JP7161505B2 - Information communication system and information communication device - Google Patents

Description

The present invention relates to an information communication system and an information communication device for synchronizing a plurality of information communication devices through communication.

IEEE1588 Precision Time Protocol (PTP) of Non-Patent Document 1, for example, is known as a general time synchronization method between a plurality of information communication devices. In Non-Patent Document 1, a master device that has a reference time and a slave device that time synchronizes with the time of the master device are defined, and time synchronization packets are periodically exchanged between the master device and the slave device. Correct the time of the slave device.

Specifically, the transmission time of the master device and the reception time of the slave device of the packet transmitted from the master device to the slave device, and the transmission time of the slave device and the reception of the master device of the packet transmitted from the slave device to the master device Using the time, the slave device estimates and corrects the time offset, which is the time difference between the master device and the slave device.

"IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems." IEEE Standard 1588-2008.

Information transmitted and received between the master device and the slave device is frame information in which finite-length frames are continuous in time series. Each frame is processed from its head time according to the order in which it is arranged. However, even if time synchronization is performed between the master device and the slave device, it is not guaranteed that each frame will be processed correctly from the beginning time at the synchronized time.

In other words, if at least the synchronized time and the head time of the frame to be processed do not match, interference occurs between the frames and normal processing cannot be performed. For example, if the information is audio data, the audio cannot be reproduced. More preferably, common frames are processed at the same time between the devices, thereby preventing the occurrence of sound discrepancies between the devices.

In order to cope with this, it is conceivable to separately transmit and receive a frame synchronization signal to and from an external device, and synchronize the frame processing timings between the devices based on this synchronization signal. However, transmission and reception of the synchronizing signal puts pressure on the bandwidth, resulting in a decrease in communication speed.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and it is an object of the present invention to provide an information communication system and an information communication apparatus capable of synchronizing frames based on synchronization time.

The present invention is an information communication system for communicating information between a master device and a slave device, wherein the information includes a synchronization time, which is a time when the master device and the slave device are synchronized, and a certain length of time. frame information in which a plurality of frames are arranged in time series and each frame is given an index for identifying the arrangement order, and the master device and the slave device synchronize the processing timing of the frames. The frame synchronization unit has a frame timing calculation unit that obtains a frame timing, which is the start time of a frame to be synchronized, based on the synchronization time and the frame length, and the frame synchronization unit includes the frame an index calculation unit that obtains the index of a frame to be synchronized based on the length and the frame timing; The synchronization unit synchronizes the periodic timing and the frame timing based on timing information including periodic timing, which is a timing signal generated periodically, and time information uniquely corresponding to each periodic timing .

The present invention is an information communication device that communicates information with another information communication device, wherein the information is
Synchronization time, which is a time synchronized with another information communication device, and frame information in which a plurality of frames of a certain length are arranged in time series and each frame is given an index for identifying the order of arrangement. and a frame synchronization unit for synchronizing the processing timing of the frames, the frame timing calculation unit for obtaining frame timing, which is the head time of the frame to be synchronized, based on the synchronization time and the frame length. wherein the frame synchronization unit has an index calculation unit that obtains the index of the frame to be synchronized based on the frame length and the frame timing, and the frame information includes a plurality of indexes having a common sequence of the indexes. is a repetition structure in which frames are repeated, and the frame synchronization unit generates the period based on timing information including periodic timing, which is a timing signal that is periodically generated, and time information uniquely corresponding to each periodic timing. Synchronize the timing with the frame timing.

According to the present invention, it is possible to obtain an information communication system and an information communication apparatus capable of synchronizing frames based on synchronization time.

1 is a schematic diagram of an information communication system according to an embodiment; FIG. 1 is a functional block diagram of an information communication device that constitutes an information communication system according to an embodiment; FIG. 4 is a functional block diagram of a control unit according to the embodiment; FIG. FIG. 4 is a diagram showing a mode of communication for counting the number of clock pulses; It is a figure which shows the aspect of the communication for synchronizing the information communication system which concerns on embodiment. FIG. 4 is a diagram showing frame information; FIG. 4 is a diagram showing a mode of synchronization of frame timing; It is a figure which shows another aspect of communication for synchronizing the information communication system which concerns on embodiment. FIG. 4 is a diagram for explaining a mode of obtaining frame timing; FIG. FIG. 4 is a diagram for explaining a mode of obtaining a frame index; FIG. FIG. 4 is a diagram for explaining a mode of obtaining frame timing to be synchronized with period timing; It is an example of the operation|movement flowchart of time synchronization. It is an example of an operation flowchart of frame synchronization.

Hereinafter, an information communication system and an information communication device according to embodiments will be described with reference to the drawings.

[Constitution]
FIG. 1 is a schematic diagram of an information communication system 100 according to an embodiment. FIG. 2 is a functional block diagram of the information communication device 1 configuring the information communication system 100 according to the embodiment. FIG. 3 is a functional block diagram of the controller 70 of FIG.

The information communication system 100 according to the present embodiment is composed of a plurality of information communication devices 1, and each information communication device 1 is synchronized by information communication. The information communication device 1, which is a slave device, synchronizes with the information communication device 1, which is a master device. A master device is an information communication device 1 to be synchronized with another information communication device 1 in the information communication system 100 . A slave device is an information communication device 1 that synchronizes with another information communication device 1 that is a master device in the information communication system 100 . The slave device synchronizes with the master device through transmission and reception of synchronization information, which is information for achieving time synchronization from the master device to the slave device.

In the following description, the information communication device 1 serving as a master device is referred to as a master device 1a, and the information communication device 1 serving as a slave device is referred to as a slave device 1b. At least one slave device 1b may be provided for the master device 1a, but as shown in FIG. 1, a system including a plurality of slave devices 1b may be used.

The master device 1a and the slave device 1b communicate information by wire or wirelessly. As wireless communication, short-range wireless communication such as wireless LAN and Bluetooth (registered trademark) can be used. Here, an example in which the information communication device 1 achieves synchronization by transmitting and receiving information by wire will be described.

(Information communication device)
The information communication device 1 includes a computer, and the CPU executes a program stored in advance in a storage unit such as an HDD or SSD to perform necessary calculations in a control unit, which will be described later.

Specifically, as shown in FIG. 2, the information communication device 1 has a communication section 10, a clock 20, a clock 30, a counter 40, a storage section 50, an external interface 60, and a control section . For example, each unit 10 to 70 is configured as hardware. The control unit 70 may be configured by software including programs and data. It is possible to appropriately change the design of which part of the control unit 70 is configured as software.

