TELECOM Digest     Mon, 21 Mar 94 09:52:30 CST    Volume 14 : Issue 140

Inside This Issue:                           Editor: Patrick A. Townson

   Re: CDPD, PCS, PCN, and Digital Cellular? (Michael D. Sullivan)
   Re: Wanted: Alphanumeric Pager Software (Mark McClain)
   Re: Boca V-Mail Modem: Request For Tech-Specs (Russell Nelson)
   Re: History of the Term "Switch" (Bill Mayhew)
   Re: Local CID Showing Out of Area (Cliff Sharp)
   Re: 911 Used From Car Phone (Douglas Adams)
   Cut-Rate Domestic and International Calling Cards (Richard Barry)
   E3 Interface Chips? (Paulo Libano Monteiro)
   Cordless Question (Joseph R. Szurek)
   Re: Time Reports 80% Oppose Clipper Chip (A. Padgett Peterson)
   Re: Prisoner Starts Own 900 Number (Chris Norloff)
   Re: Prisoner Starts Own 900 Number (Christoper Ogren)

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From: [email protected] (Michael D. Sullivan)
Subject: Re: CDPD, PCS, PCN, and Digital Cellular?
Date: 20 Mar 1994 01:33:37 -0500
Organization: Express Access Online Communications, Greenbelt, MD USA


[email protected] (Dan Leifker) writes:

> I am taking an introductory (grad level) course in telecommunications,
> and the professor has asked us to write a short paper defining the
> following terms: digital cellular, CDPD, PCS, PCN, and wireless.  I
> have been scouring the area (Washington, D.C.) and have found almost
> nothing in the way of technical literature.  Could some kind soul
> outline the differences between these terms and give me some pointers
> for more information?

Two DC-area sources you should contact: CTIA (Cellular Telephone
Industry Association) at 202-785-0081, and PCIA (Personal
Communications Industry Association, formerly Telocator Network of
America) at 202-467-4770.  Both of these trade associations are
involved with all of the technologies you mention.  In fact, they are
essentially competing trade associations.  (Only in Washington! Only
in America!)  (When looking for specialized information in Washington,
one essential starting point is TRADE ASSOCIATIONS -- they ALL have a
Washington presence.  Wonder why?)

My take on a not-so-simple answer to your question is as follows:

(1) digital cellular is (generically) cellular telephone service that
uses digital transmission for the voice channels as well as the
control channels.  Mobile/portable telephone service is "cellular" if
it employs base stations that transmit over relatively short (<20
mile) radius distances, with overlapping coverage "cells".  Less
generically, US cellular service operates in the 800 MHz band on
defined frequency blocks, of which there are two (the A block and the
B block), so there are two carriers.  All US cellular carriers are, at
present, required to support analog cellular service, which uses
digital control channels and analog voice channels.  This is known as
the "AMPS" standard (after Advanced Mobile Phone Service (AT&T's
moniker circa 1979)).  The FCC allows cellular carriers to use other
technology as well as analog, as long as they keep compatibility with
analog for the benefit of the installed base.

There are one analog and two digital alternative standards that have
developed.  The analog alternative is N-AMPS, for Narrowband AMPS,
developed by Motorola, which can increase system capacity by up to 3x.
Digital alternative #1, which was recently turned on by the B carrier
in DC (Bell Atlantic) is TDMA, or Time Division Multiple Access.
Digital alternative #2 is CDMA, or Code Division Multiple Access.  The
difference between these is too complicated to explain now, but basic-
ally, TDMA is here now and can increase capacity 3-6x over analog,
while CDMA is about a year or so further down the road and can
increase capacity (I think) 10-20x over analog.  The technology used
is very different; TDMA uses time-slices of conventional channels to
derive multiple channels, while CDMA uses spread-spectrum
transmission, which is conceptually like teleportation in the old
Superman comics -- break the message up into tiny bits that get trans-
mitted at quasi-random frequencies and get reassembled at the end --
except that it works.

