrical-electronic equipment and the like. For this reason, in the technology that performs communication based on the result of the previous packet transmission, such as the technology described in the conventional patent document 3, if the state of the channel to be used is significantly worse, Even if the speed was changed, good transmission characteristics could not be obtained, and it was still difficult to carry out communication suitable for the state of the transmission path during communication.

 [0010] In addition, it is necessary to perform packet transmission simultaneously on all the carriers that can use the frequency band to a plurality of nodes, and to investigate the transmission characteristics of all the carriers for each node, which requires high processing capacity and is optimal. There is a disadvantage that it takes a lot of time to estimate the transmission characteristics.

 [0011] The present invention has been made in view of the above-described problems, and can perform communication suitable for the transmission path state during communication, and each node can be efficiently connected even when a plurality of nodes are connected. Another object of the present invention is to provide a power line communication system, a power line communication method, and a power line communication program that can detect the optimum transmission characteristics.

 Means for solving the problem

 The present invention employs the following configuration in order to solve the above problems. That is, the externally acquired information power line communication system of the present invention includes an external information acquiring device that acquires external real-time information, and a data transmitting device that transmits the real-time information acquired by the external information acquiring device as acquired data via the power line. And a data receiving device that receives the acquired acquisition data via a power line, and an output device that displays the acquired data received by the data receiving device. Transmitting device power Depending on the reception status of the transmitted signal, it detects notches or noise in the frequency band used for power line communication, and avoids the frequency band in which these notches or noise exist, and transmits and receives the acquired data. A plurality of channel arrangements to be performed are selected, and the data transmission apparatus Transmits the serial acquisition data, the data receiving device, based on the arrangement of the channel selected!, Te, characterized in that receiving the acquisition data.

[0013] Further, the data transmission device for externally acquired information according to the present invention is acquired by the external information acquiring device. A data transmission device for externally acquired information that transmits real-time information as acquired data to a data receiving device via a power line, a pilot tone transmitting unit that transmits a pilot tone to the data receiving device, and the pilot A channel information receiving unit that receives arrangement information of a plurality of channels selected by avoiding a frequency band in which notches or noise exist returned from the data receiving apparatus according to a tone, and a received channel arrangement information. Accordingly, a transmission channel setting unit that sets a channel to be used in power line communication, a transmission side data processing unit that performs a process of distributing and arranging the acquired data in the set channel, and the acquired data as a power line And a data transmission unit that transmits the data to the data reception device.

 [0014] In addition, the data acquisition device for externally acquired information according to the present invention is a data receiver for externally acquired information that receives real-time information acquired by the external information acquiring device as acquired data via a power line. A pilot tone receiving unit that receives a pilot tone from the data transmission device, and a detection unit that detects a notch or noise existing in a frequency band used for power line communication according to a reception state of the received pilot tone. A channel selection unit that selects an arrangement of a plurality of channels to be used when performing power line communication while avoiding the detected notch or frequency band in which noise exists, and the data transmission apparatus receives the arrangement information of the selected channel. Channel information transmitting unit for transmitting to the data, and data for receiving the acquired data from the data transmitting device And a receiving unit.

[0015] In addition, the externally acquired information power line communication method of the present invention is an external acquisition in which real-time information acquired by the external information acquiring device is transmitted as data to the data transmitting device via the power line and received by the data receiving device. An information power line communication method according to a first step of transmitting a signal via a power line by the data transmission apparatus, and depending on a reception state of the signal transmitted by the data reception apparatus by the data transmission apparatus Second step of detecting notches or noise existing in a frequency band used for power line communication and selecting an arrangement of a plurality of channels for transmitting and receiving the acquired data while avoiding the frequency band in which these notches or noise exist A third step of transmitting the acquired data based on the selected channel arrangement by the data transmitting device; Serial data And a fourth step of receiving the acquired data based on the selected channel arrangement by the data receiver.

 [0016] Further, the externally acquired information power line communication program according to the present invention transmits real-time information acquired by the external information acquiring apparatus as acquired data from the data transmitting apparatus via the power line and is received by the data receiving apparatus. A power line communication program for externally acquired information, comprising: a first step of transmitting a signal via a power line by the data transmission device; and a reception state of the signal transmitted by the data transmission device by the data reception device. In response to this, a notch or noise existing in a frequency band used for power line communication is detected, and the arrangement of a plurality of channels that perform transmission / reception of the acquired data while avoiding the frequency band in which these notch or noise exists is selected. The acquired data is transmitted based on the second step and the arrangement of the selected channel by the data transmission device. 3 and steps of, by said data receiving device, characterized in that to execute a fourth step of receiving the resultant data collected on the basis of the arrangement of said selected channel, to the computer.

 [0017] In the power line communication system, the data transmission device, the data reception device, the power line communication method, and the power line communication program of these externally acquired information, there is a frequency band used for power line communication according to the reception state of the transmitted signal. Since notch or noise is detected and multiple channels are arranged to transmit and receive data avoiding the frequency band in which these notches or noise exist, the notch or noise is always present.電力 Power line communication can be performed using channels optimally arranged in the frequency band, and communication quality can be improved. As a result, it becomes possible to always send and receive the acquisition data of the external information acquisition device satisfactorily in accordance with the state of the propagation path that differs depending on the installation environment of the external information acquisition device such as a camera.

[0018] Also, in the power line communication system for externally acquired information according to the present invention, the external information acquiring device and the data transmitting device are provided at a plurality of locations, and the data receiving device is configured to be the external information acquiring device and the data transmitting device. The arrangement of the respective channels is selected so that the acquired data can be multiplexed and transmitted for each apparatus, the data transmitting apparatus transmits the acquired data based on the corresponding arrangement of the channels, and the data receiving apparatus includes: Multiplex receiving the acquired data transmitted from a plurality of the data transmitting devices, To do.

 That is, in this power line communication system for externally acquired information, acquired data obtained by each external information acquiring device is distributed and multiplexed and transmitted in a channel that is optimally arranged for each corresponding data transmitting device. Therefore, by simultaneously multiplex-receiving these acquired data with the data receiving device, it is possible to transmit and receive the acquired data from a plurality of external information acquiring devices with high quality.

 [0020] In addition, the power line communication system for externally acquired information of the present invention includes at least a camera that uses the external information acquisition device and the video captured as the real-time information as the acquisition data, and the output device includes the acquisition data It includes a monitor device that reproduces and displays the image.

 Also, the power line communication system for externally acquired information of the present invention includes at least a microphone that uses the external information acquisition device and the sound acquired as the real-time information as the acquired data, and the output device reproduces the acquired data It is characterized by including a speaker device.

