Return-Path: Received: by massis.lcs.mit.edu (8.7.4/NSCS-1.0S) id CAA01390; Tue, 27 May 1997 02:15:26 -0400 (EDT) Date: Tue, 27 May 1997 02:15:26 -0400 (EDT) From: editor@telecom-digest.org Message-Id: <199705270615.CAA01390@massis.lcs.mit.edu> To: ptownson Subject: TELECOM Digest V17 #133 TELECOM Digest Tue, 27 May 97 02:15:00 EDT Volume 17 : Issue 133 Inside This Issue: Editor: Patrick A. Townson Mobiles Safe, Study Finds, But They do Heat Brain (Monty Solomon) Re: Are Cordless' as Bad as Cellulars? (Dub Dublin) Re: Are Cordless' as bad as Cellulars? (Stewart Fist) Re: Dial Tone Device For a Cell Phone (Russell E. Sorber) Re: Dial Tone Device For a Cell Phone (Simon Edgett) Central Office Photos Wanted (ken@randomc.com) Re: Audio Monitoring When Phone is On Hook (Thomas Tonino) Re: ISDN U Interface Wiring/Electrical Interface (Eric Ewanco) Re: How Do You Dial a Vanity 800 Number? (Bill Newkirk) Re: How Do You Dial a Vanity 800 Number? (Barry Margolin) Re: New Toll-Free Number Coming (Linc Madison) 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 America On Line. It is also gatewayed to Usenet where it appears as the moderated newsgroup 'comp.dcom.telecom'. Subscriptions are available to qualified organizations and individual readers. Write and tell us how you qualify: * subscriptions@telecom-digest.org * The Digest is edited, published and compilation-copyrighted by Patrick Townson of Skokie, Illinois USA. You can reach us by postal mail, fax or phone at: Post Office Box 4621 Skokie, IL USA 60076 Phone: 847-727-5427 Fax: 773-539-4630 ** Article submission address: editor@telecom-digest.org ** Our archives are available for your review/research. The URL is: http://telecom-digest.org (WWW/http only!) They can also be accessed using anonymous ftp: ftp hyperarchive.lcs.mit.edu/telecom-archives/archives (or use our mirror site: ftp ftp.epix.net/pub/telecom-archives) A third method is the Telecom Email Information Service: Send a note to archives@telecom-digest.org to receive a help file for using this method or write me and ask for a copy of the help file for the Telecom Archives. ************************************************************************* * TELECOM Digest is partially funded by a grant from the * * International Telecommunication Union (ITU) in Geneva, Switzerland * * under the aegis of its Telecom Information Exchange Services (TIES) * * project. Views expressed herein should not be construed as represent-* * ing views of the ITU. * ************************************************************************* Finally, the Digest is funded by gifts from generous readers such as yourself who provide funding in amounts deemed appropriate. Your help is important and appreciated. A suggested donation of twenty dollars per year per reader is considered appropriate. See our address above. 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. ---------------------------------------------------------------------- Date: Tue, 27 May 1997 00:14:50 -0400 From: Monty Solomon Subject: Mobiles Safe, Study Finds, But They Do Heat Brain Reply-To: monty@roscom.COM FYI. From Reuters. 11:39 AM ET 05/22/97 Mobiles safe, study finds, but they do heat brain (Recasts to include later comments on brain warming) By Roland Moller HELSINKI, Finland (Reuter) - A Finnish study partly funded by the telecommunications industry has found mobile phones pose no health threat to phone users, although they do transmit heat to people's brains, researchers said Thursday. The study by four Finnish institutes examined the effect of radio frequencies used by mobile phones on the brains of 19 people and on mice, and found no health hazards. Researchers said it was clear human brains do convert mobile phone radio waves into heat, but the levels were far from hazardous. However, they are near the top end of international safety recommendations so should be examined more. Human brains can absorb up to 60 percent of the energy from mobile phone radiowaves, which would still be well below biologically risky levels, said Kari Jokela, researcher at the Finnish Center for Radiation and Nuclear Safety. Citing international radiation safety recommendations that people's brains should not be exposed to more than two watts of energy per kg of head weight, he said the potential maximum exposure from a mobile phone was near that limit. ``Since we are close to the limits here, more research is needed,'' he told a news conference. Maila Hietanen, researcher at the state-funded Occupational Health Institute, said a separate test to see if brainwaves were in any way affected by mobile signals had shown no hazards. ``The results are so consistent that the tests