This standard is known as ‘enhanced Primary Reference Clocks’ (ePRC) and is from the International Telecommunication Union (ITU) for timing characteristics of enhanced primary reference clocks. It has been introduced to raise the bar for frequency accuracy by an order of magnitude from 1x10E-11 to 1x10E-12.
All clocks in a network must be referenced to a Primary Reference Source (PRS). Microsemi says its Cesium frequency standards 5071A, TimeCesium 4400 and TimeCesium 4500 with ePRC compliance, provide the ‘highest level’ of autonomous frequency accuracy for PRS deployment in telecom networks as required by international standards.
According to data from the International Bureau of Weights and Measures (BIPM), responsible for managing the coordinated universal time (UTC) with time keeping institutions worldwide, and internal research from Microsemi, more than 99% of the Cesium clocks deployed for the world’s time keeping and national time standards are being driven by Microsemi’s Cesium products.
Microsemi has introduced a number of solutions which it says has provided customers within the communications, power utilities, public safety, data centre and government network markets with a secure and resilient timing environment, reducing dependency on Global Navigation Satellite System (GNSS). The foundation of these solutions are Microsemi’s Cesium atomic clocks, which provide an ‘autonomous frequency reference’ utilising enhanced timescale algorithms.
Microsemi’s BlueSky GPS Firewall, for example, can be connected to a Cesium clock to provide extended holdover by continuing to deliver a synthesised GPS signal to downstream GPS receivers, even in the case of complete loss of live sky GPS reception.
“As next-generation networks increasingly rely more on accurate time to achieve higher transport speeds and increased reliability, the pervasive use of GNSS technology as a time reference has become a major concern because of vulnerabilities to threats such as jamming and spoofing,” explains Ramki Ramakrishnan, director of product management at Microsemi. “As a result, use of Cesium technology as the primary reference clock has become critical.”
