POTS to broadband... Part 1: Anatomy of the telephone system for data communication.

Abstract

Biomedical Instrumentation & Technology 277 This installment of IT World takes a look at the evolution of POTS (Plain Old Telephone System—and for my regular readers, I did not invent this acronym!) and modems to set the scene for examining newer “broadband” services. As usual the terminology gets a bit blurred in everyday use. This is why I put quotation marks around the broadband term—I’ll show you what I mean later in the column. We’ll talk about data communication on analog phone lines and digital lines along with their expected transfer speeds. In part 2 of this column, in the September-October issue of BI&T, I will focus on ISDN, X.25, Frame Relay mechanisms and protocols. This all leads to a discussion of xDSL, the latest in telephone broadband connections to telephone subscribers. I’m hoping to also cover broadband data communications via CATV cables and systems in part 2 (This is contingent on how wordy I get in part 2. The CATV portion may be delegated to a part 3). In any event, at the end of the discussion, we’ll be able to compare the virtues and disadvantages of each of these broadband techniques.