WO2022244156A1 - Measuring device, measuring method, and time synchronization system - Google Patents

Abstract

A measuring device (40) according to the present disclosure includes: a UTC acquisition unit (41) that acquires a reference time from a satellite signal; a GMC time acquisition unit (42) that acquires time information of an intra-device time of a first device having a master function; a UTC-GMC offset calculation processing unit (43) that calculates an offset between a UTC and a GMC; a GMC-BC offset calculation processing unit (44) that calculates an offset between the GMC and a BC; a BC-client offset calculation processing unit (45) that calculates an offset between the BC and a client; and a time accuracy calculation processing unit (46) that measures accuracy of the intra-device time of each of a plurality of devices on the basis of the offset between the UTC and the GMC, the offset between the GMC and the BC, and the offset between the BC and the client.

Description

Measuring instrument, measuring method and time synchronization system

The present disclosure relates to measuring instruments, measuring methods, and time synchronization systems.

The PTP (Precision Time Protocol) defined by the IEEE-1588 standard is a protocol that synchronizes the time (device time) of computers on a LAN (Local Area Network) with high accuracy (see Non-Patent Document 1). FIG. 15 is a diagram showing a configuration example of a conventional time synchronization system 1a that synchronizes the time of devices on a network using the PTP protocol.

The time synchronization system 1a shown in FIG. 15 includes a Grand Master Clock 100, a Boundary Clock 200, a client device 300, and a measuring device 400. Grand Master Clock 100 and Boundary Clock 200 can communicate via a network such as a LAN. Also, the Boundary Clock 200 and the client device 300 can communicate via a network such as a LAN.

The Grand Master Clock 100 includes a GNSS antenna that receives signals (GNSS signals) from satellites of a global navigation satellite system (GNSS) such as GPS (Global Positioning System). The Grand Master Clock 100 receives GNSS signals via a GNSS antenna and obtains Universal Time Coordinated (UTC) from the received GNSS signals. The Grand Master Clock 100 has a master function that distributes the acquired UTC as a reference time via a network.

The Boundary Clock 200 functions as a device with a slave function with respect to a higher-level device with a master function, and functions as a device with a master function with respect to a lower-level device with a slave function. In this embodiment, the Boundary Clock 200 functions as a device having a slave function to the Grand Master Clock 100 and functions as a device having a master function to the client device 300 . Therefore, the Boundary Clock 200 synchronizes the internal time of the Boundary Clock 200 with the time (reference time) distributed from the Grand Master Clock 100 by transmitting and receiving PTP packets to and from the Grand Master Clock 100 . Then, the Boundary Clock 200 distributes the internal device time to the client device 300 by transmitting and receiving PTP packets with the client device 300 .

The client device 300 has a slave function that synchronizes the internal time of the device with the time delivered from the device with the master function. In the time synchronization system 1a shown in FIG. 15, the client device 300 synchronizes the internal time of the device with the time distributed from the Boundary Clock 200. FIG. The client device 300 is, for example, a base station device in a mobile phone network.

As shown in FIG. 15, in a time synchronization system 1a in which a plurality of devices synchronizes the time, as a measurement method for measuring the accuracy of the internal time of each device (Boundary Clock 200 and client device 300) having a slave function, FIG. As shown in , the measuring device 400 synchronized with GNSS (synchronized with the time delivered by GNSS) is connected to each device, and the signal quality of the timing reference signal such as the 1PPS (Pulse Per Second) signal output by each device and the time delivered by GNSS (for example, see Non-Patent Document 2). The 1PPS signal is a signal output one pulse per second in synchronization with the internal time of the device. The 1PPS signal is input from each device to the measuring device 400 by connecting the measuring device 400 and each device with a coaxial cable, for example. Therefore, the Boundary Clock 200 and the measuring device 400a connected to the Boundary Clock 200 need to be installed within a range where connection by coaxial cable is possible, for example, within the same building. Also, the client device 300 and the measuring device 400b connected to the client 300 need to be installed within a range where they can be connected by a coaxial cable, for example, within the same building.

The conventional measurement method explained with reference to FIG. There is a constraint that the instrument 400 must be transported to the measurement site and the measurement performed before it is out of sync. Therefore, the conventional measurement method has the problem that prior preparation of the environment and a large amount of human labor are required in order to measure the accuracy of the time in the device. In addition, there is a problem that the measurement may be difficult due to the restriction that a GNSS antenna is required or the restriction that the measurement must be performed before the measuring device 400 is out of synchronization. In addition, it is necessary to connect the measuring device 400 to each device that measures the accuracy of the internal time, which is costly and time-consuming.

An object of the present disclosure, which has been made in view of the above-described problems, is to provide a measuring instrument and a measuring method capable of relaxing the above-described restrictions and more easily measuring the accuracy of the internal time of a plurality of devices. and to provide a time synchronization system.

In order to solve the above problems, a measuring instrument according to the present disclosure is a measuring instrument that measures the accuracy of the internal time of each of the plurality of devices with respect to a reference time in a plurality of devices that synchronize the internal time of the device, The plurality of devices includes a first device, a second device, and a third device, and the first device synchronizes the device internal time with the reference time, and lowers the device internal time by transmitting and receiving packets. and the second device has a master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception. wherein the third device has the slave function of synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception, and a first acquisition unit that acquires the reference time from a satellite signal and a second acquisition unit that acquires time information related to the device internal time of the first device, the reference time acquired by the first acquisition unit, and the time information acquired by the second acquisition unit a first calculation processing unit for calculating a first offset, which is the difference between the reference time and the internal time of the first device, and time stamp information indicating the time when the packet was transmitted and received between the devices, based on and a second calculation processing unit that calculates a second offset that is a difference in device internal time between the devices based on the acquired time stamp information; and a third calculation processing unit that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the offset.

Further, in order to solve the above problems, a measurement method according to the present disclosure is a measurement method using a measuring device that measures the accuracy of the internal time of each of a plurality of devices with respect to a reference time in a plurality of devices that synchronize the internal time of the device. wherein the plurality of devices includes a first device, a second device, and a third device, and the first device synchronizes the internal time of the device with the reference time, and transmits and receives packets to the The second device has a master function for distributing the internal time to a lower device, and the second device synchronizes the internal time with the time distributed from the higher device having the master function by transmitting and receiving packets with the master function. and the third device has the slave function of synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception, and acquires the reference time from the satellite signal. a step of obtaining time information relating to the internal time of the first device; and the reference time and the internal time of the first device based on the obtained reference time and the obtained time information. obtaining time stamp information indicating the time when the packet was transmitted and received between the devices, and based on the obtained time stamp information, performing intra-device processing between the devices calculating a second offset that is a difference in time; measuring the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset; including.

Further, in order to solve the above problems, the time synchronization system according to the present disclosure includes a plurality of devices that synchronize the device internal time, and the accuracy of the device internal time of each of the plurality of devices with respect to the reference time in the plurality of devices. and a measuring instrument for measuring, wherein the plurality of devices includes a first device, a second device and a third device, and the first device is within the device at the reference time The second device has a master function for synchronizing the time and distributing the internal time to a lower device by packet transmission and reception, and the second device receives the master function and the upper device having the master function by packet transmission and reception. and a slave function for synchronizing the internal time with the distributed time, and the third device has the slave function for synchronizing the internal time with the time distributed from the second device by packet transmission/reception. , said measuring instrument is
a first acquisition unit that acquires the reference time from a satellite signal; a second acquisition unit that acquires time information related to internal time of the first device; and a reference time acquired by the first acquisition unit. , based on the time information acquired by the second acquisition unit, a first calculation processing unit that calculates a first offset that is a difference between the reference time and the device internal time of the first device; a second calculation for obtaining time stamp information indicating the time when the packet was transmitted and received between the devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information; a processing unit; and a third calculation processing unit that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.

