TELECOM Digest Tue, 31 Jun 94 07:07:00 CDT Volume 14 : Issue 259 Inside This Issue: Editor: Patrick A. Townson Some D-Day Telecom History (Donald E. Kimberlin) Book Review: "Exploring the Internet" by Malamud (Rob Slade) Communication Courses at Berkeley This Summer (Richard V. Tsina) Dialing Changes For West Virginia and Connecticut (Carl Moore) Pac*Bell Plans to Become Internet Provider? (Robert L. McMillin) Current List of Areacodes Wanted (Michael Conley) How do You Simulate Telco Battery Voltage? (Kevin Centanni) ETSI Contact (Joao Perdigoto) Why Does Long Distance Cost Extra? (James Baker) Cost of Caller ID in PA (Greg Vaeth) 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. 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Any organizations listed are for identification purposes only and messages should not be considered any official expression by the organization. ---------------------------------------------------------------------- Date: Mon, 30 May 94 15:56 EST From: Donald E. Kimberlin <0004133373@mcimail.com> Subject: Some D-Day Telecom History As the 50th anniversary of D-Day nears, here are a couple of sntaches of an incomplete story about the parts radio people played in the largest invasion so far accomplished by man. There were at least two relatively unpublished items of interest to the technically-inclined about radio in that era: First, there are lots of recordings of bits of Edward R. Murrow from London during the blitz, as well as other correspondents like Richard C. Hottelet dating back to before D-Day. Bear in mind we are speaking here of a time before telephone cables crossed the Atlantic (although 21 telegraph cables had been laid dating back to 1866, so "cablegrams," competing with RCA's "radiograms" were the business communications norm of the era for civilians). There was telephone connectivity available, dating back to 1927. In addition to the one (ever) low-frequency telephone circuit between New York and London (50 kHz USB eastbound; 60 kHz USB westbound), HF radio links that operated ISB with channel shifters to produce two 3 kHz speech channels on each sideband had been put into operation between various capital cities. Within the limits of the selective fading and noise of HF radio, broadcasters could order, in general, either a 3 kHz "message grade" channel or a 6 kHz "program channel," by special arrangement, occupying the space of two telephone circuits and using program-equalized channels linking the HF radio plants and the broadcasters. The cost was rather high for those, of course. There was strain on the capacity of the total installed plant, however, and in fact, a different mode of operation called "EB circuits" for "Emergency Bandwidth" was put into place as the U.S. entered the European war and Eisenhower's SHAPE settled into the buildup of the invasion force in England. "EB" used the channel filtering abilities of the Type A "band-splitting" Privacy units developed in the late 1930's. A Type A Privacy was a beastly affair containing iron/copper speech channel filters and modulators that could split a 3 kHz voice channel into five sub-bands, and shift each sub-band to a different range for transmission, while restoring the proper sequence at the receiver. Type A Privacies were beastly things, each one for a typical four-channel HF link occupying THREE 30-inch-wide, eleven-foot high relay racks. In addition to shifting sub-bands around, the Type A Privacy also contained a motor-driven cam switch that could change the shifting pattern every few seconds. However, maintaining sync between the transmitting and recieving Type A's was so difficult that after only a few years, they were generally operated in a fixed pattern, perhaps changing the code once a day at most. (By the early 1960's, they were largely disused, but maintained, as technical operators would use them for an adjustable band-stop filter when needed to knock out one sub-band to get rid of QRM by plugging out one filter.) But, at the time of D-Day, the Type A Privacies, with some minor modifications, were pressed into service, to split the nominal 3 kHz channels into two "Emergency Band" telephone circuits, effectively doubling the number of circuits by producing telephone circuits of around 1700 Hz bandwidth. Thus, if you hear some WWII actualties from HF radio that sound rather muffled and lacking any sibilance or fricatives in the speech, it's likely they were on EB circuits. That's one aspect, fine for public communications where on the U.S. end, it was AT&T connecting into the telephone network, met on the U.K. (or in later cases, other country's) government-owned telephone "Adminstration," as they are called in ITU lingo. But another, far-less published aspect has to do with the actual invasion of Normandy and the rush across Europe to end the war in just eleven months -- that of the people of a firm called Press Wireless in its support of actualities from the moving Allied Expeditionary Force. No small part of operating a full-bore war effort and keeping the "folks at home" at maximum interest and