In Europe, they use different frequencies and protocols, but digital
cellular there is TDMA without any analog compatibility; the standard
is known as GSM (Groupe Systeme Mobile).  The irony is that digital
cellular systems are optimized for voice (using adaptive decoders,
etc.) and are unlikely to be as good for carrying modem calls as
analog systems, at least in the immediate future.

(2) CDPD -- Should be CPDP, Cellular Packet Data Protocol -- This is a
system that the cellular industry has developed for squeezing pure data
transmissions in between cellular voice calls.  Cellular systems use
multiple channels for transmitting voice calls, and there may be gaps
when a channel is not needed for voice transmission, but in busy systems
these gaps will be pretty short.  CPDP allows the carrier to send data
packets whenever there is a gap; the receiver has to switch back and
forth between the channels to get all the packets, then reassemble them.

(3) PCS -- Personal Communications Services -- this is defined by the
FCC so broadly as to be generic.  Basically, a family of services
allowing for tetherless (i.e., not tied down to the telephone network)
communications connected to a variety of networks.  The generic
definition includes cellular, paging, cordless telephones, and many
other existing services.  The FCC has allocated spectrum from the 900
MHz band for "new narrowband PCS" -- also known as advanced messaging
services, such as mobile data, portable email, and two-way paging --
and from the 2 GHz band for "new broadband PCS" -- which includes,
potentially, clones of today's cellular service, as well as
"microcell" service, with base stations that may be only 1000 feet or
so apart, oriented toward handheld service for pedestrians, not
motorists.  The 2 GHz band also has an allocation for "unlicensed
PCS," which could include new generations of cordless telephone
service that include public microcell access (known as CT-2, CT-2+,
and CT-3, in some of its iterations), wireless LAN, and any number of
other mobile/portable low-power voice and data applications, such as
wireless PBX access.

(4) PCN -- Personal Communications Network(s).  This is the name the
U.K.  gave to a specific frequency allocation for PCS.  It was
supposed to be a microcellular service but was also supposed to
compete with cellular and landline service.  Three licenses were
awarded.  Two systems merged and the resulting joint venture is
on-line; and one is yet to go on.  The on-line system, known as
Mercury one2one, is a joint venture of Mercury (the MCI of the U.K.)
and US WEST; Mercury one2one is offering a service that is
functionally similar to cellular, using a 1.8 GHz port of the GSM
digital cellular spec.

(5) WIRELESS -- without wires <g>.  In the olden days, this was the name
for what we know as radio.  The name stayed around longer in the U.K.
Now it seems to mean about the same as PCS -- mobile or portable
communications connected to the wireline network.  I.e., you can use it
like a phone, but no wires.

> Are these things in a competitive sort of relationship?

Broadband PCS *will* be in competition with cellular (analog and
digital), when it happens, more or less.  Narrowband PCS *will* be in
competition with CPDP and other mobile data services, when it gets off
the ground.  PCN is in the U.K., so it can't be in competition with
any of these.  All of the above are wireless, as is AM, FM, TV, and
garage door openers; I refuse to opine whether garage door openers,
Howard Stern, or Oprah Winfrey are likely to be in a competitive
relationship with Cellular One (which is a generic name, and not a
specific company; the name is owned jointly by McCaw and Southwestern
Bell).

> (I'm not asking anyone to do my work ... I'm just looking for a starting
> place.)

Yeah, right.

P.S., in the interest of full disclosure, I'm an attorney with the
firm of Wilkinson, Barker, Knauer & Quinn, practicing in the area of
cellular, PCS, and other wireless services before the FCC and the
federal courts, and I was (in a previous life as a government
attorney) responsible for writing the original cellular rules.
Therefore, I know at least some of what I just said is probably right.
This is not a legal opinion; you have to pay for that.  None of the
above necessarily reflects the views of my firm or my clients.


