JP4495617B2 - Communication apparatus and communication method - Google Patents

Description

  The present invention uses multi-tone modulation schemes such as FH-MMFSK (Frequency Hopping-M-ary Multilevel FSK), FH-MMMFSK (Frequency Hopping-M-ary Multilevel Multitone FSK), and OFDM (Orthogonal Frequency Division Multiplexing). Related to communication technology.

  Patent Document 1 discloses a technique for assigning time slots in a demand assignment type TDMA (Time Division Multiple Access) wireless communication system composed of a reference station and a plurality of terminal stations. In this technique, when receiving a time slot assignment request from a terminal station, the reference station refers to the priority order and assignment rule of the requesting terminal station and preferentially assigns time slots to terminal stations with higher priority order.

  Patent Document 2 discloses a technique for performing priority control at the time of best effort data transmission in a wireless packet communication system that performs autonomous distributed access control as a whole system. In this technology, the radio base station changes to a service class with a low priority when the amount of data transmitted / received per unit time Ts with the subordinate radio terminal continuously exceeds the threshold value Rd. In addition, when the amount of best effort data transmitted / received per unit time Ts continuously with a wireless terminal set to a service class with a low priority falls below the threshold Ru, Change the service class for sending and receiving during the period to a higher priority.

JP 2000-341192 A JP 2002-247042 A

  By the way, when constructing a network using a multi-tone modulation method (a method of modulating a baseband using a plurality of tones (frequency)) such as FH-MMFSK, FH-MMMFSK, OFDM, etc., the bandwidth of each communication channel is set by TDMA. Is generally guaranteed. However, if the bandwidth of each communication channel is simply guaranteed by time division by the TDMA method, if stream data that cannot be retransmitted is assigned to a tone whose quality has deteriorated due to the influence of multipath, the stream data is missing. This causes a stop of streaming playback. Therefore, it is preferable that priority control of communication can be performed even when a network is constructed using the multitone modulation method. Note that the communication priority control technology in TDMA described in Patent Documents 1 and 2 described above relates to priority control of time slots assigned to communication, and does not consider the above-described case.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a priority control technique using a multi-tone modulation method.

  In order to solve the above problems, in the present invention, a non-contention channel is provided, and for example, a tone (frequency) and a slot (time) with little quality degradation are allocated to the non-contention channel. Tones and slots to which no priority channel is assigned are assigned to contention channels. Carrier sense is performed in a protection period (contention control space) provided in a non-contention channel header added to a non-contention channel and a payload storing the contention channel. Information (non-contention channel configuration information) indicating the tone and slot assigned to the non-contention channel is included in the non-contention channel header. The tone and slot to which the contention channel is assigned include the non-contention channel tone and slot specified by the non-contention channel configuration information in the non-contention channel header, and predetermined payload configuration information (tone and slot information) Identify from.

For example, a communication method using a multi-tone modulation method,
A communication device that transmits data (referred to as non-contention channel data) using a non-contention channel transmits a non-contention channel header including a non-contention channel synchronization signal and a contention control space on the communication medium, and The non-contention data portion for storing non-contention channel data that is multi-tone modulated using a combination of tone (frequency) and slot (time) assigned to the non-contention channel synchronization signal is synchronized with the transmitted non-contention channel synchronization signal. Send on the medium,
A communication device that transmits data (referred to as contention channel data) using a contention channel detects a non-contention channel header synchronization signal transmitted on the communication medium, and is identified by the detected non-contention channel header synchronization signal. When carrier sensing is performed in the contention control space and a contention channel is acquired, contention channel data that has been subjected to multi-tone modulation using a combination of tones and slots other than the tone and slot combinations assigned to non-contention channels The contention data part to be stored is transmitted on the communication medium in synchronization with the detected non-contention channel synchronization signal so that it is multiplexed with the non-contention data part transmitted on the communication medium.

A communication method using the multitone modulation method of the present invention is as follows.
A communication device that receives non-contention channel data detects a non-contention channel synchronization signal transmitted on the communication medium, and based on the detected non-contention channel synchronization signal, a non-contention data portion that transmits the communication medium Identify and demodulate multi-tone modulated non-contention channel data using the combination of tones and slots assigned to the non-contention channel from the identified non-contention data portion;
A communication device that receives contention channel data detects a non-contention channel synchronization signal transmitted on the communication medium, and identifies a contention data portion to be transmitted on the communication medium based on the detected non-contention channel synchronization signal. Then, from the identified contention data portion, multi-tone modulated contention channel data is demodulated using a combination of a tone and a slot other than a combination of a tone and a slot assigned to a non-contention channel.

A communication apparatus using the multitone modulation method of the present invention is
Transmitter for transmitting data using contention channel and non-contention channel, receiver for receiving data using contention channel and non-contention channel, tone (frequency) and slot (time) of channel used for data transmission / reception A use channel setting unit that sets a combination with a competing channel control unit,
The transmitter is
Multitone modulation means for multitone modulating data using a combination of a tone and a slot set by the use channel setting unit;
Communication frame generating means for generating a communication frame storing data that has been subjected to multitone modulation by the multitone modulation means;
AFE for transmission (Analog Front End) means for transmitting the communication frame generated by the communication frame generation means to a communication medium,
The receiver is
Receiving AFE means for receiving a modulated signal from the communication medium;
Communication frame detecting means for detecting a communication frame from the modulated signal output from the receiving AFE means;
Multi-tone demodulation means for demodulating multi-tone modulated data included in the communication frame detected by the communication frame detection means using a combination of a tone and a slot set by the used channel setting unit; Have
The use channel setting unit includes:
When a non-contention channel is preset as a channel used for data transmission / reception, a process for setting a combination of a tone and a slot allocated to the non-contention channel in the transmission unit and the reception unit, and a channel used for data transmission / reception When a contention channel is set in advance as the transmission unit and the reception unit, a process of setting a combination of a tone and a slot other than a combination of a tone and a slot allocated to a non-contention channel, and
The communication frame generation means includes
When a non-contention channel is set in advance, the multi-tone modulation is performed by a combination of a non-contention channel header including a non-contention channel header synchronization signal and a contention control space, and a tone and a slot set by the used channel setting unit. Generating a communication frame having a non-contention data portion including data that is multi-tone modulated by the means;
When a contention channel is set in advance, the multi-tone modulation is performed by a combination of a tone and a slot set in the used channel setting unit, which is multiplexed on a non-contention data portion of a communication frame existing on a communication medium A process of generating a competing data portion including data that has been subjected to multitone modulation by the means,
The contention channel controller is
When a contention channel is set in advance and no other carrier output is detected in the contention control space specified by the non-contention channel header synchronization signal of the communication frame existing on the communication medium, the contention Instructs the transmitter to generate a data part.

  According to the present invention, a non-contention channel is provided separately from the contention channel, and both channels can be specified by the non-contention channel header. Further, carrier sense for acquiring a contention channel is performed in a contention control space provided in the non-contention channel header. In this way, a priority control technique using a multitone modulation method can be provided.

  Embodiments of the present invention will be described below.

  FIG. 1 is a schematic diagram of a network system to which an embodiment of the present invention is applied. As shown in the figure, the network system of the present embodiment is configured by connecting a plurality of communication devices 1 to which an information processing device 2 such as a PC or an information appliance is connected via a communication medium 3 such as a power line. The communication device 1 communicates with another communication device 1 by FH-MMMFSK or the like.

  Here, when a plurality of communication apparatuses compete and communicate, for example, CSMA (Carrier Sense Multiple Access) is used. Hereinafter, a contention channel is read as a CSMA channel, and a non-contention channel that preferentially communicates specific data is read as a priority channel. Multitone modulation will be described using FH-MMMFSK as an example.

