# US 12,191,983 B2 · Time-point synchronization apparatus, time-point synchronization method, and non-transitory computer readable medium > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,191,983 B2 - Document ID: US12191983B2 - Status: Granted - Kind: B2 - Application number: 17/987,148 - Filed: 2022-11-15 - Published: 2023-03-09 - Granted: 2025-01-07 - Earliest claimed: 2020-07-09 - Assignees: Mitsubishi Electric Corporation - Applicants: Mitsubishi Electric Corporation - Inventors: Ryuma Matsushita; Sachiko Taniguchi; Yoshifumi Hotta - Web page: https://patentgrep.com/patent/US12191983B2 ## CPC - H04J 3/0658: {Clock or time synchronisation among packet nodes} - H04J 3/0697: {Synchronisation in a packet node} - H04J 3/0667: {Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays (arrangements for monitoring round trip delays in packet switching networks H04L43/0864)} - H04L 7/0016: {correction of synchronization errors} - H04J: MULTIPLEX COMMUNICATION (transmission in general H04B; peculiar to transmission of digital information H04L5/00; systems for the simultaneous or sequential transmission of more than one television signal H04N7/08; in exchanges H04Q11/00; stereophonic systems H04S) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A time-point synchronization apparatus (10) includes a time-point management unit (144), a time-gap counter (145), and a time-gap calculation unit (142). The time-point management unit (144) manages an apparatus time point equivalent to a current time point. The time-gap counter (145) records a time gap which is a different between a time point indicated in reception information and the apparatus time point. When a frequency in the time-gap counter (145), corresponding to the time gap corresponding to a latest reception time point corresponding to latest reception information is treated as the highest among all of frequencies indicated in the time-gap counter (145), the time-gap calculation unit (142) synchronizes the apparatus time point to the latest reception time point. ## Claims ### Claim 1 A time-point synchronization apparatus, which receives as a plurality of pieces of reception information, a plurality of pieces of information each of which includes time-point correspondence information which is information used for calculating a current-time-point equivalent time point that indicates a time point at present and that is equivalent to a current time point which changes with passage of time, the time-point synchronization apparatus comprising: processing circuitry to manage and maintain the current-time-point equivalent time point as an apparatus time point; and a memory to store a time-gap counter which includes one or more individual counters, on a premise that reception information received the most lately by the time-point synchronization apparatus serves as latest reception information and one or more pieces of reception information other than the latest reception information collectively serve as past reception information, among the plurality of pieces of reception information, where the time-gap counter has been provided according to counter granularity which is granularity corresponding to a time point, and also has been provided by converting into a frequency, each of one or more time gaps indicating each difference between each of current-time-point equivalent time points and each of apparatus time points, and by recording one or more frequencies, each of the current-time-point equivalent time points being calculated using each piece of time-point correspondence information included in each piece of past reception information, each of the apparatus time points being corresponding to a time when the time-point synchronization apparatus receives each piece of past reception information, and wherein the processing circuitry adopts as a latest reception time point, a current-time-point equivalent time point calculated using time-point correspondence information included in the latest reception information, calculates as a calculated time gap, a time gap indicating a difference between the latest reception time point and an apparatus time point corresponding to a time when the latest reception information is received, adopts as a selected counter, a counter in the time-gap counter, corresponding to the calculated time gap, increments a frequency in the selected counter by one, and when the frequency indicated in the selected counter is treated as the highest among all of frequencies indicated in the time-gap counter, synchronizes an apparatus time point at present to a time point corresponding to the latest reception time point. ### Claim 2 (depends on 1) The time-point synchronization apparatus according to claim 1, wherein the processing circuitry determines whether or not the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap is treated as the highest among all of the frequencies indicated in the time-gap counter. ### Claim 3 (depends on 2) The time-point synchronization apparatus according to claim 2, wherein when the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap is the highest among all of the frequencies indicated in the time-gap counter, the processing circuitry treats the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap, as the highest among all of the frequencies indicated in the time-gap counter. ### Claim 4 (depends on 3) The time-point synchronization apparatus according to claim 3, wherein when the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap is treated as the highest among all of the frequencies indicated in the time-gap counter, the processing circuitry shifts a whole time-gap counter in parallel so that the calculated time gap is treated as not existing. ### Claim 5 (depends on 4) The time-point synchronization apparatus according to claim 4, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 6 (depends on 3) The time-point synchronization apparatus according to claim 3, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 7 (depends on 2) The time-point synchronization apparatus according to claim 2, wherein when the counter in the time-gap counter, corresponding to the calculated time gap is adjacent to a counter in the time-gap counter, corresponding to the highest frequency among all of the frequencies indicated in the time-gap counter, the processing circuitry treats the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap, as the highest among all of the frequencies indicated in the time-gap counter. ### Claim 8 (depends on 7) The time-point synchronization apparatus according to claim 7, wherein when the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap is treated as the highest among all of the frequencies indicated in the time-gap counter, the processing circuitry shifts a whole time-gap counter in parallel so that the calculated time gap is treated as not existing. ### Claim 9 (depends on 8) The time-point synchronization apparatus according to claim 8, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 10 (depends on 7) The time-point synchronization apparatus according