TELECOM Digest Fri, 19 Nov 93 02:53:00 CST Volume 13 : Issue 770 Inside This Issue: Moderator: Patrick A. Townson Re: TDMA vs. CDMA = Betamax vs. VHS? (David Boettger) Re: Crummy Service in NY (Bob Schwartz) Re: Finally Got REAL Phone Service (Tony Pelliccio) Re: TRW Phone Print to Fight Cellular Fraud (David Woolley) Re: Long Distance Company Offers 800 Internet Access (james@kaiwan.com) Re: Call Waiting 14.4 Modems (David Devereaux-Weber) Re: Canada Goes 1 + 10D For All Long Distance, Sept '94 (John Little) Re: Earthquakes and Telecommunications (Dick Rawson) Re: Earthquakes and Telecommunications (Ron DeBlock) Instant Modem Banks (Martin McCormick) TAPS Software (John Little) Sprint Modem Offer/Impressions (Sean Slattery) Sprint Modem Offer :-( (Stan Hall) Automated FAX Delivery (Luis Delgado) ---------------------------------------------------------------------- Date: Thu, 18 Nov 1993 12:18:00 +0000 From: David Boettger Subject: Re: TDMA vs. CDMA = Betamax vs. VHS? In article , Alex Cena writes: > Attached are comments from Tom Crawford at Qualcomm after I forwarded > him a copy of the TDMA vs CDMA debate on the Digest. > Alex, > I am sure you knew the TDMA vs. CDMA comments would get under my skin > and I would have to respond. How do I send this response to Ed Casas, > or to the network? My comments are in caps: > CARRIERS ARE GOING TO INVEST HUNDREDS OF MILLIONS OF DOLLARS, IF NOT > MORE, IN DIGITAL TECHNOLOGY. I SUSPECT THEY WILL LOOK BEYOND THE > "BEST MARKETING" PITCH TO THE UNDERLYING CAPABILITIES OF THE > TECHNOLOGIES. You would hope so, but that isn't always the case, as Mr. Crawford (a marketing exec) knows. > "GROSSLY UNFAIR COMPARISONS" ARE HARDLY AN ACCURATE WAY TO DESCRIBE > CLEAR ADVANTAGES. QUALCOMM'S CAPACITY IS 10X TO 20X AMPS CAPACITY Get real! 20X has only been demonstrated on paper (e.g., W. C. Y. Lee) or, perhaps (now I am guessing), in a Qualcomm laboratory. > QUALITY COMMUNICATIONS LINK USING A HALF RATE VOCODER. IF WE ARE > WRONG AND A GOOD HALF RATE VOCODER IS AVAILABLE, QUALCOMM CAN ALSO USE > IT IN A VARIABLE RATE IMPLEMENTATION (AGAIN THROTTLING DOWN DURING > PAUSES) TO ACHIEVE AN ADDITIONAL FACTOR OF 2 IN CAPACITY GAIN, IE NOW > 20X TO 40X AMPS. ALSO, ETDMA'S USE OF DIGITAL SPEECH INTERPOLATION > ABOUT 12X OR 15X, ASSUMING EVERYTHING WORKS WELL). CDMA, WITH A HALF RATE > VOCODER WILL THEN BE AT 20X TO 40X (EVEN WITHOUT BETTER USE OF > SECTORIZATION). Wrong again. The relationship between source coder rate and absolute channel capacity (I am using "capacity" not in an information theory sense, but in a "number of telephone conversations" sense) is not linear. Using a half-rate coder in CDMA does not automatically double the number of conversations that can occur, even under ideal conditions. > RECEIVER IF FILTER WOULD BE UNABLE TO DO. THE WHOLE POINT OF CDMA IS THAT > YOU DO NOT HAVE TO SEPARATE THE SIGNALS OVER THE CHANNEL BY FREQUENCY OR > TIME. DIFFERENT CODES PERMIT YOU TO PICK OUT YOUR CONVERSATION. True enough. > "TRICKS" IMPLY DECEPTION. CDMA'S TECHNICAL PERFORMANCE AND BENEFITS HAVE > BEEN WELL TESTED AND PROVEN AGAIN AND AGAIN IN NUMEROUS TRIALS. THESE How many commercial cellular CDMA systems are deployed and stable? Approximately zero. "Well tested and proven" is a bit of a stretch, but then again, Mr. Crawford is in marketing. David Boettger boettger@bnr.ca I don't speak for my employer. ------------------------------ Subject: Re: Crummy Service in NY From: bob@bci.nbn.com (Bob Schwartz) Date: Thu, 18 Nov 93 16:51:35 PST Organization: Bill Correctors, Inc., Marin County, California oppedahl@panix.com (Carl Oppedahl) writes: > I called the telephone company business office. There's a reason that > I can't use *69, namely that my telephone exchange is too old. > Oh, and there is no scheduled date for upgrading my telephone exchange > to more modern equipment, according to the business office. Hearing about crummy lines and transmission in beautiful Manhatten makes me wonder jusy why/how the Local Loop, and End User Common Line charges are so darned high. Could it be that they have incentive for patchwork and repair which is lacking for replacements and upgrades? Bob Schwartz bob@bci.nbn.com Bill Correctors, Inc. +1 415 488 9000 