The present invention relates to a satellite antenna integrated time-synchronization device for generating a time-synchronization signal from a satellite signal received from a satellite, which includes a case, a 1PPS synchronization module which is disposed in the case and is configured to generate at least a 1PPS signal from the satellite signal, and a signal processing means which is disposed in the case and is configured to generate an IRIG signal and communication data using the 1PPS signal input from the 1PPS synchronization module.

According to various embodiments, a watch may be provided. The watch may include: a timing circuit configured to provide information about a current time; a smart watch circuit configured to provide smart watch functionality; a first battery configured to provide energy to the timing circuit; a second battery configured to provide energy to the smart watch circuit; and a communication circuit configured to provide communication between the timing circuit and the smart watch circuit; wherein the communication circuit includes a safety circuit configured to prevent leakage of current from the first battery to the second battery.

According to various embodiments, a watch may be provided. The watch may include: a timing circuit configured to provide information about a current time; a smart watch circuit configured to provide smart watch functionality; a first battery configured to provide energy to the timing circuit; a second battery configured to provide energy to the smart watch circuit; and a communication circuit configured to provide communication between the timing circuit and the smart watch circuit; wherein the communication circuit includes a safety circuit configured to prevent leakage of current from the first battery to the second battery.

A communication system (1) comprises a central (100) and a peripheral (200). The central (100) receives location information and time information from NTP servers (10) and a location server (30). The central (100) creates first offset information of the time measured by its own device and the time information received from the NTP servers (10). The central (100) acquires from map information a time difference corresponding to a location presented by the location information received from the location server (30). The central (100) creates first updated time information based on the time measured by its own device, first offset information, and time difference corresponding to the location presented by the location information received from location server (30) and transmits the first updated time information to the peripheral (200). The peripheral (200) changes the time displayed by its own device based on the received first updated time information.

The present disclosure provides an on-board synchronization device. The on-board synchronization device includes: a first circuit and at least one second circuit. The first circuit is configured to receive an initial signal containing Universal Time Coordinated (UTC), generate a first signal containing the UTC, and output the first signal to at least one on-board device, such that the at least one on-board device synchronizes its built-in clock with the UTC based on the first signal. The second circuit is configured to receive a Pulse Per Second (PPS) signal, generate a periodic second signal with a same phase as the PPS signal, and output the second signal or the PPS signal to the at least one on-board device, such that the at least one on-board device performs a predetermined action based on the second signal or the PPS signal.

[Problem] To provide a time synchronization mechanism that is not affected by link asymmetry between time synchronization devices.

[Solution] A DC 4 used in a time transmission system that transmits and receives a PTP packet between a master node 1 and a slave node 2 via the DC 4 and synchronizes time of the slave node 2 based on time information on the transmission and reception includes a PTP clock unit 12 that synchronizes time information by the arrived PTP packet, a frequency clock unit 21 that synchronizes time information by a frequency signal, a delay setting unit 22 that sets, such that a transmission delay of the PTP packet between the master node 1 and the slave node 2 becomes a setting delay Lmax, a waiting time of the PTP packet based on a time difference between a departure time of the PTP packet and an arrival time of the PTP packet at the DC 4, which is determined from the time information of the frequency clock unit 21, and a time adjustment unit 26 that corrects a time shift from reference time in the time information of the frequency clock unit 21 based on the time information of the PTP clock unit 12.

[Problem] A time synchronization mechanism with which an impact of link asymmetry between time synchronization devices is reduced is provided.

[Solution] A SW 3 used in the time transmission system in which a master node 1 and a slave node 2 performs transmission and reception of a PTP packet via the SW 3 and the time of the master node 1 is synchronized based on time information of the transmission and reception includes a delay calculator 32 that measures an intra-device delay between input and output of the PTP packet to and from the SW 3, and a delay information writing unit 33 that appends the intra-device delay measured by the delay calculator 32 to a packet subsequent to the PTP packet, and outputs the appended packet to an output destination of the PTP packet.

A system for managing a time reference includes a real-time clock, an interface, and a processor. The real-time clock store an RTC time. The interface is configured to receive a GPS time and a cellular time. The processor is configured to: indicate to start a time-speed adjustment loop; determine a true time based at least in part on the GPS time and the cellular time; determine an error between the true time and the RTC time; determine an RTC speed calibration adjustment based at least in part on the error; and adjust the real-time clock speed based at least in part on the RTC speed calibration adjustment.

A system for managing a time reference includes a real-time clock, an interface, and a processor. The real-time clock store an RTC time. The interface is configured to receive a GPS time and a cellular time. The processor is configured to: indicate to start a time-speed adjustment loop; determine a true time based at least in part on the GPS time and the cellular time; determine an error between the true time and the RTC time; determine an RTC speed calibration adjustment based at least in part on the error; and adjust the real-time clock speed based at least in part on the RTC speed calibration adjustment.

A device for transmitting synchronized timing including a receiver, a transmitter, one or more processors, memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the programs including instructions for receiving through the receiver a timing signal comprising first time information that is synchronized to a time standard, determining second time information based at least partially on the first time information, composing a message formatted in accordance with a global navigation satellite system (GNSS) standard, wherein the message comprises the second time information, and transmitting the message through the transmitter on a radio signal having a frequency in the frequency modulation (FM) radio frequency band.