Here is another issue of private line! Thanks again. THIS IS THE TEXT OF PRIVATE LINE NUMBER 5 -- VOLUME 2, NO. 1 This issue contains four photographs and 16 illustrations, including some nice exploded diagrams of COCOTS. Send me $5.00 if you want the hardcopy version. My address is: private line 5150 Fair Oaks Blvd. #101-348 Carmichael, CA 95608 $24 a year for 6 issues. Price goes to $27 on July 1, 1995. Mexican and Canadian subscriptions are $31 and overseas subscribers have to pay $44 :( I. Editorial Page II. Updates and Corrections III. Cell Phone Basics, Part 1 IV. The Roseville Telephone Museum V. Telecom Related Magazines and Newsletters I. EDITORIAL PAGE 1. Damien Thorn has agreed to be the technical editor for private line. Damien has written for Tap and 2600. He now writes a great column called Full Duplex Communications for Nuts and Volts. Damien brings more than 15 years of practical, hands on hacking experience to private line. Let me explain a little about what he'll be doing for the magazine and what it means to you. 2. Damien won't be checking every technical fact in my writing or in this magazine, any more than I will check on his writing. Instead, he'll help me with questions that I can't answer. I can't tell you, for example, which cell phones are the easiest to work on and why. He can. I can tell you in general about cell phone theory and operation but I can't tell you much about real field experiences. He can. His advice will help me make fewer mistakes and keep private line more interesting and more practically grounded. In addition, he's also open to the idea of writing a column on a regular basis. I am very happy that he has signed on. 3. What will this magazine cover in the future? I intend to write general pieces about specific subjects. An issue on PBX's, one on outside plant equipment, another on business telecom equipment and so on. I will not write any specific hacking pieces myself. That's for any reader of the magazine to do. I could put two months of effort into a piece about hacking ROLMs but what good would that do someone who doesn't know about PBX operation to begin with? Someone that doesn't know a port from a pier? Reader submitted articles may be as specific as you like. But I'll keep my pages and my articles oriented toward beginners. 4. Today is January 1, 1995. The start of a new year. It's odd to think that these words won't be read until March. In reality, my deadline is only three or four weeks before the cover date. But you have to get each page done when you can. It's one of many oddities that I am dealing with for the first time. Magazine distribution is certainly another. A newssrack for a small magazine is like a consignment stand. Practically every magazine will be bought the real question is how many. You're doing well if 25% of your magazines go unsold. I explained the costs of producing private line last issue but I didn't figure in the cost of returns. Instead of $1.18 a copy, therefore, the true cost is more like $1.47. Quite a difference. On the positive side, it looks like I'll have at least 1200 copies printed up of this issue instead of 600 for the last. That will lower the per unit cost quite a bit. On the other hand, the better cover for this issue will make costs go up. And first class mail rates have also gone up. Oh, well. It feels like I am reinventing the wheel in learning all these things. When I don't have the time to learn them to begin with. What's a solution? 5. Well, the solution might be easy if I had a great deal of money. I could hire staff and advertising people. Then I'd go back to writing and research. But I don't have the money nor would I really want to change the character of the magazine by hiring a paid staff. Perhaps a better idea might be to organize a loosely structured publishing house for alternative technical magazines. Six or seven 'zines using the same printer to lower costs, sharing the same advertiser list and promoting each other's magazines with free ads in each others publications. Nothing too formal or involved. More like an association. No dues or fees. We could all keep in touch with fax machines, the mail and the internet. A quick check of Factsheet5 reveals several technologically oriented magazines: 2600, 2600 Connection, 3W, Short Circuit and Historically Brewed. Throw in all the electronic zines on the net that don't go into hardcopy and you've got quite a few people who aren't in the mainstream writing about tech. I don't have the time to explore this right now but feel free to write if you have any thoughts along this line. Lastly, I want to thank all my new readers, especially those subscribers who signed up without seeing a copy of private line first. That takes faith. In return, I'll try to put out the best magazine I can, something with articles you'll be interested in. The mailbox and the electronic door are always open . . . Tom Farley Carmichael, California privateline@delphi.com II. UPDATES AND CORRECTIONS 6. The internet patent connection got turned off for a few weeks in January. Try it again if you were disappointed before. Internet Multicasting Service and the Patent and Trademark Office were apparently involved in a turf war, with the PTO doing the instigating. There's hope, though, for the future. Bruce Lehman, commissioner of the Patent Office, told the IEEE Spectrum that his agency intends to put the entire patent collection online by the end of the decade. Hot damn. That means the text of all patents dating back to 1790. Wouldn't it be possible, however, to get text and illustrations at a web site? The patents are simple black and white line drawings. Speaking of web sites, I didn't include the PTO's in last issue. It is: http://www.uspto.gov/ 7. Def Con III will be held at the Tropicana Hotel in Las Vegas on August 4th, 5th, and 6th. Speakers will talk on the fifth and sixth. Get there. The Tropicana Hotel is located at 3801 Las Vegas Blvd. South, Las Vegas, Nevada, 89109. Rooms are $65 for a single or a double Monday through Thursday. Rates climb to $90 for a single or double from Friday to Sunday. Ask for the Def Con III convention to get those rates when you call. The Tropicana is at (800) 4689494 or (702) 7392448 (Fax). Yes, Dark Tangent knows that those rates are expensive. That's why he encourages everyone to keep track of developments as the con draws near. Keep up on details and you'll find cheaper motels, people to drive with or people to crash with. The ftp site is: ftp.fc.net /pub/defcon. Subscribe to the mailing list by sending email to the following: majordomo@fc.net. Put the following statement in the body of your message: subscribe dcannounce. This will put you on the mailing list and you will receive updated information on a regular basis. DT's voice mail is 07008264368 from a phone with AT&T LD. His email address is dtangent@defcon.org. There's also a bulletin board at Alliance Communications +1 612251 2511. Or write