In the United States the Federal Communications Commission (FCC) serves a watchdog role, overseeing the various telecommunications service providers to ensure that the general consumer receives high-quality, fair-priced telecommunications services. Now, every telecommunications executive is familiar with the phrase "FCC-reportable outage." Any service outage that affects more than 30,000 subscribers must be reported to the FCC and the general process is involved, costly and an onerous drain on resources - economic and human. In an industry report available at http://www.atis.org/pub/nrsc/jrunyonpresentation.pdf, a blue-ribbon panel ascertained that fully 9.4% of all FCC-reportable outages were related to timing during 2000-2001. Analysis of the report and its findings and recommendations indicates that if just a little more attention were given to synchronization, most of these timing related outages could have been prevented. Two shop-worn clichés come to mind: "an ounce of prevention is worth a pound of cure", and "a stitch in time saves nine" - or, in the case at hand, nine-point-four.
The need for synchronization arose primarily because of the transformation of the network from analog to digital. The original telecommunication network was geared to handle telephone traffic and was achieved by establishing analog paths between end-point station sets (telephones). Sync was not a major consideration, the focus being on minimization of additive noise and maintaining signal-to-noise ratio (SNR). In the modern telecommunication network voice signals are digitized and, once in digital form, are transported as bits (or octets) and the notion of additive noise is replaced by the notions of bit-error-rate (BER) and slips. Bit-error-rate is related to the ability of transmission systems to deliver information (bits) over a transmission medium (copper, fiber or radio); a slip is a phenomenon related to sync and timing. Modern equipment can provide excellent BER performance, a feature rendered moot if the associated sync is inadequate.
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