Michael D. Sullivan | [email protected]        [email protected]
Washington, D.C.    | [email protected]     [email protected]

------------------------------

From: [email protected] (Mark McClain)
Subject: Re: Wanted: Alphanumeric Pager Software
Date: Mon, 21 Mar 1994 05:21:07 -0800
Organization: Connected INC -- Internet Services


Jeff Regan ([email protected]) wrote:

> Anybody know of a source for software that will use the modem to dial
> an alphanumeric pager and to send a message to that pager?

> Motorola uses these keyboard-like devices now.  It would be nice to
> replace them with software.

If you are using Windows, you might try to pick up a copy of 'MessageFlash'
from your nearest McCaw office. It's a pretty cool package and usually
available at no cost. I have it and it works well. Good luck.


Mark S McClain   [email protected]
Redmond,  WA   MCI Mail: 530-2222   206-885-6770

------------------------------

From: [email protected] (Russell Nelson)
Subject: Re: Boca V-Mail Modem: Request For Tech-Specs
Date: 20 Mar 1994 08:55:50 GMT
Organization: Crynwr Software


In article <[email protected]> [email protected] (Ken
Stillson) writes:

> The hardware manual casually mentions a few of the extended AT#
> commands used for the voice-subsystem, but doesn't give anywhere near
> enough details to actually use them.

> Does anyone know (or know where to get) more information on how to
> directly use the voice system, so one can write their own software?

This card, also known as the Computer Communicator EZ (the half-length
card w/ diagonal cut), is very easy to program.  Call Cirrus Logic,
and ask for their "CL-MD9624AT/EC2 Programmer's Guide".  They're at
1-408-436-7110.

And, it's only $69 from PC Connection, 800-800-5555, +1-603-446-5555.


russ <[email protected]>  ftp.msen.com:pub/vendor/crynwr/crynwr.wav
Crynwr Software  11 Grant St.  +1 315 268 1925 (9201 FAX)  Potsdam, NY 13676

------------------------------

From: [email protected] (Bill Mayhew)
Subject: Re: History of the Term "Switch"
Organization: Northeastern Ohio Universities College of Medicine
Date: Mon, 21 Mar 1994 10:33:27 GMT


When I was a kid, my dad worked as an administrator for the local
school system.  The then Ohio Bell regularly provided mountains of
wonderful public relational material to the schools.  Items ranged
from preschool telephone etiquitte type stuff to gradeuate school
level technical briefs.  The Bell System also provided many films.

If I reall correctly, the "Mr. Watson" wrote a wonderful little
booklet called, "The Birth and Babyhood of the Telephone."  There is
are a lot of neat reminissnaces and many pictures of early
telephonica.  There is one picture of a switchboard that, I believe,
has four eight-position rotary switches that have what looks like a
knife switch handle that can be moved to contact eight thumb-tack like
contacts arranged in a circle: completely manual, of course.  I had
that book for many years, but can not locate it at the moment.  I
don't remember if that was supposedly the first switchboad or just an
early example.

With the advent of divestiture and cost slashing, I suspect that much
of the material provided for schools by the former Bell Ssytem is long
gone.


Bill Mayhew        NEOUCOM Computer Services Department
Rootstown, OH  44272-0095  USA      phone: 216-325-2511
[email protected]       amateur radio 146.58: N8WED


[TELECOM Digest Editor's Note: Yeah, the present day people running
the company don't seem to care much about that stuff any longer.  We
used to get a lot of that material when I was in school also.   PAT]

------------------------------

From: indep1!clifto (Cliff Sharp)
Date: Mon, 21 Mar 1994 07:24:45 CST
Subject: Re: Local CID Showing Out of Area


In article <[email protected]> [email protected] writes:

>> When CID was deployed in my area (516 area code), I tried calling home
>> from a pay phone and the number was displayed.  However, when I call
>> home while I'm having my car serviced at a local service station, the
>> number doesn't show.

> This sounds to me like your area might be served by a CO with two
> vintages of switches (i.e., one is SS7 compatible, and the other
> isn't) The Nynex telephone is probably connected to the SS7 compatible
> switch in that CO and the COCOT telephone is probably connected to the
> non-SS7 switch.  As you can see, this also results in some prefixes in
> your exchange being able to get and display CID and the rest not being
> able to.