him at 2709 E. Madison #102, Seattle, WA, 98112. That will also get you on a list. I do not want any excuses from any of you for not going. You have the whole spring and summer to save up. You have months and months to schedule an entire week off. Which is what you'll need to really enjoy yourself. And you will enjoy yourself. I won't be speaking but I will ask Dark Tangent about setting aside an hour or two for telephone talk. Anyone interested in that could just show up at a certain place at a certain time. No big deal. I wrote at length about Def Con II in private line #3. Please, please try to get there. I'll be writing a little more on this as the con draws near. 8. I just got a copy of Public Communications Magazine. It's the trade magazine that covers customer coin operated telephones most. A careful reading clears up many mysteries surrounding the wiley COCOT. Even the ads are interesting. The inside cover of the November issue, for example, has a Mars Electronic International ad that shows their MS16 electronic coin validator. It's an electronic beastie that checks each coin deposited into a COCOT. While these units were originally designed to guard against fraud, some telcos have been installing them in an apparent attempt to prevent red boxing. Unlike a COCOT, a telco payphone doesn't check every coin deposited during a conversation. It usually just checks the initial deposit. It can't do much more since it's just a dumb box of relays. No memory or intelligence. It sends tones to the central office to indicate a coin deposit. A red box simulates those tones. A coin validator can help stop this if added to a telco payphone. There are other ways for a telco to stop red boxing. One of my readers reports that GTE in some parts of the midwest has gone away from ACTS or automated coin toll service. They're now routing 1+ calls to the operator. You can still try boxing but you lose your anonymity. Public Communications also mentions some other interesting things. Ever notice the housing on these COCOTs? They look like a telco brand (W.E.) but cheaper? Quadram Telecom probably makes them. And who supplies the boards for these so called smart phones? The boards that let the COCOT total coins, rate calls and provide an ACTS like voice to tell you how much they are ripping you off for? Leading suppliers are Protel, maker of the BB and 2000 board, Intellistar, Elcotel and Intellicall. These fit on a chassis as illustrated on page 48. And the locking mechanisms? The most sophisticated is from Medeco High Security Locks, Inc. It's part of a whole system of key management. Check out the March 7, 1994 issue of Design News for more information on this coin box lock. Look for this system to come into wider use in the future. 9. Speaking of the future, the telephone industry is going nuts over debit cards. And I mean nuts. Even Teleconnect is going overboard. Public Communications and Telecard World are fueling the fire but it is the private payphone owner and the card seller that will shove these things into our lives. What's worse is the talk of putting debit card payphones in a neighborhood near you. No coins accepted, thank you. Coinless phones were limited before to airports, train stations or highway rest stops. Places where you had lots of other phones to choose from or no other phones at all. One example is Ameritech's LobbyLine indoor coin phone. You call with a calling card or debit card. Or you call collect or bill to a third party. The present debit phones, though, are being discussed as a replacement to the omnipresent COCOT. The reason? Pure greed. Protel's president, Jerry Yachabach, says that more than 70% of the cost of maintaining payphones is due to coin related functions. He reasons that the industry should find a substitute for coins. Great. His comments go along with pictures of two expensive looking credit card phones. No doubt Protel will make big bucks by selling these things. And what about the rest of the trade? What do they think? Eric Stebel, Managing Editor of Public Communications, nearly drools when he writes "And talk about vandalism and theft switching to a debit card payphone would virtually eliminate that. When was the last time you heard of someone blowing up a payphone just for the fun of it? No, most vandals have an ulterior motive to get to your payphone's coin box. And just think of the float money your company could make off of lost or unused cards. Heck, some people would even buy your debit cards as a collectible and never use them." Hey, Eric, float this! Let's go over some of these terms. 10. The most common form of debit card is the prepaid long distance calling card. Or talk and toss. Industry types call it centralized debit card technology. You pay for a certain amount of long distance in advance at a retail store. In return you get a card. Such as the "AT&T PrePaid Calling Card" available at Office Depot. It has an 800 number and a calling card number on the back. The pictures on the front, in part, drive collector mania. These can be anything from Satan to Santa. Let's say you want to call Germany. You call a number like 1800357 PAID. Your call is routed to a PBX somewhere. Industry favorites for prepaid cards are the NACT LCX 120C from National Applied Computer Technologies and the Harris Digital Systems 20/20 switch. Harris has an entire system called Protocall to handle prepaid debit cards. Their 20/20 switch is called a NGC for some strange reason when it's part of Protocall. In any case, the card seller's switch gets your call. What then? Next step is to enter the calling card number. Could be anything. Like 533 442 5968. The automated attendant tells you the value on your card. It then tells you to dial your number. Your call now goes out from the PBX to the Federal Republic. The robot comes back on after your call to tell you how much you have left on your card. You're now free to make another call or hang up. It's a pretty neat system and you can't beat the anonymity when you're calling from a payphone. The Tonya Harding Gang did have their toss and talk card calls monitored. But that's because the FBI was already watching. 11. What are the economics of all this? Here's a quotation from December's Teleconnect. This article had the happy title "Cash Cow": "Imagine you have a 100 store chain. You sell one $20 prepaid calling card per day per store. You bring in $60,000 a month. ($3,000 cards). You sell calls for 35 cents a minute. Your call cost is 24 cents a minute. 