The present invention employs the following configuration in order to solve the above-described problems. That is, the power line communication system of the present invention is a power line communication system that communicates data between a master unit and a plurality of nodes via the power line, and the master unit is in a dormant state and receives data. When transmitting idle information indicating that it is possible to the node periodically, the idle information is transmitted by using a plurality of carriers having different frequencies and transmitting the idle information including the carrier information. A transmitting unit; and a base-side receiving unit that receives data transmitted from the node; the idle information receiving unit that receives the idle information; and the carrier information when the idle information is received. And a statistical information storage unit for storing the reception state as statistical information, and a carrier having a good reception state based on the latest stored statistical information. An optimal carrier information transmitting unit that transmits information selected as an appropriate carrier to the base unit as optimal carrier information, and a node side transmitting unit that transmits data to the base unit using the carrier changed based on the optimal carrier information. And the base-side receiving unit changes its own carrier setting based on the received optimal carrier information. [0022] Further, the power line communication method of the present invention is a power line communication method in which data is communicated between a parent device and a plurality of nodes via a power line, and the device can be received because it is in a dormant state. When transmitting idle information indicating that the information is periodically transmitted to the node, performing the transmission using a plurality of carriers having different frequencies and transmitting the idle information including the carrier information; The node receiving the idle information; storing the carrier information and reception state as statistical information when the idle information is received; and based on the latest stored statistical information! Information selected as an optimal carrier among those having a good reception state is transmitted as optimal carrier information to the parent device, and based on the optimal carrier information. Transmitting the data to the parent device using the carrier changed based on the carrier, and the parent device changing the setting of its own carrier based on the received optimum carrier information. Features.

 [0023] Further, the power line communication program of the present invention is a power line communication program for performing data communication between the parent device and a plurality of nodes via the power line, and is self-suspension and can be received. When transmitting idle information indicating that the information is periodically transmitted to the node using a plurality of carriers having different frequencies and transmitting the idle information including the carrier information; and A step of receiving the idle information; a step of storing the carrier information and reception state as statistical information when the idle information is received; and a step of storing the carrier based on the latest statistical information stored. Information selected as an optimum carrier among those having a good reception state is transmitted to the parent device as optimum carrier information, and the optimum carrier is transmitted. Transmitting data to the base unit using the carrier changed based on rear information, wherein the base unit changes the setting of its own carrier based on the received optimal carrier information. Computer.

[0024] In these power line communication system, power line communication method, and power line communication program, when the idle power is periodically transmitted to the node, transmission is performed with a plurality of carriers having different frequencies! The idle information reception status is memorized as statistical information and the optimal carrier with good reception status is selected based on the latest statistical information. Since the machine communicates with the node, it is not necessary to transmit pilot tones separately by using idle information transmitted periodically, and it is easily optimized using the latest statistical information that is updated sequentially. A simple transmission path can be estimated.

 [0025] Further, the power line communication system of the present invention is characterized in that the idle information transmission unit divides a plurality of carriers into a plurality of sets, and performs the transmission by periodically switching these sets. In other words, in this power line communication system, each group of carriers divided into a plurality of groups is periodically switched and transmitted, so that each node needs to process only a limited number of divided carriers simultaneously. It is not necessary to increase capacity, and optimal transmission characteristics (carriers) can be estimated in a short time from stored statistical information.

 [0026] The power line communication system of the present invention is characterized in that the optimum carrier information transmitting unit selects the optimum carrier based on the number of received packets for each carrier stored as the statistical information. That is, in this power line communication system, since the optimum carrier is selected based on the number of received packets for each carrier, the optimum carrier can be easily obtained by selecting a carrier having a higher number of received packets.

 [0027] Further, the power line communication system of the present invention is characterized in that the periodic force for switching the carrier set is set to 10 msec. In other words, in this power line communication system, the carrier switching cycle is set to 10 msec, so it is necessary to correspond to the 20 msec switching cycle that is often used in home appliances driven by 50 Hz AC. Therefore, it is possible to efficiently obtain an optimal carrier in accordance with a cycle in which the state of the transmission line is likely to change.

 [0028] In the power line communication system of the present invention, the node has a sensor function, and the node-side transmission unit transmits data measured by the sensor function. In other words, in this power line communication system, measurement data of each node having a sensor function is transmitted, so an automatic meter reading system that collects measurement data from multiple nodes in a centralized manner with good communication quality on the master unit. Can be realized.

 The invention's effect

[0029] According to the present invention, the following effects can be obtained.

That is, the externally acquired information power line communication system, data transmission device, according to the present invention, According to the data reception device, the power line communication method, and the power line communication program, transmission and reception are performed by optimally arranging a plurality of channels for communicating acquired data according to the reception state of the signal. However, it is possible to perform high-quality power line communication in the frequency band, and the external information acquisition device can always perform well in response to different transmission path conditions depending on the installation environment of the external information acquisition device such as a camera. The acquired data can be sent and received. In particular, when external information acquisition devices are installed at multiple locations, the optimal arrangement of channels is performed so that multiple acquisition data from these external information acquisition devices can be multiplexed and transmitted. Multiple reception can be performed simultaneously.

 Moreover, according to this invention, there exist the following effects.

 That is, according to the power line communication system, power line communication method, and power line communication program of the present invention, idle information is transmitted on a plurality of carriers having different frequencies from each other, and idle information is received by a node. The state is stored as statistical information, and the optimum carrier is selected based on the latest statistical information, and communication is performed between the master unit and the node.Therefore, there is no need to transmit a pilot tone separately, and the latest statistical information The optimal transmission path can be easily estimated using Therefore, it is possible to easily select the optimum carrier from among the carriers that can be used by each node using the periodical reception state of idle information and perform communication, thereby improving the communication quality and improving the transmission speed. Can do. By applying this technology to an automatic meter reading system, measurement data from multiple sensors can be collected intensively with good communication quality.

 Brief Description of Drawings

 FIG. 1 is an overall configuration diagram showing a power line communication system for externally acquired information according to a first embodiment of the present invention.

 FIG. 2 is a block diagram showing a configuration of a data transmission device for externally acquired information in the first embodiment.

 FIG. 3 is a circuit diagram showing a circuit for performing data operation processing in the first embodiment.

FIG. 4 is a block diagram showing a configuration of a data receiving device for externally acquired information in the first embodiment. FIG. 5 is a sequence diagram showing a flow of processing in the power line communication method of externally acquired information in the first embodiment.

 FIG. 6A is a diagram showing a transmission waveform of a pilot tone in the first embodiment.

FIG. 6B is a diagram showing a waveform indicating a notch occurrence state in the first embodiment.

FIG. 6C is a diagram showing a received waveform of a pilot tone in the first embodiment.

FIG. 6D is a diagram showing a waveform of acquired data when performing communication in the first embodiment.

FIG. 7A is a diagram showing a channel arrangement state of each acquired data multiplexed and transmitted from two data transmitting apparatuses and a channel arrangement state of each acquired data multiplexed and received by the data receiving apparatus in the first embodiment. is there.