production was to provide them news actualities, in an time after "no radio" (WWI) and the Satellite Era (Vietnam). The scheme drawn up was to have mobile HF broadcast transmitting facilities landed as soon as possible after a beachhead was established, and make origination facilities available to radio journalists as close to the front as possible. Fortunately, although sunspot counts were nearing their eleven-year cyclic minimum in 1944, solar disturbances were also relatively minor, so HF radio across the Atlantic was rather reliable. To accomplish this, the services of a firm called Press Wireless were engaged. Few people know much about "Pree-Wee," jargon that grew out of its telegraphic route address of PreWi, but it actually dated back to the earliest days of HF radio, PreWi was established in the time when RCA, Westinghouse and GE tied up purchase of HF radio gear, by setting conditions under which you effectively had to purchase a complete transmitter from RCA using the patented high-power vacuum tubes of GE or Westinghouse, or nothing. This was tied to a strong suggestion that "you might as well rent channels from RCA rather than do so." Well, that was fine, except then getting RCA to run channels where the press wanted them was not always realistic. So, the press associations formed Press Wireless, to purchase high-powered tubes from Brown-Boveri in Switzerland, and develop its own HF links. And, develop a lot, PreWi did. if you ever get into those musty old textbooks and IRE Proceedings of the 1920's and 1930's, many of the studies of HF propagation can be found to be of PreWi origin. Although not well known to the public, PreWi was well known in the HF radio community and the press establishment. And, its people had built any number of prioneering and/or one-time HF links to connect sites around the world; places that the public telephone or telegraph establishments weren't prepared to handle. D-Day was an event tailor-made for PreWi to make its largest single effort ever, as well. The PreWi engineers built up 50 kW HF transmitter plants into sets of trailers, complete with an AC power trailer and a studio trailer, and staffed them with "war correspondents" who were, in fact civilian radio broadcast engineers seconded to PreWi for the job. They landed right behind the troops on the firing line, and were in operation back to the PreWi receivers at Southampton, Long Island by the night of June 6, with German bullets still whizzing close by, providing program channels back to the States for radio journalists of the several networks from a war-torn Normandy. When you hear actualities from HF radio during this week that originated in Normandy, they were on those PreWi HF links, received at Southampton, then carried into New York on phoneco facilities to the several radio networks. (Similarly, PreWi trailer-mounted links were operating from Juno and Gold Beaches back to England for the BBC to get its feeds, when you hear British actualities of the events of D-Day.) The entire operation continued, moving with the Allied Expeditionary Force, providing Eisenhower his HF radiotelephone links back to the telephone networks of England and the U.S. once he moved onto the continent, and until the war was over and the regular facilities of the government-owned PTTs were rebuilt in each nation. You'll likely hear snatches about the heroics of the journalists and even the Army Signal Corps, which went about placing AM broadcast transmitters (sometimes jammers) in carious cities as the armies moved across the Continent, but you're not likely to hear anuything about the civilians who supported the Allies in war as PreWi provided the news to "back home." I know I wouldn't, if I had never had the privilege of working for Gene Rider, who had been Chief Engineer of WQAM and later WIOD at Miami, who had himself been one of those "civilian war correspondents" on loan to PreWi at the time. Gene never spoke about it, and only tipped his hand to me a while after I went to work for ITT, and sent him a postcard from the rather famous Westbury Hotel in London. His only real comment, in a reply card was, "The Westbury" Oh, yeah, I know that place!" Only then did some of his comments made over the years fall into place. (epilogue) PreWi went on after the war to continue its pioneering work, and was purchased by ITT. ITT merged PreWi into ITT's World Communications operations, which took over the PreWi transmitters at Brentwood and receivers at Southampton. One of its later innovations that never flew was a proposal to put HF radiotelephones onto Captain Eddie Rickenbacker's Constellations that flew passengers to Latin America. Regrettably, Captain Eddie declined, saying there was not sufficient payload space on the Connies to accommodate the function. I have a copy of Rickenbacker's letter to the president of PreWi declining the offer. So, I hope that little story gives you some interesting insight into a little-published portion of the D-Day Story. [TELECOM Digest Editor's Note: As always Don, thanks for another very interesting history lesson. An