  It's not necessarily even that the other switch isn't SS7-compatible.
Lombard, IL, for the longest time, had a 5ESS which delivered CNID and
a 1AESS which didn't.  My friend at 708-916-xxxx was always identified,
and my friend at 708-932-xxxx wasn't.

  A call to customer service some time last year got me the information
that they hadn't even scheduled the 1AESS for the software update that
would allow CNID to be sent!  However, around December (I think), my
other friend's name and number suddenly started showing up.

  Might be a nit, but even if the software wasn't SS7-compatible, the
switch certainly was/is ...


Cliff Sharp  WA9PDM

------------------------------

From: [email protected] (Adams Douglas)
Subject: Re: 911 Used From Car Phone
Organization: CTS Network Services (CTSNET/crash), San Diego, CA
Date: Mon, 21 Mar 1994 07:03:01 GMT


Carl Moore ([email protected]) wrote:

> KYW news-radio has noted the use of 911 from a car phone.  That's
> apparently how a tanker-truck crash at Conshohocken, PA was reported
> (this happened on I-76/I-476 interchange) this week.  The driver of
> that truck was killed, and nobody else was hurt.

There was an instance east of San Diego here two winters ago. A hiker
got lost and couldn't find his way back to the road. Snow was blowing
in, so he pulled his cellular out of his backpack and dialed 911.
Choppers were sent and they found him in less than an hour.

Ironically, he was less than 1000 feet from his car at the time.

------------------------------

From: Richard Barry <[email protected]>
Subject: Re: Cut-Rate Domestic and International Calling Cards
Date: 21 Mar 1994 18:59:41 -0000
Organization: Ireland On-Line


> I have heard of a company that presumably offers calls to Finland at
> about $0.45 per minute.  That does not sound unreasonable to me as one
> can call Germany for way less than that.

[stuff deleted]

> [TELECOM Digest Editor's Note: If you are getting international calls
> between the USA and Europe for 45 cents per minute you are not getting
> a bad deal at all. I cannot imagine calling Germany from the USA for
> 'way less' than 45 cents per minute.   PAT]

There is a (US based) company providing calls to the USA from Ireland
for 20p (30 cents)/minute weekends -- it used to be as low as 16p/min
until a few weeks ago.  It operates through a local access number and
subscribers pre-pay for a block of message units in advance.  I believe
they also have access numbers in the UK and perhaps other states.

Surely there is no reason why a transatlantic call should cost more
than a coast to coast call in the US -- maybe a cent or two a minute
more/minute at most, in a competitive market? The days of the 30 channel
transatlantic submarine cables and bad connections are gone. Unfortun-
ately, many of the established operators in the market still want to
hang on to the good old rip-off international call pricing. Fortunately
their days are numbered!


Richard Barry   Ballsbridge
IRL-Dublin 4    [email protected]

------------------------------

From: [email protected] (Paulo Libano Monteiro)
Subject: E3 Interface Chips?
Reply-To: [email protected] (Paulo Libano Monteiro)
Organization: INESC - Inst. Eng. Sistemas e Computadores, LISBOA. PORTUGAL.
Date: Mon, 21 Mar 1994 12:25:05 GMT


I'm looking for chips to implement an E3 interface (34.368Mbit/s), both
the framing and line interface functions. And ATM cells over 34.368Mbit/s.
Any advice would be appreciated (please e-mail me).


Thanks,

Paulo Libano Monteiro   ([email protected])
INESC  -  R. Alves Redol, 9  1000 LISBOA   PORTUGAL
Tel: +351.1.3100285   Fax: +351.1.525843

------------------------------

From: [email protected] (Joseph R Szurek)
Subject: Cordless Question
Date: 21 Mar 94 12:33:43 GMT
Organization: University of Pittsburgh


Can anyone tell me if the base station for a cordless phone broadcasts
all calls on the line or just when the cordless handset is on.  This
came up in a discussion of how private your conversations are when you
have a cordless phone in the house.