are completely sufficient,'' she said. The tests on mice examined development of cancer and showed that radio frequency radiation did not foster the disease, but the report said more research on the dead animals would be needed for final conclusions. ``There were no mortality differences between the animals exposed to radiowave radiation and the control group,'' the report said. Begun in 1994, the study was part of a broader European investigation of the effects of electromagnetic fields. It was carried out by researchers from the University of Kuopio, the Finnish Center for Radiation and Nuclear Safety, the Occupational Health Institute and the Technical Research Institute VTT. Among those funding it were telecommunications operators including Telecom Finland Oy and the Helsinki telephone company HPY and mobile phone makers Nokia and Benefon. ------------------------------ From: Dub Dublin - Sun Network Ambassador Subject: Re: Are Cordless' as Bad as Cellulars? Date: Mon, 26 May 1997 16:53:11 -0500 Organization: Sun Microsystems Houston Michael Wright wrote: > Bemson wrote: > There is no research out there that has established ANY causal > relationship between cell phones and brain tumors. And there never > will be. I'm not the least bit paranoid about these things, nor do I think there's any cause for alarm, but blanket statements like the one above deny the fact that there is an unknown (but we expect, low) risk associated with exposure (particularly long-term exposure) to various types of EM radiation. Epidemiological research is generally hard-pressed to prove causality at all -- a correlation is the best that can be hoped for without the type of long-term, large-scale studies that have the tobacco companies in hot water lately. I wouldn't bet on the second sentence -- not because I feel cellphones are dangerous (if I did, I wouldn't have the cellular bill$ I do), but simply because it is at least possible that long-term exposure to narrowband near-microwave radiation could have some harmful effects. By the time we know for sure, it will be too late to matter (see below.) > A cell phone operates with a transmitter power of only 3/4 of > a watt. As you read this, you are sitting in a far more powerful > electromagnetic field, the one generated by your computer monitor. Your monitor and your cellphone are as different as they look. There are several components to the EM radiation we are exposed to. In particular, electric and magnetic fields appear to have different effects on biological organisms. These effects are complex (and not at all well-understood) functions of at least: electric and magnetic field strengths, radited power/power density, frequency density and distribution, waveform shape (risetime), and possibly many other factors as well. We just don't know yet. > As to cordless phones, they operate with a transmitter power of 100 > milliwatts (one-tenth of a watt) so they, too, constitute no hazard > whatsoever ... at least from the magnetic field. Magnetic field is virtually zero. But the lower radiated power, as well as the lower frequency probably make cordless phones much safer than cellulars (which are themselves probably nearly harmless.) > By way of comparison, many radio stations throw off 100,000 watts ( > one million times the energy of a cordless phone) and the transmitter > personnel sit in that electromagnetic field all day, every day with no > problems. Well, they're not keeling over like they've been poleaxed, but there's anecdotal evidence that there may be some minor long-term effects. For example, Air Force pilots and police and Highway Patrol officers have fewer male children than would ordinarily be expected. Some people think their occupational exposure to relatively high levels of microwave energy may be responsible. (Only a few years ago, before instant-on radar, cops routinely left their radar guns on and resting inches from their gonads while waiting for the next unlucky revenue provider to crest the rise. Sometimes I wish they'd been using 2 kW units ...) I think it's fair to say we don't know enough to accurately gauge the effects (or lack thereof) of such exposure yet. > The cellphone / brain-tumor *scare* is just another example of Junk > Science Meets Tabloid Media. I'll agree most of the scare is unfortunately driven by political agenda and modern media's bent for "infotainment" (read sensational garbage). It would be good to have more hard data on the effects of EM radiation, though ... that's what leads to intelligent engineering decisions. In any case, as mentioned above, by the time we know the risks of the current technologies, it won't matter anymore, because the