The communication unit 10 transmits and receives information to and from another information communication device 1 . The communication section 10 has a transmitter 11 , a receiver 12 , a transmission timing detection section 13 and a reception timing detection section 14 .

The transmitter 11 is a device that transmits input information. Specifically, the transmitter 11 decomposes the information into the minimum components in time series and transmits the information to the outside. The information packet length (amount of communication information) is arbitrary and may differ for each communication. Information is input, for example, from an input unit that converts an audio signal input from a microphone into audio data. Note that a packet is a data unit in a layer different from a frame, which will be described later, and one frame is a set of one or more packets.

The receiver 12 is a device that receives information from the outside. Specifically, the receiver 12 reconstructs the information received from the outside of the information communication device 1 and is decomposed into the minimum components in time series, and outputs the reconstructed information to other components within the information communication device 1 . For example, it converts audio data into an audio signal and outputs it to an ear receiver or a reproducing unit that outputs to a speaker. Here, the information communicated by the information communication device 1, that is, the information transmitted by the transmitter 11 and the information received by the receiver 12 includes synchronization information, timing information, and frame information, which will be described later.

Information communication device 1 has both transmitter 11 and receiver 12 . In the case of wireless communication, the transmitter 11 and the receiver 12 may each be provided with an antenna, or a switch may be provided to share one antenna.

The transmission timing detection unit 13 detects transmission timing, which is the timing at which a predetermined information element position of information transmitted by the transmitter 11 is transmitted to the outside of the information communication apparatus 1 . The information element position is the position on the time series of the minimum component decomposed into time series. This transmission timing is detected based on the clock cycle of the clock 20 (in other words, the cycle of pulses generated by the clock 20), which will be described later. That is, the transmission timing is expressed based on an integer multiple of the clock period.

Also, the transmission timing detection unit 13 outputs the detection result to other components in the information communication device 1 . The information referred to here is, for example, a packet, and in this case, a predetermined information element position (hereinafter referred to as a predetermined information element position) is a bit position. For example, when the information is decomposed into eight minimum components in time series, the transmission timing detection unit 13 detects the timing at which the third information element position (bit position) is transmitted, It outputs the timing at which the position (bit position) was transmitted to the outside.

The reception timing detection unit 14 detects the reception timing, which is the timing at which the predetermined information element position of the information received by the receiver 12 is received from the outside of the information communication device 1 . This reception timing is detected based on the clock cycle of the clock 20 (in other words, the cycle of pulses oscillated by the clock 20), which will be described later. That is, the reception timing is expressed as an integral multiple of the clock period.

Also, the reception timing detector 14 outputs the detection result to other components in the information communication device 1 . For example, when information is decomposed into eight minimum components in time series, the reception timing detection unit 14 detects the timing at which the third information element position (bit position) is received, and detects the timing when the third information element position (bit position) is received. It outputs the timing at which the position (bit position) is received.

In the above example of the transmission timing and the reception timing, the position of the same minimum component is detected. is detected, and the reception timing detection unit 14 of the information communication device 1 serving as a receiver detects the eighth element. )), it is not necessary to detect the same position.

Also, the transmission timing may be detected before or after a specified time from the actual transmission timing. The reception timing may be detected before or after a specified time from the actual reception timing. These default values may be fixed within the communication unit, or set statically or dynamically from the outside.

The clock 20 oscillates at a predetermined frequency and outputs a signal for giving the operation timing of each part of the information communication device 1 . Thereby, each part in the information communication device 1 operates in synchronization with the clock 20 . The entire information communication device 1 may be synchronized with a single clock 20 all at once, or may be independently synchronized with a plurality of clocks 20 for each of a plurality of functional units. This clock 20 has an inherent finite oscillation frequency tolerance. That is, the clock 20 has an error (eg, 20 ppm) with respect to a predetermined oscillation frequency (eg, 10 MHz). As the clock 20, for example, a fixed-frequency oscillator such as a crystal oscillator can be used.

Even if the nominal frequency of the clock 20 is the same between the master device 1a and the slave device 1b, individual differences actually exist. That is, there is a frequency deviation between the frequencies of the clocks 20 of the master device 1a and the slave device 1b. The clock 20 may receive a frequency control signal from the outside and variably control the oscillation frequency corresponding to the signal.

The clock 30 keeps time using the output signal of the clock 20 as a source oscillation, and outputs the relative time since the start-up of the information communication device 1 . Clocking may be synchronized with the divided frequency of the input clock signal. The time is referred to in a prescribed unit, and this prescribed value may be fixed within the clock or set statically or dynamically from the outside. The output of the relative time of the clock 30 is performed, for example, in response to an external reference request. Note that the clock 30 can output an arbitrary epoch time, which will be described later. The counter 40 counts the number of pulses generated by the clock 20 (hereinafter referred to as the number of pulses).

The storage unit 50 is a recording medium such as an HDD, SSD, memory, register, or the like. The storage unit 50 stores information necessary for the control unit 70 to perform calculations. The time of the clock 30 corresponding to transmission timing or reception timing, which will be described later, is preferably stored in a recording medium that can be stored only by hardware access without CPU or software intervention. This is because jitter caused by software can be eliminated. Note that it is important not to suffer software jitter in associating the transmission/reception timing with the time, and after the transmission/reception timing and the time are associated, they may be stored in a low-speed access area.

The memory as the storage unit 50 inputs and outputs arbitrary information and stores the information in a designated storage area. Information is stored according to a storage request from the outside. At that time, information to be stored and a storage area are input. Information is referenced by a reference request from the outside. At that time, the storage area of the reference information is input, and the information in the storage area specified by the input is output. Information may be retained in memory only while the device is in operation, or may be permanent, including when the device is not in operation.

An external interface 60 (hereinafter also referred to as an external I/F 60) connects the inside and outside of the information communication device 1 and inputs/outputs arbitrary information. The information includes, for example, transmission/reception data and the time of the clock 30 . The external I/F 60 acquires information to be stored in the storage unit 50 from the outside, for example. Further, the external I/F 60 may acquire from the outside the time from the reception timing detected by the reception timing detection unit 14 to the transmission timing detected by the transmission timing detection unit 13, and use the obtained time in the scheduler 75 described later. .

Note that the master device 1a has at least an external I/F 60 that transmits synchronization information. The slave device 1b has an external I/F 60 that receives at least synchronization information. However, the master device 1a may have an external I/F 60 for receiving synchronization information, and the slave device 1b may have an external I/F 60 for transmitting synchronization information. Furthermore, the information communication device 1 may have a user interface such as a display device capable of controlling and displaying the internal state.

