Supplemental Information

This page provides pointer to websites containing additional information on time keeping and on other protocols for synchronizing clocks.

General timekeeping and time related websites

United States Naval Observatory: This site describes the mission of the USNO and the services it provides. Be sure to click on the 'Time Service' link on their home page. Elsewhere on the site there are pointers to other useful sites, conferences, etc. This site also contains information on the Global Positioning System (GPS) maintained by the US Department of Defense which is also useful as a world wide time standard.
Time and Frequency Department at the NIST, Boulder facility. This site contains a wealth of material on the science of timekeeping. This site also contains information on the Global Positioning System (GPS) maintained by the US Department of Defense which is also useful as a world wide time standard.

Other clock synchronization and general synchronization protocols or standards

Network Time Protocol (NTP): NTP is the most widely used protocol for synchronizing the clocks in a general computer environment. This site contains extensive descriptions of the protocol, references to papers, implementations, pointers to the relevant RFCs, etc.
Time Triggered Protocol (TTP): TTP is a protocol developed for use in safety critical systems such as automotive or aircraft. While synchronization is a part of TTP, the protocol addresses many other issues. This site contains extensive descriptions, references, implementation information, etc.
SERCOS: SERCOS is a synchronization protocol developed for the motion control industry. While synchronization is a part of SERCOS, the protocol addresses many other issues. This site contains extensive descriptions, references, implementation information, etc.
TTEthernet: TTEthernet is a fault-tolerant transparent clock algorithm and will be standardized as SAE AS6802 - please refer to www.ttagroup.org and Link: http://www.sae.org/servlets/works/documentHome.do?comtID=TEAAS2D&docID=AS680