  In the network system of the present embodiment, the CSMA single mode in which only the CSMA channel is transmitted on the communication medium 3 and the CSMA channel on the communication medium 3 and the priority channel separately provided for the CSMA channel for priority control are mixed. It operates in either CSMA / priority channel mixed mode.

  FIG. 2A is a diagram schematically showing a communication frame transmitted and received between the communication apparatuses 1 in the CSMA single mode. As shown in the figure, the communication frame 310 for the CSMA single mode has a CSMA channel header 311 and a payload 312 composed of an FH-MMMFSK signal. The CSMA channel header 311 includes a CSMA synchronization signal 3111 for recognizing the communication frame 310 and an SN (Signal to Noise) detection signal 3112.

  The SN detection signal 3112 is for detecting a tone (a tone with little quality degradation) used when data is transmitted on the priority channel to the transmission source of the CSMA channel data 313 to be described later. It has an all-tone synthesized signal that is a synthesized signal of all tones used for FH-MMMFSK, and a no-signal that is a section with no signal. The FH-MMMFSK signal stored in the payload 312 is CSMA channel data 313. The CSMA channel data 313 includes a transmission source address 3131, a transmission destination address 3132, and transmission data 3133.

  FIG. 2B is a diagram schematically showing a communication frame transmitted / received between the communication apparatuses 1 in the CSMA / priority channel mixed mode. As shown in the figure, the communication frame 320 for the CSMA / priority channel mixed mode includes a priority channel header 321 and a payload 322 composed of an FH-MMMFSK signal. The priority channel header 321 includes a priority channel synchronization signal 3211 for recognizing the communication frame 320, priority channel configuration information 3212 for specifying hopping, tones and the like used for the priority channel, an SN detection signal 3213, and an SN detection. Signal 3215, and CSMA channel gap 3214, which is a protection period for carrier sense, provided between priority channel configuration information 3212 and SN detection signal 3213.

  The communication apparatus 1 that has output the CSMA synchronization signal 3215 in the CSMA channel gap 3214 can use the CSMA channel. The SN detection signal 3213 is used to detect a tone (a tone with little quality degradation) used when data is transmitted on the priority channel to the transmission source of the priority channel data 323 described later. On the other hand, the SN detection signal 3215 is used to detect a tone used when data is transmitted on a priority channel to a transmission source of CSMA channel data 324 described later. Although not shown, the SN detection signals 3213 and 3215 include an all-tone synthesized signal that is a synthesized signal of all tones used for FH-MMMFSK and a no-signal that is a section without a signal. The FH-MMMFSK signal stored in the payload 322 is priority channel data 323 or mixed data of priority channel data 323 and CSMA channel data 324. The priority channel data 323 includes a transmission source address 3231, a transmission destination address 3232, and transmission data 3233. Similarly, the CSMA channel data 324 includes a transmission source address 3241, a transmission destination address 3242, and transmission data 3243.

  FIG. 3A is a diagram schematically showing the FH-MMMFSK signal stored in the payload 312 of the communication frame 310 for the CSMA single mode. FIG. 3B is a diagram schematically showing the FH-MMMFSK signal stored in the payload 322 of the communication frame 320 for the CSMA / priority channel mixed mode. Here, a case where an FH-MMMFSK signal having 8 tones and 10 slots is stored in the payloads 312 and 322 is illustrated. 3A and 3B, among the elements 330 specified by the combination of the tone and the slot, the hatched elements are the elements assigned to the priority channel, and the plain ones are the CSMA channels. Is the element assigned to. As shown, in CSMA only mode, all elements 330 are assigned to CSMA channels. On the other hand, in the CSMA / priority channel mixed mode, some elements 330 (here, the first, fourth, fifth, and eighth tones in the first to fifth slots) are assigned to the priority channels, and the remaining elements 330 are assigned to the CSMA channels. Assigned to. By assigning tones with low quality degradation to priority channels, it is possible to realize a priority channel suitable for transferring stream data or the like that is not allowed to be retransmitted.

  Note that the payloads 312 and 322 of the communication frames 310 and 320 are configured by FH-MMMFSK signals for a plurality of hopping. In the present embodiment, for simplification of explanation, as shown in FIG. 3, the number of slots of the payloads 312 and 322 is 10, and the first hopping FH-MMMFSK signal including the first slot to the fifth slot, It is assumed that payloads 312 and 322 are configured by the second hopping FH-MMMFSK signal including the sixth slot to the tenth slot.

  FIG. 4 is a schematic diagram of the communication device 1. As shown in the figure, the communication device 1 of the present embodiment includes a transmission unit 11, a reception unit 12, a used channel setting unit 13, a CSMA / CA (Collision Avoidance) control unit 14, an SN table storage unit 15, Have

  The transmission unit 11 converts the transmission data transmitted from the information processing apparatus 2 into an FH-MMMFSK signal and outputs the FH-MMMFSK modulation unit 111, and the FH-MMMFSK signal output from the FH-MMMFSK modulation unit 111 as a payload. The communication frame generation unit 112 that generates and outputs the communication frame (the communication frame 310 for the CSMA single mode or the communication frame 320 for the CSMA / priority channel mixed mode) stored in the communication frame unit 112 and the communication frame ( A DA (Digital Analog) converter 113 that converts a digital signal) into an analog signal and outputs the analog signal; and an AFE (Analog Front End) unit 114 that outputs the analog signal output by the DA converter 113 to the communication medium 3. Have.

  FIG. 5 is a schematic diagram of the FH-MMMFSK modulation unit 111. As illustrated, the FH-MMMFSK modulation unit 111 includes an S / P (Serial / Parallel) conversion unit 1111, a level conversion unit 1112, a pattern conversion unit 1113, a hopping pattern storage unit 1114, an addition unit 1115, A remainder calculation unit 1116, a level / tone conversion unit 1117, and a level / tone conversion table storage unit 1118 are included.

The S / P converter 1111 receives the number of bits K associated with each of the first and second hoppings constituting the payloads 312 and 322 of the communication frames 310 and 320 from the used channel setting unit 13 described later. Obtained from configuration information. Then, the number of bits K ₁ associated with the first hopping, the serial data (transmission data) of the number of bits obtained by adding the number of bits K ₂ determined according to the number of bits K ₁ (K ₁ + K ₂₎ Obtained from the information processing apparatus 2 and converts the obtained serial data into parallel data. Then, the upper (or lower) K ₁ bit is output to the level conversion unit 1112, and the remaining K ₂ bits are output to the pattern conversion unit 1113. Then, the number of bits K ₁ associated with the second hopping, the serial data of bits obtained by adding the number of bits K ₂ determined according to the number of bits K ₁ (K ₁ + K ₂₎ from the information processing apparatus 2 The acquired serial data is converted into parallel data. Then, the upper (or lower) K ₁ bit is output to the level conversion unit 1112, and the remaining K ₂ bits are output to the pattern conversion unit 1113. Here, the bit number K ₁ is a value determined by the number of tones usable for the priority channel. Further, the number of bits K ₂ is the number of possible hopping pattern realized with the possible tones available to the priority channel is calculated by multiplying the coefficients W defined on the basis of experience, for example, in number of bits K ₁ .

When the number of bits K ₁ corresponding to a certain hopping is 0, the process of acquiring serial data from the information processing device 2 for the hopping and converting it into parallel data, and outputting the parallel data to the level conversion unit 1112 and the pattern conversion unit 1113 is as follows. Not done.

The level conversion unit 1112 converts the K _1- bit parallel data input from the S / P conversion unit 1111 into a level corresponding to the value indicated by the parallel data. Then, a level pattern in which the converted level is continuously formed for the number of slots constituting one hopping is output to the adder 1115 together with the number of values (level number) that the K _1- bit parallel data can take. . FIG. 6 is a diagram schematically showing the level pattern 11121 output from the level converter 1112. As described above, in this embodiment, the payloads 312 and 322 of the communication frames 310 and 320 are configured by two hopping FH-MMMFSK signals, and the number of slots of one hopping FH-MMMFSK signal is five. In this example, the number of bits K ₁ included in the used channel configuration information is 3 and the parallel data of K ₁ bits is “100”.