Marin County, California ------------------------------ From: Anthony_Pelliccio@brown.edu (Tony Pelliccio) Subject: Re: Finally Got REAL Phone Service Date: 18 Nov 1993 20:51:28 GMT Organization: Brown University Alumni & Development Office In article , ao944@yfn.ysu.edu (Jack Decker) wrote: > 1) My on-hook line voltage increased from ~15 volts to ~44 volts DC. > Also, the tip/ring polarity reversed from what it had been when I was > on the carrier. {stuff deleted to save space} Sounds to me like they've upgraded you to something equivalent to a SLIC-96. They tend to work very well and keep the line quality up. Tony Pelliccio, KD1NR Anthony_Pelliccio@Brown.edu Brown University Alumni & Development Computing Services Box 1908 Providence, RI 02912 (401) 863-1880 ------------------------------ From: david@djwhome.demon.co.uk (David Woolley) Subject: Re: TRW Phone Print to Fight Cellular Fraud Reply-To: david@djwhome.demon.co.uk Date: Thu, 18 Nov 93 15:36:41 GMT In article is written: > Why not public key? There are several companies with commercial > applications using public key ... the government only gets antsy when > it's used for general purpose encryption of data/messages and the > register bits are long enough to eliminate any realistic crunch by a > supercomputer (i.e. a day or two). Use as an authentication device > (i.e. digital signitures) is not a big deal. In fact my Mac at home > implements this capability in the operating system! Why specifically public key? Why not allow encryption of the message as well, as done by GSM? The government can still get the keys from the network operator, or tap the signal in the fixed network. (The network operator needs to know both the session keys used for communication and the subscriber master key used to encrypt the session key when sending it to the subscriber.) The only problem I can see is if the subscriber's home network is outside the jurisdiction. In this case there is no access to the master key and there is no one place where the session keys can always be found, although the number of Visitor Location Registers which would have to be covered ought to be small. (Visitor Location Registers are the entities in GSM which store details about subcribers who are currently in the area that they cover. Amongst other things, they maintain a small cache of session keys for that subscriber.) David Woolley, London, England david@djwhome.demon.co.uk ------------------------------ From: james@kaiwan.com Subject: Re: Long Distance Company Offers 800 Internet Access Organization: KAIWAN Internet Access Date: Thu, 18 Nov 1993 08:20:48 GMT In article , Klaus Dimmler wrote: > Telephone Express, a regional long distance carrier in the Western > States, is offering national 800 Internet access for less than the > cost of a long distance phone call! For only 13 cents per minute, > access to a T1-Internet connected host is available from anywhere in > the United States, Puerto Rico, the Virgin Islands, Hawaii, and Alaka! > The host is connected directly to the ANS backbone. > For information on this, please call 800-748-1200 (voice), or write to > service@cscns.com. Just called AT&T and they quoted me no installation fee, monthly fee $10.00 ... $0.25/minute daytime $0.17/minute evening $0.14/minute night Volume calls with discount. info@kaiwan.com,Anonymous FTP,Telnet kaiwan.com(192.215.30.2)FAX#714-638-0455 DATA# 714-539-0829,830-6061,310-527-4279 818-579-6701 16.8k/14.4k 8-N-1 ------------------------------ Date: Thu, 18 Nov 93 12:56:26 CDT From: weberdd@clover.macc.wisc.edu Reply-To: weberdd@macc.wisc.edu Subject: Re: Call Waiting 14.4 Modems In a previous message, Thomas Neudeker writes: > I recently upgraded my modem to LineLink 14.4 modem. I now use a SLIP > connection to connect to the network. On the other modems I have had > Call Waiting would break the connection. I know about the *70 tone > signal to deactivate call waiting. My problem is that the error > correction on the modem doesn't accept the call waiting tones until > after eight to twelve rings and people I need to talk to can't get > through. Bell of PA said they hadn't seen this use of call waiting > before and that the 5ESS switch at my CO is has a very short off hook > time for the tone to be sent. Does anyone know of a modem init string > to let call waiting and the modem work as I wish? The meaning of your message isn't clear. You said that on your other modems, call waiting would break the connection. You don't say whether call waiting breaks the connection on the 14.4 modem. The message seems to imply that you are in fact hoping to be notified of a call waiting while a modem call is in progress. If this is what you want, you would have to find a way to put your data connection "on hold" (or simply abandon the data call in progress), switch your modem into voice mode, and pick up your telephone handset. Usually call waiting is not considered when data calls are in progress. There is no easy way to support call waiting while a data call is in progress (another way of saying this is that there is no easy way of keeping a data call going when call waiting occurs). If it is important to be able to reach you when data calls are in progress, I recommend a second telephone line. David Devereaux-Weber (608) 262-3584 (voice) MACC Communications; B263 (608) 262-4679 (FAX) 1210 W Dayton St. weberdd@macc.wisc.edu (Internet) Madison, WI 53706 ------------------------------ From: jlittle@AccessPoint.North.Net (John Little) Subject: Re: Canada Goes 1 + 10D For All Long Distance, Sept '94 Organization: UUNorth's AccessPoint Service Date: Thu, 18 Nov 1993 18:26:18 GMT Alabama (area code 205) has been doing 1 + 10D LD calling within your area code for over two years now. Area code 407 (Central FL) has also moved to 1 + 10D calling. These are just to that I have had personal experiences with, I'm sure there are many others. John ------------------------------ Date: Thu, 18 Nov 93 12:55:35 PST From: drawson@Tymnet.COM (Dick Rawson) Subject: Re: Earthquakes and Telecommunications > I've been told that after an earthquake, if you can't get a call > through, try using a payphone. Supposedly, the phone company will > arbitrarily put some calls through and not others when the load is too > high, but payphone calls will always go through. Correct (except for two quibbles), according to Pacific Bell. Here is (my memory of) what they tell public emergency service agencies. Lines can be categorized as "essential service lines". These are not deliberately denied service or delayed access while the switch is configured to shed some of its load. Also, the repair service gives priority to restoring outages of essential service lines. Emergency services like fire and police, and quite a few others, are supposed to have (at least some of) their lines categorized this way. Public telephones always have essential service lines. Note that not all pay telephones are public telephones. (That's quibble 1.) We've discussed that here before. A pay phone in a bar probably isn't a public telephone; one in a public area available 24 hours a day, particularly at road-side, generally is a public telephone. The other quibble is with "will always go through"; that would be hard to guarantee. But the call would not be blocked to shed load. Dick Rawson drawson@tymnet.com ------------------------------ Date: Thu, 18 Nov 93 11:13:50 EST From: rdb1@homxb.att.com Subject: Re: Earthquakes and Telecommunications Organization: AT&T In article nathan@seldon.foundation. tricon.com writes: > From a possibly unreliable source, I heard that in > downtown San Francisco, the phone exchanges actually have JET engines > running turbines to provide power during emergencies. (Locally, the > phone company uses diesels, but I do not know the capacity). I've heard from techs who work/worked in CO's that some do indeed have "jet" engines for backup power. I suspect that they are generators powered by turbine engines of some sort. I was in AT&T's Saint Louis 4ESS(tm) office when it was running on backup power one day. The equipment sure sounded like a jet engine, but I did not actually see it. The generators were running because one of the power transformers had blown up. The techs said that molten copper flew all over the room -- YIKES! I would expect the transformer to be in a cabinet of some kind, but what do I know -- that's a hardware problem. At the time, I wondered why the power equpment was on the