The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 28, 1995
Filed:
Oct. 29, 1993
Yukari Kou, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
In a satellite communication network, a reference station simultaneously announces a reference time of a reference clock once in a predetermined duration of time to all terrestrial stations of the network. In each terrestrial station which comprises a local clock, a packet forming arrangement, a data extracting arrangement for extracting a local time datum from a packet received from a different terrestrial station, and a calculation unit for calculating a propagation delay time between the different terrestrial station and the terrestrial station under consideration by subtracting from the local time datum a current time indicated by the local clock when the local time datum is extracted, a time setting arrangement sets the current time at a sum of the local time datum and a constant preassigned to the terrestrial station in question. The constant is preliminarily decided by calculating a distance on the earth between the terrestrial station and the reference station based on their longitudes and latitudes, calculating a physical length of a communication link by using the distance, and calculating a time necessary for electromagnetic waves to travel the physical length.