 FIG. 7B is a diagram showing a channel arrangement state of each acquired data multiplexed and transmitted from two data transmitting apparatuses and a channel arrangement state of each acquired data multiplexed and received by the data receiving apparatus in the first embodiment. is there.

 FIG. 7C is a diagram showing a channel arrangement state of each acquired data multiplexed and transmitted from two data transmitting apparatuses and a channel arrangement state of each acquired data multiplexed and received by the data receiving apparatus in the first embodiment. is there.

 FIG. 8 is an overall configuration diagram showing a power line communication system for externally acquired information according to a second embodiment of the present invention.

 FIG. 9 is a configuration diagram showing the entire system in a power line communication system, a power line communication method, and a power line communication program according to a third embodiment of the present invention.

FIG. 10 is a flowchart regarding transmission and reception of idle information in the present embodiment.

FIG. 11 is an explanatory diagram showing selection of an optimum carrier based on idle information reception in the present embodiment.

 FIG. 12 is a flowchart regarding data transmission / reception in the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... Power line 102 ... Data transmission device 121 ... Pilot tone transmission part 122 ... Channel information reception part 123 ... Transmission channel setting part 124 ... Data storage part 125 ... Data processing part (transmission side) Data processing unit), 126 ... Data transmission unit, 13 ... Data reception device, 131 ... Pilot tone reception unit, 132 ... Notch detection unit (detection unit), 133 ... Channel selection 134: Channel information transmission unit, 135 ... Data reception unit, 136 ... Data processing unit, 104 ... Monitor device (output device), CA ... Camera (external information acquisition device), マ イ ク ... Microphone (external information acquisition device) )

 [0033] 201 ····························································································································· • 207 ··· Idle information receiving unit, 208 ··· Statistical information storage unit, 209 ... Optimal carrier information transmitting unit, 210 ··· Node side transmitting unit, 211 ··· Node side receiving unit, L ... Power line, S ... Sensor part

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0034] Hereinafter, a first embodiment of a power line communication system, data transmission device, data reception device, power line communication method, and power line communication program for externally acquired information according to the present invention will be described with reference to FIGS. 1 to 7C. explain.

 [0035] As shown in Fig. 1, the power line communication system for externally acquired information according to the present embodiment is, for example, a monitor installed at various locations in a building (in this embodiment, two locations such as a front door and a room on the second floor). Camera (external information acquisition device) For example, when the video captured as real-time information by the CA is transmitted as the acquisition data from the data transmission device 102 via the power line 101 and received by the data reception device 103, It is a power line communication system. This power line communication system for camera video includes a camera CA, a data transmission device 102 that transmits video captured by the camera CA as acquired data via the power line 101, and receives transmitted acquired data via the power line 101. A data receiving device 103 and a monitor device (output device) 104 for reproducing and displaying the acquired data received by the data receiving device 103 are provided.

 [0036] The camera CA is provided with a CCD (Charge coupled device) or the like, and has a function of signaling video captured by the CCD or the like as digital data and sending it to the connected data transmission device 102. ing.

 The data transmission device 102 includes a plug portion 102a that is connected to the camera CA and that can be connected to the outlet portion 101a of the power line 101. The data transmitting apparatus 102 has a function of transmitting a pilot tone as a signal to the data receiving apparatus 103 via the power line 101.

In addition, the data receiving device 103 can be connected to the outlet unit 101a of the power line 101. A plug portion 102 a is provided and connected to the monitor device 104. Data receiving apparatus 103 detects notches existing in the frequency band used for power line communication in accordance with the reception state of the pilot tone (signal) transmitted from data transmitting apparatus 102, and these notches are detected. It has a function to select the arrangement of multiple channels (subchannels) that transmit and receive acquired data while avoiding existing frequency bands. Then, the data transmission device 102 transmits acquisition data based on the selected channel arrangement, and the data reception device 103 has a function of receiving acquisition data based on the selected channel arrangement. ing.

 [0038] The monitor device 104 is a personal computer having a monitor 104a such as a liquid crystal display and a computer main body 104b for reproducing and displaying the acquired data from the data receiving device 103 on the monitor 104a.

 The power line 101 supplies power for driving the data transmitting apparatus 102 and the data receiving apparatus 103 via the connected plug unit 102a. The camera CA is supplied with power from the power line 101 via the data transmission device 102, and the monitor device 104 is supplied with power from the power line 101 via the data reception device 103.

 [0039] The configurations of the data transmitting apparatus 102 and the data receiving apparatus 103 will be described in further detail below.

 [0040] As shown in Fig. 2, the data transmitting apparatus 102 includes a pilot tone transmitting unit 121, a channel information receiving unit 122, a transmission channel setting unit 123, a data storage unit 124, and a data processing unit ( Transmission side data processing unit) 125 and data transmission unit 126.

 The pilot tone transmitter 121 has a function of continuously changing the frequency of the pilot tone (signal). The pilot tone data whose frequency changes continuously is transmitted to the data receiving apparatus 103 via the power line 101.

[0041] Channel information receiving section 122 receives arrangement information (hereinafter referred to as "channel information") of a plurality of channels selected avoiding the frequency band in which notches are returned from data receiving apparatus 103 in response to the pilot tone. The power line 101 is received. At this time, in the present embodiment, since the plurality of cameras CA and the data transmission device 102 are connected to the power line 101, the data reception device 103 transmits each camera CA, that is, the data transmission device. Since individual “channel information” is allocated and returned for each device 102, the channel information receiving unit 122 is set to receive only the corresponding “channel information”.

 The channel information receiving unit 122 has a function of outputting “channel information” received via the power line 101 to the transmission channel setting unit 123.

In addition, transmission channel setting section 123 sets a channel to be used for power line communication based on “channel information” input from channel information receiving section 122 and outputs it to data processing section 125. Has the function of

 The data storage unit 124 temporarily stores acquired data input from the camera CA, and has a function of outputting the stored acquired data to the data processing unit 125. The data processing unit 125 compresses the acquired data input from the data storage unit 124, and then distributes the acquired data to channels avoiding the frequency band where the notch exists, and the processed acquired data is transmitted to the data transmitting unit. It is set to output to 126! The data transmission unit 126 transmits the acquired data input from the transmission channel setting unit 123 to the data reception device 103 via the power line 101.

