The Importance of Network Time Synchronization (PDF 50k)
 As you read this, your network of workstations and servers, each with their own clock, are time stamping files, email, transactions, etc., all the while your server logs are recording every manner of transaction in the event you need that information. At some point during the day it is quite likely that automatic processes such as archiving, directory synchronization, cron jobs, etc. will execute and alter files based on time stamps. Fundamental to all of this is the belief that the time is correct. Even if the time is not absolutely correct there is often a belief that at least the time is “close enough.” This paper describes why “close enough” is no substitute for accurate network time and why network time synchronization is critically important.

 Synchronization Essentials of VoIP (PDF 68k)
 As we accelerate into the New World of VoIP we assume we can leave some of the trappings of wireline telecom behind, such as the need for synchronization. After all, an IP network is about as asynchronous as it gets. While this may be true in some respects, precise time and synchronization continue to permeate many areas of IP telephony operations. Customer expectations of voice quality and service reliability remain unchanged, and as a result, the need for precise time remains unchanged though it manifests itself in different ways. The bottom line is that trying to design a VoIP network without considering network synchronization is probably the shortest path to realizing that you need it.

 Stochastic Model Estimation of Network Time Variance (PDF 276k)
 This white paper presents a study of clock drift in computers and other networked devices. The paper starts with a introduction to clock architecture, distribution of standard time, drift in oscillators, and efforts to improve clock precision. This is followed by an equation for clock drift that shows the how the calculation for modeling drift in networks was established. Finally, statistical projections are presented along with results and conclusions about the significance of network clock error, even in relatively small networks.

GPS Antenna Basics
This application note covers the basics of GPS antennas, installation and cables. The paper starts with the basics of why antennas are necessary and moves into the practical areas of installation and how to be the most successful in receiving satellite signals.