Thanks,

J. Szurek   [email protected]


[TELECOM Digest Editor's Note: The base should not be transmitting anything
when the cordless is not in use. I've seen older cordless phones whose
base would respond to spurious radio signals of one kind or another and
as a result cause interference on wired phones. An old cordless of mine
a number of years ago was very sensitive to illegally high power from CB
radios, and when a neighbor of mine talked on his CB (at something like
a thousand watts) it caused the relays in my cordless base to chatter and
in turn messed up my wired phone and (I suspect) transmitted my wired
calls as a result. But normally, no -- the base should remain silent if
the cordless handset is not in use.   PAT]

------------------------------

Date: Mon, 21 Mar 1994 02:47:20 -0500
From: [email protected] (A. Padgett Peterson)
Subject: Re: TIME Reports 80% Oppose Clipper Chip


> [email protected] (Charles Randall Yates) writes:

> Why shouldn't the government have the right to listen in? Any
> law-abiding citizen should have nothing to hide. I'm for it.

Sorry for the quoting but having nothing to hide has nothing to do
with it. The issue here is not whether "our homes, person & papers"
are safe from search but whether we can trust a third (or fourth, or
fifth...)  party to secure our communications and *that* is something
very different.

I *expect* everything that transmitted electronically is subject to
search (whether legal or not, will never know that it happened unless
someone *else* tells me). Therefore *it is my responsibility* to make
sure that what goes out is only what I want to send under those conditions.

Has nothing to do with what I want or permit.


Warmly,

Padgett

------------------------------

Date: Mon, 21 Mar 1994 00:17:39 EST
From: [email protected]
Subject: Re: Prisoner Starts Own 900 Number


> ...As the date draws near for Gacy's execution -- this time, no
> more stalling or delays -- a group calling itself the American
> Civil Liberties Union has stated it will intervene to prevent
> Gacy from being persecuted further by the state and the
> criminals in our society of which Gacy is but a victim.

I can understand your revulsion at someone protecting a criminal's
rights, but the law applies to the criminals and to the non-criminals.

> Those folks are forced to pay perfectly outrageous rates for
> collect calls from their loved ones in prison because the
> prisoners can no longer place calls via Genuine Bell. Rates of
> three or four dollars *per minute* ...

> ... the AOS's are ripping off the families of prisoners big-time having
> them as a captive customer base.

Evidently you, too, think criminals have rights, sometimes.


[TELECOM Digest Editor's Note: Well certainly their families and
friends have rights, and they are the ones paying for the calls. Until
about 1970 prison inmates were not allowed to use phones at all. Commun-
ication with the outside world is a fairly recent innovation. Jail in-
mates have always gotten their one free phone call since about 1905, but
the routine use of payphones for other calls in jails began during the
1970's also. By virtue of their position, AT&T had all the corrections
payphone business for several years and they took a bad beating on it;
it was probably one part about competition AT&T liked -- let the COCOT
operators have it; that was their attitude. :)   PAT]

------------------------------

From: [email protected] (Christoper Ogren)
Subject: Re: Prisoner Starts Own 900 Number
Reply-To: [email protected]
Organization: Brown University Department of Computer Science
Date: Sun, 20 Mar 1994 19:54:34 GMT


In article <[email protected]>, [email protected]
(Colin Owen Rafferty) writes:

> The Eighth Amendment explains how cruel punishments shall not be
> inflicted.  What can be a crueler punishment than execution?

Mind you, 'cruel' in a relative term.  Cruel in who's eyes?  The
convicted might think any punishment is cruel or maybe he/she might
think life imprisonment is cruel.

Hmmm.  Certainly makes for interesting discussion.  I just didn't think
I would find it here.


[TELECOM Digest Editor's Note: And you won't find it here. We have
strayed too far from the topic.  Poof! To the bit bucket with all of you!
Nice discussion, but one of those that never comes to an end.   PAT]

------------------------------

End of TELECOM Digest V14 #140
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