15% of the cards are not active (breakage). Your first month's operating margin is $24,000. Your first year's operating margin is $486,300. Where does the 24 cents a minute come from? You pay seven cents a minute for inbound 800 calls. Eight cents a minute for calls going out. Staff and space two cents. Equipment is five cents. Printing of cards is half a cent. Dedicated T1s [the leased line running from the telephone company to the switch] are one and a half cents a minute. The name of the game is volume. Without volume you can't get your prices down enough." Well, you know that AT&T can get costs down. Yet they charge 60 cents a minute for a call within the United States on their card. Much of that must go to places like Office Depot that actually sell the card. But it's still an expensive service. Remember, too, that a one minute and one second call will get you dinged for two minutes. The other kind of debit card is one with a magnetic stripe. You swipe these in the reader of a debit card payphone. Many countries have this service. Some telcos are playing with it now. Want to call home from the Quickie Mart? Buy a card from the store or go to a vending machine. Just like a BART card. Calls go directly to their destination once the payphone approves the card. The Public Utilities Commission in each state will probably require that 911, 800 numbers and 10X codes can be dialed without a card. Whether the COCOT actually allows those calls is another story. You may also hear about a debit card with an integrated circuit built in. This is chip technology. The chip itself maintains the account balance of the card. VISA and Mastercard are coming out with these soon. You'll be able to make small transactions of all sorts, including phone calls. I think, though, that calling them debit cards is wrong. Chip cards are based on credit and not on money put up front. That makes them a credit card and not a debit card. 12. I will be printing letters in upcoming issues. Tell me if you don't want your name printed. I want to welcome CONSUMERTRONICS aboard as private line's first paid advertiser. I've heard many good things about John Williams' company and I am happy to have them along. Speaking of advertising, my rates are now $100 for a full page, $50.00 for a half and $25.00 for a quarter. See what you missed by not signing on earlier? All subscribers get free classified ads of twenty five words or less. Thanks again to all my new subscribers!. I now have 39 paid subscriptions! Life is good. . . III CELLULAR TELEPHONE BASICS, PART 1 -- BY TOM FARLEY 13. Welcome to the world of cellular telephony. It's a fascinating place. Used phones prices are falling rapidly. It's time to experiment or at least to read up. Let's look at the big picture first. Telephone over radio is nothing special or unusual. Long distance radio telephony dates back to at least 1927, with the introduction of overseas service on short wave between the United States and Great Britain. AT&T and the British Postal Office put that project on the air after four years of experimenting. They expanded it later to communicate with Canada, Australia, South Africa, Egypt and Kenya as well as ships at sea. This service had fourteen dedicated channels or frequencies eventually assigned to it. The main transmitter was at Rugby, England. [1] Cables and satellites have replaced radio telephone for nearly all long distance use but many ships still use it. Radio amateurs on short wave still handle noncommercial telephone calls over short wave. These patches often handle emergency traffic. 14. Local, noncommercial radio telephony has also been going on for years, possibly since the 1950's. Enterprising radio amateurs wired simple telephone interfaces to their base stations long before any direct connection to Bell System equipment was allowed. These home built kits preceded today's sophisticated autopatches. An autopatch is, essentially, a remotely controlled phone. You activate and control one from afar with your radio's DTMF keypad. This could be a 6 meter, 2 meter, 70 cm or even a 1.2 GHz handheld or car mounted rig. You can then make calls from anywhere that you can key up the autopatch. 15. Car mounted mobile telephones carried out local commercial traffic for decades. Companies like Motorola still make them. It's an excellent choice for areas not well served by cellular. Cellular service may cover 90% of urban areas, but it only reaches 30% to 40% of the geographical area of America. Many people refer to mobile telephone by just saying IMTS, which stands for Improved Mobile Telephone System. It's the newest form of mobile radio. [2] Most IMTS equipment operates in the UHF band. A centrally located transmitter and receiver serves a wide area with a relatively few frequencies and users. It's the same concept that taxi fleets and tow truck companies use to dispatch vehicles. Most areas allow you to dial out directly from your car, however, there are still places where the operator comes up on frequency to place the call for you. [3] A single customer could drive 25 miles or more from the transmitter, however, only one person at a time could use that channel. 16. This limited availability of frequencies and their inefficient use were two main reasons for cellular's development. The breakup of the Bell System in 1984 allowed real cellular development to begin. The key to the system is the concept of frequency reuse as depicted in the upper right. Let's look at that as well as some basic cell phone theory. II Basic Theory and Background 17. Cell phone theory is simple. Executing that theory is extremely complex. Each cell site has a base station with a computerized 800 megahertz transceiver and an antenna. This radio equipment provides coverage for an area that's usually from two to ten miles in radius. Even smaller cell sites cover tunnels, subways and specific roadways. The amount of area depends on topography, population, and traffic. The MTSO decides which cell and which frequencies in that cell should carry your call. How does it do that? 18. Your telephone's signal strength declines or increases as you move toward or away from a tower. The nearest base station constantly reports this signal strength to the MTSO. The mobile switch transfers your call to another cell when your signal level drops to a predetermined point. This handoff usually occurs automatically when the switch determines that another cell's transmitter can provide a better, stronger connection. You may drive fifty miles, use 8 different cells and never once realize that your call has been transferred. Let's look at some basics of this amazing technology. 19. The FCC allocates frequency space in the United States for many services. Some of these assignments may be coordinated with the International Telecommunications Union but many are not. Much debate and discussion over many years placed cellular frequencies in the 800 megahertz band. The FCC also issues the necessary operating licenses to the different cellular providers. Cellular development began in earnest after the Bell System breakup in 1984. The United States decided to license two carriers in each geographical area. One license went automatically to the local exchange carriers. The LECs. The other went to an individual, a company or a group of investors who met a long list of requirements and who properly petitioned the FCC. Cellular parlance calls these LECs wireline carriers. Each company in each area took half the spectrum available. What's called the "A Band" and the "B Band." There's no real advantage in having either one. The nonwireline carriers usually got the A Band and the wireline carriers got the B band. Depending on the technology used, however, one carrier might provide three times the connections a competitor does with the same amount of spectrum. 