The hopping pattern storage unit 1114 has a hopping pattern group for each of a plurality of predetermined different levels. The hopping pattern group includes hopping patterns associated with values that can be obtained by bit data of the number of bits obtained by multiplying the number of bits of bit data necessary to represent the corresponding number of levels by the coefficient W. It is remembered. That is, when the bit number K ₁ bit data input to the level conversion unit 1112 from the S / P converter 1111 to the number of bits of data required to represent the number of levels corresponding to the hopping pattern, the hopping pattern group the number of patterns of the hopping match the number of possible values for bit data of the bit number K ₂ that is input to the pattern conversion unit 1113 from the S / P converter 1111. FIG. 7 is a diagram schematically showing a hopping pattern 11141 stored in the hopping pattern storage unit 1114. Here, the number of slots in the hopping pattern is the number of slots for one hopping.

As described above, in this embodiment, the payloads 312 and 322 of the communication frames 310 and 320 are configured by two hopping FH-MMMFSK signals, and the number of slots of one hopping FH-MMMFSK signal is five. This example shows a case where the number of bits K ₁ = 3 included in the used channel configuration information. The hopping pattern associated with each value that can be taken by the bit data is a combination that can be used as a hopping pattern among the patterns that can be taken as a matrix of the number of slots × the number of levels (a combination that can be distinguished from other hopping patterns). Selected from.

The pattern conversion unit 1113 receives the hopping pattern corresponding to the value indicated by the _2- bit parallel data K input from the S / P conversion unit 1111, and the number of bits K input from the S / P conversion unit 1111 to the level conversion unit 1112. The data is read out from the hopping pattern group stored in the hopping pattern storage unit 1114 in association with the number of levels that _one bit data can take and output to the adding unit 1115.

  The adder 1115 adds the level of the level pattern output from the level converter 1112 and the level of the hopping pattern output from the pattern converter 1113 for each slot. Then, the addition result is output to the remainder calculation unit 1116 together with the number of levels output from the level conversion unit 1112.

The remainder calculation unit 1116 adds the number of levels output from the addition unit 1115 together with the addition result to the addition result of each slot output from the addition unit 1115 (corresponding to the hopping to be processed and used channel configuration information). calculating a remainder number of bits of data of the bit number K ₁ which is registered possible values). That is, when the addition result is x and the number of levels is n, x (mod n) is calculated. Then, the calculation result is output as a level to the level / tone conversion unit 1117 together with the number of levels output from the adding unit 1115. When the calculation result is 0, the level number n is output as a level.

  The level / tone conversion table storage unit 1118 has a level / tone conversion table for each of a plurality of predetermined different numbers of bits. In the level / tone conversion table, for each value (level) that can be taken by the bit data of the corresponding number of bits, a tone combination (frequency spectrum) corresponding to the value is registered. FIG. 8 schematically shows a level / tone conversion table 11181 registered in the level / tone conversion table storage unit 1118. As shown in the figure, for each value (level) that the bit data of the corresponding number of bits can take, a combination of at least one tone among m tones is associated. Here, the number of tones m is determined in advance according to the number of values (levels) that the bit data of the number of bits corresponding to the level / tone conversion table 11181 can take. Note that the tone used is an integral multiple of the slot frequency.

The level / tone conversion unit 1117 is the number of bits necessary for expressing the number of levels output from the remainder calculation unit 1116 as bit data (the bits registered in the used channel configuration information in association with the hopping to be processed). Using the level / tone conversion table stored in the level / tone conversion table storage unit 1118 in association with the number K ₁ ), the level of each slot output from the remainder calculation unit 1116 is changed to the combination of tones ( Frequency spectrum) and output. FIG. 9 is a diagram schematically showing a transmission spectrum 11171 for one hopping output from the level / tone conversion unit 1117. In this example, the level pattern and hopping pattern input to the adder 1115 are the patterns shown in FIGS. 6 and 7, and the number of bits necessary to express the number of levels output from the remainder calculator 1116 as bit data. FIG. 8 shows the transmission spectrum output from the level / tone conversion unit 1117 when the level / tone conversion table stored in the level / tone conversion table storage unit 1118 in association with is the table shown in FIG. .

  FIG. 10 is a schematic diagram of the communication frame generation unit 112. As shown in the figure, the communication frame generation unit 112 includes a payload generation unit 1121, an SN detection signal addition unit 1122, an IFFT (Inverse Fast Fourier Transform) unit 1123, a CSMA synchronization signal addition unit 1124, and priority channel configuration information addition. Unit 1125 and a priority channel synchronization signal adding unit 1126.

The payload generation unit 1121 generates payloads 312 and 322 of the communication frames 310 and 320. Specifically, the number K of bits associated with each of the first and second hoppings constituting the payloads 312 and 322 is acquired from the used channel configuration information received from the used channel setting unit 13 described later. Next, when the number K of bits associated with the first hopping is not 0, the tone combination of each slot for the first hopping first output from the FH-MMMFSK modulation unit 111 is the FH-MMMFSK signal of the first hopping. To do. On the other hand, when the number of bits K associated with the first hopping is 0, slots for one hopping that do not include any tone are generated and used as the first hopping FH-MMMFSK signal. Next, when the number of bits K ₁ associated with the second hopping is not 0, the FH-MMMFSK modulation unit 111 outputs the second number (however, the number of bits K associated with the first hopping is 0. In this case, the tone combination of each slot for one hopping (which is output first) is the second hopping FH-MMMFSK signal. On the other hand, when the number of bits K ₁ associated with the second hopping is 0, slots for one hopping that do not include any tone are generated, and these are used as FH-MMMFSK signals for the second hopping. Then, payloads 312 and 322 composed of the first hopping FH-MMMFSK signal and the second hopping FH-MMMFSK signal are generated and output.

  The SN detection signal addition unit 1122 adds SN detection signals 3112, 3213, and 3215 to the payloads 312 and 322 output from the payload generation unit 1121 (see FIG. 2). Specifically, when the operation mode specified by the mode information received from the used channel setting unit 13 described later is the CSMA single mode, the SN detection signal 3112 is added to the head of the payload 312. In addition, when the operation mode specified by the mode information is the CSMA / priority channel mixed mode and the use channel type information received from the use channel setting unit 13 described later is the priority channel (the own device uses the priority channel). In this case, the SN detection signal 3213 is added to a position ahead of the payload 322 by a space corresponding to the SN detection signal 3215. On the other hand, when the operation mode specified by the mode information is the CSMA / priority channel mixed mode and the used channel type information received from the used channel setting unit 13 described later is a CSMA channel (the own device uses the CSMA channel). The SN detection signal 3215 is added to the head of the payload 322.

  As described above, the SN detection signals 3112, 3213, and 3215 have an all-tone synthesized signal and no signal. The all tone composite signal is a composite signal of all tones used in each level / tone conversion table 1181 stored in the level / tone conversion table storage unit 1118, that is, all tones used in FH-MMMFSK. is there. Note that the signal duration of each of the all-tone synthesized signal and the non-signal is an integral multiple of the slot (for example, one slot).

  The IFFT unit 1123 includes an output signal from the SN detection signal adding unit 1122 (a payload 312 to which an SN detection signal 3112 is added, a payload 322 to which an SN detection signal 3213 is added, and a payload 322 to which an SN detection signal 3215 is added. Any one of them) is subjected to IFFT processing and converted into waveform data for each slot.