to claim 7, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 11 (depends on 2) The time-point synchronization apparatus according to claim 2, wherein when the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap is treated as the highest among all of the frequencies indicated in the time-gap counter, the processing circuitry shifts a whole time-gap counter in parallel so that the calculated time gap is treated as not existing. ### Claim 12 (depends on 11) The time-point synchronization apparatus according to claim 11, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 13 (depends on 2) The time-point synchronization apparatus according to claim 2, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 14 (depends on 1) The time-point synchronization apparatus according to claim 1, wherein when the frequency indicated in the counter in the time-gap counter, corresponding to the calculated time gap is treated as the highest among all of the frequencies indicated in the time-gap counter, the processing circuitry shifts a whole time-gap counter in parallel so that the calculated time gap is treated as not existing. ### Claim 15 (depends on 14) The time-point synchronization apparatus according to claim 14, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 16 (depends on 1) The time-point synchronization apparatus according to claim 1, wherein each of the plurality of pieces of reception information includes information conforming to generalized Precision Time Protocol, as the time-point correspondence information, and wherein the processing circuitry calculates a current-time-point equivalent time point corresponding to the time-point correspondence information included in each of the plurality of pieces of reception information, based on the generalized Precision Time Protocol, using the time-point correspondence information included in each of the plurality of pieces of reception information. ### Claim 17 A time-point synchronization method by a time-point synchronization apparatus which receives as a plurality of pieces of reception information, a plurality of pieces of information each of which includes time-point correspondence information which is information used for calculating a current-time-point equivalent time point that indicates a time point at present and that is equivalent to a current time point which changes with passage of time, the time-point synchronization method comprising: managing and maintaining, by a time-point management unit, the current-time-point equivalent time point as an apparatus time point; storing, by a counter storage unit, a time-gap counter which includes one or more individual counters, on a premise that reception information received the most lately by the time-point synchronization apparatus serves as latest reception information and one or more pieces of reception information other than the latest reception information collectively serve as past reception information, among the plurality of pieces of reception information, where the time-gap counter has been provided according to counter granularity which is granularity corresponding to a time point, and also has been provided by converting into a frequency, each of one or more time gaps indicating each difference between each of current-time-point equivalent time points and each of apparatus time points, and by recording one or more frequencies, each of the current-time-point equivalent time points being calculated using each piece of time-point correspondence information included in each piece of past reception information, each of the apparatus time points being corresponding to a time when the time-point synchronization apparatus receives each piece of past reception information; and adopting, by a time-gap calculation unit, as a latest reception time point, a current-time-point equivalent time point calculated using time-point correspondence information included in the latest reception information, calculating as a calculated time gap, a time gap indicating a difference between the latest reception time point and an apparatus time point corresponding to a time when the latest reception information is received, adopting as a selected counter, a counter in the time-gap counter, corresponding to the calculated time gap, incrementing a frequency in the selected counter by one, and when the frequency indicated in the selected counter is treated as the highest among all of frequencies indicated in the time-gap counter, synchronizing an apparatus time point at present to a time point corresponding to the latest reception time point. ### Claim 18 A non-transitory computer readable medium storing a time-point synchronization program which causes a computer which receives as a plurality of pieces of reception information, a plurality of pieces of information each of which includes time-point correspondence information which is information used for calculating a current-time-point equivalent time point that indicates a time point at present and that is equivalent to a current time point which changes with passage of time, the computer storing a time-gap counter which includes one or more individual counters, on a premise that reception information received the most lately by the computer serves as latest reception information and one or more pieces of reception information other than the latest reception information collectively serve as past reception information, among the plurality of pieces of reception information, where the time-gap counter has been provided according to counter granularity which is granularity corresponding to a time point, and also has been provided by converting into a frequency, each of one or more time gaps indicating each difference between each of current-time-point equivalent time points and each of apparatus time points, and by recording one or more frequencies, each of the current-time-point equivalent time points being calculated using each piece of time-point correspondence information included in each piece of past reception information, each of the apparatus time points being corresponding to a time when the computer receives each piece of past reception information: to manage and maintain the current-time-point equivalent time point as an apparatus time point; and to adopt as a latest reception time point, a current-time-point equivalent time point calculated using time-point correspondence information included in the latest reception information, calculate as a calculated time gap, a time gap indicating a difference between the latest reception time point and an apparatus time point corresponding to a time when the latest reception information is received, adopt as a selected counter, a counter in the time-gap counter, corresponding to the calculated time gap, increment a frequency in the selected counter by one, and when the frequency indicated in the selected counter is treated as the highest among all of frequencies indicated in the time-gap counter, synchronize an apparatus time point at present to a time point corresponding to the latest reception time point.