top floor, rather than in the basement. After this year's floods, I can under- stand why. Back to earthquakes ... I was in San Franscisco about two months after the 1989 quake. I was surprised at the LACK of destruction. TV reports on the East Coast made things sound worse than they really were. The AT&T office was unscathed. The equipment I was interested in (a bunch of Conversants (tm) ) and the 4ESS in the next room continued to operate on backup power following the quake. One Conversant that was used for administrivia and testing was just sitting on a table and had crashed to the floor, it was the only casualty. The other Conversants were mounted in racks that were bolted down. I don't know if a jet engine provides backup power in the SF office. The only power equipment I saw was a very impressive array of batteries. Ron DeBlock rdb1@homxb.att.com (that's a number 1 in rdb1, not letter l) AT&T Bell Labs Somerset, NJ USA ------------------------------ Subject: Instant Modem Banks Date: Thu, 18 Nov 1993 06:53:47 -0600 From: Martin McCormick In recent postings, several people told of modem banks which can be attached directly to a T1 and use DSP to simulate 24 dial-up modems. Do any of these systems connect to an Ethernet and act as a terminal server such that one would have the V.35 cable to the T1 as one port and an Ethernet connector as the other port? Three or four such systems would free an amazing amount of rack realestate and would most likely prove to be more reliable in the long run. If anybody knows of such a system and whether or not it has a good track record, please let me know. Thank you. Martin McCormick WB5AGZ Stillwater, OK O.S.U. Computer Center Data Communications Group ------------------------------ From: jlittle@AccessPoint.North.Net (John Little) Subject: TAPS Software Organization: UUNorth's AccessPoint Service Date: Thu, 18 Nov 1993 13:29:42 GMT I am looking for a program to send alpha numeric data to my pager using the TAPS protocol. I use Bell Canada's pager (standard Bell Mobility). Looking for something that runs under Windows 3.1 (Microsoft). Free would be great, but I may consider buying a package. I have one for UNIX (commercial), but that doesn't do me any good from home. John ------------------------------ Date: Thu, 18 Nov 93 08:50 EST From: Sean Slattery Subject: Sprint Modem Offer/Impressions I switched to Sprint a month ago on the promise of a modem. Posts in the Digest lead me to believe that it was a 9600 baud modem but the Sprint rep set me straight when I called. I did not hear the original offer on the radio. Sprint made some mistakes; this is easy to do when you have marketing people targeting a technically savvy population that is intolerant of lack of knowledge on the part of the general population (you know it's true !). It is my belief that Sprint acted in good faith and did not intentionally misrepresent this offer. In the case of Mr. Ambler's conflict with Sprint I was originally on Sprint's side. That is until I read Mr. Ambler's last post. If it is at all representative of what actually occurred the I feel that I must warn Sprint that they are spending good will here. I, like many Digest readers, specify long distance carriers for my organization as well as myself. I want Sprint to maintain a high level of professionalism here. The account of the phone call received by Mr. Ambler did not make me fell good about Sprint, it left me cold. I will continue to follow this dispute. While I think Mr. Ambler should find better things to do with his time, I believe that the resolution of this dispute will tell us a lot about the corporate character of Sprint. Sean Slattery Network Administrator Airflow Research This post does not necessarily represent the opinions of my employer. PS: I switched from the modem to the Star Trek Screen saver, which I have not yet received. ------------------------------ Subject: Sprint Modem Offer :-( From: kilgore@wuntvor.pillar.com (Stan Hall) Date: Thu, 18 Nov 93 10:56:09 CST Organization: The Eternal Apprentice BBS, Oklahoma City, Ok Well it seems that every step of the way Sprint has screwing everything up. I switched two of my personal phone line to Sprint for this modem offer. When the word came