According to the measuring instrument, measuring method, and time synchronization system according to the present disclosure, it is possible to more easily measure the accuracy of the internal time of multiple devices.

1 is a diagram illustrating a configuration example of a time synchronization system according to an embodiment of the present disclosure; FIG. It is a figure which shows the more detailed example of a structure of the time synchronous system shown in FIG. It is a figure showing the example of composition of the time synchronous system concerning another one embodiment of this indication. 4 is a diagram showing a more detailed configuration example of the time synchronization system shown in FIG. 3; FIG. 3 is a flow chart showing an example of the operation of the measuring instrument shown in FIG. 2; 6 is a diagram for explaining calculation of a GMC-BC offset by a GMC-BC offset calculation processing unit shown in FIG. 5; FIG. FIG. 11 is a diagram showing a configuration example of a time synchronization system according to yet another embodiment of the present disclosure; 8 is a diagram showing a more detailed configuration example of the time synchronization system shown in FIG. 7; FIG. FIG. 11 is a diagram showing a configuration example of a time synchronization system according to yet another embodiment of the present disclosure; 10 is a diagram showing a more detailed configuration example of the time synchronization system shown in FIG. 9; FIG. 9 is a flow chart showing an example of the operation of the measuring device shown in FIG. 8; FIG. 9 is a diagram for explaining calculation of a GMC-BC offset by a GMC-BC offset calculation processing unit shown in FIG. 8; FIG. 9 is a diagram for explaining transmission delay calculation by a transmission delay calculation processing unit shown in FIG. 8; It is a figure which shows an example of the hardware configuration of the measuring device which concerns on this indication. It is a figure which shows the structural example of the conventional time synchronous system.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of a time synchronization system 1 according to an embodiment of the present disclosure.

As shown in FIG. 1, the time synchronization system 1 according to this embodiment includes a Grand Master Clock 110, a Boundary Clock 20, a client device 30, and a measuring device 40.

The Grand Master Clock 10 as the first device receives GNSS satellite signals (GNSS signals) via the GNSS antenna. The Grand Master Clock 10 acquires UTC (reference time) from the received GNSS signal, and synchronizes the device internal time with the acquired UTC. The Grand Master Clock 10 has a master function of distributing the device internal time by sending and receiving PTP packets via the network 2 . In the time synchronization system 1 shown in FIG. 1, the Grand Master Clock 10 distributes the device internal time to the Boundary Clock 20 . Also, the Grand Master Clock 10 outputs a pulse signal (1PPS signal) at 1PPS to the measuring device 40 in synchronization with the device internal time.

The Boundary Clock 20 as a second device functions as a device with a slave function for a higher-level device with a master function, and functions as a device with a master function for a lower-level device with a slave function. In this embodiment, the Boundary Clock 20 functions as a device having a slave function with respect to the Grand Master Clock 10 and functions as a device having a master function with respect to the client device 30 . Therefore, the Boundary Clock 20 synchronizes the internal time of the Boundary Clock 20 with the time (reference time) delivered from the Grand Master Clock 10 by sending and receiving PTP packets with the Grand Master Clock 10 . Then, the Boundary Clock 20 distributes the device internal time to the client device 30 by sending and receiving PTP packets with the client device 30 .

Although FIG. 1 shows an example in which one Boundary Clock 20 is provided between the Grand Master Clock 10 and the client device 30, it is not limited to this. A plurality of Boundary Clocks 20 connected in series may be provided between the Grand Master Clock 10 and the client device 30 . In this case, the Boundary Clock 20 synchronizes the device internal time with the time distributed from the upper device (Grand Master Clock 10 or other Boundary Clock 20), and the lower device (other Boundary Clock 20 or client device 30) Distribute the time.

Also, the Boundary Clock 20 transmits time stamp information indicating the time when the PTP packet was transmitted and received between the Grand Master Clock 10 and the Boundary Clock 20 to the measuring instrument 40 via the network.

The client device 30 as the third device has a slave function. Specifically, the client device 30 synchronizes the device internal time with the time distributed from the Boundary Clock 20 by transmitting/receiving PTP packets to/from the Boundary Clock 20 . The client device 30 transmits time stamp information indicating the time when the PTP packet was transmitted and received between the Boundary Clock 20 and the client device 30 to the measuring device 40 via the network.

The measuring device 400 measures the accuracy of the internal time of each of the multiple devices that synchronize the internal time in the time synchronization system 1, that is, the Grand Master Clock 10, the Boundary Clock 20, and the client device 30. Specifically, the measuring device 40 acquires the reference time (UTC) from the GNSS signal received via the GNSS antenna. Also, the measuring instrument 40 acquires time information regarding the internal time of the Grand Master Clock 10 from the 1PPS signal output from the Grand Master Clock 10 . Also, the measuring device 40 acquires time stamp information transmitted from the Boundary Clock 20 and the client device 30 via the network. Based on the obtained reference time, time information, and time stamp information, the measuring device 40 measures the accuracy of the device internal time with respect to the reference time in each of the plurality of devices.

In the time synchronization system 1 shown in FIG. 1, the measuring device 40 acquires the 1PPS signal from the Grand Master Clock 10 and acquires time information from the acquired 1PPS signal. Therefore, the Grand Master Clock 10 and the measuring device 40 must be provided within a range where they can be connected by a coaxial cable that transmits a 1PPS signal, for example, within the same building.

Next, the configuration of the Boundary Clock 20, the client device 30 and the measuring device 40 will be described with reference to FIG. Note that the configuration of the Grand Master Clock 10 is the same as that of a device with a general master function that acquires the reference time from the GNSS signal and synchronizes the time in the device with the acquired reference time, so the explanation is omitted. .

First, the configuration of the Boundary Clock 20 will be explained.

As shown in FIG. 2, the Boundary Clock 20 includes packet transmission/ reception units 21 and 22, a time synchronization processing unit 23, and a time stamp transmission unit 24.

The packet transmission/reception unit 21 transmits/receives PTP packets to/from the Grand Master Clock 10 . The packet transmission/reception unit 22 transmits/receives PTP packets to/from the client device 30 .

The time synchronization processing unit 23 acquires the time delivered by the Grand Master Clock 10 from the PTP packets acquired from the Grand Master Clock 10 via the packet transmission/reception unit 21, and synchronizes the internal time of the Boundary Clock 20 with the acquired time.

The time stamp transmission unit 24 transmits time stamp information indicating the time when the PTP packet was transmitted and received between the packet transmission/reception unit 21 and the Grand Master Clock 10 to the measuring instrument 40 via the network. The Grand Master Clock 10 also stores part of the time stamp information of the PTP packets transmitted and received between the Grand Master Clock 10 and the Boundary Clock 20 . Therefore, the Grand Master Clock 10 may transmit the timestamp information to be saved to the measuring device 40 . Also, both the Grand Master Clock 10 and the Boundary Clock 20 transmit time stamp information to the measuring instrument 40, and the measuring instrument 40 receives the time stamp information transmitted from the Grand Master Clock 10 and the time stamp information transmitted from the Boundary Clock 20. may be compared.

Next, the configuration of the client device 30 will be described.

As shown in FIG. 2, the client device 30 includes a packet transmission/reception section 31, a time synchronization processing section 32, and a time stamp transmission section 33.

The packet transmission/reception unit 31 transmits/receives PTP packets to/from the Boundary Clock 20 .