The control unit 70 controls the overall operation of each unit of the information communication device 1 . The control unit 70 has a common configuration and a different configuration between the master device 1a and the slave device 1b. The master device 1a does not need a configuration specific to the slave device 1b, and the slave device 1b does not need a configuration specific to the master device 1a. However, one information communication device 1 may have both the function as the master device 1a and the function as the slave device 1b. For example, the position of the master device 1a and the position of the slave device 1b may be reversed between the two information communication devices 1. FIG. Further, one information communication device 1 may function as a master device 1a in relation to another information communication device 1, and may function as a slave device 1b in relation to another information communication device 1 (master device 1a). . Therefore, the control unit 70 in FIG. 3 is shown as the information communication device 1 having both the function as the master device 1a and the function as the slave device 1b.

(Control section of master device)
The control unit 70 of the master device 1 a has a main control unit 71 , a transmission/reception data I/F 72 , a communication control unit 73 , a time recording unit 74 , a scheduler 75 , a counter control unit 76 and a count number transmission control unit 77 .

The main control section 71 cooperates with each section in the control section 70 and controls the operation of each section in the control section 70 . The transmission/reception data I/F 72 puts the information of the storage unit 50 and the external I/F 60 into a format that allows transmission/reception to/from the information communication apparatus 1 outside. Further, the transmission/reception data I/F 72 converts information received from the outside of the information communication device 1 into a format suitable for the control unit 70 and the storage unit 50 .

The communication control section 73 controls the operation of the communication section 10 . The communication control unit 73 inputs and outputs transmission/reception information between the communication unit 10 and the control unit 70 .

The time recording unit 74 associates the transmission timing of the predetermined information element position of the information transmitted by the transmission timing detection unit 13 with the time of the clock 30 at the transmission timing, and stores them in the memory of the storage unit 50 . For this association, for example, the time recording unit 74 receives a signal indicating that the transmission timing of the predetermined information element position of the transmitted information has been detected from the transmission timing detection unit 13, and refers to the time of the clock 30. , to associate the time and the transmission timing.

The time recording unit 74 also serves as a time addition unit that adds the time corresponding to the transmission timing to the information to be transmitted. The time recording unit 74 associates the reception timing of the predetermined element position of the information received by the reception timing detection unit 14 with the time of the clock 30 at the reception timing, and stores it in the memory, as in the transmission. In addition, the time recording unit 74 causes the transmitter 11 to transmit the time corresponding to the reception timing on the information.

Thus, in this embodiment, "time" refers to the time of the clock 30 corresponding to the detected transmission timing or reception timing of the predetermined information element position of the information, and "time" refers to the difference between the times. .

The scheduler 75 causes the transmitter 11 to transmit information on a preset schedule. For example, the scheduler 75 causes the transmitter 11 to transmit synchronization information at regular intervals. The constant interval is, for example, 1 second. The scheduler 75 manages the schedule from reception to transmission of information. That is, the scheduler 75 transmits information at preset transmission/reception intervals. The scheduler 75 changes, via the external I/F 60, the transmission interval, which is the interval from the transmission of information to the next transmission, or the reception/transmission interval, which is the interval from the reception of information to the transmission of information. can be

The counter control section 76 causes the counter 40 to count the number of pulses of the clock 20 . Specifically, as shown in FIG. 4, the master device 1a transmits the synchronization information to the slave device 1b at least twice at a transmission interval _ΔTm . At that time, the counter 40 is controlled by the counter control unit 76 to count the number of pulses of the clock 20 in the transmission interval _ΔTm of the synchronization information from the master device 1a to the slave device 1b. This transmission interval _ΔTm is, for example, 1 second.

The count number transmission control section 77 causes the transmitter 11 to transmit the number of pulses counted by the counter 40 and the counter control section 76 to the slave device 1b. The count number transmission control unit 77 causes the transmitter 11 to transmit information including, for example, the number of pulses.

(Control part of slave device)
The control unit 70 of the slave device 1 b has a main control unit 71 , transmission/reception data I/F 72 , communication control unit 73 , time recording unit 74 , scheduler 75 and time synchronization unit 800 . The time synchronization unit 800 performs time synchronization between the master device 1a and the slave device 1b. The time synchronization unit 800 includes a synchronization request unit 80, a frequency acquisition unit 82, a transmission/reception interval calculation unit 83, a reception/transmission interval calculation unit 84, a propagation time calculation unit 85, a time difference calculation unit 86, a synchronization control unit 87, and a timing information output unit 88. have Since the units 71 to 75 are the same as the units 71 to 75 of the master device 1a, their description is omitted.

The synchronization request unit 80 causes the transmitter 11 to transmit a signal requesting information for synchronizing with the master device 1a. The information for synchronizing with the master device 1a includes the number of pulses in the transmission interval _ΔTm , the transmission time of the synchronization information of the master device 1a for calculating the transmission interval _ΔTm , and the master device 1a for calculating the transmission/reception interval _Δts . It is the reception time of another synchronization information of the device 1a.

Note that the slave device 1b has a counter control section 76, like the master device 1a. The counter 40 is controlled by the counter control section 76 to count the number of pulses of the clock 20 in the reception interval _ΔTs of the synchronization information transmitted from the master device 1a to the slave device 1b. This reception interval _ΔTs is a time interval corresponding to the transmission interval _ΔTm .

The frequency acquisition unit 82 acquires the frequencies f _m and f _s from the number of pulses of the clock 20 in the transmission interval ΔT _m and the number of pulses of the clock 20 in the reception interval ΔT _s . Assuming that the number of pulses of the clock 20 in the transmission interval ΔT _m is the number of pulses of the clock 20 of the master device 1a in one second in the master device 1a, the number of pulses is the clock frequency _fm itself of the clock 20 of the master device 1a. be. Also, since the reception interval _ΔTs is a time interval corresponding to the transmission interval _ΔTm , the number of pulses of the clock 20 at the reception interval _ΔTs is the clock frequency _fs of the clock 20 of the slave device 1b itself.

The frequency acquisition unit 82 may convert the transmission interval ΔTm into the number of pulses per second even when the transmission interval _ΔTm is other than one second. For example, if the transmission interval _ΔTm is 10 ms, the frequency _fm is obtained by multiplying the number of pulses of the clock 20 of the master device 1a by 100, and the frequency fm is obtained by multiplying the number of pulses of the clock 20 of the slave device 1b by 100. _fs .