20. Cell phone frequencies start at 824.04 MHz and end at 893.7 MHz. [4] That's 69.66 megahertz worth of radio frequency spectrum. Quite a chunk. By comparison, the AM broadcast band takes up only 1.17 megahertz of space. This band, however, provides only 107 frequencies to broadcast on. Cellular may provide thousands of frequencies to carry conversations and data. This large number of frequencies and the large channel width required for each channel account for the large amount of spectrum space. For example, AT&T's Advanced Mobile Phone Service or AMPS uses 832 channels that are 30 kHz wide. It's the most common system right now. AMPS, though, has been replaced with NAMPS in crowded cell site areas. NAMPS stands for Narrowband Advanced Mobile Service. It's a Motorola technology. It produces 2412 narrow channels. A NAMP's channel is 10 kHz wide. AMPS, NAMPS and Hughes' ENAMPS are all FM based, analog systems. Digital systems like CDMA and TDMA provide even more channels in the same space. CDMA, in particular, could provide 20 times the number of frequencies that an AMPS system can. Let's back up a little before we drown in a sea of acronyms. 21. I mentioned that a typical cell channel is 30 kilohertz wide compared to the ten kHz allowed an AM radio station. How is it possible, you might ask, that a one to three watt cellular phone call can take up a path that is three times wider than a 50,000 watt broadcast station? Well, power does not necessarily relate to bandwidth. A high powered signal might take up lots of room or a high powered signal might be narrowly focused. A wider channel helps with audio quality. An FM stereo station, for example, uses a 150 kHz channel to provide the best quality sound. A 30 kHz channel for cellular gives you great sound almost automatically, nearly on par with the normal telephone network. That's what's impressive about Motorola's NAMPS. The base station uses a special frequency control circuit to keeps calls exactly on frequency. No wavering or moving off frequency to destroy a call's quality. Things should sound fine with this narrow band _if_ everything is working right. 22. I also mentioned that the cellular band runs from 824.04 MHz to 893. 97 MHz. In particular, cell phones use the frequencies from 824.04 MHz to 848.97 and the base stations operate on 869.04 MHz to 893.97 MHz. 45 MHz separates each transmit and receive frequency within a cell. That keeps them from interfering with each other. Getting confusing? Let's look at the frequencies of a single cell for a single carrier. Maybe that will clear things up. For this example, let's assume that this is one of 21 cells in an AMPS system: Cell#1 of 21 in Band A (The nonwireline carrier) Channel 1 (333) Tx 879.990 Rx 834.990 Channel 2 (312) Tx 879.360 Rx 834.360 Channel 3 (291) Tx 878.730 Rx 833.730 Channel 4 (270) Tx 878.100 Rx 833.100 Channel 5 (249) Tx 877.470 Rx 832.470 Channel 6 (228) Tx 876.840 Rx 831.840 Channel 7 (207) Tx 876.210 Rx 831.210 Channel 8 (186) Tx 875.580 Rx 830.580 etc., etc., (Each cell has at least 15 frequencies or channels) 23. The cellular network assigns these frequency pairs carefully and in advance. The layout is confusing since the pattern is non-intuitive and because there are so many numbers involved. Don't get too caught up with exact frequency assignments unless you want to go further. [5] Speaking of numbers, check out the sidebar. Channels 800 to 832 are not labeled as such. Cell channels go up to 799 in AMPS and then stop. Believe it or not, the numbering begins again at 991 and then goes up to 1023. That gives us 832. Why offset at all? Cellular is not like CB radio. Citizen's band uses the same frequency to transmit and receive. A push to talk setup. Cellular provides full duplex communication like nearly all modern radios. It's more expensive since the mobile unit and the base station need the circuitry to transmit on one frequency while receiving on another. But it's the only way that permits a normal, back and forth, talk when you want to, conversation. 24. Some Important Frequency Terms Okay, so what do we do we have? Three things: 1) Cell phones transmit on certain, dedicated frequencies, 2) base stations transmit on certain, dedicated frequencies and 3) a certain amount of bandwidth separates these frequencies. Let's get even more specific. We call a cell site's transmitting frequency the forward channel. A forward channel contains everything you hear since it is the cell site that transmits it. The cell phone's transmitting frequency, by comparison, is called the reverse channel. There's more. Certain channels carry only data. We call these control channels. They, too, have a forward and reverse frequency. This control channel is usually the first channel in each cell. It's responsible for call setup. Getting confusing? Let's go back to our friendly cell site for an example. [TABLE] 25. The first channel is always the control channel for each cell. You'll have 21 control channels if you have 21 cells. Calls get setup on these. A call gets going, in other words, on the control channel first. The MTSO then assigns a normal channel to carry the conversation. The voice channels and the control channel may handle signaling during the actual conversation. A single call, therefore, involves two kinds of forward and reverse channels. One for voice and data and one for data only. Makes it hard to follow, doesn't it? But there are real benefits to figuring it out. A phone's ESN number, for example, is only transmitted on the reverse control channel. A person poaching ESNs need only monitor one of 21 frequencies. They don't have to look through the entire band. I'll use the terms reverse control channel and reverse voice channel to keep these terms separate from now on. One last point at the risk of loosing everybody. You'll hear about dedicated control channels, paging channels, and access channels. These are not different channels but different uses of the control channel. Let's clear up the confusion by looking at call processing. We'll start out with AMPS since it's the most common system and because TDMA uses the AMPS protocol to first set up calls. Even a CDMA carrier uses an AMPS system in the background to carry calls from non-digital phones. We'll also touch on a number of new terms along the way. III Call Processing 26. Let's look at how cellular uses data channels and voice channels. Keep in mind the big picture while we discuss this. A call gets set up on a control channel and another channel actually carries the conversation. The whole process begins with registration. It's what happens when you first turn on a phone but before you punch in a number and hit the send button. It only takes a few hundred milliseconds. Registration lets the local system know that a phone is active, in a particular area and that it can now take incoming calls. What cell folks call pages. The local system then notifies, in theory, the entire nationwide cellular network that this phone has come on line. Registration begins when you turn on your phone. Registration -- Hello, World! 