The time synchronization processing unit 32 acquires the time delivered by the Boundary Clock 20 from the PTP packets received from the Boundary Clock 20 via the packet transmission/reception unit 31, and synchronizes the internal time of the client device 30 with the acquired time.

The time stamp transmission unit 33 transmits time stamp information indicating the time when the PTP packet was transmitted and received between the Boundary Clock 20 and the packet transmission/reception unit 31 to the measuring instrument 40 via the network. The time stamp information of the PTP packets transmitted and received between the Boundary Clock 20 and the client device 30 is partially stored in the Boundary Clock 20 as well. Therefore, the Boundary Clock 20 may transmit the timestamp information to be saved to the measuring device 40 . Also, both the Boundary Clock 20 and the client device 30 transmit time stamp information to the measuring device 40, and the measuring device 40 receives the time stamp information transmitted from the Boundary Clock 20 and the time stamp information transmitted from the client device 30. may be compared.

Next, the configuration of the measuring device 40 will be described.

As shown in FIG. 2, the measuring device 40 includes a UTC acquisition unit 41, a GMC time acquisition unit 42, a UTC-GMC offset calculation processing unit 43, a GMC-BC offset calculation processing unit 44, and a BC-client offset calculation unit. A processing unit 45 and a time accuracy calculation processing unit 46 are provided.

The UTC acquisition unit 41 as a first acquisition unit receives GNSS signals, which are satellite signals transmitted from GNSS satellites, via GNSS antennas. The UTC acquisition unit 41 acquires the reference time (UTC) from the received GNSS signal, and synchronizes the internal time of the measuring device 40 with the acquired time. The UTC acquisition unit 41 outputs the acquired reference time to the UTC-GMC offset calculation processing unit 43 .

The GMC time acquisition unit 42 as the second acquisition unit acquires time information regarding the internal time of the Grand Master Clock 10 as the first device. Specifically, the GMC time acquisition unit 42 acquires the time information from the 1PPS signal output from the Grand Master Clock 10 and output at 1PPS in synchronization with the internal time of the Grand Master Clock 10 . The GMC time acquisition unit 42 outputs the acquired time information to the UTC-GMC offset calculation processing unit 43 .

The UTC-GMC offset calculation processing unit 43 as a first calculation processing unit, based on the reference time acquired by the UTC acquisition unit 41 and the time information acquired by the GMC time acquisition unit 42, the reference time (UTC) and Grand A UTC-GMC offset (first offset), which is the difference from the internal time of the master clock 10, is calculated. The UTC-GMC offset calculation processing unit 43 outputs the calculated UTC-GMC offset to the time accuracy calculation processing unit 46 .

The GMC-BC offset calculation processing unit 44 as a second calculation processing unit is a time stamp indicating the time when the PTP packet was transmitted and received between the Grand Master Clock 10 and the Boundary Clock 20, which was transmitted from the Boundary Clock 10 via the network. Get information. The GMC-BC offset calculation processing unit 44 calculates the GMC-BC offset (second offset), which is the difference between the internal device time of the Grand Master Clock 10 and the internal device time of the Boundary Clock 20, based on the acquired time stamp information. do. The GMC-BC offset calculation processing unit 44 outputs the calculated GMC-BC offset to the time accuracy calculation processing unit 46 .

The BC-client offset calculation processing unit 45 as a second calculation processing unit is a time indicating the time when the PTP packet was transmitted and received between the Boundary Clock 20 and the client device 30, which is transmitted from the client device 30 via the network. Get stamp information. The BC-client offset calculation processing unit 45 calculates the BC-CL offset (second offset), which is the difference between the internal device time of the Boundary Clock 20 and the internal device time of the client device 30, based on the acquired time stamp information. do. The BC-client offset calculation processing unit 45 outputs the calculated BC-CL offset to the time accuracy calculation processing unit 46 .

In this way, the GMC-BC offset calculation processing unit 44 and the BC-client offset calculation processing unit 45 as the second calculation processing unit acquire time stamp information indicating the time when the PTP packet was transmitted and received between the devices, Based on the acquired time stamp information, a second offset (GMC-BC offset and BC-CL offset), which is the difference in device internal time between devices, is acquired. In addition, as described above, a plurality of Boundary Clocks 20 may be provided between the Grand Master Clock 10 and the client device 30 . In this case, an offset, which is the difference in device time between the two Boundary Clocks 20, may be calculated based on time stamp information indicating the times at which PTP packets were transmitted and received between the Boundary Clocks 20.

The time accuracy calculation processing unit 46 as a third calculation processing unit uses the UTC-GMC offset output from the UTC-GMC offset calculation processing unit 43, the GMC-BC offset output from the GMC-BC offset calculation processing unit 44 Based on the offset and the BC-CL offset output from the BC-client offset calculation processing unit 45, measure the precision of the internal time of each device (Grand Master Clock 10, Boundary Clock 20 and client device 30) with respect to the reference time. do.

As described above, in this embodiment, the measuring instrument 40 acquires the time stamp information from the Boundary Clock 20 and the client device 30, and uses the acquired time stamp information to calculate the internal time offset between the devices (the second offset ). Then, the measuring device 40 measures the accuracy of the device internal time of each device with respect to the reference time based on the UTC-GMC offset (first offset) and the device internal time offset (second offset) between the devices. . Therefore, it is not necessary to carry the measuring device 40 to the installation place of each device when performing the measurement. In addition, it is possible to alleviate restrictions such as the installation location of the GNSS antenna and bringing in the measuring instrument 400 synchronized with the reference time, as in the conventional time synchronization system 1a. Therefore, according to the measuring device 40 according to the present disclosure, it is possible to more easily measure the accuracy of the device internal time of a plurality of devices. In addition, according to the measuring instrument 40 according to the present disclosure, it is possible to remotely measure the accuracy of the internal time of each device, so maintenance can be quickly performed when a time error occurs.

In FIG. 1, the measuring device 40 has been described using an example in which the time information of the Grand Master Clock 10 is obtained from the 1PPS signal, but it is not limited to this.

FIG. 3 is a diagram showing a configuration example of a time synchronization system 1A according to another embodiment of the present disclosure, which uses a different method of acquiring time information from the time synchronization system 1 shown in FIG. In FIG. 3, the same components as in FIG. 1 are denoted by the same reference numerals, and descriptions thereof are omitted.

The time synchronization system 1A shown in FIG. 3 includes a Grand Master Clock 10A, a Boundary Clock 20, a client device 30, and a measuring device 40A. The time synchronization system 1A shown in FIG. 3 differs from the time synchronization system 1 shown in FIG. 1 in that the Grand Master Clock 10 is changed to a Grand Master Clock 10A and the measuring device 40 is changed to a measuring device 40A. .

The Grand Master Clock 10A transmits and receives PTP packets to and from the measuring instrument 40 via the network instead of transmitting 1PPS signals.

The measuring instrument 40A acquires the time information of the Grand Master Clock 10 by sending and receiving PTP packets with the Grand Master Clock 10A. The configuration of the measuring device 40A will be described with reference to FIG. In addition, in FIG. 4, the same reference numerals are assigned to the same configurations as in FIG. 2, and the description thereof is omitted.

As shown in FIG. 4, the measuring device 40A includes a UTC acquisition unit 41, a GMC time acquisition unit 42A, a UTC-GMC offset calculation processing unit 43, a GMC-BC offset calculation processing unit 44, and a BC-client offset calculation unit. It includes a processing unit 45 , a time accuracy calculation processing unit 46 and a packet transmission/reception unit 47 . A measuring instrument 40A shown in FIG. 4 differs from the measuring instrument 40 shown in FIG.