  When the operation mode specified by the mode information received from the use channel setting unit 13 described later is the CSMA single mode, the CSMA synchronization signal adding unit 1124 follows the CSMA channel transmission instruction received from the CSMA / CA control unit 14 described later. The CSMA synchronization signal 3111 is added to the head of the waveform data of the payload 312 output from the IFFT unit 1123 and to which the SN detection signal 3112 is added. Thus, a communication frame 310 of the CSMA channel used in the CSMA single mode is generated (see FIG. 2A).

  Also, the CSMA synchronization signal adding unit 1124, when the operation mode specified by the mode information is the CSMA / priority channel mixed mode and the used channel type information received from the used channel setting unit 13 described later is the CSMA channel (When the own apparatus uses the CSMA channel), in accordance with the CSMA channel transmission instruction received from the CSMA / CA control unit 14 described later, the CSMA channel transmission instruction from the beginning of the waveform data of the payload 322 output from the IFFT unit 1123 The CSMA synchronization signal 3215 is added to the front position for the time specified by. As a result, a CSMA channel communication frame 320 used in the CSMA / priority channel mixed mode is generated (see FIG. 2B).

  The priority channel configuration information adding unit 1125 is a CSMA / priority channel mixed mode in which the operation mode specified by the operation mode information received from the use channel setting unit 13 described later is used, and the use received from the use channel setting unit 13 described later. When the channel type information is a priority channel (when the own device uses a priority channel), priority channel configuration information 3212 including used channel configuration information received from the used channel setting unit 13 described later is created. Then, the created preferential channel configuration information 3212 is placed at a position ahead by a predetermined CSMA channel gap 3214 from the beginning of the waveform data of the payload 322 to which the SN detection signal 3213 is added, output from the IFFT unit 1123. It is added (see FIG. 2B).

  The priority channel synchronization signal adding unit 1126 uses the CSMA / priority channel mixed mode when the operation mode specified by the operation mode information received from the use channel setting unit 13 described later is used, and the use channel received from the use channel setting unit 13 described later. When the channel type information is a priority channel (when the own device uses a priority channel), the priority channel synchronization signal 3211 is added to the head of the priority channel configuration information 3212 added by the priority channel configuration information adding unit 1125. As a result, the communication channel 320 of the priority channel used in the CSMA / priority channel mixed mode is generated (see FIG. 2B).

  Returning to FIG. The DA conversion unit 113 converts the communication frames 310 and 320 output from the communication frame generation unit 112 into analog signals. The AFE unit 114 outputs this analog signal onto the communication medium 3.

  The receiving unit 12 includes an AFE unit 121, an AD (Analog Digital) conversion unit 122, a communication frame detection unit 123, and an FH-MMMFSK demodulation unit 124.

  The AFE unit 121 receives an analog signal transmitted over the communication medium 3. The AD (Analog Digital) conversion unit 122 converts the analog signal received by the AFE unit 121 into a digital signal and outputs the digital signal to the communication frame detection unit 123.

  The communication frame detection unit 123 detects the communication frames 310 and 320 from the digital signal output from the AD conversion unit 122. FIG. 11 is a schematic diagram of the communication frame detection unit 123. As illustrated, the communication frame detection unit 123 includes a priority channel synchronization signal detection unit 1231, a priority channel configuration information detection unit 1232, a CSMA synchronization signal detection unit 1233, an FFT (Fast Fourier Transform) unit 1234, and an SN detection. A unit 1235 and a used channel extraction unit 1236.

  The priority channel synchronization signal detection unit 1231 tries to detect the priority channel synchronization signal 3211 from the digital signal output from the AD conversion unit 122. When the priority channel synchronization signal 3211 is detected, the priority channel synchronization detection signal is output to the used channel setting unit 13 and also output to the respective units 1232 to 1236 of the communication frame 123.

  The priority channel configuration information detection unit 1232 detects the priority channel configuration information 3212 from the digital signal output from the AD conversion unit 122 based on the priority channel synchronization detection signal output from the priority channel synchronization signal detection unit 1231. Then, the detected priority channel configuration information is output to the use channel setting unit 13.

  The CSMA synchronization signal detection unit 1233 tries to detect the CSMA synchronization signals 3111 and 3215 from the digital signal output from the AD conversion unit 122. When the CSMA synchronization signals 3111 and 3215 are not detected, the CSMA synchronization non-detection signal is output to the CSMA / CA control unit 14, while when it is detected, the CSMA synchronization detection signal is transmitted to the CSMA / CA control unit 14 and the FFT. Output to unit 1234, SN detector 1235, and used channel extractor 1236.

  Specifically, when the priority channel synchronization detection signal is output from the priority channel synchronization signal detection unit 1231, the CSMA channel gap 3214 specified by the priority channel synchronization detection signal is output until the predetermined time elapses. When the synchronization signal 3215 is not detected, a CSMA synchronization non-detection signal is output. On the other hand, when the CSMA synchronization signal 3215 is detected, a CSMA synchronization detection signal is output.

  In addition, when the priority channel synchronization detection signal is not output from the priority channel synchronization signal detection unit 1231, a predetermined time elapses after the no-signal state is reached (by a predetermined time elapses from the end position of the communication frame 310). ), A CSMA synchronization non-detection signal is output when the CSMA synchronization signal 3111 is not detected, while a CSMA synchronization detection signal is output when the CSMA synchronization signal 3111 is detected.

  The FFT unit 1234 performs FFT processing on the waveform detection data 3112 of the communication frame 310 and the waveform data of each slot constituting the payload 312 included in the digital signal output from the AD conversion unit 122 to obtain a frequency spectrum (tone Combination) and output. Alternatively, FFT processing is performed on the waveform data of each slot constituting the SN detection signals 3213 and 3215 and the payload 322 of the communication frame 320 included in the digital signal output from the AD converter 122, and the frequency spectrum (tone combination) ) And output.

  Specifically, when the priority channel synchronization detection signal is output from the priority channel synchronization signal detection unit 1231, the SN detection signals 3213 and 3215 specified by the priority channel synchronization detection signal and the waveform data of each slot constituting the payload 322 Is subjected to FFT processing, converted into a frequency spectrum and output.

  In addition, when the priority channel synchronization detection signal is not output from the priority channel synchronization signal detection unit 1231 and the CSMA synchronization detection signal is output from the CSMA synchronization signal detection unit 1233, the SN detection specified by the CSMA synchronization detection signal is performed. The FFT processing is performed on the waveform data of each slot constituting the signal 3112 and the payload 312 to convert it into a frequency spectrum and output it.

  The SN detector 1235 detects the SN of each tone that can be used for frequency hopping by FH-MMMFSK from the frequency spectrum of each slot constituting the SN detection signals 3112, 3213, and 3215 output from the FFT unit 1234.

  Specifically, when the priority channel synchronization detection signal is output from the priority channel synchronization signal detection unit 1231 and the CSMA synchronization detection signal is output from the CSMA synchronization signal detection unit 1233, the priority channel synchronization detection is performed. Based on the signal, the frequency spectrum of each slot constituting the SN detection signal 3213 is specified. Next, based on the frequency spectrum of the tone synthesis signal included in the SN detection signal 3213, the signal level of each tone that can be used for frequency hopping by FH-MMMFSK is detected. Further, based on the non-signal frequency spectrum included in the SN detection signal 3213, the noise level of each tone that can be used for frequency hopping by FH-MMMFSK is detected. Then, SN, which is the ratio of the noise level to the signal level, is calculated for each tone. Then, the calculated SN is registered in the SN table storage unit 15 in association with the transmission source address 3231 of the priority channel data 323 notified from the FH-MMMFSK demodulation unit 124.

