An atomic clock that provides a very accurate source of time. There are different types of atomic clock, which is located mostly in the laboratory: cesium clocks, watches, hydrogen and rubidium clocks. Longer commercially available systems atomic clock synchronization using a radio or GPS time signal that a precise time reference rate of interest is bound. In this way, a very accurate source of time is readily available for users of all days, excluding the costs of installing a very expensive andcomplex systems.

This article provides an overview of atomic clock systems with particular emphasis on their use with NTP server systems for PC and network synchronization of computer time.

Atomic Clock Radio

References Time radio broadcast time derivatives such as MSF-60 (UK), DCF-77 (Germany) and WWVB (U.S.) time to transmit signals accurate time information from a radio transmitter. The period of coverage of an atomic clock time point, may and timing devices with a low-cost radio receivers are received. MSF-60 radio signal from Rugby in the UK, with coverage of the British Isles and throughout most of North-West Europe transferred. The DCF-77 from Frankfurt, Germany, transfer, and covers most of central Europe. While the WWVB signal in Fort Collins, Colorado, United States transferred.

MSF-60 time of transmission

MSF-60 time signal is a long wave> Transmission of radio signal at 60kHz clock of rugby in the United Kingdom. The radio signal is received by BT Engineering Services. MSF-60 time signal is extremely accurate atomic clocks at the National Physical Laboratory (NPL) is generated. When decoded, provides a very precise timing reference clocks for NTP time servers and other equipment.

DCF-77-Transmission

The DCF-77 is a clock radio transmission signal waveat 77.5 kHz from Mainflingen near Frankfurt, Germany. The radio signal is maintained by T-Systems, a division of Deuche Telecom and in operation since 1959. The DCF-77 highly accurate atomic clocks German National Physics Laboratory is generated. When decoded, provides a very precise timing reference for clocks and computer timing equipment.

WWVB transmission time

The WWVB time signal continuously transmits time andSignal at a frequency of 60 kHz, Fort Collins, Colorado, USA. The time reference is received from the U.S. National Institute of Standards and Technology. WWVB continuously transmits time and frequency since 1962 made available. The signal is a time reference with an accuracy of less than 100 microseconds.

GPS Time Atomic Clock Reference

The Global Positioning System (GPS) is a U.S. military for navigation around the world. The system consists of 24 satellites in orbit, eachSatellite has an extremely accurate atomic clock on board the UTC synchronized time. The satellites continuously transmit time and position data. The timing and location information can be obtained throughout the world with a GPS receiver and antenna. GPS works continuously, whether the conditions for everyone, anywhere in the world. Addition, there are no set-up fee or subscription charges to use GPS systems. Many computer timing systems and NTP server systems for use as an external GPS accurateReference time. GPS timing is generally much more accurate than the baseline time radio.

Computer Time Synchronization

Computer time synchronization can be achieved by combining a precise timing GPS receiver and radio with RS232 or USB interface to achieve. Driver software can be installed on the host PC to obtain the correct time and the host PC, synchronize the system time. Most PC operating systems can be synchronized, including Microsoft Windows 2000, 2003 and XPLinux, Unix and Novell. In many cases, the time of the host PC within a few microseconds, the time synchronized.

Network Time Synchronization

The standard protocol for the implementation of the network synchronization of the computer time is the Network Time Protocol (NTP). NTP is the standard way to distribute the time on the Internet and other networks. Stratum 1 NTP server to receive an external reference time, such as GPS, MSF-60, DCF or WWVB-77. The weather outsideReference is then used to set the NTP server to synchronize the system time. Time synchronized system is then used by the NTP server to distribute the correct time to time, the network clients on an IP network. NTP is a hierarchical way, less time to NTP server to get to higher level devices.

NTP server systems can be synchronized within a few microseconds, the right time. Depending on network traffic you can synchronize NTP client, a few milliseconds of NTPServer.