FIG. 5 is a diagram showing a mode of communication for time synchronization in the information communication system according to the embodiment. The transmission/reception interval calculator 83 calculates a transmission/reception interval _Δtm from when the master device 1a transmits the synchronization information to the slave device 1b until it receives the synchronization information transmitted from the slave device 1b. Specifically, the transmission/reception interval calculator 83 calculates the difference between the reception time of the synchronization information received from the slave device 1b and the transmission time of the synchronization information transmitted from the master device 1a to the slave device 1b. The transmission time and the reception time are the times included in the information transmitted from the master device 1a. The transmission time is added to the information by the time recording unit 74 functioning as the time adding unit of the master device 1a.

As shown in FIG. 5, the transmission/reception interval calculating section 84 calculates a transmission/reception interval _Δts from when the synchronization information is received from the master device 1a to when the synchronization information is transmitted to the master device 1a. Specifically, the transmission/reception interval calculator 84 obtains the transmission/reception interval _Δts from the difference between the transmission time of the synchronization information to the master device 1a and the reception time of the synchronization information from the master device 1a. The transmission/reception interval calculation unit 84 acquires the transmission time and the reception time from the storage unit 50 or the time recording unit 74 .

The propagation time calculator 85 calculates the propagation time _td of information transmitted between the master device 1a and the slave device 1b. The time difference calculator 86 calculates the time difference between the master device 1a and the slave device 1b based on the propagation time _td obtained by the propagation time calculator 85. FIG. Specifically, the time difference calculator 86 calculates the time difference by adding the propagation time and the transmission/reception interval _Δts . The time difference here is the interval _t0 from the transmission timing of the master device 1a to the transmission timing of the slave device 1b, as shown in FIG.

The synchronization control section 87 synchronizes the time based on the time difference obtained by the time difference calculation section 86 . Specifically, the synchronization control unit 87 corrects the clock value of the clock 30 of the slave device 1b based on the time difference. For example, the synchronization control section 87 may control the clock 30 itself to correct the time. Alternatively, the synchronization control unit 87 may control the clock 30 so that when the clock 30 outputs the time, the time is corrected for the time difference. In this way, the synchronization control unit 87 corrects the ticking of the clock 30 or the output time of the clock 30 based on the time difference, and the time difference is defined by the difference between the transmission timings of the master device 1a and the slave device 1b. , time difference control is synonymous with transmission timing control.

The timing information output section 88 outputs timing information. The timing information includes periodic timing, which is a timing signal that is periodically generated based on the synchronization time synchronized by the synchronization control section 87 . The cycle of the cycle timing is set to a constant value in advance. Also, the timing information includes time information uniquely corresponding to each cycle timing. The time information corresponds to synchronization time.

(Frame synchronization section)
Further, the control section 70 of the information communication device 1 has a frame synchronization section 900 as a common configuration for the master device 1a and the slave device 1b. The frame synchronization unit 900 synchronizes processing timings of frames of frame information.

As shown in FIG. 6, the frame information is information in which a plurality of frames of a certain length are arranged in time series and an index for identifying the arrangement order is given to each frame. The information communication device 1 divides the frame information into frames and processes them. For example, a frame to which 1 indicating the head index is added is referred to as frame 1 . Frame 1 is followed by frame 2, frame 3, . An example of the gap is the frame interval (interframe gap) that is used to indicate and detect unused states of Ethernet (registered trademark) transmission lines. BLE Inter Frame Spacing, which is used as a channel switching period, is also an example of a gap.

As the frame information, for example, audio data and video data can be used. Each frame is a bit string with a fixed length, that is, a fixed number of bits. Therefore, the processing time for each frame depends on the processing speed of the device. However, in this embodiment, the frame processing time corresponding to the frame length is fixed, and various calculations for frame synchronization are performed by dividing the time by the frame length. That is, in the following description, the frame length and the time length of the frame are synonymous. Also, a chronological collection of a series of frames is called a stream, and each information communication device 1 processes one or more streams. A stream in the information communication device 1 is an array of independent information, such as an audio stream and a video stream.

Frame information may be a repeating structure of a set of frames. A repeating structure of a set of frames is a structure in which a common index is repeated. For example, if the number of frames in the repeating structure is N, frames 1, 2, . . . N are followed by frames 1, 2, .

In frame synchronization, the head time of any frame in the frame information, that is, the frame head time is synchronized with timing information described later. The start time of a frame is the start time of frame processing. By synchronizing the frame head times with the timing information, frame synchronization can be realized by synchronizing the frame head times among the plurality of information communication devices 1 . Note that in the following description, the frame start time may be referred to as frame timing. Each frame may be processed sequentially at periodic timing intervals.

Based on the timing information and the frame information, the frame synchronization unit 900 synchronizes the processing timings of frames in which the information communication devices 1, that is, the master device 1a and the slave device 1b perform processing such as transmission/reception and input/output.

When desired processing is performed on a frame-by-frame basis in a plurality of devices, it is desirable that the frames are synchronized between the devices. Synchronization of frames refers to a state in which, in frame information processed between different information communication apparatuses 1, the difference between the start times of frames containing the same arbitrary timing falls within a certain range. Ensuring such a state is called frame synchronization. Note that the difference between the head times of the frames is called a frame phase difference. In FIG. 7, the head times of the frames of all the slave devices 1b are finally the same. However, the phase difference does not necessarily have to be 0, and a slight deviation is allowed as long as it is within a certain range.

The frame synchronization section 900 has a timing information reference section 90 , a frame timing calculation section 91 and an index calculation section 92 . The timing information reference section 90 refers to the timing information from the timing information output section 88 of the time synchronization section 800 . The frame timing calculator 91 obtains the head time of the frame to be synchronized, that is, the frame timing, based on the synchronization time and the frame length. Here, the synchronization time is obtained as time information in the timing information. The index calculator 92 obtains the index of the frame to be synchronized based on the synchronization time, frame length and frame timing. The frame timing calculation unit 91 and the index calculation unit 92 identify frame information on a frame-by-frame basis and carry out calculations.

Note that the control unit 70 may have a frequency deviation calculation unit. The frequency deviation calculator calculates the frequency deviation between clocks between transmission and reception or corresponds to the frequency deviation from the difference between the reception timing interval time associated with two information receptions and the transmission timing interval time associated with two corresponding information transmissions. Find the time difference. The time synchronization unit 800 may perform time synchronization including correction of the time difference corresponding to this frequency deviation.