  Further, when the priority channel synchronization detection signal is output from the priority channel synchronization signal detection unit 1231 and the CSMA synchronization non-detection signal is output from the CSMA synchronization signal detection unit 1233, the priority channel synchronization detection signal is Based on this, the frequency spectrum of each slot constituting the SN detection signal 3215 is specified. Next, based on the frequency spectrum of the tone synthesis signal included in the SN detection signal 3215, the signal level of each tone that can be used for frequency hopping by FH-MMMFSK is detected. Further, based on the non-signal frequency spectrum included in the SN detection signal 3215, the noise level of each tone that can be used for frequency hopping by FH-MMMFSK is detected. Then, SN, which is the ratio of the noise level to the signal level, is calculated for each tone. Then, the calculated SN is registered in the SN table storage unit 15 in association with the transmission source address 3241 of the CSMA channel data 324 notified from the FH-MMMFSK demodulation unit 124.

  Further, when the CSMA synchronization detection signal is output from the CSMA synchronization signal detection unit 1233 in a state where the priority channel synchronization detection signal is not output from the priority channel synchronization signal detection unit 1231, the SN detection signal is based on the CSMA synchronization detection signal. The frequency spectrum of each slot constituting 3112 is specified. Next, the signal level of each tone that can be used for frequency hopping by FH-MMMFSK is detected based on the frequency spectrum of the tone synthesis signal included in SN detection signal 3112. Further, based on the non-signal frequency spectrum included in the SN detection signal 3112, the noise level of each tone that can be used for frequency hopping by FH-MMMFSK is detected. Then, SN, which is the ratio of the noise level to the signal level, is calculated for each tone. Then, the calculated SN is registered in the SN table storage unit 15 in association with the transmission source address 3131 of the CSMA channel data 313 notified from the FH-MMMFSK demodulation unit 124.

  The used channel extracting unit 1236 extracts and outputs the frequency spectrum of each slot constituting the hopping of the reception target channel (used channel) from the frequency spectrum of each slot constituting the payload 310, 320 output from the FFT unit 1234. .

  Specifically, first, the number K of bits associated with each of the first and second hoppings constituting the payloads 312 and 322 is acquired from the used channel configuration information received from the used channel setting unit 13 described later.

Then, if the preferred channel synchronous detection signal from the priority channel synchronization signal detector 1231 is output, if the number of bits K ₁ of the first hopping is not 0, based on the priority channel synchronous detection signal, the first hopping The frequency spectrum of each slot that constitutes is specified and output. Then, if the number of bits K ₁ of the second hopping is not 0, the frequency spectrum of each slot constituting the second hopping is specified and output based on the priority channel synchronization detection signal (see FIG. 3B). .

Further, when the CSMA synchronization detection signal is output from the CSMA synchronization signal detection unit 1233 in a state where the priority channel synchronization detection signal is not output from the priority channel synchronization signal detection unit 1231, the number of bits K ₁ of the first hopping is If it is not 0, the frequency spectrum of each slot constituting the first hopping is specified and output based on the CSMA synchronization detection signal. If then, the number of bits K ₁ of the second hopping is not 0, based on the CSMA synchronization detection signal, identify and outputs the frequency spectrum of each slot constituting a second hopping (see Figure 3 (A)).

  Returning to FIG. 4, the description will be continued. The FH-MMMFSK demodulator 124 converts the FH-MMMFSK signal of the used channel output from the communication frame detector 123 into received data and outputs the received data to the information processing apparatus 2.

FIG. 12 is a schematic diagram of the FH-MMMFSK demodulator 124. As illustrated, the FH-MMMFSK demodulation unit 124 includes a level / tone conversion table storage unit 1241, a tone / level conversion unit 1242, a hopping pattern storage unit 1243, a plurality of subtraction units 1244 _{1 to} 1244 _n , and a plurality of subtraction units 1244 _{1 to} 1244 _n . Residue calculating units 1245 _{1 to} 1245 _n , a majority decision determining unit 1246, and a P / S (Parallel / Serial) converting unit 1247.

  The level / tone conversion table storage unit 1241 stores a level / tone conversion table registered in the level / tone conversion table storage unit 1118 in association with the predetermined number of bits for each of a plurality of predetermined different numbers of bits. The same table is registered.

The tone / level conversion unit 1242 acquires the number of bits K ₁ associated with each of the first and second hoppings constituting the payloads 312 and 322 from the used channel configuration information received from the used channel setting unit 13 described later. . Next, if the number of bits K ₁ associated with the first hopping is not 0, the level / tone conversion table stored in the level / tone conversion table storage unit 1241 is associated with the number of bits K _1. The tone combination (frequency spectrum) of each slot for one hopping first output from the communication frame detection unit 123 is converted into a level and output to the subtraction units 1244 _{1 to} 1244 _n together with the bit number K ₁ . Next, if the bit number K ₁ associated with the second hopping is not 0, the level / tone conversion table stored in the level / tone conversion table storage unit 1241 is associated with the bit number K _1. used, output from the communication frame detecting unit 123 to the second (However, if the number of bits K ₁ associated with the first hopping is 0 is output first) tone combinations of each slot of one hopping component Is converted into a level and output to the subtracting units 1244 _{1 to} 1244 _n together with the bit number K ₁ .

  The hopping pattern storage unit 1243 stores, for each of a plurality of different predetermined levels, the same group as the hopping pattern group registered in the hopping pattern storage unit 1114 in association with the number of levels.

Subtraction units 1244 _{1 to} 1244 _n are provided in the same number as the number of hopping patterns in the hopping pattern group having the largest number of hopping patterns among the hopping pattern groups stored in hopping pattern storage unit 206 (referred to as the maximum hopping pattern group). It has been. Further, each of the subtraction units 1244 _{1 to} 1244 _n is provided for each value corresponding to each hopping pattern belonging to the maximum hopping pattern group, and the bit data of the number of bits K ₁ output from the tone / level conversion unit 1242 is obtained. A hopping pattern having a value associated with its own subtracting units 1244 _{1 to} 1244 _n is read from the hopping pattern group stored in the hopping pattern storage unit 206 in association with the number of levels that can be taken, and the read hopping and pattern level, the level of 1 hopping worth of slots outputted from the tone / level conversion unit 1242 with the number of bits K ₁ is subtracted for each slot, and outputs the subtraction result with the number of bits K _1. Here, the bit number K ₂ is determined in the same manner as the relationship between the parallel data of the bit number K _{1 and} the parallel data of the bit number K ₂ output from the S / P conversion unit 1111 of the FH-MMMFSK modulation unit 111. Note that the subtraction unit 1244 ₁ of its own is added to the hopping pattern group stored in the hopping pattern storage unit 206 in association with the number of levels that the bit data of the bit number K ₁ output from the tone / level conversion unit 1242 can take. When there is no hopping pattern having a value associated with ˜1244 _n , the subtraction process is not performed. That is, the subtraction result is not output.

Remainder operation unit 1245 ₁ ~1245 _n, like the subtraction unit 1244 ₁ ~1244 _n, are provided in the same number as the hopping pattern number up hopping patterns. Further, each of the remainder calculation units 1245 _{1 to} 1245 _n is provided for each value (level) corresponding to each hopping pattern belonging to the maximum hopping pattern group, and subtraction units 1244 _{1 to} 1244 associated with the same value. If the subtraction result from the _n and the bit number K ₁ is output for subtraction result, it calculates the remainder of the maximum value of bit data of the bit number K ₁ can take. That is, when the subtraction result y, the maximum value of bit data of the bit number K ₁ can take is n, calculates the y (mod n). Then, the calculation result is output to the majority decision determining unit 1246 together with the bit number K ₁ .

