Timing Reference for SatComm

The ViaLite range of fibre optic links connect antennas with control rooms, network operation centres or broadcast headends. In most SatCom installations a reference signal is required to lock oscillators in both up and down converters, the LNB and BUC or transceiver. It is not always possible to achieve this with internally generated signals in each piece of equipment. The ViaLite Timing Reference fibre optic link is designed to be used when a central timing reference signal is required to be distributed to remote locations in a SatCom installation using new or existing single mode fibre network.

Overview - Timing and Frequency Applications

Timing and Synchronisation Applications

The ViaLite Time & Frequency Fibre Optic Links have been designed to transmit accurate timing and frequency reference signals over optical fibre. This new transport platform services a growing need to access a reliable and very stable PRC (Primary Reference Clock) or UTC (Coordinated Universal Time) to maintain network and or system synchronicity.

Technical Specification - Low Frequency Timing Module

Public and Private networks and operating systems need to maintain a high level of integrity through accurate synchronisation. Accurately synchronised clocks are critical for network log file accuracy, security, billing systems, electronic transactions and database integrity. The new ViaLite Timing Reference Fibre Optic Link platform provides a low-cost method that enables RF timing distribution of various timing reference standards such a MSF, DCF, HBG, eLORAN, GPS GLONASS, Galileo etc., in addition to other common frequency reference signals at 1, 10 & 50MHz.

The ViaLite Time & Frequency Fibre Optic Link has now been used in many different situations. As an example the ViaLite platform has been deployed to facilitate cellular base station time slot alignment (i.e. handover in mobile networks avoiding drop calls) for TETRA, Wimax and other TDD based radio technologies.

In networks or operating systems that are extensive, it is not possible to access the NTS using standard Ethernet link. To fulfil the need for synchronicity in this case it is possible to deploy a point to multiple-point timing reference signal star-based topography using ViaLite fibre links. This approach is particularly well suited to SFN (Single Frequency Networks) where the primary off-air feed deliver a precise time and frequency reference to synchronised DVB / DAB servers to avoid picture freezing.

In another application seismic monitoring networks are deployed to map and measure seismic disturbances throughout industrial plants and exploration sites. The integrity of municipal building and structures are also monitored in regions of the world prone to seismic activity. Critical to mapping the extent of a seismic event is the synchronicity of data gathered from field-based sensor (also known as a geophone) array. Where the site coverage is extensive, PPM’s ViaLite GPS over PONs (Passive Optical Network) platform enables accurate time stamping from individual sensor elements, facilitating the acquisition of a coherent image of a seismic event across the entire site.

ViaLite products are INFOSEC, EMSEC and TEMPEST compliant, so guaranteeing the delivery of services such as GPS/ MSF Time signals, Digital TV, VHF / UHF Radio, Cellular and Satellite L- and C-Band. The use of secure optical fibre to deliver these services also provides added benefits in securing information gathering centres against lightning & EMP strikes, as well as preventing attempts to eavesdrop or corrupt critical operational and sensitive data.

PPM’s ViaLite Time & Frequency solution is easy to install in a plug and play manner.

Technical Specification - Low Frequency Timing Module