Re: The embarrassment of American broadband

[David Farber <dave () farber net>]

Begin forwarded message:

From: Brett Glass <brett () lariat net>
Date: April 30, 2009 12:12:49 PM EDT
To: dave () farber net, "ip" <ip () v2 listbox com>
Subject: Re: [IP] Re:     The embarrassment of American broadband

At 09:34 AM 4/28/2009, David Reed wrote:

> Here's why American "broadband" is an embarrassment.  Ignorance at all
> levels.

I disagree. There are many, many smart people out there, all working  
very hard to deploy the best broadband possible. Not all of them  
understand all the parts of the puzzle, but that's OK; there's plenty  
of room for specialization.

The big problem is that many of our country's policy makers fully  
understand NO piece of the puzzle, and are frequently misled by  
special interests which want to steer our nation's policy off course  
so as to serve their own interests. For example, many of them have no  
idea that lobbyists who come to them preaching "network  
neutrality" (which sounds like a sensible idea) are in fact promoting  
the corporate agendas of Internet content providers and advertisers  
such as Google at the expense of the public good.

> As a technical term, broadband is not the opposite of "baseband", nor
> does it have anything to do specifically with multiplexing, FDM or
> otherwise. Broadband is the opposite of Narrowband - to an engineer.

As an engineer who has worked on networks in the field for more than  
30 years, I can state with authority that this is not correct. The  
antonym of "narrowband" is "wideband," which denotes a a single  
transmission that uses a large percentage of the usable spectrum  
within the medium.

To someone who hears the term but is not familiar with its real world  
usage, "broadband" sounds like it might mean the same thing. However,  
in real world usage, it means that there are multiple transmissions  
occurring over the same medium, and that these transmissions are  
multiplexed by frequency. Early in my career, I worked extensively  
with IBM broadband LAN equipment. (I believe that I still have one or  
two of the cards in storage.) This short lived technology realized  
significant cost savings because it did not require buildings to be  
rewired for data. It worked, albeit at low speeds, over existing CATV  
cables within a building or group of buildings. Because it used  
different frequencies than the video (which was sent through the cable  
using the same standards as over-the-air TV), it did not interfere  
with it.

Ironically, while this IBM product was short lived, it has left behind  
a legacy which persists to this day: it contained the first  
implementation of IBM's NetBIOS protocol. Virtually every computer  
sold today contains software that can implement this protocol, which  
still forms the basis of Microsoft's file and printer sharing  
software. (Aside: when I wrote an article on NetBIOS for BYTE magazine  
in 1985 and was asked by the editors for a programming example, I  
included the Turbo Pascal source code for a program which -- I am told  
-- caused countless hours of time to be wasted in offices around the  
world. It was called "NetChat," and was, as far as I know, the first  
IM program for IBM PC networks -- very similar to Twitter. Plus c,a  
change....)

But I digress. In any event, modern commercial cable TV systems --  
which transmit video in one direction on some frequencies and two-way  
high speed Internet on others -- are another example of broadband.

In "baseband" transmission, one transmission -- which is not modulated  
onto a "carrier" signal as it is when frequency division multiplexing  
is done -- monopolizes the entire medium. In the optimal case, the  
bandwidth of the transmission is close to that of the medium itself  
(though in many real world systems it is limited to reduce RF leakage  
through the shielding of coaxial cables).

> However, this has nothing whatever to do with the policy debate
> surrounding the term "Broadband".   In that debate, Broadband means
> whatever the cable and telcos want it to mean.  Sometimes it means
> High-Speed Internet Access.  Sometimes it means lots of TV channels.

I agree. And this ambiguity is unfortunate. It would help to clarify  
the debate if people used the terms "high speed Internet access" when  
that was what they meant, and "broadband" only when they meant a mix  
of services that shared a common medium via frequency division  
multiplexing.

--Brett Glass





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