The majority decision unit 1246 performs majority decision on the calculation result of one hopping slot output together with the number of bits K ₁ from each of the remainder calculation units 1245 _{1 to} 1245 _n , and includes the most slots having the same calculation result. The remainder calculation units 1245 _{1 to} 1245 _n that output the calculation results of the slots for one hopping are specified. Then, the bit data of the bit number K ₁ having a value corresponding to the calculation result (level) of the slot that is output most by the specified remainder calculation units 1245 _{1 to} 1245 _n is output. Further, bit data having a value associated with the specified remainder calculation units 1245 _{1 to} 1245 _n and having a bit number K ₂ determined according to the bit number K ₁ is output.

The P / S conversion unit 1247 uses the two parallel data output from the majority decision determination unit 1246 as one of the upper (or lower) bit data and the other as the remaining bit data (K ₁ + K ₂ ) bits. Converted to serial data (received data) and output.

  Further, the P / S conversion unit 1247 detects the transmission source address from the received data. Specifically, when the received data is CSMA channel data 313, the source address 3131 is detected. When the received data is priority channel data 323, the source address 3231 is detected. When the received data is CSMA channel data, the source address 3241 is detected. To do. Then, the detected transmission source address is notified to the communication frame detection unit 123.

Returning to FIG. 4, the description will be continued. For each predetermined number of tones, the use channel setting unit 13 sets the number of bits K ₁ (the number of levels) corresponding to the number of levels (= number of hopping patterns) that can be expressed by the number of tones and the number of slots constituting one hopping. A bit number K management table (not shown) in which is registered the number of bits necessary to represent the bit data. In addition, in the use channel setting unit 13, use channel type information indicating whether the priority channel is used for data transmission / reception or the CSMA channel is used is registered in advance. In addition, based on the priority channel synchronization detection signal sent from the communication frame detection unit 123, the use channel setting unit 13 operates the network system of this embodiment in either the CSMA single mode or the CSMA / priority channel mixed mode. Is detected (mode switching process). Further, the used channel setting unit 13 generates used channel configuration information based on the priority channel configuration information sent from the communication frame detecting unit 123 or the SN information stored in the SN table storage unit 15 (used channel configuration information). Configuration information generation processing).

  FIG. 13 is a flowchart for explaining the mode switching process of the used channel setting unit 13.

  When the use channel setting unit 13 receives the priority channel synchronization detection signal from the communication frame detection unit 123 (YES in S1301), the use channel setting unit 13 detects that the network system of the present embodiment is operating in the CSMA / priority channel mixed mode. (S1302). Then, the mode information indicating the CSMA / priority channel mixed mode is output to the communication frame generation unit 112 and the CSMA / CA control unit 14 together with the used channel type information registered in advance (S1303). Then, the measurement value of a timer (not shown) for measuring the duration of the non-reception state of the priority channel synchronization detection signal is reset (S1304).

  In addition, the used channel setting unit 13 sets a measured value of a timer (not shown) for measuring the duration of the non-reception state of the priority channel synchronization detection signal for a predetermined time (at least longer than the CSMA channel gap 3214). (S1305: YES), it is detected that the network system of this embodiment is operating in the CSMA single mode (S1306). Then, mode information indicating the CSMA single mode is output to the communication frame generation unit 112 and the CSMA / CA control unit 14 together with the used channel type information registered in advance (S1303). Then, the measurement value of a timer (not shown) for measuring the duration of the non-reception state of the priority channel synchronization signal is reset (S1304).

  FIG. 14 is a flowchart for explaining the used channel configuration information generation processing of the used channel setting unit 13.

  The used channel setting unit 13 determines whether the latest mode detected by the mode switching process (see FIG. 13) is the CSMA / priority channel mixed mode or the CSMA single mode (S1310). In the CSMA / priority channel mixed mode, the used channel setting unit 13 waits for the priority channel configuration information to be sent from the communication frame detection unit 123. If priority channel configuration information is received (YES in S1311), it is determined whether the pre-registered used channel type information is a priority channel or a CSMA channel (S1312). When the used channel type information is a priority channel, the used channel setting unit 13 uses the received priority channel configuration information as used channel configuration information, and generates a communication frame generation unit 112, an FH-MMMFSK modulation unit 111, a communication frame detection unit 123, And it outputs to FH-MMMFSK demodulation part 124 (S1313).

  On the other hand, when the used channel type information is the CSMA channel in S1312, the used channel setting unit 13 receives the received priority channel configuration for each hopping (first and second hopping) constituting the FH-MMMFSK signal of the payload 322. Each tone other than the tone used for the priority channel in the hopping specified by the information is specified. Then, each tone specified for each hopping is determined as a tone used for the CSMA channel in the hopping. For example, in the case of FIG. 3B, in the first hopping, the second tone, the third tone, the sixth tone, and the seventh tone are determined as the tones used for the CSMA channel, and in the second hopping, all the tones (the first tone) Tone to seventh tone) is determined as a tone used for the CSMA channel.

In addition, the used channel setting unit 13 manages the number of bits K in association with the number of tones used for the CSMA channel for each hopping (first and second hopping) constituting the FH-MMMFSK signal of the payload 322. specifying the number of bits K ₁ which is registered in the table. Then, CSMA channel configuration information including a tone and a bit number K ₁ used for the CSMA channel in each of the first and second hopping is created (S1314). Then, the used channel setting unit 13 uses the generated CSMA channel configuration information as used channel configuration information to the communication frame generating unit 112, the FH-MMMFSK modulating unit 111, the communication frame detecting unit 123, and the FH-MMMFSK demodulating unit 124. It outputs (S1315).

  When the determination result in S1310 is the CSMA single mode, the used channel setting unit 13 determines whether the used channel type information registered in advance is a priority channel or a CSMA channel (S1316). ). When the used channel type information is a CSMA channel, every tone is determined as a tone used for the CSMA channel for each hopping (first and second hopping) constituting the FH-MMMFSK signal of the payload 312. To do. For example, in the case of FIG. 3A, all tones (first to seventh tones) are determined as tones used for the CSMA channel in each of the first and second hopping.

In addition, the used channel setting unit 13 associates the number of bits described above with each hopping (first and second hopping) constituting the FH-MMMFSK signal of the payload 312 in association with the number of tones used for the CSMA channel in the hopping. The number K of bits registered in the K management table is specified. Then, first, the tone used for CSMA channel in each of the second hopping, creating a CSMA channel configuration information including the number of bits _{K 1} (S1319). Then, the use channel setting unit 13 outputs the generated CSMA channel configuration information as use channel configuration information to the communication frame generation unit 112, the FH-MMMFSK modulation unit 111, the communication frame detection unit 123, and the FH-MMMFSK demodulation unit 124. (S1320).

  On the other hand, when the used channel type information is the priority channel in S1316, the used channel setting unit 13 determines hopping using predetermined hopping (at least one of the first and second hopping) as the priority channel. Further, on the basis of the SN information of each tone stored in the SN table storage unit 15 in association with the transmission destination address of the priority channel data, the tone used when transmitting the priority channel data to the transmission destination address is determined. decide. For example, each tone whose SN indicated by the SN information is equal to or less than a predetermined threshold value is determined as a tone used in the priority channel. If the SN information associated with the transmission destination address of the priority channel data is not stored in the SN table storage unit 15, each predetermined tone is determined as a tone used in the priority channel.

Furthermore, specifying the number of bits K ₁ which is associated with the number of tones is registered in the number of bits K management table described above for use in the priority channel. Then, using the channel setting unit 13, hopping (first, second hopping) constituting the FH-MMMFSK signal payload 322 for each priority channels including tone used for priority channel in the hopping, the number of bits _{K 1} Configuration information is created (S1317). For example, in the case of FIG. 3B, in the first hopping, the tones used for the priority channel are the first tone, the fourth tone, the fifth tone, and the eighth tone, and the bit number K ₁ is, for example, 3 bits (the number of levels). = 8, see FIG. In the second hopping, there is no tone used for the priority channel, and the number of bits K ₁ = 0. Then, the used channel setting unit 13 uses the generated priority channel configuration information as used channel configuration information to the communication frame generation unit 112, the FH-MMMFSK modulation unit 111, the communication frame detection unit 123, and the FH-MMMFSK demodulation unit 124. Output (S1318).