Note that the data processing unit 125 described above includes a circuit 111 shown in FIG. The data processing unit 125 multiplies the four subchannels (XO—YO, XI—Yl, Χ2—Υ2, Χ3—Υ3) by the coefficients OC and β recorded in the coefficient table (not shown), Repeat the addition / subtraction process. Hereinafter, a specific processing method of the circuit 111 illustrated in FIG. 3 will be described. First, the result of multiplying the subchannel (XI—Y1) by the center frequency is obtained from the result of multiplying the subchannel (ΧΟ—ΧΟ) by the center frequency. Next, the result of multiplying the subchannel (XI—Y1) by the center frequency is the result of multiplying the subchannel (チ ャ ネ ル 2—Υ2) by the center frequency. Next, the result of multiplying the subchannel (Χ3− Υ3) by the center frequency is obtained from the result of multiplying the subchannel (Χ2− Υ2) by the center frequency.

 In this way, the data processing unit 125 calculates a multi-channel signal で that is a transmission signal using a recursive process.

In FIG. 3, unit calculation section 200 is configured with a combination power of a multiplier, an adder, and a subtractor necessary for processing each subchannel in units of subchannels. Here, if the number of subchannels to be processed is increased, the unit operation unit 200 is increased by the increased number. Can be connected in multiple stages.

 Thus, by using a recursive process, it becomes easy to change the hardware configuration in accordance with the change in the number of subchannels to be transmitted in a multichannel communication system.

 By configuring the data processing unit 125 as shown in FIG. 3, the subchannels in the frequency band where the notch exists are not used for data transmission, and the acquired data is distributed to the subchannels in the frequency band where the notch does not exist. By arranging them, it is possible to perform power line communication with good communication quality.

[0045] The data receiving apparatus 103 includes a pilot tone receiving unit 131, a notch detecting unit (detecting unit) 132, a used channel selecting unit 133, a channel information transmitting unit 134, a data receiving unit 135, and a data processing unit. 136.

 The noise tone receiver 131 has a function of receiving pilot tone data transmitted from the data transmitter 102 via the power line 101 and outputting the data to the notch detector 132.

 [0046] Notch detecting section 132 checks the notch state of the pilot tone input from pilot tone receiving section 131, detects information on the frequency band in which the notch exists as “notch information”, and uses channel selecting section 133. Has a function of outputting to.

 Based on the “notch information” input from the notch detection unit 132, the use channel selection unit 133 determines the arrangement of a plurality of channels used when performing power line communication while avoiding the frequency band in which the detected notch exists. It has a function of selecting and transmitting this as “channel information” to the data transmitting apparatus 102 via the power line 1.

At this time, in the present embodiment, since the plurality of cameras CA and the data transmission device 102 are connected to the power line 101, the use channel selection unit 133 acquires the acquired data for each camera CA, that is, for each data transmission device 102. It has a function to select the arrangement of each channel individually so that multiplex transmission is possible. In other words, the used channel selection unit 133 individually selects “channel information” for each data transmission device 102 so that the data reception device 103 can perform multiple reception so that the channels do not overlap each other. At this time, the channels may overlap with each other as long as the required quality can be maintained. Also, each other Even if there are duplicated messages, if the probability of simultaneous transmission is low, it may be time-divided and transmitted.

 In addition, the used channel selection unit 133 has a function of outputting each “channel information” to the data processing unit 135.

 The data receiving unit 135 has a function of receiving “acquired data” transmitted from the data transmitting apparatus 102 via the power line 101 and outputting the data to the data processing unit 136. At this time, in the present embodiment, since the plurality of cameras CA and the data transmission device 102 are connected to the power line 101, the data reception unit 135 receives a plurality of “acquisition data” transmitted from each data transmission device 102. Multiple functions are received via the power line 101, and each “acquired data” is output to the data processing unit 136.

 [0049] Based on the "channel information" output from the used channel selection unit 133, the data processing unit 136 is distributed to channels that can be multiplexed and transmitted in a frequency band without a notch input from the data reception unit 135. Each of the acquired data is restored, and the compressed acquired data is decompressed and output to the monitor device 104.

 The monitor device 104 has a function of reproducing each “acquired data” input from the data processing unit 135 and recording each “acquired data” on a hard disk or the like. The monitor device 104 may have a function of decompressing the compressed acquired data in the data processing unit 136. In that case, the monitor device 104 may record the acquired data in a compressed state.

[0050] It should be noted that each processing unit of pilot tones and acquired data in this system, that is, pilot tone transmitting unit 121, channel information receiving unit 122, transmission channel setting unit 123, data storage unit 124, data processing unit 125, data Transmitter 126, pilot tone receiver 131, notch detector 132, used channel selector 133, channel information transmitter 134, data receiver 135, data processor 136, monitor device 104, etc. are realized by dedicated hardware. In addition, each processing unit is configured by a memory and a CPU (Central Integrated Device) as a computer system to realize the function of each processing unit and the communication method of this embodiment described later. By loading and executing a program in memory You can make it happen.

 That is, the program is a computer-readable program, and may be for realizing a part of the functions described above and a communication method described later. Furthermore, the above program is a so-called difference file (difference program) that can be realized in combination with a program in which the above-described functions are already recorded in a computer system.

 [0052] Further, the program may be transmitted to another computer system via a computer system power transmission medium in which the program is stored in a storage device or the like or by a transmission wave in the transmission medium. Good. The above transmission medium is a medium having a function of transmitting information, such as a network (communication network) such as the Internet and a communication line (communication line) such as a power line and a telephone line.

 The above-mentioned memory is a non-volatile memory such as a hard disk device, a magneto-optical disk device, or a flash memory, a recording medium that can only be read such as a CD-ROM, and a volatile memory such as a RAM (Random Access Memory). It shall consist of a recording medium that can be read and written by a computer or a combination of these.

 Next, the operation of the power line communication system for externally acquired information according to the present embodiment, that is, the power line communication method for dynamic image will be described with reference to FIG. 5 and FIGS. 6A to 6D.

 [0054] First, in a state where the plug unit 102a of each data transmission device 102 and the data reception device 103 is connected to the outlet unit 101a of the power line 101, the pilot tone transmission unit 121 of each data transmission device 102 As shown in FIG. 5 and FIG. 6A, the frequency of pilot tone p is continuously changed to fl, f2, f3, and f4 and transmitted to data receiving apparatus 103 via power line 101 (step S01).

 Note that notches nl and n2 as shown in FIG. 6B are present in the frequency band received by the data receiver 103 due to the installation environment of the data transmitter 102, particularly the influence of home appliances around the power line 101. If it occurs, explain it.

[0055] Pilot tone receiving section 131 of data receiving apparatus 103 receives the pilot tone transmitted from pilot tone transmitting section 121 of data transmitting apparatus 102 via power line 101 (step S02). Next, the notch detector 132 of the data receiver 103 detects whether or not a notch exists in the frequency band used for the received pilot tone (step S03).

 In the communication environment of the power line between the data transmitting apparatus 102 and the data receiving apparatus 103, notches nl and n2 as shown in FIG. 6B are generated, so that the pilot tone receiving unit 131 of the data receiving apparatus 103 is The received pilot tone (see Fig. 6C) also has distortion corresponding to notches nl and n2.