modulation methods will have changed so much as to render the research useless (i.e., we'll be faced with yet another unknown risk.) With the rapid move to digital signals, the cahracteristics of the biological effects change significantly: On one hand, the risetime effect is worsened because of the sharp square waveform of digital signals, on the other hand, power density and frequency distribution (particularly with spread spectrum techniques) are expected to significantly reduce the risk. Which effect is greater? It will be a long time until we know for sure ... In the mean time, if you're worried, use handheld radio devices based on spread spectrum techniques -- they work better anyhow! (Hey! Maybe that's how I can justify a Q-phone! Anything else would just be unsafe!) Dub Dublin Sun Microsystems Market Segment Manager 12 Greenway Plaza, Suite 1500 Healthcare & Petroleum Houston, Texas 77046 USA dub.dublin@sun.com ------------------------------ Date: Mon, 26 May 1997 12:32:43 +1000 From: fist@ozemail.com.au (Stewart Fist) Subject: Re: Are Cordless' as bad as Cellulars? Bill Sohl (billsohl@planet.net) writes: > Please point us (me) to the specific study or studies that hae made > such a conclusion. For the more notable of the DNA/tumour specific studies see For a brief bibliography of the wider field, about 250 research reports, see and for an overview of the current controversy, see > I have never seen any such references or conclusions made in relation > to ham radio operators (I am a ham), or most of these other jobs and > occupations. Without specific references, your comments are hearsay > at best and without substantiation at all. The fact that you haven't heard of this, is a problem that you alone can solve Bill. But to accuse me of "hearsay" and "without substantiation at all" is a bit much when I have included in each posting a direct link to a bibliography of 250 research papers, with a mass of layman's explanations. The whole of my site, and most of my postings have been littered with references which can be easily checked. The ham and radio-operators studies that you dismiss as hearsay, have been widely discussed and quoted in the medical and biomedical literature for a decade. The main study on ham radio operators was conducted by Milham in California and Washington. He used the FCC records to look up the death rates for amateur radio operators from 1979 to 1984. He showed an excess of leukemia deaths (over what would be expected from the general rate in the population) of 31 to (an expected) 24.3 in California (Washington wasn't large enough to be significant). Tumours and other lymphatic cancers were higher also, at 38, compared to (expected) 22.3. These figures were all highly significant. But most significant of all, was the acute form of Myelogeneous Leukemia (AML) which was nearly double -- 15 cases compared to 8.5 (expected). The total numbers were low, but the rise in the incidence and mortality among radio hams was highly significant. There are also many airforce and army studies which show increased rate of cancers among radio and radar operators. The Polish Miliary study in 1988 of 128,000 people, of whom 3700 were exposed to radio or radar, showed a 3-times increase in cancer incidence. And a more recent study of Norwegian female maritime radio operators revealed higher levels of breast cancer. Savitz and Calle looked at a series of eleven reports of workers who are exposed to electromagnetic fields, and they also showed a rise in general leukemias, with the AML form being especially significant. Telegraph, radio and radar operators had the highest levels here. Similar exposures are experienced by physiotherapists using radio-frequency (usually 27MHz) and microwave-frequency (915MHz and 2.4GHz) diathermy equipment, although typically they switch the gear on and leave the room -- so exposure times (for them) are short. Not all physios use this equipment. 42,403 female members of the profession were queried for pregnancy history. Miscarriages before seven weeks among those using the microwave diathermy equipment was very high (47.7% as against 14.5% for controls), while, among those using normal shortwave diathermy, the miscarriage rate was virtually the same as among non-users. I make this point to illustrate that these effects are not just with brain-tumours and leukemias, but across a range of conditions - and they appear to be frequency- and exposure-dependent, and mainly connected with DNA disruptions and supression of immune responses. Obviously genetic differences and other exposures also play a role. No one is talking about epidemics, but they are worried about increased levels of what