27. A mobile phone runs a self diagnostic when it's powered up. Once completed it acts like a scanning radio. It searches through its list of forward control frequencies, trying to pick the one with the strongest signal. The nearest base station usually provides that. The phone then transmits information to identify itself on the corresponding reverse control frequency. The mobile sends its phone number, its electronic serial number and its home system ID. Among other things. The cell site relays this information to the mobile telecommunications switching office. The MTSO, in turn, communicates with different databases, switching centers and software programs. 28. The phone gets registered with the local system if everything checks out. It can now take incoming calls since the system is aware that it is in use. The mobile then monitors a paging channel while it idles. All idle phones monitor this initial paging channel or IPCH. It's usually channel 333 for the non-wireline carrier and 334 for the wireline carrier. [6] Only larger systems have multiple paging channels. Again, this is a data based, forward control channel, transmitted by the cell site. What's different about a paging channel is that it cuts across the entire cellular service area. It's transmitted by each base station, even if that frequency isn't part of a cell's group of fifteen or sixteen. A mobile first responds to a page on the reverse control channel of the cell it is in. The MTSO then assigns yet another channel for the conversation. But I am getting ahead of myself. Let's finish registration. 29. Registration is an ongoing process. Moving from one service area to another causes registration to begin again. Just waiting ten or fifteen minutes does the same thing. It's an automatic activity of the system. It updates the status of the waiting phone to let the system know what's going on. The cell site can initiate registration on its own by sending a signal to the mobile. That forces the unit to transmit and identify itself. Registration also takes place just before you call. Again, the whole process takes only a few hundred milliseconds. 30. AMPS uses frequency shift keying to send data. Just like a modem. Data's sent in binary. 0's and 1's. 0's go on one frequency and 1's go on another. They alternate back and forth in rapid succession. Don't be confused by the mention of more frequencies. Frequency shift keying uses the existing carrier wave. The data rides 8kHz above and below, say, 879.990 MHz. Read up on modems and FSK and you'll understand the way AMPS sends digital information. Data gets sent at 10 k bps or 100,000 bits per second from the cell site. Quite impressive if we're talking about a modem on a land line. But we aren't. Cellular uses a radio link, a very high frequency signal that's subject to the vagaries of its band. Things such as billboards, trucks, and underpasses can deflect a cellular call. So the system repeats each part of each digital message five times. That slows things considerably. Add in the time for encoding and decoding the digital stream and the actual transfer rate can fall to as low as 1200 bps. [7] Remember, too, that an analog wave carries this digital information, just like most modems. It's not completely accurate to call AMPS an analog system. AMPS is actually a hybrid system, combining both digital and analog signals. Getting a Call -- The Process 31. Okay, your phone's now registered with your local system. You get a call. It's just MCI security, wondering about all those conference calls to the mideast. You laugh and hang up. As you drive off to pick up another shipment of weapons, you marvel at the process of getting a call. What happened? Your phone recognized its mobile number on the paging channel. That's usually the forward control channel. The mobile responds by sending its identifying information once again to the MTSO, along with a message confirming that it received the page. The system responds by sending a voice channel assignment to the cell you are in. The cell site's transceiver gets this information and begins setting things up. It first informs the mobile about the new channel, say, channel 10 in cell number 8. It then generates a supervisory audio tone or SAT on the forward voice frequency. What's that? 32. An SAT is a high pitched tone that acts like a marker. The mobile tunes to its assigned channel and it looks for the right supervisory audio tone. Upon hearing it, the mobile throws the tone back to the cell site on its reverse voice channel. We now have a loop going between the cell site and the phone. This verifies that the mobile is on the right frequency. No SAT means no good. The cell site can fine tune the phone's reception with the SAT. It can also use it roughly determine the phone's location, since it takes a certain time for the signal to make a go around. The cell site releases or unmutes the forward voice channel if the SAT gets returned. It follows that by sending a digital signal on the FVC. This signal alerts the mobile to an incoming call. That action, in turn, causes the mobile to take the mute off the reverse voice channel. The mobile sends an audio tone to the cell site confirming that it got the alerting message. The system then produces a ringing sound for your caller while your phone rings. But let's go back to the SAT for just a moment. 33. I said that a mobile looks for the right supervisory audio tone. AMPS uses three named frequencies: SAT 0: 5970 Hz, SAT 1: 6000 Hz, and SAT 2: 6030 Hz. Three different markers. Why? Spacing cell site frequencies carefully avoids interference. It's the same way with SATs. Call setup is ongoing in each cell. Using several frequencies makes sure that the mobile is using the right channel assignment. It's not enough to get a tone on the right forward and reverse frequency the system must get the right channel and the right SAT. Two steps. Incorrect SATs cause havoc in the cellular bands. This tone is transmitted briefly but somewhat continuously during a call. You don't hear it since the signal lasts less than 300 ms. and because it's muted during transmission. The mobile, in fact, drops a call after a certain amount of time if it looses the SAT connection. 