The GPS Clock Source is the last GPS synchronisation product by Neetra for targeting the wireless infrastruc- ture. This GPS clock combines an 50-channel GPS receiver, high quality ovenized oscillator and a 4 way distribution for 10MHZ and 1PPS signals. It is available in both single and dual GPS models (to maximize the reliability). Among its uses are synchronising the DVB infrastructure.

The GPS Clock Source outputs 4x10MHz reference signals and 4x1PPS signals with an over-determined solution synchronised to GPS or UTC time. The 10MHz reference accommodates applications requiring sub- microsecond timing.

The GPS receiver is driven directly by the 10MHz output signal of the oscillator. This is calibrated against the incoming GPS signal, with the resulting clock and frequency measurements fed into the oscillator fre- quency control algorithm.

The T-RAIM (Time-Receiver Autonomous Integrity Monitor) algorithm is used to monitor satellites to ensure signal integrity. The clock continues to distribute time and frequency signals even if the GPS input signal is lost. Furthermore, learning from its behaviour in different situations (effect attributed to aging and to temperature variations) while the GPS reference signal is present , the frequency driver improves on the accuracy of time and frequency distribution when the GPS signal is lost. Housed in a 19" - 1U rack, the equipment has a very compact structure. A display on front panel helps the user to program the working modes and to read the GPS status. LEDs on front panel gives to the operator a quick view of the status. The GPS Clock can be controlled by remote through a wired telemetry connector, via USB on front panel or via RS485 on rear panel.