organization here in Chicago is planning a complete historical re-inactment of D-Day for later this month. They are going to be using the Lake Michigan beach around Montrose Avenue for anyone interested in attending. PAT] ------------------------------ Date: Mon, 30 May 1994 12:44:28 MDT From: Rob Slade Subject: Book Review: "Exploring the Internet" by Malamud BKEXPINT.RVW 940310 Prentice Hall 113 Sylvan Avenue Englewood Cliffs, NJ 07632 (515) 284-6751 FAX (515) 284-2607 phyllis@prenhall.com 70621.2737@CompuServe.COM Alan Apt Beth Mullen-Hespe beth_hespe@prenhall.com "Exploring the InterNet", Malamud, 1993, 0-13-296898-3, U$26.95 carl@malamud.com The naive reader might be forgiven for thinking that this book is about the Internet and how to use it. The author seems to think that this book has something to do with the ITU's initial interest in, and later refusal of, publishing the "Blue Book" of telecommunications standards on the Internet. The phrase, "technical travelogue," gets bandied about as if it had some meaning. (It is interesting that on the fourth or fifth visit to Paris the author is unable to explain to anyone, including his aunt, what the phrase means.) Dan Lynch reports as Malamud's proposal a statement that makes as much sense as anything: "Buy my airplane tickets and I'll try to get into as much trouble as I can. Then, I'll write a book." After reading the cover blurbs, one suspects that if you were to try to design a project antithetical to the aims and workings of the Internet, one couldn't get much closer than a six- month trip circling the globe a few times, dropping in on a number of people engaged in esoteric projects for interviews. It isn't a travelogue, since that would imply some sort of logical plan behind the route travelled or the places visited. It isn't all that technical, except that the majority of people discussed work in technical fields. Some of it has to do with the Internet; much of it doesn't. What it is, is hilarious. While novice users looking for documentation on ftp will be mystified, net gurus, particularly those with some knowledge of the players mentioned, will be laughing their socks off. Even the net-illiterate will get some chuckles out of it -- Malamud has a dry wit and a keen eye for the absurd. I can readily sympathize with his tale of a story killed by a marketing department. I still haven't got the slightest idea what the book is supposed to be *about*, but it's a lot of fun. copyright Robert M. Slade, 1994 BKEXPINT.RVW 940310. Distribution per- mitted in TELECOM Digest and associated mailing lists/newsgroups. PAT] Vancouver ROBERTS@decus.ca Institute for Robert_Slade@sfu.ca Research into rslade@cue.bc.ca User p1@CyberStore.ca Security Canada V7K 2G6 ------------------------------ Date: Mon, 30 May 1994 03:45:47 GMT From: rtsina1@uclink.berkeley.edu (Richard V Tsina) Subject: Communication Courses at Berkeley this Summer Organization: University of California, Berkeley U.C. BERKELEY Continuing Education in Engineering Announces 2 short courses on Communication Technology: 1. WIRELESS COMMUNICATION NETWORKS (July 26-27, 1994) There are technical bottlenecks to developing a ubiquitous wireless multimedia environment: the capacity of the radio link, its unreliability due to the adverse multipath propagation channel, and severe interference from other channels. This course covers the principles and fundamental concepts engineers need to tackle these limitations (e.g., a thorough treatment of channel impairments such as fading and multipath dispersion and their effect on link and network performance). Topics include: Introduction to Wireless Channels, Cellular Telephone Networks, Analog and Digital Transmission and Wireless Data Networks. Comprehensive course notes will be provided. Lecturer: JEAN-PAUL M.G. LINNARTZ, Ph.D., Assistant Professor of Electrical Engineering and Computer Sciences, University of California, Berkeley. His work on traffic analysis in mobile radio networks received the Veder Prize, an innovative research in telecommunications award in the Netherlands. At Berkeley he works on communications for intelligent vehicle highway systems and multimedia communications. Professor Linnartz is the author of numerous publications and the book "Narrow Land-Mobile Radio Networks" (Artech House, 1993), the text for the course. 