Synchronization of the Edwards Digital Switch

Abstract

The Air Force Flight Test Center (AFFTC) at Edwards, California has installed the Edwards Digital Switch (EDS). The EDS is a DS-1 switch capable of switching voice, encrypted voice, and Time Space Position Information (TSPI) data. Communicating encrypted voice and TSPI data reliably from the EDS to any other communication system requires the two systems operate using the same frequency reference. The need to communicate with other test ranges and over commercially leased lines using the EDS requires synchronization to a standard frequency source. The current synchronization method used at the AFFTC is unacceptable for the EDS. A hierarchal system of synchronization networking will be implemented to provide a common reference to each of the systems interfacing the EDS. The Master Timing Station (MTS), which provides synchronization reference to most of the AFFTC resources, is aging and must be upgraded. The upgrade of the MTS and the restructuring of the synchronization signal distribution will be completed simultaneously. Traceability to the United States Naval Observatory (USNO) and the National Bureau of Standards (NBS) is required to provide the necessary synchronization to allow the EDS to interface reliably with other systems. The Global Positioning System (GPS) is being considered as the primary source for frequency calibration traceable to the USNO and NBS.