34. Well, enough about the SAT. I mentioned another tone that's generated by the mobile phone itself. It's called the signalling tone or ST. Don't confuse it with the SAT. You need the supervisory audio tone first. The ST comes in after that. It's necessary to complete the call. The mobile produces the ST, compared to the SAT which the cell site originates. The signaling tone is a very high audio frequency tone that you can't hear. Maybe your dog can but not you. It's 10 kHz tone. The mobile starts transmitting this signal back to the cell on the forward voice channel once it gets an alerting message. Your phone stops transmitting it once you pick up the handset or otherwise go off hook to answer its ringing. Cell folks might call this confirmation of alert. The system knows that you've picked up the phone when the ST stops. AMPS uses signalling tones of different duration's to indicate three other things. Cleardown or termination means hanging up, going on hook or terminating a call. The phone sends a signalling tone of 1.8 seconds when that happens. 400 ms. of ST means a hookflash. Hookflash requests additional services during a conversation in some areas. Confirmation of handover request is another arcane cell term. The ST gets sent for 50 ms. before your call is handed from one cell to another. Along with the SAT. That assures a smooth handoff from one cell to another. The MTSO assigns a new channel, checks for the right SAT and listens for a signalling tone when a handover occurs. Complicated but effective and all happening in less than a second. Origination -- Making a call-- 35. Making a mobile call uses many steps that help receive a call. The same basic process. Punch out the number that you want to call. Press the send button. Your mobile transmits that telephone number, along with a request for service signal, and all the information used to register a call to the cell site. The mobile transmits this information on the strongest reverse control channel. The MTSO checks out this info and assigns a voice channel. It communicates that assignment to the mobile on the forward control channel. The cell site opens a voice channel and transmits a SAT on it. The mobile detects the SAT and locks on, transmitting it back to the cell site. The MTSO detects this confirmation and sends the mobile a message in return. This could be several things. It might be a busy signal, ringback or whatever tone was delivered to the switch. Making a call, however, involves far more problems and resources than an incoming call does. 36. Making a call and getting a call from your cellular phone should be equally easy. It isn't. Originating a call from a mobile presents many problems for the user and the carrier. Especially when you are out of your local area. Incoming calls don't present a risk to the carrier. Someone on the other end is paying for them. The carrier, however, is responsible for the cost of fraudulent calls originating in its system. Most systems shut down roaming or do an operator intercept rather than allow a questionable call. I've had close friends asked for their credit card numbers by operators in order to place a call. Can you imagine giving a credit card number or a calling card number over the air? You're now back at a payphone, just like the good old days. Cellular One has shut down roaming "privileges" altogether in New York City, Washington and Miami at different times. But you can go through their operator and pay three times the cost of a normal call if you like. So what's going on? Why the problem with some outgoing calls? We first have to look at some more terms and procedures. We need to see what happens with call processing at the switch and network level. This is the exciting world of precall validation. 37. We know that pressing send or turning on the phone conveys information about the phone to the cell site and then to the MTSO. A call gets checked with all this information. There are many parts to each digital message. A five digit code called the home system identification number (SID or sometimes SIDH) identifies the cellular carrier your phone is registered with. For example, Cellular One's code in Sacramento is 00129. Go to Stockton forty miles south and Cellular One uses 00224. A system can easily identify roamers with this information. The "Roaming" lamp flashes if you are out of your local area. Or the "No Service" lamp comes on if the mobile can't pick up a useable signal. This number is keypad programmable, of course, since people change carriers and move to different areas. You can find yours by calling up a local cellular dealer. Or by putting your phone in the programming mode. [8]. This number doesn't go off in a numerical form, of course, but as a binary string of zero's and ones. These digital signals are repeated several times to make sure they get received. The mobile identification number or MIN is your telephone's telephone number. MINs are keypad programmable. You or a dealer can assign it any number desired. That makes it different than its electronic serial number that we discuss next. A MIN is ten digits long. A MIN is not your directory number since it is not long enough to include a country code. It's also limited when it comes to future uses since it isn't long enough to carry an extension number either. [9] 38. The electronic serial number or ESN is a unique number assigned to each phone. One per phone! Every cell phone starts out with just one ESN. This number gets electronically burned into the phone's ROM, or read only memory chip. A phone's MIN may change but the serial number remains the same. The ESN is a long binary number. Its 32 bit size provides billions of possible serial numbers. The ESN gets transmitted whenever the phone is turned on, handed over to another cell or at regular intervals decided by the system. Every ten to fifteen minutes is typical. Capturing an ESN lies at the heart of cloning. You'll often hear about stolen codes. "Someone stole Major Giuliani's and Commissioner Bratton's codes." The ESN is what is actually being intercepted. A code is something that stands for something else. In this case, the ESN. A hexadecimal number represents the ESN for programming and test purposes. [10] Such a number might look like this: 82 57 2C 01. 39. The station class mark or SCM tells the cell site and the switch what power level the mobile operates at and what frequencies the phone uses. The cell site can turn down the power in your phone, lowering it to a level that will do the job while not interfering with the rest of the system. The SCM also tells the switch if your phone is voice activated. That information, in turn, affects the way the MTSO handles signalling a VOX phone. 