2. COMMUNICATION NETWORKS: FROM FDDI TO ATM (August 9-10), 1994) This course provides an overview of the operating principles and design guidelines for communication networks, and includes a description of the popular current networks and a discussion of major industry trends. Topics include: History and Operating Principles, Open System Interconnection, Overview of High-Speed Networks, Physical Layer, Switching, Trends in Data Networks (FDDI, DQDB, Frame Relay, SMDS), Trends in Telecommunication Networks (SONET, Fiber to the home, ISDN, Intelligent Networks, ATM), Topological Design of Networks, Control of ATM Networks. Comprehensive course notes will be provided. Lecturers: PRAVIN VARAIYA, Ph.D., Professor of Electrical Engineering and Computer Sciences, University of California, Berkeley. At Berkeley he works on stochastic systems, communication networks, power systems and urban economics. He is the author of "Stochastic Systems: Estimation, Identification, and Adaptive Control" (Prentice-Hall, 1986) and coeditor of "Discrete Event Systems: Models and Applications" (Springer, 1988). He is a fellow of the IEEE. JEAN WALRAND, Ph.D., Professor of Electrical Engineering and Computer Sciences, University of California, Berkeley. He is the author of "An Introduction to Queuing Networks" (Prentice-Hall, 1988) and "Communication Networks: A First Course" (Irwin/Aksen, 1991). For more information (complete course descriptions, outlines, instructor bios, etc.,) contact: Richard Tsina U.C. Berkeley Extension Continuing Education in Engineering 2223 Fulton St. Berkeley, CA 94720 Tel: (510) 642-4151 Fax: (510) 643-8683 email: course@garnet.berkeley.edu ------------------------------ Date: Mon, 30 May 94 20:29:40 EDT From: Carl Moore Subject: Dialing Changes For West Virginia and Connecticut The Huntington (W.Va.) and Cumberland (Md.) directories have dialing changes for West Virginia (area 304): 16 or 30 April 1994 -- 1 + NPA + 7D for local to other area codes; 7D for long distance within 304 is permissive April 30 and mandatory October 1. There is at least one case of a local prefix outside of 304 duplicating something in 304: 722 at St. Albans (W.Va.) and Cumberland (Md.), and I wrote earlier of local calls from Ridgeley (W.Va.) to Cumberland, Md. For Connecticut, I found Southern New England Telephone directories whose effective date is 25 April, and they have 1 + 203 + 7D for long distance within Connecticut. Notice that the southwestern corner (Greenwich and vicinity) is served by NYNEX, not by SNET. ------------------------------ Date: Sun, 29 May 94 19:02 PDT From: rlm@helen.surfcty.com (Robert L. McMillin) Subject: Pac*Bell Plans to Become Internet Provider? Has anyone heard anything about Pac*Bell's plans to become an Internet provider? It seems perfectly logical that they would do so -- after all, they *do* own a lot of the physical "plant". I have heard rumblings from a couple of sources, and wondered if anyone on this forum may have heard of something. ------------------------------ From: MICHAEL.CONLEY@mogur.com (MICHAEL CONLEY) Subject: Current List of Areacodes Wanted Date: Tue, 31 May 1994 03:14:00 GMT Organization: The MOG-UR'S EMS/TGT Technologies, Los Angeles, CA Does anyone happen to know where I might acquire an ASCII text listing of current telephone area codes including the communities that they serve? Any replies should be addressed to michael.conley@cabin.com Thanks! The MOG-UR'S EMS, Granada Hills, CA: 818-366-1238/8929, @mogur.com [TELECOM Digest Editor's Note: You might check out the Telecom Archives for a general summary of area codes and the territories they serve. In addition, Carl Moore and David Leibold are our resident area code archivists here, and they may have more complete lists. In fact, I am sure they do. PAT] ------------------------------ From: kpc@panix.com (Kevin Centanni) Subject: How Do You Simulate Telco Battery Voltage? Date: 30 May 1994 13:48:11 -0400 Organization: PANIX Public Access Internet and Unix, NYC I have some voice mail cards for PC's such as Watson, BigMouth, and the NSC TyIn2000. Each of these cards has two modular jacks -- one for 'phone' and one for 'line'. I'd like to be able to send audio into the telephone and send and receive touch-tones WITHOUT being connected to an actual working teleco line. None of these cards provides the appropriate voltage to power the telephone. I've tried to just hook a 12V supply directly to the TIP and RING on my phone ... the phone works (I can hear touch-tones in the receiver) -- but I cannot decode those tones with the voice mail cards ... additionally, there is a very annoying hum (60 Hz?) in the earpiece of the telephone. Does someone sell a box that provides the right voltage? Is this a simple circuit that I can construct? Thanks. kpc@panix.com [TELECOM Digest Editor's Note: You need to wire the voicemail card in series to the telephone through the battery -- not in parallel. That is, the tip of the telephone to the ring of the card, the tip of the card to the negative of the power supply, and the positive of the power supply to the ring of the phone. If you have the phone and the voicemail card wired in parallel to the power supply, they (phone and card) won't be able to hear or talk to each other. For example, I have a Dialogic card here which I trip by applying ringing voltage to the circuit *while the phone is on hook*, thus no open path and potentially high voltage to harm the card's innards. Press the momentary switch to apply the ringing voltage; the phone rings, the card sees the ringing voltage and responds. I take the phone off hook immediatly to create the series loop the card is looking for to stay off hook and use it to do what I want to do with the card. The ringing voltage will wake up the card, but upon waking if it does not find that current from the