have been, in the past, low-incident cancerous conditions. These appear to be rising at a regular rate. We just don't know what this means with 100 million people using cell phones over a lifetime. And I must say that I am amazed at the intellectual inertia (and outright denial) of technical people in resisting any suggestion that these potential major health problems should be treated seriously and researched vigorously. Stewart Fist, Technical writer and journalist. Current Australian columns: Archives of my columns are available at the Australian and also at the ABC site: Development site: Phone:+612 9416 7458 Fax: +612 9416 4582 Old Homepage: ------------------------------ Date: Mon, 26 May 1997 16:15:50 -0500 From: Russell E. Sorber Subject: Re: Dial Tone Device For a Cell Phone In article Joe Plescia writes: > Is there a device available that provides dial tone on a cell phone? Motorola Cellular Subscriber Group makes several devices that provide dial tone and a RJ-11 jack at one end and a cellphone connection at the other end. They are called "cellular connection interface boxes." They are often used to provide dial tone to burglar alarm dialers so they can dial out via cellular. There are several different kinds of boxes (and prices) depending on the type of cellular phone you have. Some dealers have these or you can order via Motorola Subscriber Group at 1-800-331-6456. Regards, Russ ------------------------------ From: sedgett@edgett.bc.ca (Simon Edgett) Subject: Re: Dial Tone Device For a Cell Phone Date: 26 May 1997 15:52:02 GMT Organization: grouptelecom customer Joe Plescia (jplescia@plescia.com) wrote: > Is there a device available that provides dial tone on a cell phone? > I have the need for a device that would provide a dial tone to a > external device so that a regular telephone or fax machine could be > used. I do remember seeing a device, many moons ago at a construction > trade show, that connected to a GE 3000 cell phone that allowed > regular POTS phones to be used ... (the user picked up the phone, heard > a dialtone and dialed) ... I've used such a device on a Motorola Flip phone. Cost about $350 CAN. We use to use them to provide credit card terminals at trade shows. (I know, not the safest in the world) Worked fairly well. Have used them with fax machines and modems w/o much problem. Actually when I purchased the last one the cell co I bought it from told me about a setup they had assisted on. A fellow put in a whole system on his sailboat. An antenna was mounted on the top of the mast and this box was connected to his phone sitting in some cupboard. (Motorola bag phone if I recall) Then he had done local wiring through out the boat. Fax machine down below, cordless phone on deck so that he could use the reception of the antenna mounted on the mast as a handheld. He even had another small phone in the wheel house. I which I had seen that one. Cheers, Simon ------------------------------ From: Ken Subject: Central Office Photos Wanted Date: 26 May 1997 23:06:27 GMT Organization: Random Access Inc. +1 (800) 910-1190 I am looking for photos of central offices, ess, step, crossbar ... anything ... I want to start a web page dedicated to central offices and switching equipment ... Thanks, mailto:kw@randomc.com ------------------------------ From: ttonino@bio.vu.nl (Thomas Tonino) Subject: Re: Audio Monitoring When Phone is On Hook Date: Mon, 26 May 1997 20:51:33 +0100 S Hemphill wrote: [snip] > They simply, with your permission, activated a switch at the telephone > co., and they were able to hear inside your home through your phones > even though they were ON HOOK! What I want to know is, can this > actually be done??? Can my home be invaded through phones that are > HUNG UP? Yes they can. It depend on the phone model but the idea is this: Put a high frequency signal on the phone line. This signal will travel over the open hook switch, so a closed circuit forms. This signal is influenced by vibrations of the switch or the microphone. Dutch police was alleged to do this for listening in on suspects; would show up in reports as '... left the phone off hook accidentally and we overheard...'