 In the present embodiment, since the plurality of cameras CA and the data transmission device 102 are connected to the power line 101, the occurrence of such a notch differs depending on the installation environment of each data transmission device 102. The notch detection unit 132 of the data receiving apparatus 103 detects a frequency band in which a notch exists for each lot tone from each data transmitting apparatus 102.

 [0057] Next, the used channel selection unit 133 of the data receiving apparatus 103 selects the arrangement of a plurality of channels used in power line communication so as to avoid the frequency band in which the notch detected by the notch detection unit 132 exists. (Step S04).

 Then, the channel information transmitting unit 134 of the data receiving apparatus 103 sets the channels cl, c2, c3, and c4 (see FIG. 6D) in the frequency band that does not have the notch selected by the used channel selecting unit 133 as “channel information”. Then, the data is transmitted to the channel information receiving unit 122 of the data transmitting apparatus 102 via the power line 101 (step S05).

 “Channel information” transmitted from channel information transmitting section 134 is received by channel information receiving section 122 of data transmitting apparatus 102 (step S 06).

 Based on the “channel information” received by the channel information receiving unit 122, the transmission channel setting unit 123 of the data transmitting apparatus 102 uses the frequency band channels cl, c2, c3, Set c4 (see Figure 6D) (step S07).

 The data processing unit 125 of the data transmission apparatus 102 compresses the acquired data stored in the data storage unit 124 and uses the channels c 1, c 2, c 3, and c 4 set by the transmission channel setting unit 123. In order to perform power line communication, the acquired data is distributed and placed in each channel (step S08).

The data transmission unit 126 of the data transmission device 102 transmits the acquired data arranged in the channel where the notch is not present in the data processing unit 125 via the power line 101 to the data reception device 10. 3 is transmitted to the data receiving unit 135 (step S09).

[0060] The data receiving unit 135 of the data receiving device 103 receives data from the data transmitting device 102 via the power line 101 (step S10).

 Next, the data processing unit 136 of the data receiving apparatus 103 restores the acquired data arranged in the channel without the notch received by the data receiving unit 135 and decompresses the compressed acquired data (step S 11).

 Then, the monitor device 104 reproduces the “acquired data” restored and decompressed by the data processing unit 136 (step S12) and records the acquired data.

In the present embodiment, since the plurality of cameras CA and the data transmission device 102 are connected to the power line 101 in the present embodiment, the use channel selection unit 133 of the data reception device 103 is The channel arrangement is set so that multiplex transmission is possible for each data transmission device 102. Channel information transmitting section 134 transmits the corresponding “channel information” to channel information receiving section 122 of each data transmitting apparatus 102 via power line 101.

 [0062] For example, as shown in FIG. 7A, channel information receiving section 122 receives a tones from one data transmitting apparatus 2 and avoids a frequency band in which there is a detected notch and enables multiplex transmission. As shown in FIG. 7B, the frequency band where the notch detected by receiving the first channel information (channels cl1 to cl8) for which the channel arrangement has been selected and the pilot tone from the other data transmission apparatus 2 is present. The second channel information (channels c21 to c28) for which channel arrangement is selected so as to avoid the multiplex transmission and the channel information receiving unit 122 are transmitted.

[0063] Thereby, as shown in FIG. 7A and FIG. 7B, each data transmission apparatus 102 receives the received first channel information (channel cl 1 to cl8) and second channel information (channel c21 to channel c21 to channel c21). Based on c28), the acquired data is distributed and transmitted to the data receiving apparatus 103 via the power line 101. Then, as shown in FIG. 7C, the data reception device 103 multiplex-receives each acquired data from both data transmission devices 102. That is, the acquired data transmitted from one data transmission device 102 distributed in the channels cl 1 to cl 8 and transmitted from the other data transmission device 102 distributed in the channels c 21 to c 28 are transmitted. The acquired data is simultaneously multiplexed and received by the data receiving apparatus 103 without overlapping each other.

 Conventionally, power line communication using the power line 101 has a problem that the power output from the data transmitting apparatus 102 cannot be increased so much due to the relationship between the leakage electric field and the power consumption. However, if the power line communication system for externally acquired information according to the embodiment of the present invention described above is used, the acquired data to be transmitted is distributed and arranged in the channel of the frequency band where the notch is not generated. As a result, power consumption required for communication can be reduced, and power line communication can be performed while maintaining good communication quality.

 In addition, the power consumption required for power line communication can be reduced.

The leakage electric field generated from 1 can be reduced. Therefore, power line communication can be performed with better communication quality.

[0065] In particular, in order to display continuously sent images, there is a problem that it is necessary to always ensure a communication speed of a certain speed or more. If the system of this embodiment is used, The problem can be solved.

 In addition, since the power line communication is not performed using all the multi-channels, a channel having no notch is selected and used, so that the power consumed by the data transmitting apparatus 102 can be reduced.

 In this way, it is possible to always send and receive data acquired by the camera CA in a favorable manner corresponding to the state of the propagation path that differs depending on the installation environment of the camera CA.

[0066] In addition, the acquired data of the video captured by each camera CA corresponds to each corresponding data transmission device

Since the received data is multiplexed and transmitted simultaneously by the data receiving device 103, the acquired data from multiple cameras CA can be transmitted and received with high quality. Can do.

[0067] Next, a second embodiment according to the present invention will be described below. In the following description of each embodiment, the same constituent elements described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0068] The difference between the second embodiment and the first embodiment is that in the first embodiment, an external information acquisition device is used. In the second embodiment, the camera CA acquires a video as real-time information and communicates it as acquired data. In the second embodiment, as shown in FIG. A plurality of microphones M are provided, and a multi-image audio / video collection system including a multi-listening sound system that acquires sound as real-time information by these microphones M and communicates this as acquired data is configured.

[0069] In the second embodiment, the monitor device 104 incorporates a speaker device that reproduces audio acquisition data acquired by the microphone M.

 That is, in the second embodiment, the acquisition data (video data) of the video captured by the camera CA is multiplexed and received simultaneously with the audio acquisition data (audio data) acquired by the microphone M, as in the first embodiment. Similarly, power line communication is performed via the power line 101 by multiple reception.

 [0070] The force described with reference to the drawings for the embodiments of the present invention has been described above. The specific configuration is not limited to these embodiments, and the design can be changed without departing from the gist of the present invention. Etc. are possible.

 In the above-described embodiment, the force described in the case where the notch detection is performed only once before starting the power line communication is not limited to this. For example, while performing power line communication between the data transmission apparatus 2 and the data reception apparatus 103, the notch is continuously detected, and communication is always performed using a channel in a frequency band in which no notch exists. It is also possible. With such a configuration, the communication quality when performing power line communication can be further improved.