40. The switch process this information along with other data. It first checks for a valid ESN/MIN combination. You don't get a dial tone unless your phone number matches up with a correct, valid serial number. You have to have both unless, perhaps, if you call 911. The local carrier checks its own database first. Each carrier maintains its own records but the database may be almost anywhere. These local databases are updated, supposedly, around the clock by two much larger data bases maintained by Electronic Data Systems and GTE. EDS maintains records for most of the former Bell companies and their new cellular spin offs. GTE maintains records for GTE cellular companies as well as for the Cellular One group, a consortium of many different companies. Dial tone will not be returned unless everything checks out. They try to supply a current list of bad ESNs as well as information to the network on the 27,000 new cellular users coming on line every day. 41. A local caller will probably get dial tone if everything checks out. Roamers may not have the same luck if they're in another state or fairly distant from their home system. A roamer's record must be checked from afar. Many carriers still can't agree on the way to exchange this information or how to pay for it. A lot comes down to cost. A distant system may still be dependent on older switches or slower databases that can't provide a quick response. The so called North American Cellular Network is an attempt to link each participating carrier together with the same intelligent network/system 7 facilities. Still, that leaves many rural areas out of the loop. A call may be dropped or intercepted rather than allowed dial tone. In addition, the various carriers are always arguing over fees to query each others databases. Fraud is enough of a problem in some areas that many systems will not take a chance in passing a call through. Yet the fraud is fueled in part by lax network security. It's really a numbers game. How much is the system actually loosing? How much is prevention? Preventive measures may cost millions of dollars to put in place at each MTSO. In any case, the outlook is not good for roaming. Yet the ability to drive anywhere and call from anywhere was a main reason to move away from the old mobile telephone system. You used to have to call ahead to say that you would be visiting a distant city. An operator then had to make arrangements for your phone to be recognized by the local system. Well, Cellular One throughout December and January of last year was asking visiting cell phone callers to do just that before coming to New York City. Such progress! 42. In the next issue I'll write a shorter article that highlights TDMA and CDMA. I intend to have a resource list of part suppliers and publications. I'll also bring you some current information on cell fraud, including a look at Cellular Technical Service's Project Blackbird, a radio "fingerprinting" system designed to identify cloned phones. A similar system is being turned on in N.Y.C so the article should be interesting . . NOTES [1] Hawks, Ellison. Popular Science Mechanical Encyclopedia: How It Works Popular Science Publishing Co., Inc. New York. 1943 87 [2] Fike, John L. and George E. Friend. Understanding Telephone Electronics SAMS, Carmel 1990 268 [3] West, Gordon. Mobile 2Way Radio Communications, Master Publishing Company, Richardson, 1991 41 [4] Macario, Raymond. Cellular Radio: Principles and Design, McGraw Hill, Inc., New York 1993 61 ISBN 007044301 A good book that's fairly up to date and in print. Explains several cellular systems such as GSM, JTACS, etc. as well as AMPS and TDMA. Details all the formats of all the digital messages. No CDMA About $40.00. [5] Cellular Security Group is advertising free cellular frequency charts. You may want to call first. They're at (508) 7687486. The address is 106 Western Avenue, Essex, MA 01929. Sending a few dollars may help . . . [6] Damien Thorn "Cellular Telephone Programming: Focusing on Fundamentals" Nuts and Volts Magazine (December, 1992) 23 [7] Noll Introduction to Telephone Systems 123 (I've lost the cite on this one I'll have it next issue) [8] Thorn, ibid, 2 see also "Cellular Lite: A Less Filling Blend of Technology & Industry News" Nuts and Volts Magazine (March 1993) [9] Crowe, David "Why MINs Are Phone Numbers and Why They Shouldn't Be" Cellular Network Perspectives (December, 1994) I give all the information on Crowe's newsletter on page 52. IV THE ROSEVILLE TELEPHONE COMPANY MUSEUM ------------------------ The Photographs on the Opposite Page 43. The upper left hand photograph shows the interior of a typical magneto wall set. Turn a crank and you generate enough power to signal the operator. Batteries provided the line current needed to talk. Note the pad beneath the batteries used to soak up the occasional acid spill. 44. The upper right hand photograph shows an Automatic Electric, Type 1 test board that was one of four in service in Roseville from 1956 to 1984. Tests of the local loop often required one person at the test board and one person in the field to actually perform the adjustments. Many coin line tests are marked at this board. 45. The lower left hand photograph shows an operator toll switchboard in use from 1959 to 1981. Local and long distance toll calls were handled at this A.E. Model Type 31C cord toll board. Several boards were in use at any one time. 46. The lower right hand photograph shows a detail of the step by step switch. The entire mechanism is nearly six feet tall by six feet wide. All photographs by Little Sheeba" Text of Article ----------- "The notion of a museum springs from the passion for collecting, which is deeply rooted in human nature. All civilizations, from the most primitive to the most advanced, share the desire to accumulate objects that are beautiful, costly, rare, or merely curious." 47. The Roseville Telephone Company's museum in downtown Roseville, California is a marvelous collection of telephone technology. More than that, it reflects the history of an independent, progressive telephone company. Any telecom enthusiast should take the time to travel there, visit for an hour or two and engage in wondering, reflection and curiosity. What will you find? 300+ telephones. 12 switchboards. A test board and a toll board. Friendly telephone people to talk to. And best of all the pride of the museum a working step by step switch. 48. Step by step or Strowger switches were the mainstay of switching in rural and small town America for over forty years. I've described stepper operation in previous issues but I never thought I did a good job of explaining the process. Seeing one work is a great way to understand it. A large, open case contains the switch. Three phones are mounted on the left side of the case and three on the right. You can call from one phone to the other and in so doing observe all the action. Pick up a handset and go off hook. A selector jumps into action as you start dialing. Watch the wipers revolve as they search for a contact. Something's moving with every digit you dial. Hang up and everything resets itself with a satisfying clunk. Will you comprehend Strowger when you see it? Maybe not. But you should see it anyway. A stepper is like a Swiss watch with its insides revealed. You may not follow the function of each lever, sprocket and cam but you can appreciate its design and construction. And you can hear the wonderful clicking, chattering sound that steppers make, the sound that old switchmen get nostalgic about. The Roseville Telephone Company people will happily explain its operation. They'll even show you how the TraceaMatic works. It's a simple device once used to trace calls on a step switch. 