The packet transmission/reception unit 47 transmits/receives PTP packets to/from the Grand Master Clock 10A via the network, and outputs the PTP packets received from the Grand Master Clock 10A to the GMC time acquisition unit 42A.

The GMC time acquisition unit 42A acquires time information from the PTP packet received by the packet transmission/reception unit 47. The PTP packet contains a time stamp corresponding to the internal time of the Grand Master Clock 10A. The GMC time acquisition unit 42A acquires time information based on the time stamp included in the acquired PTP packet. That is, the GMC time acquisition unit 42A as a second acquisition unit acquires a PTP packet including a time stamp corresponding to the internal time of the Grand Master Clock 10A from the Grand Master Clock 10A via the network, and from the acquired PTP packet Get time information.

In the time synchronization system 1, since the measuring device 40 acquires time information from the 1PPS signal from the Grand Master Clock 10, the Grand Master Clock 10 and the measuring device 40 must be connected with a coaxial cable that transmits the 1PPS signal. Therefore, the Grand Master Clock 10 and the measuring device 40 need to be installed within a range where they can be connected with a coaxial cable, for example, within the same building. On the other hand, in the time synchronization system 1A, the Grand Master Clock 10A and the measuring device 40A should be able to transmit and receive PTP packets via the network. Therefore, it is possible to further relax the restrictions on the installation location and more easily measure the accuracy of the internal time of each of the plurality of devices.

Next, the operation of the measuring instrument 40 according to this embodiment will be described.

FIG. 5 is a flowchart showing an example of the operation of the measuring device 40 according to this embodiment, and is a diagram for explaining the measuring method by the measuring device 40. FIG.

The UTC acquisition unit 41 acquires the reference time (UTC) from the GNSS signal received from the satellite via the GNSS antenna (step S11).

The GMC time acquisition unit 42 acquires time information regarding the internal time of the Grand Master Clock 10 as the first device (step S12). In the time synchronization system 1 shown in FIG. 2 , the GMC time acquisition section 42 acquires time information from the 1PPS signal output from the Grand Master Clock 10 .

The UTC-GMC offset calculation processing unit 43 calculates the UTC-GMC offset (first offset) based on the reference time (UTC) obtained by the UTC obtaining unit 41 and the time information obtained by the GMC time obtaining unit 42. In the following it is assumed that the UTC-GMC offset is X seconds.

The GMC-BC offset calculation processing unit 44 acquires time stamp information indicating the time when the PTP packet was transmitted and received between the Grand Master Clock 10 and the Boundary Clock 20 from the Boundary Clock 20 via the network. The GMC-BC offset calculation processing unit 44 calculates a GMC-BC offset (second offset) based on the acquired time stamp information (step S14). In the following, it is assumed that the GMC-BC offset is Y seconds. Details of the calculation of the GMC-BC offset will be described later.

The BC-client offset calculation processing unit 45 acquires time stamp information indicating the time when the PTP packet was transmitted and received between the Boundary Clock 20 and the client device 30 from the client device 30 via the network. The BC-client offset calculation processing unit 45 calculates a BC-client offset (second offset) based on the acquired time stamp information (step S15). In the following, let the BC-client offset be Z seconds.

In FIG. 5, the process from step S11 to step S13, the process of step S14, and the process of step S15 are described as branching, but in reality, these processes are branched. It is executed sequentially.

The time accuracy calculation processing unit 46 measures the accuracy of the internal time of each device with respect to the reference time based on the UTC-GMC offset, the GMC-BC offset, and the BC-client offset (step S16). For example, the time accuracy calculation processing unit 46 calculates the difference (offset) between the reference time and the internal time of the client device 20 as the accuracy of the internal time of the client device 30 with respect to the reference time. Specifically, the time accuracy calculation processing unit 46 calculates the sum of the UTC-GMC offset (X seconds), the GMC-BC offset (Y seconds), and the BC-client offset (Z seconds) (X+Y+Z) , the offset between the reference time and the internal time of the client device 30 is calculated.

Next, calculation of the GMC-BC offset by the GMC-BC offset calculation processing unit 44 will be described with reference to FIG. In FIG. 6, the calculation of the GMC-BC offset is described as an example, but the BC-client offset can be calculated in the same manner.

First, the messages sent and received between the Grand Master Clock 10 and the Boundary Clock 20 according to the PTP will be explained. A message sent and received between the Grand Master Clock 10 and the Boundary Clock 20 consists of one or more PTP packets.

As shown in FIG. 6, Grand Master Clock 10 first sends a Sync message to Boundary Clock 20 (step S21). The Grand Master Clock 10 transmits to the Boundary Clock 20 a Sync message including a time stamp indicating time T1 (first time), which is the transmission time of the Sync message.

When the Boundary Clock 20 receives the Sync message transmitted from the Grand Master Clock 10 at time T2 (second time), it transmits a Delay_Req message to the Boundary Clock 10 at time T3 in response to the Sync message (step S22). . The time stamp transmission unit 24 holds a time stamp indicating the time T2 when the Sync message was received and a time stamp indicating the time T3 when the Delay_Req message was transmitted.

Upon receiving the Delay_Req message sent from the Boundary Clock 20 at time T4, the Grand Master Clock 10 sends a Delay_Resp message to the Boundary Clock 20 in response to the Delay_Req message (step S23). The Grand Master Clock 10 transmits to the Boundary Clock 20 a Delay_Resp message including a time stamp indicating time T4 (fourth time) at which the Delay_Req message was received.

The timestamp transmission unit 24 acquires the timestamp of the time T1 when the Grand Master Clock 10 transmitted the Sync message, which is included in the Sync message. Further, as described above, the time stamp transmission unit 24 holds a time stamp indicating the time T2 when the Sync message was received and a time stamp indicating the time T3 when the Delay_Req message was transmitted. Also, the time stamp transmission unit 24 acquires the time stamp indicating the time T4 when the Grand Master Clock 10 received the Delay_Req message, which is included in the Delay_Resp message. The time stamp transmission unit 24 transmits the acquired time stamp information indicating times T1 to T4 to the measuring device 40 .

The GMC-BC offset calculation processing unit 44 calculates the GMC-BC offset based on the time stamp information transmitted from the Boundary Clock 20 . Specifically, the GMC-BC offset is calculated by the following equation (1).
GMC-BC offset = ((T2-T1)-(T4-T3))/2

For example, if the GMC-BC offset is greater than a predetermined threshold, the time accuracy calculation processing unit 46 calculates the internal time of the Grand Master Clock 10 estimated from the GMC-BC offset and the actual Grand Master It can be determined that there is a large deviation from the internal time of the Clock 10 . However, the time accuracy calculation processing unit 46 cannot determine which value among the times T1 to T4 is not a normal value. Here, the Grand Master Clock 10 can acquire the times T1, T3, and T4. Therefore, the Grand Master Clock 10 may compare the acquired times T1, T3, T4 with the times T1, T3, T4 indicated in the time stamp information, and output the result of the comparison to the measuring device 40. . Based on the result of comparison by the Grand Master Clock 10, the time accuracy calculation processing section 46 can determine which value among the times T1 to T4 is not a normal value.

In the above-described embodiment, the measuring instruments 40 and 40A are explained using an example of acquiring time stamp information from the Boundary Clock 20 and the client device 30, but the present invention is not limited to this.

FIG. 7 is a diagram showing a configuration example of a time synchronization system 1B according to yet another embodiment of the present disclosure.

The time synchronization system 1B shown in FIG. 7 includes a Grand Master Clock 10B, a Boundary Clock 20B, a client device 30B, and a measuring device 40B.