 In the above-described embodiment, the frequency of the notch exists by checking the state of the pilot tone to which the pilot tone transmission unit 121 of the data transmission device 102 is also transmitted by the notch detection unit 132 of the data reception device 103. Although the case of detecting the band has been described, the present invention is not limited to this.

For example, a pilot tone is transmitted all at once in the entire frequency band used for communication instead of continuously changing the frequency of the pilot tone, and the data receiving apparatus 103 receives the pilot tone and the frequency at which the notch exists. By detecting the band, it is possible to perform power line communication using a frequency band that does not have a notch. In addition, when data transmitting apparatus 102 selects an arbitrary channel from the frequency band for communication and transmits a pilot tone, and data receiving apparatus 103 detects that a notch is present in the channel. It is also possible to reselect a channel in another frequency band and perform power line communication.

[0073] In the above-described embodiment, the case where power line communication is performed using four or eight channels has been described. However, the present invention is not limited to this, and an arbitrary number of channels can be used. Power line communication can be performed.

 In addition, the nolot tone may be transmitted according to the channel pattern selected avoiding the notch pattern detected in advance. In this case, it is possible to detect notches in a shorter time than when sweeping the entire frequency band used for communication with pilot tones, and transmit and receive acquired data at homes where the notch pattern does not fluctuate significantly. It is suitable for.

 [0074] In addition, in the above embodiment, if a notch is generated when a home appliance or the like is additionally connected, the entire channel is changed to avoid the notch. The acquired data deteriorated due to the notch ( Only the carrier channel may be dynamically changed to the frequency band without a notch!

 [0075] In the above embodiment, power line communication is performed using a frequency band in which a notch is not detected by detecting a notch, but noise is detected in the same manner instead of a notch and a frequency band in which noise is not present is used. Similarly, power line communication of acquired data may be performed.

 In addition, the computer main body 104b of the monitor device 104 may convert the acquired acquisition data into IP so that the external force acquisition data can be viewed via a network such as the Internet connected to the computer main body 104b. Ok.

 [0076] In the second embodiment, the external information acquisition device includes a plurality of cameras CA and microphones M! /, However, the external information acquisition device may include a plurality of microphones M including only a plurality of microphones M as external information acquisition devices. I do not care.

 Each of the above embodiments is suitable as a security system, but can also be applied to a home automation system, a building automation system, or the like.

[0077] Next, the power line communication system, power line communication method, and power line communication program according to the present invention A third embodiment according to the ram will be described with reference to FIGS.

 [0078] The power line communication system of the present embodiment is a system that is installed in, for example, a building or an apartment house and collects measurement data by performing automatic meter reading such as water meter or gas metering, as shown in FIG. The data is transmitted via the power line L between the master unit 201 that centrally manages various information such as measurement data and a plurality of slave units (nodes) 202 having the sensor unit S having a sensor function for meter reading. It is the power line communication system which performs communication. Note that the base unit 201 and each handset 202 are both connected to the power line L and are supplied with power.

 [0079] The base unit 201 is set to periodically transmit idle information indicating that the base unit 201 is in a dormant state and can be received to the handset unit 202, and at that time, a plurality of different frequencies are used. The idle information transmitting unit 203 that transmits the carrier information in the idle information and the base unit side receiving unit 204 that receives the data transmitted from the slave unit 202 via the power line L. A master unit storage unit 205 that stores the received data, and a master unit transmission unit 206 that transmits an instruction to the slave unit 202 to transmit data to the master unit 201 via the power line L. The

 [0080] The slave unit 202 is provided in a water meter, a gas meter or the like, and includes the sensor unit S that counts the amount of water or gas used, and an idle information reception unit 207 that receives idle information transmitted from the master unit 201. And a statistical information storage unit 208 that stores carrier information and reception status as statistical information when idle information is received, and based on the latest stored statistical information! The optimal carrier information transmitting unit 209 transmits the information selected as the optimal carrier to the base unit 201 as the optimal carrier information, and the sensor unit S with respect to the base unit 201 using the carrier changed based on the optimal carrier information. A node-side transmission unit 210 that transmits the measured data via the power line L; and a node-side reception unit 211 that receives a data transmission instruction or the like from the parent device 201 via the power line L.

 In addition, the optimum carrier information transmission unit 209 is set to select an optimum carrier based on the number of received packets for each carrier stored as statistical information.

 Also, base unit side receiving section 204 of base unit 201 is set to change its own carrier setting based on the received optimum carrier information.

[0083] Further, idle information transmitting section 203 divides a plurality of carriers into a plurality of sets, and each of these sets is divided. The transmission is set to be periodically switched. The period for switching the carrier set is set to 10 msec.

 Note that each processing unit of data in the power line communication system, that is, idle information transmission unit 203, base unit side reception unit 204, base unit side storage unit 205, base unit side transmission unit 206, idle information reception unit 207, statistical information storage unit 208, optimum carrier information transmission unit 209, node side transmission unit 210, node side reception unit 211, and the like may be realized by dedicated hardware. The computer system is configured by a memory and a CPU (central integrated device), and loads and executes a program for realizing the functions of each processing unit and the information collection method (power line communication method) of the present embodiment to be described later. It may be what realizes that function.

 That is, the program is a computer-readable program, and may be for realizing a part of the above-described function and an information collecting method described later. Further, the program may be a so-called difference file (difference program) that can be realized in combination with a program in which the above-described functions are already recorded in a computer system.

 [0086] Further, the program may be transmitted to another computer system via a computer system power transmission medium in which the program is stored in a storage device or the like, or by a transmission wave in the transmission medium. Good. The above transmission medium is a medium having a function of transmitting information, such as a network (communication network) such as the Internet and a communication line (communication line) such as a power line and a telephone line.

 [0087] Further, the memory is a non-volatile memory such as a hard disk device, a magneto-optical disk device, or a flash memory, a recording medium that can only be read such as a CD-ROM, and a random access memory (RAM). It shall consist of a readable memory or a computer readable recording medium with a combination of these.

 Next, an information collection method (power line communication method) in the power line communication system of the present embodiment will be described with reference to FIG. 10 to FIG.

First, as shown in FIG. 10, idle information transmitting section 203 of base unit 201 transmits idle information to each handset 202 via power line L (step S 201). At this time, idol feeling The information transmission unit 203 performs transmission by including in-use carrier information indicating which carrier is used in transmission in the idle information. Also, the idle information transmission unit 203 performs transmission using a plurality of carriers having different frequencies. For example, as shown in Fig. 11, if there are 19 carriers of No. 1 to 19 with different frequencies, 8 out of 19 carriers are used as a set for communication. Carriers are numbered sequentially from the low frequency side.

 [0090] At this time, the idle information transmitting unit 203 divides eight carrier combinations out of 19 into the following three groups and sequentially transmits them.

