Typing Your Modem.....................................................................................
The original concept of a modem was a way for a digital computer to produce
a communications signal that could be sent over the standard pair of copper
wires that exist within the telephone cable that goes into most homes and
offices. (Techies, as is their style and need, have even made up a name and
acronym for this century-old technology: POTS,for plain old telephone service.)
In this section I talk about the three most common direct-connection modems:
Dial-up telephone modems
Cable modems
DSL telephone modems
Cable and DSL modems, because they are capable of much greater capacities,
are considered broadband technologies.
Chapter 14 talks about two other gateways to the Internet and to various
devices in your home or office: WiFi and Bluetooth wireless communication.
For many laptop users, dial-up telecommunication is becoming less and less
attractive, replaced by WiFi communication that can connect to high-speed
Internet at commercial hotspots, Internet cafes, hotels, and at the offices of
clients. Hotspotsare public-access points within range of a wireless transmitter/
receiver for the use of visitors, subscribers, and workers.
Telephone modems ............................................................................
The first telephone modems for personal computers poked along at an
anemic 110 bps; the first modem I worked with, in a wire service newsroom,
was a box of wires and flashing lights that could move the news to a teletype
machine at about 75 bps.
Over the first two decades of the PC and laptop, modems advanced fairly
rapidly from 1,200 to 56,000 bps. Engineers have done an amazing job of
squeezing every possible bit of performance from the old phone system, but
today not much effort is being applied to new research here. It is at that 56K
point that consumer modems reached the limits of POTS.
And even though your modem may claim the ability to communicate at
56,000 bps, the truth is that in many parts of the United States and elsewhere
around the world, the POTS has not been upgraded for decades. I’ve worked
in places where the realistic speed limit for communication over old copper
Chapter 15: Modems: The Essential Translators .......................................................