The Grand Master Clock 10B receives the GNSS signal via the GNSS antenna, acquires the reference time (UTC) from the received GNSS signal, and synchronizes the internal time with the acquired reference time. The Grand Master Clock 10B distributes the acquired reference time to the Boundary Clock 20B by transmitting and receiving PTP packets to and from the Boundary Clock 20B. Also, the Grand Master Clock 10B outputs a 1PPS signal at 1PPS to the measuring device 40B in synchronization with the device internal time. In addition, the Grand Master Clock 10B outputs the PTP packet transmission delay between the Grand Master Clock 10B and the Boundary Clock 20B and the PTP packet transmission delay between the Boundary Clock 20B and the client device 30B to the measuring device 40B.

Boundary Clock 20B synchronizes the internal time of Boundary Clock 20B with the time (reference time) distributed from Grand Master Clock 10B by sending and receiving PTP packets with Grand Master Clock 10B. The Boundary Clock 20B distributes the device internal time to the client device 30B by transmitting and receiving PTP packets to and from the client device 30B.

The client device 30B synchronizes the internal time of the device with the time delivered from the Boundary Clock 20B by transmitting and receiving PTP packets to and from the Boundary Clock 20B.

The measuring instrument 40B acquires the 1PPS signal and transmission delay output from the Grand Master Clock 10B. Also, the measuring device 40B acquires a copy of the packets transmitted and received between the Grand Master Clock 10B and the Boundary Clock 20B. Also, the measuring device 40B obtains a copy of the PTP packets transmitted and received between the Boundary Clock 20B and the client device 30B. Therefore, in the time synchronization system 1B shown in FIG. 7, copy points for copying PTP packets are provided between the Grand Master Clock 10B and the Boundary Clock 20B and between the Boundary Clock 20B and the client device 30B. In the following, the acquisition of a copy of the PTP packet by the measuring device 40B via the copy point may simply be referred to as "acquiring the PTP packet."

The measuring device 40B acquires the time information of the Grand Master Clock 10B from the 1PPS signal output from the Grand Master Clock 10B. Also, the measuring device 40B acquires time stamp information from the acquired PTP packet. The measuring device 40B measures the accuracy of the internal time of each device with respect to the reference time based on the acquired time information, time stamp information, and transmission delay.

Next, the configurations of the Grand Master Clock 10B, Boundary Clock 20B, client device 30B and measuring device 40B will be described with reference to FIG. First, the configuration of the Grand Master Clock 10B will be described.

As shown in FIG. 8, the Grand Master Clock 10B includes a packet transmission/reception section 11, a 1PPS transmission section 12, a transmission delay measurement packet transmission/reception section 13, and a transmission delay calculation processing section .

The packet transmission/reception unit 11 transmits/receives PTP packets to/from the Boundary Clock 20B.

The 1PPS transmission section 12 outputs a pulse signal (1PPS signal) at 1PPS to the measuring device 40B in synchronization with the internal time of the Grand Master Clock 10B.

The transmission delay measuring packet transmitting/receiving unit 13 transmits/receives a packet (transmission delay measuring packet) for measuring the transmission delay between the Grand Master Clock 10B and the Boundary Clock 20B to/from the Boundary Clock 20B.

The transmission delay calculation processing unit 14 calculates the transmission delay between the Grand Master Clock 10B and the Boundary Clock 20B based on the transmission delay measuring packet transmitted and received by the transmission delay measuring packet transmitting/receiving unit 13. The transmission delay calculation processing unit 14 transmits the calculation result of the transmission delay to the measuring device 40B via the network. The transmission delay calculation processing unit 14 also transmits the calculation result of the transmission delay between the Boundary Clock 20B and the client device 30B, which is output from the Boundary Clock 20B described later, to the measuring device 40B via the network.

Next, the configuration of the Boundary Clock 20B will be explained.

As shown in FIG. 8, the Boundary Clock 20B includes packet transmission/ reception units 21 and 22, a time synchronization processing unit 23, transmission delay measurement packet transmission/ reception units 25 and 26, and a transmission delay calculation processing unit 27. Compared to the Boundary Clock 20 shown in FIG. 2, the Boundary Clock 20B shown in FIG. 8 is different from the Boundary Clock 20 shown in FIG. point is different.

The transmission delay measuring packet transmitting/receiving unit 25 transmits/receives the transmission delay measuring packet to/from the Grand Master Clock 10B. The transmission delay measuring packet transmitting/receiving unit 26 transmits/receives a transmission delay measuring packet to/from the client device 30B.

The transmission delay calculation processing unit 27 calculates the transmission delay between the Boundary Clock 20B and the client device 30B based on the transmission delay measurement packet transmitted and received to and from the client device 30B by the transmission delay measurement packet transmission and reception unit 26. . The transmission delay calculation processing unit 27 outputs the calculation result of the transmission delay to the Grand Master Clock 10B.

Next, the configuration of the client device 30B will be described.

As shown in FIG. 8, the client device 30B includes a packet transmission/reception section 31, a time synchronization processing section 32, a transmission delay measurement packet transmission/reception section 34, and a transmission delay calculation processing section 35. Compared to the client device 30 shown in FIG. 2, the client device 30B shown in FIG. 8 is different from the client device 30 shown in FIG. Points are different.

The transmission delay measuring packet transmitting/receiving unit 34 transmits/receives the transmission delay measuring packet to/from the Boundary Clock 20B.

The transmission delay calculation processing unit 35 calculates the transmission delay between the Boundary Clock 20B and the client device 30B based on the transmission delay measurement packet transmitted/received between the Boundary Clock 20B and the Boundary Clock 20B by the transmission delay measurement packet transmission/reception unit 34.

Next, the configuration of the measuring device 40B will be described.

As shown in FIG. 8, the measuring device 40B includes a UTC acquisition unit 41, a GMC time acquisition unit 42, a UTC-GMC offset calculation processing unit 43, a GMC-BC offset calculation processing unit 44B, and a BC-client offset calculation unit. A processing unit 45B and a time accuracy calculation processing unit 46 are provided. Compared to the measuring instrument 40 shown in FIG. 2, the measuring instrument 40B shown in FIG. 8 is different from the measuring instrument 40 shown in FIG. The difference is that the unit 45 is changed to a BC-client offset calculation processing unit 45B.

The GMC-BC offset calculation processing unit 44B acquires a copy of the PTP packets transmitted and received between the Grand Master Clock 10B and Boundary Clock 20B. Also, the GMC-BC offset calculation processing unit 44B acquires the calculation result of the transmission delay between the Grand Master Clock 10B and the Boundary Clock 20B output from the Grand Master Clock 10B. The GMC-BC offset calculation processing unit 44B acquires time stamp information from the acquired PTP packet, and calculates the GMC-BC offset based on the acquired time stamp information and transmission delay.

The BC-client offset calculation processing unit 45B acquires a copy of the PTP packets transmitted and received between the Boundary Clock 20B and the client device 30B. Also, the BC-client offset calculation processing unit 45B obtains the calculation result of the transmission delay between the Boundary Clock 20B and the client device 30B, which is output from the Grand Master Clock 10B. The BC-client offset calculation processing unit 45B obtains time stamp information from the obtained PTP packet, and calculates the BC-client offset based on the obtained time stamp information and transmission delay.

In FIG. 7, the measuring device 40 has been described using an example in which the time information of the Grand Master Clock 10 is obtained from the 1PPS signal, but it is not limited to this.