[0091] Group A: No. “1, 2, 3, 6, 9, 12, 15, 18”

 Group B: No. “1, 2, 3, 7, 10, 13, 16, 19”

 Group C: No. “1, 2, 4, 5, 8, 11, 14, 17”

 In this embodiment, the No. 1 and 2 carriers on the low frequency side are always used as fixed carriers and are included in each set.

[0092] Further, the idle information transmitting unit 203 transmits one set of the above three groups four times at 2.5 msec intervals (2.5 msec X 4 = 10 msec) to each slave unit 202, and sets the groups at 10 msec intervals. Switch between and perform transmission.

 Next, when receiving the signal, the idle information receiving unit 207 of each slave unit 202 determines whether or not the received information is idle information (step S201). The number of uses of each carrier used for transmitting dollar information is counted (step S202). Further, the idle information receiving unit 207 starts processing for every eight carriers used for idle information transmission (step S203). First, it is determined whether the idle information can be received for each carrier (step S204), and the number of times the idle information has been received for each carrier is counted (step S205). This process is repeated for all eight carriers (step S206).

[0094] The statistical information storage unit 208 determines whether or not there is a carrier whose usage count has reached, for example, 255 times (step S207), and for the carrier that has reached 255 times, updates the reception count as statistical information, Record (step S208). That is, the statistical information storage unit 208 updates the number of received packets (the number of received packets) as statistical information each time the idle information is transmitted 255 times. Further, the statistical information storage unit 208 resets the number of times the carrier having updated statistical information is used and the number of receptions (step S 209), and newly performs counting. Then, the statistical information storage unit 208 stores the top six carriers with the highest number of received statistical information (step S210).

 [0096] As shown in FIG. 11, when the base unit 201 collects data obtained by the sensor unit S from each slave unit 202A, 202B, the base unit side transmission unit 206 sends the data to each slave unit 202A, 202B. Send a data transmission instruction via power line L. The slave unit 202 that has received the data transmission instruction by the node side receiving unit 211 performs the following transmission processing.

 That is, as shown in FIG. 11 and FIG. 12, the optimum carrier information transmission unit 209 selects and obtains the carrier having the highest number of receptions and the top six carriers from the statistical information as the optimum carrier (Step S211 ), The optimal carrier information (optimum carrier information) is transmitted to the base unit 201 via the node-side transmitter 210 (step S212). In other words, the information that selects the carrier with the best reception status among the 6th carrier as the optimum carrier is the optimum carrier information.

 [0098] As shown in Fig. 1 U, [No. of handset 202Α, Carrier No. 3, 5, 7, 12, 13, 14 and Fixed carrier No. 1, 2 Eight carriers are selected. In the handset 202B, eight carrier powers are selected: Carrier No. 3, 4, 5, 9, 11, 15 and Fixed Carrier No. 1, 2.

[0099] The optimum carrier information transmitted to base unit 201 is a carrier change request command for base unit 201.

 [0100] Next, base unit side receiving section 204 receives optimum carrier information and performs carrier change setting based on the optimum carrier information (step S212). Further, node side transmitting section 210 changes the carrier based on the optimum carrier information (step S213), and transmits data to base unit 201 using the carrier (step S214).

 Furthermore, base unit side receiving section 204 receives data transmitted from each of handset 202A, 202B, and base unit side storage section 205 records and collects these data.

As described above, in this embodiment, when idle information is periodically transmitted from base unit 201 to handset 202, transmission is performed using a plurality of carriers having different frequencies, and slave unit 202 receives idle information. The state is memorized as statistical information and it is optimal based on the latest statistical information Since communication is performed by selecting a carrier, it is not necessary to separately transmit pilot tones by using periodically transmitted idle information, and it is easily optimized using the latest statistical information that is updated sequentially. A simple transmission path can be estimated.

 [0103] Furthermore, since each set of carriers divided into a plurality of sets is periodically switched and transmitted, each slave unit 202A, 202B needs to process only a limited number of divided carriers simultaneously. It is not necessary to increase the capacity, and optimal transmission characteristics (carrier) can be estimated in a short time from the stored statistical information.

 [0104] Furthermore, since the optimum carrier is selected based on the number of received packets for each carrier, the optimum carrier can be easily obtained by selecting a carrier having a higher number of received packets.

 [0105] In addition, since the cycle for switching the carrier set is set to 10 msec, it can be adapted to a switching cycle of 20 msec, which is often used in home appliances driven by 50 Hz alternating current. An optimal carrier can be obtained efficiently in accordance with a cycle in which a change in the state of the transmission line is likely to occur.

 [0106] In this way, in this power line communication system, measurement data of each slave unit 202 is collected using an optimal carrier that is sequentially updated and has few notches and noise, so the measurement data is concentrated with good communication quality. Automatic meter reading system can be realized.

 [0107] Conventionally, power line communication using the power line L has a problem that the output power cannot be increased so much due to the leakage electric field and the power consumption. However, if the power line communication system according to the above-described embodiment of the present invention is used, power consumption is required for communication because data is arranged in a notch or noise and data is placed in a small channel. It is possible to conduct power line communication while maintaining a good communication quality with a small leakage electric field.

 As described above, the force described with reference to the drawings for the embodiment of the present invention is not limited to the above-described embodiment, and there are design changes and the like within the scope not departing from the gist of the present invention. Is possible.

[0109] For example, in the third embodiment, eight carriers out of 19 carriers may be divided into three yarns, and the number of carriers other than eight may be used. Idle information may be sent separately for groups. In addition, the top six reception keys Carriers and fixed carriers are selected as optimal carriers, but any number of higher-order carriers can be selected.

Industrial applicability

 The present invention relates to a power line communication system for externally acquired information for transmitting and receiving real-time information such as video acquired by an external information acquisition apparatus such as a camera for monitoring via a power line, a power line between a master unit and a plurality of nodes. The present invention can be applied to a power line communication system, a data transmission device, a data reception device, a power line communication method, and a power line communication program that perform data communication via the network.

Claims

The scope of the claims

 [1] An external information acquisition device that acquires external real-time information;

 A data transmission device for transmitting real-time information acquired by the external information acquisition device as acquisition data via a power line;

 A data receiving device that receives the acquired data transmitted via a power line; and an output device that displays the acquired data received by the data receiving device, wherein the data receiving device transmits from the data transmitting device. Depending on the received state of the received signal, a plurality of notches or noise existing in the frequency band used for power line communication are detected, and the obtained data is transmitted and received while avoiding the frequency band in which these notches or noise exist. Select the channel placement for

 The data transmission device transmits the acquired data based on the selected channel arrangement!

 A power line communication system for externally acquired information, wherein the data receiving apparatus receives the acquired data based on the selected channel arrangement.

