Time synchronisation in the command and control network
With an increasing number of distributed sensors and their networking, the availability of a secure and precise time base also gains in importance. But what does «precise» actually mean? In everyday life, a small deviation in time can go unnoticed, but with complex sensor systems it can be tantamount to an eternity. armasuisse Science and Technology (S+T) is testing a solution for the most accurate time synchronisation possible: White Rabbit.
This should enable a more robust and more precise independent synchronisation than is possible using other methods. In many cases, time signals from satellite navigation systems such as the Global Positioning System GPS are used today for this purpose. In these systems, the time is determined together with the location. This enables a GPS receiver to have a time that is always accurate to a few billionths of a second which it can provide to other systems. However, it is well known that such systems are very susceptible to radio interference and constitute major dependency on the operators of these satellite navigation systems.
armasuisse S+T carried out the first tests with the College of Engineering and Architecture in Fribourg. A network topology was set up in a laboratory structure, as it would occur with several nodes in a typical, nationwide operation in Switzerland. Components could thus be exchanged individually and their influence on accuracy tested. Following these investigations, cooperations took place with researchers from the Federal Institute of Metrology METAS and the university network operator Switch. Together, they worked on a test setup within the Switch network. The findings obtained are now to be utilised for implementing White Rabbit in the Swiss command and control network, so that the Armed Forces’ sensor systems can use a secure, independent time base in the future. As it was possible to build on an existing solution in this case and the aim was to test its suitability, the innovation environment here was the «test run».