FIG. 9 is a diagram showing a configuration example of a time synchronization system 1C according to yet another embodiment of the present disclosure, which uses a different method of acquiring time information from the time synchronization system 1B shown in FIG. In FIG. 9, the same components as in FIG. 7 are denoted by the same reference numerals, and descriptions thereof are omitted.

A time synchronization system 1C shown in FIG. 9 includes a Grand Master Clock 10C, a Boundary Clock 20B, a client device 30B, and a measuring device 40C. The time synchronization system 1C shown in FIG. 9 differs from the time synchronization system 1B shown in FIG. 7 in that the Grand Master Clock 10B is changed to the Grand Master Clock 10C and the measuring device 40B is changed to the measuring device 40C. .

Instead of transmitting 1PPS signals, the Grand Master Clock 10C transmits and receives PTP packets to and from the measuring instrument 40C via the network.

The measuring instrument 40C acquires the time information of the Grand Master Clock 10C by transmitting and receiving PTP packets to and from the Grand Master Clock 10C. The configurations of the Grand Master Clock 10C and measuring device 40C will be described with reference to FIG. In addition, in FIG. 10, the same components as in FIG. 8 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 10, the Grand Master Clock 10C includes packet transmitting/receiving sections 11 and 15, a transmission delay measuring packet transmitting/receiving section 13, and a transmission delay calculation processing section . Grand Master Clock 10C shown in FIG. 10 differs from Grand Master Clock 10B shown in FIG.

The packet transmitting/receiving unit 15 transmits/receives PTP packets to/from the measuring instrument 40C via the network.

Next, the configuration of the measuring instrument 40C will be described.

As shown in FIG. 10, the measuring device 40C includes a UTC acquisition unit 41, a GMC time acquisition unit 42C, a UTC-GMC offset calculation processing unit 43, a GMC-BC offset calculation processing unit 44B, and a BC-client offset calculation unit. A processing unit 45B, a time accuracy calculation processing unit 46, and a packet transmission/reception unit 48 are provided. A measuring instrument 40C shown in FIG. 10 differs from the measuring instrument 40B shown in FIG. 8 in that the GMC time acquiring section 42B is changed to a GMC time acquiring section 42C and a packet transmitting/receiving section 47 is added.

The packet transmission/reception unit 48 transmits/receives PTP packets to/from the Grand Master Clock 10C via the network, and outputs the PTP packets received from the Grand Master Clock 10C to the GMC time acquisition unit 42C.

The GMC time acquisition unit 42C acquires time information from the PTP packet received by the packet transmission/reception unit 48. The PTP packet contains a time stamp corresponding to the internal time of the Grand Master Clock 10C. 42 C of GMC time acquisition parts acquire time information based on the time stamp contained in the acquired PTP packet.

In the time synchronization system 1B, the measuring device 40B acquires time information from the 1PPS signal, so the Grand Master Clock 10B and the measuring device 40B must be connected with a coaxial cable that transmits the 1PPS signal. Therefore, the Grand Master Clock 10B and the measuring device 40B must be installed within a range where they can be connected with a coaxial cable, for example, within the same building. On the other hand, in the time synchronization system 1C, the Grand Master Clock 10C and the measuring device 40C only need to be able to transmit and receive PTP packets via the network. Therefore, it is possible to further relax the restrictions on the installation location and more easily measure the accuracy of the internal time of each of the plurality of devices.

Next, the operation of the measuring instrument 40 according to this embodiment will be described.

FIG. 11 is a flow chart showing an example of the operation of the measuring device 40B according to this embodiment, and is a diagram for explaining the measuring method by the measuring device 40B. In FIG. 11, the same reference numerals are given to the same processes as in FIG. 5, and the description thereof is omitted.

The GMC-BC offset calculation processing unit 44B acquires a copy of the PTP packet transmitted and received between the Grand Master Clock 10B and the Boundary Clock 20B, and acquires time stamp information from the acquired PTP packet. The GMC-BC offset calculation processing unit 44B calculates the GMC-BC offset based on the acquired time stamp information and the transmission delay between the Grand Master Clock 10B and the Boundary Clock 20B output from the Grand Master Clock 10B ( step S21). Details of the calculation of the GMC-BC offset will be described later.

The BC-client offset calculation processing unit 45B acquires a copy of the PTP packet transmitted and received between the Boundary Clock 20B and the client device 30B, and acquires time stamp information from the acquired PTP packet. The BC-client offset calculation processing unit 45B calculates the BC-client offset based on the acquired time stamp information and the transmission delay between the Boundary Clock 20B and the client device 30 output from the Grand Master Clock 10B ( step S22).

As described below with reference to FIG. 5, based on the UTC-GMC offset, the GMC-BC offset, and the BC-client offset, the accuracy of the internal time of each device with respect to the reference time can be measured. done.

In FIG. 11, the process from step S11 to step S13, the process of step S21, and the process of step S22 are described as branching, but in reality, these processes are branched. are executed sequentially.

Next, calculation of the GMC-BC offset by the GMC-BC offset calculation processing unit 44B will be described with reference to FIG. Although calculation of the GMC-BC offset will be described below as an example, the BC-client offset can be calculated in the same manner.

As shown in FIG. 12, Grand Master Clock 10B first sends a Sync message to Boundary Clock 20B (step S31). The Grand Master Clock 10B transmits a Sync message including a time stamp indicating time T1, which is the transmission time of the Sync message, to the Boundary Clock 20B.

When the Boundary Clock 20B receives the Sync message transmitted from the Grand Master Clock 10B at time T2, it transmits a Delay_Req message to the Grand Master Clock 10B at time T3 in response to the Sync message (step S32). Boundary Clock 20B includes a time stamp indicating time T3, which is the transmission time of Delay_Req message, in Delay_Req message and transmits it to Grand Master Clock 10B.

When the Grand Master Clock 10B receives the Delay_Req message transmitted from the Boundary Clock 20B at time T4, it transmits a Delay_Resp message to the Boundary Clock 20B in response to the Delay_Req message (step S33). The Grand Master Clock 10B transmits a Delay_Resp message including a time stamp indicating time T4, which is the reception time of the Delay_Req message, to the Boundary Clock 20B.

The GMC-BC offset calculation processing unit 44B obtains a copy of the PTP packet that constitutes the message sent and received between the Grand Master Clock 10B and the Boundary Clock 20B.

That is, the GMC-BC offset calculation processing unit 44B acquires the PTP packet P1 that is a copy of the PTP packet that constitutes the Sync message. The PTP packet P1 is a packet that is transmitted from the Grand Master Clock 10B to the Boundary Clock 20B and that includes the time T1 that is the transmission time of the packet.

Also, the GMC-BC offset calculation processing unit 44B acquires the PTP packet P2 that constitutes the Delay_Req message. The PTP packet P2 is a packet transmitted from the Boundary Clock 20B to the Grand Master Clock 10B, and is a packet containing the transmission time T3 of the packet.

Also, the GMC-BC offset calculation processing unit 44B acquires the PTP packet P3 (third packet) that constitutes the Delay_Resp message. The PTP packet P3 is a packet transmitted from the Grand Master Clock 10B to the Boundary Clock 20B, and is a packet containing the time T4, which is the reception time of the PTP packet P2 forming the Delay_Req message.

The GMC-BC offset calculation processing unit 44B acquires time T1 from PTP packet P1, acquires time T3 from PTP packet P2, and acquires time T4 from PTP packet P3.