 [2] In the power line communication system for externally acquired information according to claim 1,

 The external information acquisition device and the data transmission device are provided at a plurality of locations, and the data reception device can multiplex and transmit the acquired data for each of the external information acquisition device and the data transmission device. An arrangement is selected, and the data transmission device transmits the acquired data based on the arrangement of the corresponding channel.

 A power line communication system for externally acquired information, wherein the data receiving device multiplex-receives the acquired data transmitted from a plurality of the data transmitting devices.

[3] In the power line communication system for externally acquired information according to claim 1 or 2,

 The external information acquisition device includes at least a camera that uses the video captured as the real-time information as the acquisition data,

 The power line communication system for externally acquired information, wherein the output device includes a monitor device that reproduces and displays the acquired data.

[4] In the power line communication system for externally acquired information according to claim 1 or 2, The external information acquisition device includes at least a microphone that uses the audio acquired as the real-time information as the acquisition data,

 The power line communication system for externally acquired information, wherein the output device includes a speaker device for reproducing the acquired data.

[5] A data transmitting device for externally acquired information that transmits real-time information acquired by the external information acquiring device as acquired data to the data receiving device via a power line,

 A pilot tone transmitter for transmitting a pilot tone to the data receiver, and a plurality of channels selected avoiding a frequency band in which notch or noise is returned in response to the pilot tone according to the pilot tone. A channel information receiver for receiving the arrangement information;

 A transmission channel setting unit for setting a channel to be used in power line communication based on the received channel arrangement information;

 A transmission side data processing unit that performs processing to distribute and arrange the acquired data in the set channel;

 A data transmitting device for externally acquired information, comprising: a data transmitting unit configured to transmit the acquired data to the data receiving device via a power line.

[6] A data receiving device for externally acquired information that receives real-time information acquired by an external information acquiring device as acquired data from a data transmitting device via a power line,

 A pilot tone receiving unit that receives a pilot tone from the data transmission device; a detection unit that detects a notch or noise existing in a frequency band used for power line communication according to a reception state of the received pilot tone;

 A channel selection unit that selects the arrangement of a plurality of channels to be used when performing power line communication while avoiding the detected frequency band in which the notch or noise exists;

 A channel information transmitter for transmitting the selected channel arrangement information to the data transmitter;

A data receiving device for receiving externally acquired information from the data transmitting device.

[7] A power line communication method for externally acquired information that is transmitted from a data transmitting apparatus via a power line as real-time information acquired by an external information acquiring apparatus and received by a data receiving apparatus.

 A first step of transmitting a signal via a power line by the data transmission device, and a frequency band used for power line communication according to a reception state of a signal transmitted from the data transmission device by the data reception device. A second step of detecting an existing notch or noise and selecting an arrangement of a plurality of channels for transmitting and receiving the acquired data while avoiding a frequency band in which the notch or noise exists;

 A third step of transmitting the acquired data based on the selected channel arrangement by the data transmitting device; and

 A fourth step of receiving the acquired data by the data receiving device based on the arrangement of the selected channel;

 A power line communication method for externally acquired information, comprising:

 [8] A power line communication program for externally acquired information when the real-time information acquired by the external information acquiring device is transmitted as acquisition data from the data transmitting device via the power line and received by the data receiving device,

 A first step of transmitting a signal through the power line by the data transmission device, and a frequency band used for power line communication according to a reception state of the signal transmitted from the data transmission device by the data reception device. A second step of detecting an existing notch or noise and selecting an arrangement of a plurality of channels for transmitting and receiving the acquired data while avoiding a frequency band in which the notch or noise exists;

 A third step of transmitting the acquired data based on the selected channel arrangement by the data transmitting device; and

 A fourth step of receiving the acquired data based on the selected channel arrangement by the data receiving device; and

 A power line communication program for externally acquired information, characterized by causing a computer to execute.

[9] A power line communication system that communicates data between the master unit and multiple nodes via a power line And

 When the base unit periodically transmits idle information indicating that the base unit is in a dormant state and can be received to the node, the base unit performs the transmission using a plurality of carriers having different frequencies and the idle unit. An idle information transmission unit for transmitting information including the carrier information;

 A master-side receiving unit that receives data transmitted from the node;

 An idle information receiving unit for receiving the idle information by the node;

 A statistical information storage unit that stores the carrier information and the reception state as statistical information when the idle information is received;

 An optimal carrier information transmitting unit that transmits information selected as an optimal carrier among the carriers based on the latest stored statistical information as an optimal carrier, as optimal carrier information;

 A node-side transmitter that transmits data to the base unit using the carrier changed based on the optimum carrier information,

 The power line communication system, wherein the base-side receiver changes its own carrier setting based on the received optimal carrier information.

 [10] In the power line communication system according to claim 9,

 The power line communication system, wherein the idle information transmitting unit divides a plurality of carriers into a plurality of sets, and periodically switches each set to perform the transmission.

 [11] In the power line communication system according to claim 9 or 10,

 The power carrier communication system, wherein the optimum carrier information transmitting unit selects the optimum carrier based on the number of received packets for each carrier stored as the statistical information.

 [12] In the power line communication system according to any one of claims 9 to 11,

 A power line communication system, wherein a periodic force for switching the carrier set is set to 10 msec.

 [13] In the power line communication system according to any one of claims 9 to 12,

The node has a sensor function; The power line communication system, wherein the node-side transmission unit transmits data measured by the sensor function.

 [14] A power line communication method for performing data communication via a power line between a master unit and a plurality of nodes,

 When idle information indicating that it is in a dormant state and is receivable is periodically transmitted to the node, the transmission is performed on a plurality of carriers having different frequencies, and the idle information is included in the idle information. Sending information including

 The node receiving the idle information;

 Storing the carrier information and reception status as statistical information when receiving the idle information;

 Transmitting the information selected as the optimum carrier among the carriers with the best reception state based on the latest stored statistical information as the optimum carrier information to the base unit;

 Transmitting data to the base unit using the carrier changed based on the optimum carrier information,

 The base unit has a step of changing the setting of its own carrier based on the received optimal carrier information.

[15] A power line communication program for performing data communication between a master unit and a plurality of nodes via a power line,

 When idle information indicating that it is in a dormant state and is receivable is periodically transmitted to the node, the transmission is performed on a plurality of carriers having different frequencies, and the idle information is included in the idle information. Sending information including

 The node receiving the idle information;

 Storing the carrier information and reception status as statistical information when receiving the idle information;

Transmitting the information selected as the optimum carrier among the carriers with the best reception state based on the latest stored statistical information as the optimum carrier information to the base unit; Transmitting data to the base unit using the carrier changed based on the optimum carrier information,

 A program for causing the base unit to execute a step of changing a setting of its own carrier based on the received optimum carrier information;