[Operating principle]
The operating principle of time synchronization and frame synchronization by the information communication system 100 having the above configuration will be described with reference to FIGS. 5 to 13. FIG.

[Time synchronization]
First, time synchronization by the time synchronization unit 800 will be described. The time synchronization is performed by measuring the time difference of the clocks 20 between the information communication devices 1 and the information propagation time between the information communication devices 1 and correcting the time difference.

As shown in FIG. 5, the master device 1a transmits synchronization information to the slave device 1b, the slave device 1b receives the information after the propagation time, and after receiving the information, another synchronization information is transmitted to the master device 1a. Considering a situation in which data is transmitted and received by the master device 1a after passing through the same propagation time, the propagation time and the time difference are formulated. The synchronization information transmitted by the master device 1a and the other synchronization information transmitted by the slave device 1b are for the purpose of measuring the timing for synchronization. However, the contents of the synchronization information and the other synchronization information are arbitrary.

Here, the case where the information communication system 100 has a single clock domain, that is, the case where the clock frequency of the clock 20 of the master device 1a and the clock frequency of the clock 20 of the slave device 1b are the same frequency f will be described. . In this case, the time observed and calculated by each information communication device 1 can be used by the other information communication device 1 as it is.

As shown in FIG. 5, assuming that the propagation time td from the master device 1a to the slave device 1b and the propagation time _td from the slave device 1b to the master device _1a are the same, the propagation time _td is given by the formula Obtain as per (1).

Also, as described above, the time difference _t0 between the clocks 20 is the interval from the transmission timing of the master device 1a to the transmission timing of the slave device 1b. For this time difference _t0 , the formula (2) is established from FIG.

Therefore, the time difference _t0 between the clocks 20 is obtained as shown in Equation (3) using Equation (1).

As shown in FIG. 8, when the slave device 1b transmits other information to the master device 1a without waiting for information reception from the master device 1a, the interval _Δts from reception to transmission in the slave device 1b is Although it is a negative number, the equations (1) and (3) hold as in the case where the slave device 1b waits to receive information from the master device 1a and then transmits other information to the master device 1a.

The synchronization control unit 87 of the time synchronization unit 800 of the slave device 1b can time-synchronize with the master device 1a by repeatedly adjusting the clock frequency and the time so that _t0 becomes zero.

Propagation time and internal delay between transmission and reception timings can be ignored or corrected depending on system requirements. Further, the synchronization information may be transmitted from the slave device 1b instead of starting the transmission of the synchronization information from the master device 1a. Furthermore, although one interface is sufficient for information communication, a configuration in which multiple interfaces are used at the same time, such as independent implementation of transmission and reception interfaces, is also possible.

[Frame sync]
Next, frame synchronization by frame synchronization section 900 will be described. First, in each slave device 1b, synchronization is started at an arbitrary time, and when the synchronization is completed, frame synchronization cannot be performed unless the head time of the frame to be synchronized immediately after, that is, the frame timing _tk cannot be uniquely specified. I can't. Additionally, it may be desirable to uniquely identify the frame index k of the frame to be synchronized. Frame synchronization can be performed by inputting frame timing t _k and frame index k from an external device. However, in this embodiment, without obtaining such information from the outside, the frame timing t _k and the frame index k are obtained from the time synchronized by the time synchronization in each information communication device 1 by the processing described below. frame synchronization can be performed.

Here, when considering handling of time t, an arbitrary timing at which time t=0 is called an epoch. The time can be expressed in any epoch, but the epoch that is unified within the time synchronization system is used. If the subsystems use different epochs, they shall be converted to and from the unified epoch beforehand.

Similarly, the frame timing, which is the head time of the originating frame on the stream, is called a frame epoch. The frame epoch, which may be a virtual concept, uniquely corresponds to a desired time, and the first frame of the stream is started from that frame timing.

(function definition)
Define the necessary functions for frame synchronization. First, the function sgn(x) that returns 1 if the given value is positive and -1 if it is negative is formula (4).

A positive and negative symmetrical floor function sfl(x) is shown in Equation (5). In equation (5), [x] is the floor function that returns the largest integer less than or equal to x. That is, sfl(x) is a function that obtains the largest integer that is equal to or less than the absolute value of x, regardless of whether the original x is positive or negative, and returns it with the original positive or negative.

Also, a function smd(x, y) for obtaining a positive and negative remainder symmetrically is shown in Equation (6). This function obtains the remainder by subtracting from x the value obtained by multiplying the quotient (integer) obtained by dividing x by y and multiplying it by y. where y is greater than 0 and is a member of the set of integers N, ie y is a positive integer.

Note that, as a premise of the calculation, the time in each device is uniformly referred to in a predetermined unit time. Then, when a number below the decimal point appears as time in subsequent calculations, unit time conversion is performed so that the time is referred to as an integer.

(basic frame synchronization)
Basic frame synchronization, in which synchronization is performed at arbitrary frame epochs, will be described with reference to FIG.
(Calculation of frame timing)
First, calculation of the frame timing by the frame timing calculator 91 will be described. Assuming that the time length of the frame is constant at w _F , the frame epoch is uniformly negotiated within the information communication system 100 as t _FE . Then, the frame timing t _F(0) of the frame on the stream at time t after t _FE is given by equation (7). That is, as shown in FIG. 6, the remainder obtained by dividing the time from the frame epoch _tFE to time t by the time length _wF is the offset time from frame timing tF ₍₀₎ to time t. By subtracting this offset time from the time t, the time of the frame timing tF ₍₀₎ is obtained.

However, frame synchronization may be performed at arbitrary timing without the need to determine the frame epoch _tFE . In that case, equation (7) can be simplified by setting t _FE =0.

When the time t is the time when the time synchronization is completed, that is, the synchronization completion time, the frames for which the frame synchronization is possible are the frames with the frame timing after the processing time required for the frame synchronization has passed from the time t.

From the frame on the stream at time t, the frame timing t _F(x) after x frames can be obtained according to equation (8). That is, the frame timing tF _(x) can be calculated by adding the value obtained by multiplying the frame duration _wF by x to the frame timing tF ₍₀₎ .

Assuming that the processing time required for frame synchronization is _dsp , the following formula (9) holds for the number x of subsequent frames for which frame synchronization is possible. That is, the value obtained by adding the processing time _dsp to the offset time from frame timing tF ₍₀₎ to time t is smaller than the time length for x frames, that is, the value obtained by multiplying the time length _wF by x. As a result, the frame timing tF _(x) becomes the start time of the frame after the processing time _dsp required for the frame synchronization has elapsed from the completion time of the time synchronization.

