Analysis of Delays in Transmitting Time Code Using an Automated Computer Time Distribution System

摘要

An automated computer time distribution system broadcasts standard time to users using computers and modems via telephone lines. For users who need traceable time, it is of particular interest to know the uncertainty of time information received. Factors that contribute to transmission delays in a telephone network have been measured and analyzed. The results revealed several dominant factors that contributed to delays - software platform (50% of the delay), transmission speed of time-codes (25%), telephone network (15%), modem and others (10%). The standard deviation of delays is below 20 ms in all cases. The results allow us to estimate that, within Singapore, an uncertainty of about 20 milliseconds is achievable using the system.