Time and Frequency Distribution
Power grids, cable plants, telecom switches, commercial time-scales and other time-based systems need not only a precise time and frequency source but also a reliable method to acquire time and frequency from the source. Symmetricom has both ends covered (and every point in between). We understand the factors that can introduce time and frequency errors anywhere across the distribution chain — and how best to mitigate them. Learn about today’s best technologies for distributing precise time and frequency in complex, highly synchronized systems.
The Precise Time-Scale system is a fully integrated, world class timing system capable of providing timing accuracies comparable to the best national laboratories. It can combine up to six high performance cesium frequency standards or active Hydrogen Masers in a time scale that drives the local real-time clock (RTC) signal. A high performance timing quality GNSS receiver provides the information used to steer the system output to UTC and generate GPS common-view (CV) data. This allows the frequency standards to be reported to the BIPM for inclusion in the international time scale.
The Precise Time-Scale System is a fully integrated solution that provides industry leading frequency stability, phase-noise performance and Time-Scale availability in a unit as small as one instrument rack.
Satellite two-way time transfer has traditionally been used as a periodic measurement of the offset between two-clocks. It is often used as a secondary measurement to GPS or a sole means of time recovery with performance that is superior to GPS time transfer. In this paper, we propose a continuous two-way system based on commercial modems where the two-way time transfer is performed in the background of normal data transfer.
Besides electricity, regional power authorities must also learn to distribute synchronized time across the gird if they want to prevent blackouts like the one on August 14, 2003. This white paper delves into the role of time, specifically synchronized time, in looking at the conditions leading up to this event.
During the recent spate of hurricanes and tropical storms that punished the state of Florida, Loran-C once again demonstrated its robustness under the harshest of environmental conditions. However, this weather “attack” pointed out the need for emergency capability in the event of other types of attacks, for critical infrastructure protection, or simply for rapid deployment of Loran for tactical use. This paper discusses the concept of, and the need for, a modern Tactical Loran system. We also provide a conceptual framework under which Low Cost Digitally Enhanced Loran for Tactical Applications (LC DELTA) might be developed.
This white paper focuses on the Xli Time and Frequency System. Continuously locked to GPS, the disciplined 5071A Cesium Oscillator Option is an ultra precise time and frequency reference that offers the ultimate in stability against environmental effects.
1999, U.S. Congress has continued to provide funds via the Federal Aviation Administration (FAA) to develop and recapitalize the LORAN-C infrastructure. As a result of this recapitalization, the timing systems at the LORAN-C transmitting stations are being upgraded from its 1960’s technology. This paper re-introduces LORAN-C with an emphasis on the improvements that are being provided to the LORAN-C user community and the timing performance and applications of the new system. These improvements include new timing systems, new transmitters and new user equipment.
Maintaining synchronization in a DOCSIS network is critical. Without accurate and precise synchronization, cable modems will transmit at the wrong time causing complete loss of transmission. This white paper discusses how an M-CMTS architecture can be reliably deployed with a variety of configurations to meet the scalability and economic requirements of each cable operator.