The minimum value x _MIN of x, ie, the minimum value x _MIN of the number of frames x from the frame at time t, is obtained according to equation (10). That is, by adding 1 to the quotient (integer) obtained by dividing the value obtained by adding the processing time _dsp to the time from frame timing tF ₍₀₎ to time t by the time length _wF of the frame, the minimum Calculate the value x _MIN . The reason for adding 1 is that the starting index is 1. If the starting index is 0, no addition is necessary.

Assuming that the processing time required for frame synchronization is _{dsp, the relationship of equation (9) also holds for the minimum value xMIN of} the number of subsequent frames that enable frame synchronization. By substituting this minimum value x _MIN for x in equation (8), the frame timing t _{F (} x MIN) of the frame at which frame synchronization is possible at the shortest time from time t is obtained.

(Calculation of frame index)
Next, the process of calculating the frame index of the frame to be synchronized by the frame timing calculator 91 will be described with reference to FIG. This is done when frame synchronization requires specification of the frame index as well as the frame timing. First, let i _FE be the frame index of a frame whose frame timing matches the frame epoch t _FE in a frame-synchronized stream. It is also assumed that the frame index is sequentially increased by g between adjacent frames so that the subsequent frame of frame x is frame x+g. For example, g is 1 when the frame index is incremented by 1, such as 1, 2, 3, .

Here, the frame index _iF of the frame existing at time t, that is, the frame being processed is obtained according to equation (11). That is, the quotient (integer) obtained by dividing the time from the frame epoch t _FE to time t by the time length w _F of the frame is multiplied by g, and the frame index i _FE is added.

Note that equation (11) can be simplified by setting i _FE =0 if it is not necessary to negotiate the frame index of the frame whose frame timing coincides with the frame epoch t _FE .

Also, the frame index _{iF (x)} after x frames from iF is obtained according to equation (12). That is, the value obtained by multiplying x by the increment g is added to _iF .

Note that the frame index _iF(xMIN) of the frame timing tF( _xMIN ) of the frame that can be frame-synchronized at the shortest time from time t is obtained by substituting the minimum value _xMIN for x in equation (12).

As described above, basic frame synchronization is performed by obtaining the frame timing and frame index of a frame that can be frame-synchronized at time t.

(Frame synchronization that matches cycle timing and frame timing)
As described above, when the synchronization time is obtained as timing information together with the periodic timing, or when performing time synchronization based on a periodic signal such as the GNSS 1PPS time pulse, the periodic timing and the frame timing are matched. need arises.

Here, if the period of the periodic signal and the time length of the frame are the same, the period timing and the frame timing always match. However, when the period and the time length of the frame are different, the two timings match at least once in a plurality of timings. For this reason, it is necessary to determine in advance the timing at which the period timing and the frame timing are matched. Frame synchronization for matching the period timing and the frame timing will be described with reference to FIG.

Let the period of the periodic signal be _wc . Further, let t _CE be the time at which the frame epoch t _FE coincides with the desired periodic timing. That is, t _FE =t _CE . Here, if the cycle _wc and the frame time length _wF are not the same, the adjacent interval _wu between the timings at which the cycle timing and the frame timing match is obtained according to equation (13). However, the function lcm( , ) is a function that returns the least common multiple of two given numbers. That is, by _obtaining the least common multiple of the cycle wc and the frame time length _wF , the minimum cycle in which the start times of both coincide is obtained.

A period from when both timings match to when they match again is defined as an adjacent interval _wu . In the adjoining interval _wu , the time series of the time differences of both timings exhibits a fixed structure, and the common structure is repeated for each adjoining interval _wu .

In this repetitive structure, the number of frames N _u appearing in the stream is obtained according to equation (14). Note that N _u is an integer because it is obtained from equation (14), that is, by dividing the least common multiple of two numbers.

In the repetitive structure, the time difference between the frame timing of each frame appearing on the stream and its neighboring periodic timing is unique for each frame. Within such a repeating structure, it is useful to identify frames relative to each other. In FIG. 11, each frame is displayed as a relative frame. For identification of these relative frames, relative frame indices i _Fr(0) from 1 to N _u can be assigned, as shown in equation (15). In other words, the quotient (integer) obtained by dividing the remainder of dividing the time from time t _CE to time t where the frame epoch t _FE coincides with the desired periodic timing by the adjacent interval w _u by the time length w _F of the frame is Add 1. The reason why 1 is added is that the frame index is set to 1 instead of 0 when both timings match.

Therefore, the frame index i _Fr(x) , which is x frames after i _Fr(0) , can be obtained according to equation (16). It should be noted that, as in the basic frame synchronization described above, it is assumed that the frame index is sequentially increased by g between adjacent frames. That is, 1 is added to the remainder obtained by dividing the value obtained by subtracting 1 from i _Fr(0) and adding the value obtained by multiplying x by the increment g by N _u .

Therefore, the frame timing t _{Fr( x) in the frame i Fr(x)} can be calculated according to Equation (17). That is, the offset time from the latest time at which the cycle timing and the frame timing match to time t is obtained from the remainder obtained by dividing the time from time _tCE to time _t by the adjacent interval wu. Also, by multiplying the value obtained by subtracting 1 from the frame index _iFr(0) by the frame time length _wF , Find the offset time of . By subtracting the offset time from the latest time at which the cycle timing and frame timing match to time t from the latest time at which cycle timing and frame timing match to the start time of the frame immediately before time t. , the offset time from the top time of the frame immediately before time t to time t is obtained. Then, the value obtained by subtracting the offset time from the start time of the frame immediately before time t to time t from time t is added to the value obtained by multiplying the number of frames x by the time length _wF of the frame to obtain the frame timing. Determine t _Fr(x) .

Note that if there is no need to specify the relative frame index, the frame timing t _Fr(x) can also be obtained according to equation (18).

Assuming that the processing time required for frame synchronization is _dSP , the number x of succeeding frames that can be frame-synchronized satisfies the relationship of Equation (19). That is, the value obtained by adding the processing time d _SP to the offset time from the latest time at which the cycle timing and the frame timing match to the time t is smaller than the time length W _F x for x frames.

