What started with the sundial has, thus far, been refined to a level of precision based on atomic resonance: Time. Our obsession with time is evident in this continued scaling down to nanosecond resolution and beyond. But this obsession is not without warrant. Precision and time synchronization are critical in many applications, such as air traffic

Carefully coordinated, reliable, and accurate time synchronization is vital to a wide spectrum of fields—from air and ground traffic control, to buying and selling goods and services, to TV network programming. Ill-gotten time could even lead to the unimaginable and cause DNS caches to expire, leaving the entire Internet to implode on the root servers. Written by the original developer of the Network Time Protocol (NTP), Computer Network Time Synchronization: The Network Time Protocol on Earth and in Space, Second Edition addresses the technological infrastructure of time dissemination, distribution, and synchronization—specifically the architecture, protocols, and algorithms of the NTP. This system has been active in one form or another for almost three decades on the Internet and numerous private networks on the nether side of firewalls. Just about everything today that can be connected to a network wire has support for NTP. This book: Describes the principal components of an NTP client and how it works with redundant servers and diverse network paths Provides an in-depth description of cryptographic and other critical algorithms Presents an overview of the engineering principles guiding network configuration Evaluating historic events that have taken place since computer network timekeeping started almost three decades ago, the author details a number of systems and drivers for current radio, satellites, and telephone modem dissemination and explains how we reckon the time, according to the stars and atoms. The original 16 chapters of the first edition have been rewritten, updated, and enhanced with new material. Four new chapters cover new algorithms and previously uncovered concepts, including timekeeping in space missions. Praise for the first edition: "... For those that need an exhaustive tome on all of the minutiae related to NTP and synchronization, this is the source. ... definitive ... this book should be considered the last word on the topic." —Ben Rothke on Slashdot.org "... the bible of the subject... contains enough information to take you just as far as you want to go....Dr. Mills is the original developer of NTP." —Books On-Line

This report describes the analysis and design of a sophisticated real-time detector and decoder for manually-sent Morse code signals transmitted via high-frequency radio circuits. The system software is designed to run if required in a distributed computer network such as the DCN and can provide simultaneous multicircuit decoding capabilities, using a multiplexed analog-digital converter and multiple terminals, in a single machine. The system uses the principles of optimum filtering and receiver design, including matched filtering and Viterbi decoding. The statistical structure of the Morse process is encapsulated in a Markov model which includes a-priori probabilities and transition probabilities reflecting the entire alphabetical structure of the code. A key component in the design is a new algorithm, called ratio-weighted estimation (RWE) which provides extremely fast adaptation to the time-varying Morse code parameters typical of multioperator circuits

This paper describes a set of algorithms proposed for recovery from hardware and software failure in a distributed computer network. These algorithms are designed so that, in most cases of temporary failure in a processor, storage medium or input/output device, the remaining components elsewhere in the network continue to function. When the failure is repaired the system automatically reconfigures itself to include the failed component. (Author).

The Distributed Computer Network (DCN) is a resource-sharing computer network which includes a number of DEC PDP11 computers. The DCN supports a number of processes in a multiprogrammed distributed environment. Processes can communicate with each other and interface with their environment in a manner which is independent of their residence within a particular computer. Resources such as processors, devices and storage media can be remotely accessed and shared so as to provide increased reliability, flexibility and system utilization. The DCN now supports several programming languages and applications packages. Common programming languages such as LISP, BASIC and others, along with an extensive library of interactive graphics procedures, can be executed in processes which take full advantage of the distributed architecture of the system. Most of the components of the Disk Operating System (DOS) for the PDP11 can be executed in a special emulator-type virtual process now being constructed for this purpose.