The GMC-BC offset calculation processing unit 44B calculates the GMC-BC offset by the following equation (2) based on the times T1 to T4.
GMC-BC offset=((T2-T1)-(T4-T3))/2 Expression (2)

As described above, the GMC-BC offset calculation processing unit 44B can receive times T1, T3, and T4 from the obtained copy of the PTP packet. However, since the time T2, which is the reception time of the sync message by the Boundary Clock 20B, cannot be obtained from the PTP packet, the GMC-BC offset calculation processing section 44B needs to obtain the time T2 separately. As a method of acquiring the time T2, there is a method of using the transmission delay between the master clock 10B and the boundary clock 20B. The transmission delay between the master clock 10B and the boundary clock 20B is calculated by the transmission delay calculation processor 14 by transmitting and receiving transmission delay measurement packets between the master clock 10B and the boundary clock 20B. Calculation of the transmission delay by the transmission delay calculation processing unit 14 will be described below with reference to FIG.

In FIG. 13, a method using ETH-DM (Ethernet (registered trademark) Delay Measurement) will be described. ETH-DM is a delay measurement method specified in JT-Y1731 OAM functions and mechanisms for Ethernet based networks. There are two types of ETH-DM, 1WAY ETH-DM and 2WYA ETH-DM, but the case of using 2WAY ETH-DM will be described below as an example.

As shown in FIG. 13, the transmission delay measuring packet transmitting/receiving section 13 of the Master Clock 10B transmits the DMM frame to the Boundary Clock 20B (step S41). Upon receiving the DMM frame, the transmission delay measuring packet transmitter/receiver 25 of the Boundary Clock 20B transmits the DMR frame to the Master Clock 10B (step S42). Hereinafter, the DMM frame transmission time by the master clock 10B is Tx Time stampf, and the DMM frame reception time by the Boundary Clock 20B is Rx Time stampf. Let Tx Time stampb be the transmission time of the DMR frame by the Boundary Clock 20B, and Rx Time stampb be the reception time of the DMR frame by the Master Clock 10B. The Boundary Clock 20B includes the reception time Rx Time stampf of the DMM frame and the transmission time Tx Time stampb of the DMR frame in the DMR frame and transmits it to the Master Clock 10B.

The ETH-DM frame delay (time required for round trip between Master Clock 10B and Boundary Clock 20B) can be calculated by the following equation (3).
Frame delay = (Rx Time stampb - Tx Time stampf) - (Tx Time stampb - Rx Time stampf)
... formula (3)

The transmission delay calculation processing unit 14 acquires Rx Time stampf and Tx Time stampb from the DMR frame received from the Boundary Clock 20B. The transmission delay calculation processing unit 14 can acquire Tx Time stampf and Rx Time stampb from transmission of DMM frames and reception of DMR frames by the transmission delay measuring packet transmission/reception unit 13 . Therefore, the transmission delay calculation processing unit 14 can calculate the frame delay using equation (3). The transmission delay calculation processing unit 14 outputs the transmission result of the transmission delay (frame delay) to the measuring device 40B.

The round-trip transmission delay of PTP packets between the master clock 10B and the boundary clock 20B can be calculated by the following equation (4) using times T1 to T4 described with reference to FIG.
Round-trip transmission delay=(T2-T1)+(T4-T3) Equation (4)

The GMC-BC offset calculation processing unit 44B can calculate the time T2 based on the transmission delay calculated by the transmission delay calculation processing unit 14 and equation (4). Then, the GMC-BC offset calculation processing unit 44B calculates the GMC-BC offset based on the following equation (5).
GMC-BC offset=((T2-T1)-(T4-T3))/2 Expression (5)

It should be noted that the transmission delay calculation method described with reference to FIG. 13 is merely an example, and any method may be used as long as the transmission delay can be obtained.

Next, the hardware configuration of the measuring instrument 40 according to the present disclosure will be described. In addition, although the measuring device 40 will be described below as an example, the same applies to the measuring devices 40A, 40B, and 40C.

FIG. 14 is a diagram showing an example hardware configuration of the measuring device 40 according to an embodiment of the present disclosure. FIG. 14 shows an example of the hardware configuration of the measuring device 40 when the measuring device 40 is configured by a computer capable of executing program instructions. Here, the computer may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal computer), an electronic notepad, or the like. Program instructions may be program code, code segments, etc. for performing the required tasks.

As shown in FIG. 14, the measuring instrument 40 includes a processor 410, a ROM (Read Only Memory) 420, a RAM (Random Access Memory) 430, a storage 440, an input section 450, a display section 460 and a communication interface (I/F) 470. have Each component is communicatively connected to each other via a bus 490 . The processor 410 is specifically a CPU (Central Processing Unit), MPU (Micro Processing Unit), GPU (Graphics Processing Unit), DSP (Digital Signal Processor), SoC (System on a Chip), etc. may be configured by a plurality of processors of

The processor 410 is a controller that controls each configuration and executes various arithmetic processing. That is, processor 410 reads a program from ROM 420 or storage 440 and executes the program using RAM 430 as a work area. The processor 410 performs control of the above components and various arithmetic processing according to programs stored in the ROM 420 or the storage 440 . In this embodiment, the ROM 420 or storage 440 stores a program for causing a computer to function as the measuring instrument 40 according to the present disclosure. By reading and executing the program by the processor 410, each configuration of the measuring instrument 40, that is, the UTC acquisition unit 41, the GMC time acquisition unit 42, the UTC-GMC offset calculation processing unit 43, the GMC-BC client offset A calculation processing unit 44, a BC-client offset calculation processing unit 45, and a time accuracy calculation processing unit 46 are realized.

Programs are stored in non-transitory storage media such as CD-ROM (Compact Disk Read Only Memory), DVD-ROM (Digital Versatile Disk Read Only Memory), USB (Universal Serial Bus) memory, etc. may be provided in Also, the program may be downloaded from an external device via a network.

The ROM 420 stores various programs and various data. RAM 430 temporarily stores programs or data as a work area. The storage 440 is configured by a HDD (Hard Disk Drive) or SSD (Solid State Drive) and stores various programs including an operating system and various data.

The input unit 450 includes a pointing device such as a mouse and a keyboard, and is used for various inputs.

The display unit 460 is, for example, a liquid crystal display, and displays various information. The display unit 460 may employ a touch panel method and function as the input unit 450 .

The communication interface 470 is an interface for communicating with other devices such as external devices (not shown), and uses standards such as Ethernet (registered trademark), FDDI, and Wi-Fi (registered trademark), for example.

A computer can be preferably used to function as each part of the measuring instrument 40 described above. Such a computer is realized by storing a program describing the processing details for realizing the function of each part of the measuring instrument 40 in the memory of the computer, and reading and executing the program by the processor of the computer. be able to. That is, the program can cause the computer to function as the measuring instrument 40 described above. It is also possible to record the program on a non-temporary recording medium. It is also possible to provide the program via a network.

Regarding the above embodiments, the following additional remarks are disclosed.

(Appendix 1)
A measuring instrument for measuring the accuracy of the internal time of each of the plurality of devices with respect to a reference time in a plurality of devices that synchronize the device time,
the plurality of devices includes a first device, a second device and a third device;
The first device has a master function for synchronizing the device time with the reference time and distributing the device time to a lower device by transmitting and receiving packets,
The second device has the master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception,
The third device has the slave function for synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception,
the meter comprises a processor;
The processor
obtaining the reference time from a satellite signal;
Acquiring time information related to the internal device time of the first device;
calculating a first offset, which is a difference between the reference time and the internal device time of the first device, based on the reference time and the acquired time information;
Obtaining time stamp information indicating the time when the packet was transmitted and received between devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information;
A measuring device that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.

(Appendix 2)
In the measuring instrument according to item 1,
The measuring instrument, wherein the processor acquires the time information from a pulse signal output from the first device at 1 PPS in synchronization with the internal time of the first device.