. Police denied, but hacker organization Hack-Tic gave a demonstration over a short line and publicized the schematic used. I still should have it around somewhere; it was not very complex, but wouldn't work on very long lines either. This equipment is not in standard phone offices, so it is not a matter of just throwing a switch. Thomas Tonino ------------------------------ From: Eric Ewanco Subject: Re: ISDN U Interface Wiring/Electrical Interface (High Rise Apartment) Date: 26 May 1997 19:06:00 -0400 Organization: US Robotics Thanks for all who wrote me advice on identifying the newly installed ISDN line on the six pairs which go to my junction box. Several people correctly pointed out that damage should only be expected when plugging a TA into a POTS line, not plugging a POTS phone into an ISDN line. A POTS phone on an ISDN line will give either hissing or clicking at one second intervals. So I plugged in a POTS phone and the pair I suspected gave me the clicking. One person also confirmed the voltage. The next day I got my I-modem TA, plugged it into the pair I had identified, and it works great. Of course NYNEX did not give me any assistance in this so good thing I found it. # __ __ Eric Ewanco # IC | XC eje@world.std.com # ---+--- http://www.wp.com/Eric_Ewanco # NI | KA Framingham, MA; USA ------------------------------ From: Bill Newkirk Subject: Re: How Do You Dial a Vanity 800 Number? Date: Mon, 26 May 1997 16:04:34 -0400 Organization: Rockwell Collins, Inc. Reply-To: wenewkir@collins.rockwell.com > The letters Q and Z are normally not used in words forming phone > numbers. When they are used in other phone applications such as > voicemail, they are not standardized. Frequently the Q will appear > with the 1 and the Z with the zero, which instead of being zero > clicks is actually ten clicks. Sometimes Q and Z will both be with > the 1. You might want to check out the Telecom Archives file which > deals with 'words to numbers' in telephone numbers. PAT] On the rolm phone system here, the voice mail uses 7 for Q and 9 for Z. The logic being that "they are on the keys where they should logically go." of course, the initial questions about Q and Z were answered with the "logical" answer instead of telling us about 7 and 9 ... in the training class, i'd pointed out that my grandmother's phone in Terre Haute (way back when they had 5 digit dialing there) had QZ on the 1 and of course "they'd never heard of such a silly thing.." and by the time the phone system was "up", most had forgotten the training class answer anyway. Simply amazing how many people have Q and Z in the names ... not just as a first letter ... and since a feature was "dial by name" function, folks ran into the missing Q and Z more often than expected. Bill Newkirk Collins General Aviation Division Publications Department Rockwell Collins, Inc., Melbourne Florida wenewkir@collins.rockwell.com ------------------------------ From: Barry Margolin Subject: Re: How Do You Dial a Vanity 800 Number? Date: 26 May 1997 15:00:14 -0400 Organization: BBN Planet, Cambridge, MA In article , PAT wrote: > The letters Q and Z are normally not used in words forming phone > numbers. When they are used in other phone applications such as > voicemail, they are not standardized. Frequently the Q will appear > with the 1 and the Z with the zero, which instead of being zero > clicks is actually ten clicks. Sometimes Q and Z will both be with > the 1. The phones on our AT&T PBX have the Q and Z included on the same key as the adjacent letters, so 7 = PQRS and 9 = WXYZ. Barry Margolin, barmar@bbnplanet.com BBN Corporation, Cambridge, MA (BBN customers, call (800) 632-7638 option 1 for support) Support the anti-spam movement; see ------------------------------ From: Telecom@Eureka.vip.best.NOSPAM (Linc Madison) Subject: Re: New Toll-Free Number Coming Date: Mon, 26 May 1997 20:27:38 -0700 Organization: No unsolicited commercial e-mail! In article , nwdirect@netcom.com wrote: > From Reuters > AT&T Corp. said it plans to introduce a new toll-free prefix in one > year to meet a growing demand for toll-free services. A year ago, AT&T > created an 888 toll-free code to supplement a dwindling supply of 800 > numbers. The company said those new numbers are being consumed so > quickly that it is working to create another pool of available numbers > using an 877 code. "Of 7.78 million available combinations, 7.71 > million, or 99.9%, are working, reserved or otherwise taken from the > pool of available numbers," AT&T said of the original batch of 800 > numbers. The next code, 877, is scheduled to be operational by April > 4, 1998. I'm surprised that Reuters would publish such nonsense. *AT&T* didn't create 888, and it won't create 877. Bellcore, which has no connection at all to AT&T, serves as the administrator of the North American Numbering Plan, under which function it makes the decisions regarding activation of new toll-free codes. ** Do not spam e-mail me! ** Linc Madison * San Francisco, Calif. * Telecom@Eureka.vip.best-com >> NOTE: if you autoreply, you must change "NOSPAM" to "com" << ------------------------------ End of TELECOM Digest V17 #133 ******************************