0004133373@mcimail.com (Donald E. Kimberlin) (03/27/91)
Numerous posts in the Digest are from people puzzled by a wide
variety of what seems to be the "secret lore" of telecommunications.
And, not all the people who seem puzzled are neophytes. Some are even
graduate Electrical Engineers who confess that despite all their
formal education, they have a problem fitting their knowledge into the
framework "the phone company" seems to operate in. Among the self
educated, or life-experienced, the major gap seems to be transmission
technology. And, of course, today's digital methods make understanding
of transmission matters an absolute must.
There have been books over the years, but the "fog factor" in
the classic books is enormous. It's not that the writers were bad
people; neither were they incompetent. Their largest problem was most
likely trained into them ... that of trying to be exactly correct and
make no error of accuracy in describing systems. This is intrinsic to
learning to be a trained technologist. But, explaining everything of
telecommunications technology with complete accuracy in simple, short
sentences would make for a book longer than you want to read.
Today, I received a new book (1991 copyright) that really
impressed me; one I can recommend to the puzzled "outsider." Robert
L. "Bob" Dayton, its author, is a name known to many as a long-term
"mouthpiece" for AT&T's marketing departments. He takes no credit for
this in the book. In fact, there's no comment attached to him nor any
biography in the book ... just his name alone as the author. But, for
those who have read his material over the years, he's very
recognizable.
Bob's book focuses on taking extreme care to minimize the
math, and use simple mechanical analogies and examples as much as
possible. He succeeds in doing so in large measure. You'll see
examples like a bean jar with an input hopper and bean gate at the
top, an output chute with a bean gate run by another clock, and a bean
overflow in case the two clocks drift apart. What's the operation? A
"bean buffer," of course ... and a great explanation of a bit or
character buffer as used in electronics. In a whole, short chapter
(only eleven fast-reading pages), you'll build a "FUNMO" -- Bob's
homemade acronym for "FUNdamental MOdem." In those eleven short
pages, Bob even finds a way to show how Phase-Shift and Quadrature AM
modems do their job, and why. That's a topic most so-called "datacomm
books" just avoid trying to explain. Right after that, he has you
building a "HYPOMUX," or "HYPOthetical MUX." And, he gives similar
simple explanation of the functional parts of a digital multiplexer.
Bob makes no bones that there are times when he cuts corners
in order to simplify. He makes no claim for writing an engineering
text. But, he succeeds, as I read it, beautifully in being 90 percent
or more accurate while reducing the "fog factor" to near invisibility.
This first edition does have some typos ... I found a severe
one concerning the overall net loss of a four-wire data circuit, and
in an anecdotal line about changes in "the phone business" since the
Bell breakup, he's relating that in the monopoly era, a Telco employee
could get a billing complaint from anyone who found out where he
worked, saying, "However, working at the phone company never solicited
complaints." I'm sure that sentence was supposed to say "... never
solicited compliments." In the context, it makes no sense otherwise.
And, even as broad a mind as Bob's can't avoid some of the "good old
System" and its viewpoint. There's a decided lack of notice taken
that the ultimate digital systems of today had roots going back to
telegraphy. Instead, there's but passing mention that the telegraph
existed first, but no mention that anything of significance descended
from it. In one statement, he makes light of use of the terms
"marking" and "spacing" for binary 1 and 0, and the use of bipolar
signaling as simply " a leftover from telegraph days." In fact,
telegraph engineers used polar signaling to get longer reach, just as
RS-232 does. In the following paragraph, he then describes AMI
(Alternate Mark Inversion) in T-1 span lines in terms that make it
sound like the telephone people discovered all the good reasons for
having bipolar signals on line.
Despite any editorial or technical imperfections, or even the
(quite minor) Bell bias one can find, I regard Bob's work as one of
real value to the puzzled neophyte in telecommunications ... even
entertaining and illustrative to writers and teachers about "the
business."
So, I really mean it when I say, "You should read THIS book:"
Telecommunications (The Transmission of Information)
Dayton, Robert L., McGraw-Hill, 1991, 184 pp., case bound
ISBN 0-07-016189-5
(My book club's price: $27.95)
I really think you'll be glad you got this one!carols@drilex.dri.mgh.com (Carol Springs) (04/02/91)
In Volume 11, Issue 245, Donald E. Kimberlin highly recommends the following new book which he received through his book club: > Telecommunications (The Transmission of Information) > Dayton, Robert L., McGraw-Hill, 1991, 184 pp., case bound > ISBN 0-07-016189-5 > (My book club's price: $27.95) I called the McGraw-Hill bookstore at corporate headquarters this morning to order this book. I just received a voice mail message from the bookstore saying that the book shows up as not having been published yet, and that the warehouse doesn't know exactly when it will be available. So don't be surprised if the book isn't in bookstores and libraries yet and if your efforts to get a store or library to order a copy are unsuccessful at first. The general public may have to wait a few weeks longer for the book. The woman from the McGraw-Hill bookstore recommended that I try my order again at a later time. I shall do so. Carol Springs carols@drilex.dri.mgh.com