Abstract: In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.

Abstract: It is provided a synchronization system capable of managing execution of synchronization for clocks to be mounted on various devices. A synchronization system of clocks comprising: a leader device; a follower device capable of establishing communication connection with the leader device; and a server apparatus capable of establishing communication connection with the leader device and/or the follower device, the system further comprising: a time deviation calculator configured to calculate a time deviation between the leader device and the follower device; and a time corrector configured to correct a time in the follower device based on the calculated time deviation, wherein the synchronization system executes the time deviation calculator and/or the time corrector when the server apparatus generates, transmits, and/or receives predetermined information.

Abstract: In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.

Abstract: The time of transmission and reception between stations A and B is exchanged, and any deviation in time is calculated in a corresponding manner in the stations.

Abstract: The time of transmission and reception between stations A and B is exchanged, and any deviation in time is calculated in a corresponding manner in the stations.

Abstract: A key telephone system for use in PCM telecommunications includes an office line communication units, an extension interface unit, a receiving unit, an extension communication unit, and an information transmitting and receiving unit.