down that the modem was only to be a 2400bps with 9600/4800 FAX internal I resigned myself to accept the offer despite what the sales droids had said. They sent me two Foncards for one line instead of one for each line. They billed seperately instead of on my regular phone bill. They attempted to call my Data line by voice to contact me about the Windows/DOS software and disk size. So what is the latest bit of stupidity on Sprint's part you ask? It seems that since they couldn't reach me on my Data line that they sent me a letter about two weeks ago asking me to please tell them via mail or phone which software that I would like for my modem. So last night I finally found some time to sit down and call the number that Ms. Worthy had given me and left a message telling her what software I wanted for each of my two modems. I get a call this morning from Ms. Worthy telling me that I am only to receive one modem and asking what software I would like for that modem. When I argued with her that I wanted both of the modems I had been promised she told me that the offer was limited one per household. Everytime I tried to discuss this with her she asked me what software I would like for my *modem*. I gave in and told her, hoping that I will receive somthing from Sprint (besides a bill). Has anyone else actually received more than one modem at one residence? Needless to say as soon as I get my modem (or confirmation that I am not to get a thing) I am running from Sprint as far and as fast as possible. Not that they are concerned with my low long distance usage. Though I *will* cost them as much as possible via word of mouth. Is anyone interested in getting together to visit the Sprint office in Kansas City, MO and Ms. Worthy? Stan Hall [Unhappy (soon to be former) Sprint Customer] kilgore@wuntvor.pillar.com (Stan Hall) The Eternal Apprentice BBS, Oklahoma City, OK -- +1 405 942 8794 [Moderator's Note: *Who* told you that you would get two modems? Really, I can't see what your beef is about. 'One per household' is one of the most common phrases in business promotional offers I have ever heard. Time and again you hear it, 'one per household, not good when combined with other offers or special promotions, etc ...' I got my modem several days ago. It installed easily and is working fine for sending faxes from my 386. If you honestly think you are going to get two modems, you are quite mistaken. Diane Worthy has done a great job of getting this mess straightened out; I'm sure she is sorry Sprint even decided to have such a generous promotion. PAT] ------------------------------ From: lmd@cayman.inesc.pt (Luis Delgado) Subject: Automated FAX Delivery Organization: INESC - Inst. Eng. Sistemas e Computadores, LISBOA. PORTUGAL. Date: Thu, 18 Nov 1993 14:48:17 GMT I was wondering how implement an automatic system for fax delivery. What I wanted is the following: - to have in my personal business card a unique personal fax number, like any other person in the same company. Everyone could have a unique fax number. For example: FAX # 3100234 - to me Fax # 3100235 - to you FAX # 3100236 - to him, etc. - All fax calls would be received by the local company PABX, that would redirect all calls to the same FAX card installed in a PC, for example. Then the FAX Software on the PC would decide based on the last three digits of the # specified by the sender, to which person to send the fax in an electronic mail message format. I'm not saying this should be the best way to implement, and I even don't know if there are automated systems like this. I know however that it its possible (correct me if I'm wrong) to specify, something like a destination in the fax message it self, but I don't what this solution, because it is'nt completely transparent to the sender. Does anybody know any way to do this? Is there any hard/soft solution to implement this? While waiting for your sugestions, my best regards, Luis Delgado INESC-CCAE Lisbon, Portugal. lmd@inesc.pt cis: 100024,3520 ------------------------------ End of TELECOM Digest V13 #770 ****************************** ****************************************************************************** Downloaded From P-80 International Information Systems 304-744-2253