Radio Referenced Time Servers Explained

Atomic clocks use an atomic resonance frequency standard as an indication of the time and are by far the most accurate timepieces, with the last in strontium atomic clocks boasting a precision of less than a second lost in several hundred millions' years.

The clocks maintain a continuous and stable time scale called International Atomic Time (TAI). However, for civil time, another time scale, Coordinated Universal Time (UTC), which is derived from TAI, but synchronized with the UTC leap seconds to keep it on the basis of the rotation field.

UTC is a global time which is commonly used to synchronize clocks on computer networks
allow machines around the world to communicate together and lead-time sensitive applications.

Unfortunately the pieces, atomic clocks are extremely expensive equipment and are usually only found in physics laboratories, high tech or satellites on board. However, many physics laboratories of the national transmission, the time told by their atomic clocks via a long-wave radio transmission. These signals are often collected and used by radio-controlled wall and desk clocks and NTP time servers (Network Time Protocol).

Transmission of national standards bodies to maintain an accuracy of 10-9 seconds per day (about 1 in 1014). MSF is the distribution of a signal by the National Physical Laboratory, Anthorn, Cumbria. Other countries have their common signals that are broadcast transmission Mainflingen DCF77 near Frankfurt, Germany and the United States broadcast signal WWVB in Fort Collins, Colorado.

All these times signals work in a similar way. The beginning of each signal strength is reduced from 6 to 10 dB or disabled for a specified period of time before being restored. From the moment the signal is reduced is used to indicate a stream of binary digits with marker placement. The exact format of the code varies between different signals, even if they are the same size.

Dedicated NTP time server that connect to a computer can use this signal to synchronize computer networks. These dedicated machines are ideal for keeping networks running right now and in general can maintain a network with an accuracy of a few milliseconds of UTC time.