Regarding the processing time _dsp , the relationship of Equation (19) also holds true for the minimum value x _MIN of the number of succeeding frames for which frame synchronization is possible. The minimum value x _MIN of x, ie, the minimum value x _MIN of the number of frames x from the frame at time t, is obtained according to equation (20). That is, 1 is added to the quotient (integer) obtained by dividing the value obtained by adding the processing time _dSP to the offset time from the latest time at which the cycle timing and the frame timing match to time t by the time length _wF of the frame. By doing so, the minimum value x _MIN is calculated. The reason why 1 is added is that the leading index is 1, and if the leading index is 0, addition is unnecessary.

By substituting this minimum value x _MIN for x in equation (17) or (18), the frame timing of the shortest frame that can be frame-synchronized from time t is obtained. Also, by substituting the minimum value x _MIN into equation (16), the relative frame index at that time is obtained. If the periodic timing does not need to be negotiated and is arbitrary, Equations (15) to (20) can be simplified by setting t _CE =t _FE =0.

As described above, by using equations (16), (17), (18), and (19), the frame timing and relative frame index of a frame that can be frame-synchronized can be obtained at time t. . As a result, it is possible to perform frame synchronization that requires matching of the period timing and the frame timing.

In the above description, the frame index is finite on the premise that the frame information has a repeating structure of a plurality of frames having a common index arrangement. However, the relative frame index i _Fr(0) can also be converted to a unique frame index on the stream. In this case, if i _FE is the frame index of a frame whose frame timing matches the frame epoch, a unique frame index i _F can be obtained as shown in Equation (21). Again, the frame index increment between adjacent frames is g. That is, the quotient (integer) obtained by dividing the time from time t _CE to time t by the adjacent interval w _u is multiplied by the number of frames N _u , and the value obtained by subtracting 1 from the relative frame index i _Fr(0) is to add. By multiplying this by the increment g and adding the frame index i _FE , the unique frame index i _F can be calculated.

Note that a unique frame index i _F(x) , which is x frames after i _F , can be obtained as in Equation (12). Such a unique frame index is not frame information generated in real time, for example, but like recorded data, the head position is determined, and it is necessary to synchronize the uniquely determined frame index from there. suitable for the occasion.

[motion]
The operation of the information communication system 100 of this embodiment will be described with reference to FIGS. 12 and 13. FIG. FIG. 12 is an example of a flowchart showing an operation procedure for time synchronization, and FIG. 13 is an example of a flowchart showing an operation procedure for frame synchronization.

As shown in FIG. 12, first, the slave device 1b transmits a signal requesting synchronization with the master device 1a (hereinafter also referred to as a synchronization request signal) to the master device 1a through the synchronization request unit 80 (step S101). : synchronous request).

When the master device 1a receives the synchronization request signal, the master device _1a transmits two pieces of synchronization information to the slave device 1b. The pulse number _pm is counted, and this pulse number pm is transmitted to the slave device _1b via the transmitter 11 (step _S102 : counting and transmitting the pulse number pm). The number of pulses _pm is obtained by the frequency obtaining unit 82 of the slave device 1b.

The slave device 1b receives two pieces of synchronization information from the master device 1a, and counts the number of pulses _ps of the clock 20 in the reception interval ΔT _s of the synchronization information by the counter 40 and the counter control unit 76 (step S103: count of pulse number p _s ). The number of pulses p _s is obtained by the frequency obtaining unit 82 . Here, the transmission interval _ΔTm is assumed to be 1 second. That is, since the pulse numbers p _m and p _s are the frequencies f _m and f _s , the frequency obtaining unit 82 obtains the frequencies f _m and f _s by obtaining the pulse numbers p _m and p _s . Since the two frequencies f _m and f _s are obtained in this way, the slave device 1b may perform a frequency synchronization function to synchronize its frequency f _s with the frequency f _m of the master device 1a.

Next, the synchronization information is transmitted and received between the master device 1a and the slave device 1b, and the transmission/reception interval Δtm and the transmission/reception interval _Δts are calculated (Step S104: Calculation of the transmission/reception interval _Δtm and the reception/transmission interval _{Δts )} . ).

Specifically, as shown in FIG. 5, the master device 1a transmits synchronization information to the slave device 1b. At that time, the time recording unit 74 puts the transmission time _tm1 corresponding to the transmission timing of the synchronization information on the synchronization information. The slave device 1b receives the synchronization information, and the transmission/reception interval calculator 83 acquires the transmission time _tm1 included in the synchronization information. Also, the reception/transmission interval calculator 84 acquires the reception time _ts1 of the synchronization information.

After receiving the synchronization information, the slave device 1b transmits other synchronization information to the master device 1a. The transmission/reception interval calculator 84 acquires the transmission time _ts2 at that time. The master device 1a receives the other synchronization information and transmits its reception time _tm2 to the slave device 1b. As a result, the transmission/reception interval calculator 83 acquires the reception time _tm2 .

Then, the transmission/reception interval calculator 83 obtains the transmission/reception interval _{Δtm by calculating the difference between the reception time tm2 of another synchronization information and the transmission time tm1 of the} synchronization information. The transmission/reception interval calculator 84 obtains the transmission/reception interval _Δts by calculating the difference between the transmission time _ts2 of another synchronization information and the reception time _ts1 of the synchronization information. The propagation time calculator 85 obtains the propagation time td based on the transmission/reception interval _Δtm and the transmission/reception interval _Δts (step S105: calculation of propagation time _{td )} .

The time difference calculator 86 calculates the time difference _t0s by adding the transmission/reception interval _Δts and the propagation time _tds calculated by the propagation time calculator 85 (step S106: calculation of time difference). Then, the synchronization control unit 87 corrects the time of the clock 30 of the slave device 1b based on the time difference _t0s calculated by the time difference calculation unit 86, and synchronizes it with the master device 1a (step S107: time synchronization). For example, if the time difference t _0s >0, the synchronization control unit 87 determines the time obtained by subtracting the time difference t _0s from the time output by the clock 30 of the slave device 1b as the time of the slave device 1b.

(frame synchronization)
In frame synchronization, the frame timing calculator 91 obtains the frame timing tF(x) corresponding to the head time of the frame to be synchronized. That is, as shown in FIG. 13, the frame timing calculation unit 91 calculates the frame timing _tF , which is the head time of the frame on the stream at time t, based on the time t, which is the time when synchronization is completed, and the frame length _wF . ₍₀₎ is obtained (step 201: calculation of frame timing tF ₍₀₎ ).

