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For the most part, today's telecommunications and cable networks
include both local and long distance (or trunk) transmission links.
The long distance links are analogous to a jumbo jet: low cost
per mile, high miles per hour, and relatively quiet. The local
links are analogous to the late (but not necessarily lamented)
Carey bus or taxi service to JFK: high cost per mile, low miles
per hour, and noisy. "The Last Mile" is the term used to refer
to these local telecommunications links. As in travel, lack of
economies of scale in the last mile has made high tech solutions
too costly for residential customers and small to medium sized
businesses. The last mile - often actually a few hundred feet
- is the primary constraint barring the economical provision of
a variety of new services and limiting the acceptability of certain
existing ones (in particular, access to the Web). It's also the
battleground for competition between the telephone and cable industries.
It wasn't meant to be like this. A decade ago, we were told that,
before the year 2000, optical fiber to the home would herald in
the era of the "integrated broadband network." Hype. But, in the
shadows, work proceeded on a variety of more modest solutions:
in particular, cable modems, XDSL (which increases the digital
throughput of the telcos' existing copper loops by a factor of
10 to 50), and LMDS (a fixed broadband radio service). The Fall
1997 course entitled "The Last Mile" focused on these services
as they start to enter the marketplace, as well as on new satellite
services (ranging from the modest to the decidedly immodest) and
ISDN (whose obituaries may possibly prove to have been premature).
How do they work? How do they differ in what they will offer?
What implementation snags do they face? And so on. In addressing
these questions, my aims were also (1) to cover some underlying
theory useful in addressing similar questions about infrastructure
technologies which will emerge in the future, (2) to improve ability
to see through the smoke and mirrors, and (3) to provide practice
in understanding the complex interplay of markets, technology,
and regulation. -- Prof. Martin Elton
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