series loop on there it will disconnect and go back to sleep. So remem- ber, all devices (phones, etc) on one side of the power supply have to be in series -- not parallel -- with whatever is on the other side (voice mail card, etc). And the way to get rid of that hum is by rectifying the direct current. It has to be clean. You can't just use any old power supply with the right voltage. Try one of the 13.8 volt DC supplies from Radio Shack. I have one and it works fine for intercom use with a couple phones here. Then get a separate supply for the ringing voltage and wire it in parallel with the 'clean' DC talk battery. Break the circuit through a little minature push-button you build into the phone. Superimpose ringing current on the line by depressing the little button for a second. Listen to the phone itself ring (at the same time the voicemail card is being tickled). Let go of that button and lift the phone receiver immediatly; you should be in business. I use the yellow/black second pair for this. Green/red first pair operates the phone as always; they are the two wires that are in series through the Dialogic card and the power supply. The negative of my ringing current supply is in parallel with the negative of the talk battery. I bring the positive of the ringing voltage up to the phone through the yellow wire, break it at the press-switch, and take it back down through the black wire to be in parallel to the positive of the talking battery. **As long as the phone is not off hook when you press the button for the ringing voltage** the loop will not be completed and no harm will come to the voicemail card or the talk-battery. Now if you find yourself accidentally pressing the button supplying the ring current while the phone is off hook (and looped in series to the card), you can eliminate ugly accidents (like blowing up the card) by using the 'normally closed' contact in the phone itself. (I am speaking now of a standard 500 desk set type phone). While most contacts in the phone 'network' (or innards) are 'normally open' and close only when the phone is off hook, there is one in there which functions the other way around. It is not used for anything else that I know of, so I take that ringing current and break it not only at the push button I installed, but also through the 'normally closed' contact in the phone itself. This way, when the phone is off hook, you can press the button all you like, but the ringing voltage will go nowhere because you have that loop cut off. Of course it never hurts to add a couple fuses in the line to prevent other short circuits, etc from playing nasty games. PAT] ------------------------------ From: perdigot@hp_1.dee.uc.pt (Joao Perdigoto) Subject: ETSI contact Date: 30 May 1994 08:54:08 GMT Organization: Dep. de Matematica da Univ. de Coimbra Hi, Does anyone knows if ETSI has an ftp site available? joao perdigoto ------------------------------ From: jbaker@halcyon.com (James Baker) Subject: Why Does Long Distance Cost Extra? Date: Mon, 30 May 1994 18:13:22 -0800 Organization: Northwest Nexus Inc. As I understand it, 90 percent of the cost phone service is for the 'last mile', ie the local loops. So 10 percent or less is for long distance. Yet we pay dearly for the use of this 10 percent. I also understand it costs more to track and bill for long distance than to provide the service. Is this correct? And somebody has to pay for those TV ads ... or do they? I know the historical reasons for charging extra for what years ago was technically difficult (sendind undistorted signals over long wires). And how business users were thought to be bigger users and better able to afford long distance. That's not what I'm asking here. I'm wanting more technical info for a possible article. Does anybody know how much the national long distance plant cost to build? And what would it cost if useage doubled or increased five times because long distance was "free"? In case you can't guess I think it would be great for the economy and the country as a whole to have one nationwide calling zone. But is it technically feasable? Comments? James Baker Seattle, WA jbaker@halcyon.com ------------------------------ From: gvaeth@netcom.com (Greg Vaeth at Jerrold Communications) Subject: Cost of Caller ID in PA Organization: NETCOM On-line Communication Services (408 261-4700 guest) Date: Mon, 30 May 1994 00:48:37 GMT Hi, An insert in my latest bill contained a notice that Bell Atlantic will offer Caller ID in Pennsylvania in August. The cost for residential customers is $6.50/month, business is $8.50. Call blocking and anonymous call rejection are free. This charge seem outrageous considering that the equipment to do it is already there, right? How else does return call, repeat call and all that stuff work. How does this rate compare to other states? Regards, Gregory Vaeth General Instrument internet: gvaeth@netcom.com Communications Division voicenet: (215) 956-6488 2200 Byberry Road faxnet: (215) 675-4059 Hatboro, PA 19040 ------------------------------ End of TELECOM Digest V14 #259 ******************************