Then, the frame timing calculator 91 obtains the minimum number of frames x _MIN that can be frame-synchronized, which is the number of frames following the frame timing t _F(0) (step 202: calculation of the minimum number of frames x _MIN ). The term “frame synchronizable” as used herein refers to a frame after the processing time d _SP required for frame synchronization has elapsed from time t. Further, the frame timing calculator 91 obtains the frame timing _tF(XMIN) , which is the start time of the frame after the minimum number of frames x _MIN , from the frame timing tF( ₀ ) (step 203: frame timing _{tF(XMIN )} calculation)

Next, the index calculator 92 obtains the index of the frame to be synchronized. That is, the index calculator 92 obtains the frame index _iF of the frame at the time t based on the time t and the frame length _wF (step 204: frame index _iF calculation). Then, the index calculator 92 obtains the frame index iF( _{XMIN )} after the minimum number of frames _XMIN from the frame index iF (step 205: frame index _iF(XMIN) calculation). The slave device 1b synchronizes the frame processing by processing the frame of the frame index iF _{( XMIN)} at the frame timing tF(XMIN) thus calculated (step 206: frame synchronization).

[effect]
(1) The information communication system 100 of the embodiment is an information communication system 100 that performs information communication between the master device 1a and the slave device 1b, and the information is synchronized between the master device 1a and the slave device 1b. It includes synchronization time, which is time, and frame information in which a plurality of frames of a certain length are arranged in time series and each frame is given an index for identifying the arrangement order.

The master device 1a and the slave device 1b have a frame synchronization unit 900 for synchronizing frame processing timing. It has a frame timing calculator 91 for obtaining timing.

Further, the information communication device 1 of the embodiment has a frame synchronization unit 900 for synchronizing frame processing timing. It has a frame timing calculator 91 for obtaining the corresponding frame timing.

Therefore, even if there is no frame synchronization signal from an external device, the frame timing can be synchronized based on the synchronization time, and interference between frames can be prevented. Therefore, the device configuration required for frame synchronization can be simplified. In addition, there is no need to communicate frame synchronization signals, unnecessary communication bands can be reduced, and a decrease in communication speed can be suppressed.

(2) The frame synchronization section 900 has an index calculation section 92 that obtains the index of the frame to be synchronized based on the frame length and frame timing. Therefore, it is guaranteed that frames common to each device are processed at the same time by synchronizing the frame index in each device. Therefore, there is no need for complicated frame adjustment work, such as the case where information about which frame is to be synchronized is sent and received between the devices for adjustment.

(3) The frame synchronization section 900 selects a frame to be synchronized as a frame after the synchronization processing time by the frame synchronization section 900 from the synchronization time. Therefore, it is possible to guarantee synchronization with a synchronizable frame. By using the minimum value x _MIN as described above, frame synchronization can be achieved in a short time.

(4) The frame information has a repeating structure in which a plurality of frames having a common index sequence are repeated. Therefore, it is suitable for processing information that repeatedly uses a finite index, such as frame information that is generated in real time.

(5) The frame synchronization unit 900 synchronizes the periodic timing and the frame timing based on timing information including periodic timing, which is a timing signal generated periodically, and time information uniquely corresponding to each periodic timing. Therefore, frame synchronization can be performed by obtaining timing information from the outside. It should be noted that the time synchronization unit 800 may be omitted when timing information is supplied from the outside.

[Other embodiments]
The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the scope of the present invention at the implementation stage. Further, various inventions can be formed by appropriate combinations of the plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments.

If the synchronization time is obtained, frame synchronization can be executed. Therefore, by obtaining the synchronization time from an external clock source, the time synchronization unit 800 may be omitted, or the timing information may be obtained from the outside. The output section 88 may be omitted.

100 Information communication system 1 Information communication device 1a Master device 1b Slave device 10 Communication unit 11 Transmitter 12 Receiver 13 Transmission timing detection unit 14 Reception timing detection unit 20 Clock 30 Clock 40 Counter 50 Storage unit 60 External interface 70 Control unit 71 Main Control unit 72 Transmission/reception data I/F
73 communication control unit 74 time recording unit 75 scheduler 76 counter control unit 77 count number transmission control unit 800 synchronization control unit 80 synchronization request unit 82 frequency acquisition unit 83 transmission/reception interval calculation unit 84 transmission/reception interval calculation unit 85 propagation time calculation unit 86 time difference calculation unit 87 synchronization control unit 88 timing information output unit 900 frame synchronization unit 90 timing information reference unit 91 frame timing calculation unit 92 index calculation unit

Claims (4)

An information communication system for communicating information between a master device and a slave device,
Said information is
a synchronization time that is the time when the master device and the slave device are synchronized;
Frame information in which a plurality of frames of a certain length are arranged in chronological order and each frame is given an index for identifying the arrangement order;
including
The master device and the slave device are
a frame synchronization unit for synchronizing the processing timing of the frame;
The frame synchronization unit has a frame timing calculation unit that obtains a frame timing, which is the head time of a frame to be synchronized, based on the synchronization time and the frame length ,
The frame synchronization unit has an index calculation unit that obtains the index of the frame to be synchronized based on the frame length and the frame timing,
the frame information has a repeating structure in which a plurality of frames having a common sequence of indices are repeated;
The frame synchronization unit synchronizes the periodic timing and the frame timing based on timing information including periodic timing, which is a timing signal generated periodically, and time information uniquely corresponding to each periodic timing. An information communication system characterized by: 2. The information communication system according to claim 1 , wherein said frame synchronization section sets the frame to be synchronized to a frame after the synchronization processing time by said frame synchronization section from said synchronization time. An information communication device that communicates information with another information communication device,
Said information is
Synchronization time, which is time synchronized with another information communication device;
Frame information in which a plurality of frames of a certain length are arranged in chronological order and each frame is given an index for identifying the arrangement order;
including
a frame synchronization unit for synchronizing the processing timing of the frame;
The frame synchronization unit has a frame timing calculation unit that obtains a frame timing, which is the head time of a frame to be synchronized, based on the synchronization time and the frame length ,
The frame synchronization unit has an index calculation unit that obtains the index of the frame to be synchronized based on the frame length and the frame timing,
the frame information has a repeating structure in which a plurality of frames having a common sequence of indices are repeated;
The frame synchronization unit synchronizes the periodic timing and the frame timing based on timing information including periodic timing, which is a timing signal generated periodically, and time information uniquely corresponding to each periodic timing. An information communication device characterized by: 4. The information communication apparatus according to claim 3 , wherein said frame synchronization section sets the frame to be synchronized to a frame after the synchronization processing time by said frame synchronization section from said synchronization time.

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