(Appendix 3)
In the measuring instrument according to item 1,
The measuring instrument, wherein the processor acquires a packet including a time stamp corresponding to the first internal time from the first device via a network, and acquires the time information from the acquired packet.

(Appendix 4)
In the measuring instrument according to item 1,
The measuring instrument, wherein the processor obtains the timestamp information transmitted from the second device and the third device via a network.

(Appendix 5)
In the measuring instrument according to item 1,
The processor acquires a copy of a packet transmitted and received between the devices via a network, acquires the time stamp information from the acquired packet, and transmits the time stamp information and the packet between the devices. and a transmission delay of .

(Appendix 7)
A measurement method using a measuring device for measuring the accuracy of the internal time of each of the plurality of devices with respect to a reference time in a plurality of devices that synchronize the device time,
the plurality of devices includes a first device, a second device and a third device;
The first device has a master function for synchronizing the device time with the reference time and distributing the device time to a lower device by transmitting and receiving packets,
The second device has the master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception,
The third device has the slave function for synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception,
obtaining the reference time from a satellite signal;
Acquiring time information related to the internal device time of the first device;
calculating a first offset, which is a difference between the reference time and the device internal time of the first device, based on the obtained reference time and the obtained time information;
Obtaining time stamp information indicating the time when the packet was transmitted and received between devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information;
A measurement method, comprising: measuring the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.

(Appendix 8)
a plurality of devices for synchronizing internal time;
A time synchronization system comprising a measuring device that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time in the plurality of devices,
the plurality of devices includes a first device, a second device and a third device;
The first device has a master function for synchronizing the device time with the reference time and distributing the device time to a lower device by transmitting and receiving packets,
The second device has the master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception,
The third device has the slave function for synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception,
The meter comprises a processor,
The processor
obtaining the reference time from a satellite signal;
Acquiring time information related to the internal device time of the first device;
calculating a first offset, which is a difference between the reference time and the device internal time of the first device, based on the obtained reference time and the obtained time information;
Obtaining time stamp information indicating the time when the packet was transmitted and received between devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information;
A time synchronization system that measures accuracy of internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.

Although the above-described embodiments have been described as representative examples, it will be apparent to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, this invention should not be construed as limited by the above-described embodiments, and various modifications and changes are possible without departing from the scope of the claims. For example, it is possible to combine a plurality of configuration blocks described in the configuration diagrams of the embodiments into one, or divide one configuration block.

1, 1A, 1B, 1C, 1a Time synchronization system 10, 10A, 10B, 10C, 100 Grand Master Clock (first device)
11 packet transmitter/receiver 12 1PPS transmitter 13 packet transmitter/receiver for transmission delay measurement 14 transmission delay calculation processor 15 packet transmitter/ receiver 20, 20B, 200 Boundary Clock (second device)
21, 22 packet transmission/reception unit 23 time synchronization processing unit 24 time stamp transmission unit 25, 26 transmission delay measurement packet transmission/reception unit 27 transmission delay calculation processing unit 30, 30B, 300 client device (third device)
31 packet transmission/reception unit 32 time synchronization processing unit 33 time stamp transmission unit 34 transmission delay measurement packet transmission/reception unit 35 transmission delay calculation processing unit 40, 40A, 40B, 40C, 400 measuring instrument 41 UTC acquisition unit (first acquisition unit)
42, 42A, 42C GMC time acquisition unit (second acquisition unit)
43 UTC-GMC offset calculation processing unit (first calculation processing unit)
44, 44B GMC-BC offset calculation processing unit (second calculation processing unit)
45, 45B BC-Client Offset Calculation Processing Unit (Second Calculation Processing Unit)
46 time accuracy calculation processing unit (third calculation processing unit)
47, 48 packet transmitter/receiver

Claims (7)

1. A measuring instrument for measuring the accuracy of the internal time of each of the plurality of devices with respect to a reference time in a plurality of devices that synchronize the device time,
   the plurality of devices includes a first device, a second device and a third device;
   The first device has a master function for synchronizing the device time with the reference time and distributing the device time to a lower device by transmitting and receiving packets,
   The second device has the master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception,
   The third device has the slave function for synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception,
   a first acquisition unit that acquires the reference time from a satellite signal;
   a second acquisition unit that acquires time information related to the internal device time of the first device;
   A first offset, which is a difference between the reference time and the device internal time of the first device, based on the reference time acquired by the first acquisition unit and the time information acquired by the second acquisition unit a first calculation processing unit that calculates
   A second method for obtaining time stamp information indicating a time when the packet was transmitted and received between devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information. a calculation processing unit;
   a third calculation processing unit that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.
2. The measuring instrument according to claim 1,
   The measuring instrument, wherein the second acquiring unit acquires the time information from a pulse signal output from the first device at 1 PPS in synchronization with the internal time of the first device.
3. The measuring instrument according to claim 1,
   The second acquisition unit acquires a packet including a time stamp corresponding to the first internal time from the first device via a network, and acquires the time information from the acquired packet. vessel.
4. In the measuring instrument according to any one of claims 1 to 3,
   The measuring instrument, wherein the second calculation processing unit acquires the time stamp information transmitted from the second device and the third device via a network.
5. In the measuring instrument according to any one of claims 1 to 3,
   The second calculation processing unit acquires a copy of a packet transmitted and received between the devices via a network, acquires the time stamp information from the acquired packet, and stores the acquired time stamp information and the device. calculating the second offset based on the transmission delay of the packet in between.
6. A measurement method using a measuring device for measuring the accuracy of the internal time of each of the plurality of devices with respect to a reference time in a plurality of devices that synchronize the device time,
   the plurality of devices includes a first device, a second device and a third device;
   The first device has a master function for synchronizing the device time with the reference time and distributing the device time to a lower device by transmitting and receiving packets,
   The second device has the master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception,
   The third device has the slave function for synchronizing the internal time of the device with the time delivered from the second device by packet transmission/reception,
   obtaining the reference time from a satellite signal;
   a step of acquiring time information relating to the internal device time of the first device;
   calculating a first offset, which is a difference between the reference time and the internal device time of the first device, based on the obtained reference time and the obtained time information;
   obtaining time stamp information indicating the time when the packet was transmitted and received between devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information;
   and measuring the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.
7. a plurality of devices for synchronizing internal time;
   A time synchronization system comprising a measuring device that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time in the plurality of devices,
   the plurality of devices includes a first device, a second device and a third device;
   The first device has a master function for synchronizing the device time with the reference time and distributing the device time to a lower device by transmitting and receiving packets,
   The second device has the master function and a slave function for synchronizing the internal time of the device with the time delivered from the host device having the master function by packet transmission/reception,
   The third device has the slave function for synchronizing the internal time of the device with the time delivered from the second device by packet transmission and reception,
   The measuring instrument
   a first acquisition unit that acquires the reference time from a satellite signal;
   a second acquisition unit that acquires time information related to the internal device time of the first device;
   A first offset, which is a difference between the reference time and the device internal time of the first device, based on the reference time acquired by the first acquisition unit and the time information acquired by the second acquisition unit a first calculation processing unit that calculates
   A second method for obtaining time stamp information indicating a time when the packet was transmitted and received between devices, and calculating a second offset, which is a difference in device internal time between the devices, based on the obtained time stamp information. a calculation processing unit;
   A time synchronization system comprising: a third calculation processing unit that measures the accuracy of the internal time of each of the plurality of devices with respect to the reference time based on the first offset and the second offset.
   
   

Images