  Returning to FIG. 4, the description will be continued. The CSMA / CA control unit 14 instructs the communication frame generation unit 112 on the transmission timing of the communication frames 310 and 320.

  FIG. 15 is a diagram for explaining the operation of the CSMA / CA control unit 14.

  The CSMA / CA control unit 14 determines whether the latest mode information received from the used channel setting unit 13 is the CSMA / priority channel mixed mode or the CSMA single mode (S1401).

  In S1401, in the CSMA / priority channel mixed mode, the CSMA / CA control unit 14 waits for a CSMA synchronization detection signal or a CSMA synchronization non-detection signal sent from the communication frame detection unit 123. When the CSMA synchronization detection signal is received (YES in S1402), the process returns to S1401. If a CSMA synchronization non-detection signal is received (YES in S1403), it is determined whether the used channel type information received from the used channel setting unit 13 is a priority channel or a CSMA channel (S1404). In the case of a priority channel, the process returns to S1401. In the case of the CSMA channel, a CSMA channel transmission instruction including designation of a time interval between the CSMA synchronization signal 3215 and the payload 322 is generated, and the CSMA channel transmission instruction is output to the communication frame generation unit 112 (S1405), and then to S1401 Return. Note that the time interval between the CSMA synchronization signal 3215 and the payload 322 includes the output timing of the CSMA synchronization non-detection signal (elapsed time from the start position of the CSMA channel gap 3214) and the total continuation of the CSMA channel gap 3214 and the SN detection signal 3213. Based on the time, the CSMA / CA control unit 14 calculates.

  On the other hand, in S1401, when the channel is a single channel, the CSMA / CA control unit 14 waits for a CSMA synchronization detection signal or a CSMA synchronization non-detection signal sent from the communication frame detection unit 123. If a CSMA synchronization detection signal has been received (YES in S1406), the process returns to S1401. If a CSMA synchronization non-detection signal is received (YES in S1407), it is determined whether the used channel type information received from the used channel setting unit 13 is a priority channel or a CSMA channel (S1408). In the case of the CSMA channel, a CSMA channel transmission instruction is output to the communication frame generation unit 112 (S1409), and the process returns to S1401. In the case of the priority channel, a priority channel transmission instruction is output to the communication frame generation unit 112 (S1410), and the process returns to S1401.

  FIG. 16 is a diagram illustrating an example of a flow of communication frames transmitted and received between the communication apparatuses 1 in the network system illustrated in FIG. In this figure, communication device A and communication device B communicate using a priority channel, communication device C and communication device D communicate using a CSMA channel, and communication device C and communication device D communicate with a CSMA channel. Use to communicate. Reference numeral 51 denotes all communication frames flowing on the communication medium 3 such as a power line, reference numeral 52 denotes a communication frame transmitted / received between the communication apparatuses A and B, and reference numeral 53 denotes between the communication apparatuses C and D. The reference numeral 54 represents a communication frame transmitted / received between the communication device E and the communication device F.

  As illustrated, in the CSMA single mode section 55, there is no communication device 1 that uses the priority channel. In this case, carrier sense (detection of the CSMA synchronization signal) is performed between the communication devices C to F whose use channel type information is set to the CSMA channel, and the communication devices C to F that have acquired the use of the CSMA channel A communication frame 310 including a CSMA channel header 311 and a payload 312 storing CSMA channel data 313 is transmitted on the communication medium 3. In the example illustrated in FIG. 16, first, the communication device E acquires the use of the CSMA channel and transmits the communication frame 310 to the communication device F, and then the communication device C acquires the use of the CSMA channel and performs communication. A communication frame 310 is transmitted to the device D.

  In the CSMA single mode, if a state in which the CSMA synchronization signal 3111 is not detected continues for a predetermined time after the communication frame 310 no longer exists on the communication medium 3, the communication device A that transmits transmission data using the priority channel The priority channel header 321 (excluding the CSMA synchronization signal 3215) and the payload 322 storing the priority channel data 323 are transmitted on the communication medium 3. As a result, a transition is made from the CSMA single mode section 55 to the CSMA / priority channel mixed mode section 56.

  In the CSMA / priority channel mixed mode, the communication devices C to F whose use channel type information is set to the CSMA channel performs carrier sense (detection of a CSMA synchronization signal) at the CSMA channel gap 3214 of the priority channel header 321. Then, the communication devices C to F that have acquired the use of the CSMA channel transmit the CSMA synchronization signal 3215 and the priority channel data 323 on the communication medium 3 specified by the priority channel synchronization signal 3211 of the priority channel header 321. A payload 322 storing CSMA channel data 324 synchronized with the stored payload 322 is transmitted. In the example illustrated in FIG. 16, first, the communication device C acquires the use of the CSMA channel, transmits the payload 322 to the communication device D, and then the communication device E acquires the use of the CSMA channel. A payload 322 is transmitted to F. A payload 322 storing priority channel data 323 and a payload 322 storing CSMA channel data 324 are multiplexed on the communication medium 3, thereby forming a communication frame 320.

  In the CSMA / priority channel mixed mode, the communication device B that receives transmission data using the priority channel separates and receives the priority channel data 323 from the communication frame 320. On the other hand, the communication devices D and F that receive transmission data using the CSMA channel receive the CSMA channel data 324 separately from the communication frame 320.

  The embodiment of the present invention has been described above.

  According to the present embodiment, the priority channel 323 is provided separately from the CSMA channel 324 so that both channels can be specified by the priority channel header 321 (CSMA / priority channel mixed mode). Further, carrier sense for acquiring the CSMA channel is performed by the CSMA channel gap 3214 provided in the priority channel header 321. In this way, a priority control technique using a multitone modulation method can be provided.

  In addition, this embodiment is not limited to said embodiment, Many deformation | transformation are possible within the range of the summary. For example, each configuration of the communication device 1 described above may be executed by hardware using an integrated logic IC such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA), or may be a DSP (Digital Signal). It may be executed by a computer such as a processor.

  In the above embodiment, the case where FH-MMMFSK is used as a multitone modulation method for modulating baseband using a plurality of tones has been described as an example. However, the present invention is a multitone modulation method other than FH-MMMFSK. The same applies to (FH-MMFSK, OFDM, etc.). Further, a competing channel method other than the CSMA method may be used.

