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) TELECOM Digest is an electronic journal devoted mostly but not exclusively to telecommunications topics. It is circulated anywhere there is email, in addition to various telecom forums on a variety of public service systems and networks including Compuserve and GEnie. Subscriptions are available at no charge to qualified organizations and individual readers. Write and tell us how you qualify: * telecom-request@eecs.nwu.edu * The Digest is compilation-copyrighted by Patrick Townson Associates of Skokie, Illinois USA. We provide telecom consultation services and long distance resale services including calling cards and 800 numbers. To reach us: Post Office Box 1570, Chicago, IL 60690 or by phone at 708-329-0571 and fax at 708-329-0572. Email: ptownson@townson.com. ** Article submission address only: telecom@eecs.nwu.edu ** Our archives are located at lcs.mit.edu and are available by using anonymous ftp. The archives can also be accessed using our email information service. For a copy of a helpful file explaining how to use the information service, just ask. TELECOM Digest is gatewayed to Usenet where it appears as the moderated newsgroup comp.dcom.telecom. It has no connection with the unmoderated Usenet newsgroup comp.dcom.telecom.tech whose mailing list "Telecom-Tech Digest" shares archives resources at lcs.mit.edu for the convenience of users. Please *DO NOT* cross post articles between the groups. All opinions expressed herein are deemed to be those of the author. Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- From: mds@access.digex.net (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 dleifker@mitre.org (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 . 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 | mds@access.digex.net avogadro@well.sf.ca.us Washington, D.C. | 74160.1134@compuserve.com mikesullivan@bix.com ------------------------------ From: n6oby@hebron.connected.com (Mark McClain) Subject: Re: Wanted: Alphanumeric Pager Software Date: Mon, 21 Mar 1994 05:21:07 -0800 Organization: Connected INC -- Internet Services Jeff Regan (jeregan@FLASH.LakeheadU.CA) 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 n6oby@hebron.connected.com Redmond, WA MCI Mail: 530-2222 206-885-6770 ------------------------------ From: nelson@crynwr.crynwr.com (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 stillson@mitre.org (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 ftp.msen.com:pub/vendor/crynwr/crynwr.wav Crynwr Software 11 Grant St. +1 315 268 1925 (9201 FAX) Potsdam, NY 13676 ------------------------------ From: wtm@uhura.neoucom.EDU (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 wtm@uhura.neoucom.edu 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 JMDCHICAGO@delphi.com 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: adamsd@crash.cts.com (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 (cmoore@BRL.MIL) 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 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 rbarry@iol.ie ------------------------------ From: plm@gandalf.inesc.pt (Paulo Libano Monteiro) Subject: E3 Interface Chips? Reply-To: plm@gandalf.inesc.pt (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 (plm@inesc.pt) INESC - R. Alves Redol, 9 1000 LISBOA PORTUGAL Tel: +351.1.3100285 Fax: +351.1.525843 ------------------------------ From: szurek+@pitt.edu (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 szurek@vms.cis.pitt.edu [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: padgett@tccslr.dnet.mmc.com (A. Padgett Peterson) Subject: Re: TIME Reports 80% Oppose Clipper Chip > yatesc@zeus.ec.usf.edu (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: cnorloff@tecnet1.jcte.jcs.mil 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: cro@ssdc-220.maxcy.brown.edu (Christoper Ogren) Subject: Re: Prisoner Starts Own 900 Number Reply-To: nm1z@anomaly.sbs.com Organization: Brown University Department of Computer Science Date: Sun, 20 Mar 1994 19:54:34 GMT In article , craffert@nostril.lehman.com (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 ****************************** ------------------------------------------------------------------------------- Downloaded From P-80 International Information Systems 304-744-2253