Recent Type Approval Testing of an eLoran Receiver for Telecom Applications - (PPT)

摘要

The European network of Loran transmitters has recently enjoyed a new lease of life with infrastructure support and investment from the governments of France, Norway and Great Britain. This means that Loran could now be considered for applications other than navigation if the service is robust and stable. One particular application which has been dominated by another off-air navigation service (GNSS) is the provision of timing for telecommunications networks. The UTC traceable timing stability of GNSS is leveraged to manage bit and packet rate timing in a telecom network. In recent times as GPS applications proliferate and instances of localised interference become more prevalent, Loran has emerged as a possible alternative contender for a technologically independent source of stability for use in telecommunications networks. The Eurofix UTC messages enable modern Loran receivers to become a UTC traceable timing element and therefore a source of "time" as well as "timing". The latest transmitter technology and significant advances in receiver internal firmware design and external antenna technology has eliminated or mitigated many of the sources of error traditionally found in previous generations of Loran receivers. These new features are important and mean that modern eLoran receivers are now capable of being considered as tactical timing elements in telecom networks. This paper examines recent testing of the timing performance of a modern eLoran receiver and compares this performance with telecom quality GPS receivers. The results are analyzed using the ETSI and ITU Standards for primary reference clocks in telecom networks as a benchmark.