FIG. 1 is a schematic diagram of a network system to which an embodiment of the present invention is applied. FIG. 2A is a diagram schematically showing a communication frame transmitted and received between the communication apparatuses 1 in the CSMA single mode. FIG. 2B is a diagram schematically showing a communication frame transmitted / received between the communication apparatuses 1 in the CSMA / priority channel mixed mode. FIG. 3A is a diagram schematically showing the FH-MMMFSK signal stored in the payload 312 of the communication frame 310 for the CSMA single mode. FIG. 3B is a diagram schematically showing the FH-MMMFSK signal stored in the payload 322 of the communication frame 320 for the CSMA / priority channel mixed mode. FIG. 4 is a schematic diagram of the communication device 1. FIG. 5 is a schematic diagram of the FH-MMMFSK modulation unit 111. FIG. 6 is a diagram schematically showing the level pattern 11121 output from the level converter 1112. FIG. 7 is a diagram schematically showing a hopping pattern 11141 stored in the hopping pattern storage unit 1114. FIG. 8 schematically shows a level / tone conversion table 11181 registered in the level / tone conversion table storage unit 1118. FIG. 9 is a diagram schematically showing a transmission spectrum 11171 for one hopping output from the level / tone conversion unit 1117. FIG. 10 is a schematic diagram of the communication frame generation unit 112. FIG. 11 is a schematic diagram of the communication frame detection unit 123. FIG. 12 is a schematic diagram of the FH-MMMFSK demodulator 124. FIG. 13 is a flowchart for explaining the mode switching process of the used channel setting unit 13. FIG. 14 is a flowchart for explaining the used channel information configuration process of the used channel setting unit 13. FIG. 15 is a diagram for explaining the operation of the CSMA / CA control unit 14. FIG. 16 is a diagram showing an example of the flow of communication frames transmitted and received between communication devices 1 in the network system shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Communication apparatus, 2 ... Information processing apparatus, 3 ... Communication medium, 11 ... Transmission part, 12 ... Reception part, 13 ... Use channel setting part, 14 ... CSMA / CA control part, 111 ... FH-MMMFSK modulation part, 112 ... Communication frame generation unit, 113 ... DA conversion unit, 114 ... AFE unit, 121 ... AFE unit, 122 ... AD conversion unit, 123 ... Communication frame detection unit, 124 ... FH-MMMFSK demodulation unit, 1111 ... S / P conversion unit Reference numeral 1112 ... level conversion section, 1113 ... pattern conversion section, 1114 ... hopping pattern storage section, 1115 ... addition section, 1116 ... remainder calculation section, 1117 ... level / tone conversion section, 1118 ... level / tone conversion table storage section, 1121 ... Payload generation unit, 1122... SN detection signal addition unit, 1123... IFFT unit, 1124. ... priority CH configuration information addition unit, 1126 ... priority channel synchronization signal addition unit, 1231 ... priority channel synchronization signal detection unit, 1232 ... priority channel configuration information detection unit, 1233 ... CSMA synchronization signal detection unit, 1234 ... FFT unit, 1235 ... SN detection unit, 1236 ... used CH extraction unit, 1241 ... level / tone conversion table storage unit, 1242 ... tone / level conversion unit, 1243 ... hopping pattern storage unit, 1244 ... subtraction unit, 1245 ... remainder calculation unit, 1246 ... majority decision Determination unit, 1247... P / S conversion unit

Claims (7)

A communication device using a multi-tone modulation method,
Transmitter for transmitting data using contention channel and non-contention channel, receiver for receiving data using contention channel and non-contention channel, tone (frequency) and slot (time) of channel used for data transmission / reception A use channel setting unit that sets a combination with a competing channel control unit,
The transmitter is
Multitone modulation means for multitone modulating data using a combination of a tone and a slot set by the use channel setting unit;
Communication frame generating means for generating a communication frame storing data that has been subjected to multitone modulation by the multitone modulation means;
AFE for transmission (Analog Front End) means for transmitting the communication frame generated by the communication frame generation means to a communication medium,
The receiver is
Receiving AFE means for receiving a modulated signal from the communication medium;
Communication frame detecting means for detecting a communication frame from the modulated signal output from the receiving AFE means;
Multi-tone demodulation means for demodulating multi-tone modulated data included in the communication frame detected by the communication frame detection means using a combination of a tone and a slot set by the used channel setting unit; Have
The use channel setting unit includes:
When a non-contention channel is preset as a channel used for data transmission / reception, a process for setting a combination of a tone and a slot allocated to the non-contention channel in the transmission unit and the reception unit, and a channel used for data transmission / reception When a contention channel is set in advance as the transmission unit and the reception unit, a process of setting a combination of a tone and a slot other than a combination of a tone and a slot allocated to a non-contention channel, and
The communication frame generation means includes
When a non-contention channel is set in advance, the multi-tone modulation is performed by a combination of a non-contention channel header including a non-contention channel header synchronization signal and a contention control space, and a tone and a slot set by the used channel setting unit. Generating a communication frame having a non-contention data portion including data that is multi-tone modulated by the means;
When a contention channel is set in advance, the multi-tone modulation is performed by a combination of a tone and a slot set in the used channel setting unit, which is multiplexed on a non-contention data portion of a communication frame existing on a communication medium A process of generating a competing data portion including data that has been subjected to multitone modulation by the means,
The contention channel controller is
When a contention channel is set in advance and no other carrier output is detected in the contention control space specified by the non-contention channel header synchronization signal of the communication frame existing on the communication medium, the contention A communication apparatus that instructs the transmitter to generate a data part. The communication device according to claim 1,
The communication frame generation means includes
When a non-contention channel is set, a communication frame including non-contention channel configuration information for specifying a combination of a tone and a slot assigned to the non-contention channel is generated in the non-contention channel header,
The use channel setting unit includes:
A combination of a tone and a slot allocated to a non-contention channel is specified based on non-contention channel configuration information included in a non-contention channel header of the communication frame detected by the communication frame detection means. Communication device. The communication device according to claim 1,
The communication frame generation means includes
A communication frame including a quality detection signal for measuring the quality of each tone used for multi-tone modulation is generated,
The use channel setting unit includes:
When a non-contention channel is set in advance, a combination of a tone and a slot to be assigned to the non-contention channel is determined based on a quality detection signal of the communication frame detected by the communication frame detection means. apparatus. A communication method using a multi-tone modulation method,
A communication device that transmits data (referred to as non-contention channel data) using a non-contention channel transmits a non-contention channel header including a non-contention channel synchronization signal and a contention control space on the communication medium, and The non-contention data portion for storing non-contention channel data that is multi-tone modulated using a combination of tone (frequency) and slot (time) assigned to the non-contention channel synchronization signal is synchronized with the transmitted non-contention channel synchronization signal. Send on the medium,
A communication device that transmits data (referred to as contention channel data) using a contention channel detects a non-contention channel header synchronization signal transmitted on the communication medium, and is identified by the detected non-contention channel header synchronization signal. When carrier sensing is performed in the contention control space and a contention channel is acquired, contention channel data that has been subjected to multi-tone modulation using a combination of tones and slots other than the tone and slot combinations assigned to non-contention channels The contention data part to be stored is transmitted on the communication medium in synchronization with the detected non-contention channel synchronization signal so as to be multiplexed with the non-contention channel data part transmitted on the communication medium. Communication method. The communication method according to claim 4,
A communication device that receives non-contention channel data detects a non-contention channel synchronization signal transmitted on the communication medium, and based on the detected non-contention channel synchronization signal, a non-contention data portion that transmits the communication medium Identify and demodulate multi-tone modulated non-contention channel data using the combination of tones and slots assigned to the non-contention channel from the identified non-contention data portion;
A communication device that receives contention channel data detects a non-contention channel synchronization signal transmitted on the communication medium, and identifies a contention data portion to be transmitted on the communication medium based on the detected non-contention channel synchronization signal. A communication method characterized by demodulating multi-tone modulated contention channel data using a combination of a tone and a slot other than a combination of a tone and a slot assigned to a non-contention channel from the identified contention data portion . The communication method according to claim 4 or 5, wherein
A communication device that transmits non-contention channel data or contention channel data includes a quality detection signal for measuring the quality of each tone used for multi-tone modulation included in the non-contention channel header, and transmits the quality detection signal on the communication medium.
A communication device that transmits non-contention channel data detects a quality detection signal transmitted on the communication medium, measures the quality of each tone used for multi-tone modulation based on the detected quality detection signal, And determining a combination of a tone and a slot to be used when transmitting non-contention channel data. The communication method according to claim 6, comprising:
A communication device that transmits non-contention channel data includes non-contention channel configuration information for specifying a combination of a tone and a slot assigned to the non-contention channel in a non-contention channel header and transmits the non-contention channel data on the communication medium. ,
A communication device that receives non-contention channel data and contention channel data detects non-contention channel configuration information transmitted on the communication medium, and is assigned to the non-contention channel and the contention channel using the detected non-contention channel configuration information. A communication method characterized by specifying a combination of a tone and a slot.

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