49. The magneto powered cord switchboard is also interesting. Switchboards like these acted as a telephone company's central office before automation. This board dates back to 1914, the first year of RTC's operation. A small crank on the bottom right hand side allowed an operator to ring a customer's phone. Let the RTC people demonstrate how the board rings some of the phones on display. Vary the cranking at the switchboard and you vary the ring. That's important since RTC had more than ten subscribers on some party lines. What Roseville Telephone called farmers' lines. Each customer needed a distinctive ring, since it was the only way each party could tell if the call was for them. Party lines lasted until 1986 when the last open wire farmer line was retired. There's a nice exhibit that tells the story. That display includes square poles, insulators and samples of the wires. The two parties on that retired line, by the way, had their old monthly rate grandfathered in. To this day they pay less than $3.00 a month for phone service. 50. There's 4,000 square of exhibit space at the museum. The curator of the museum, Bob Parsons, says that Roseville Telephone will expand this to 8,000 feet within just a few years. Some of this new area will include outside plant equipment as well as a working open wire demonstration. They're even going to outfit an old telephone repair truck from the 1920's with a complete set of tools. 51. Thinking of going? I've had friends from Stockton and the San Francisco bay area say that it's well worth the drive. Plan to spend an hour to an hour and a half in the museum. Have lunch afterwards and help out the flood stricken economy. There are plenty of antique stores in Roseville in case someone with you gets bored. As well as one of the major train switching yards on the West Coast. Speaking of antiques, Roseville has a dealer who specializes in telephones. American Antiques and Collectables is located inside the building at 106 Judah Street. The old phones are expensive but you can handle them and look at them closely. 52. I tried to find out about telephone museums and collections in the United States but I've come up with only a small, incomplete list. Please write if you find something interesting in you area. Local antique dealers might help you. Go in to a large one and ask who collects telephones. A telephone collector will know if there are any museums or displays in the area. You might even be able to wrangle a tour of a private collection. Want to know more? Fagen's A History of Engineering and Operation in the Bell System: The Early Years 1875 1925 explains older phones and systems. It concentrates on Western Electric equipment but it is still invaluable on understanding early phones, PBX's, toll boards and switchboards. 53. Roseville is located 15 miles northeast of Sacramento, California Take Interstate 80 to the Atlantic Street off ramp. Head north into Roseville. Atlantic becomes Vernon downtown. The address of the museum is 106 Vernon. It is open on Saturdays only from 10 to 4. Look for the only building with a cell tower on top. V. TELECOM RELATED MAGAZINES AND NEWSLETTERS 54. Welcome to the telecom related magazine list of private line. This is an update to the list that first appeared in issue Number 5. I think it is the best magazine list on the Internet. I hope to update this every two months or so. Addresses are for subscriptions and samples. I didn't include editorial addresses to save space. Quoted material comes from a magazine's masthead or from a reader's comments. Let me know if you find any mistakes in this list or if you find a magazine that I should be aware of. 55. Some of these magazines will give you free subs if you take it third class and are "qualified" to have it. My advice is to ask for a sub, fill out their form and let them make the decision. Who knows? Maybe the magazine needs more subscribers so that they can charge higher ad rates. I personally am always willing to pay for a sample copy. 56. See what happens after you write in. Then start filling out product information cards in the magazines that arrive. Be specific. The trick is to get a low cost flow of information into your mailbox. Really broke but still interested? Ask for their writers' guidelines along with a sample. Or ask for a media kit. Dummy up some letterhead at Office Depot and call yourself a consultant if you have to. But I just use my real name. That's worked so far. 2600: The Hacker Quarterly General hacking. Some of the best telephone hacking articles in print. 10 years worth of back issues available. 2600 Enterprises, Inc. P.O. Box 752 Middle Island, NY 11953 (516) 751-2600 2600@well.sf.ca.us Quarterly. U.S. and Canadian subscriptions: $21 individual and $50. Overseas: $30 individual and $50 corporate in US Funds. Advanced Wireless Communications A newsletter from the Telecom group. They do say that they won't charge for a sample. And they did send me a nice catalog of their expensive publications. Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 $492. Bi-weekly with a fax alert. America's Network Formerly Telephone Engineer and Management, a well respected industry magazine. "I tried to find info for you on TE&M since I used to get it free as a kid. Loved it! Looked for it on my last dumpster mission. Alas, all I got from the spoils were a couple issues of Telephony." Advantstar Communications 131 West First Street Duluth MN 55802-2065 Twice a month. $44 a year to United States addresses. A sample is $4.95. Antique Telephone Collectors Association Newsletter A publication of the ATCA. It contains news of their organization as well as interesting articles on the history of telephony. It also has classified ads, some with pictures, from members looking to buy and sell old phones, phone parts, books, phone memorabilia and other collector items. Fascinating reading. The newsletter comes free with your membership. Write for a sample as well as for a membership application. ATCA Ann Manning, Office Manager P.O. Box 94 Abilene, KS 67410 (913) 263-1757 The newsletter is monthly. Dues are $30 a year to U.S. members, paid on a calendar basis. People joining mid-year pay pro-rated dues of $2.50 a month. There is a one time fee of $5.00 for new members. AT&T Technical Journal Not as technical as the old B.S.T.J. nor understandable as the old Bell Laboratories Record., the AT&T Technical Journal does come up with some fascinating articles. No. 73 was on AT&T switches. The 5ESS-2000 and the 4ESS were both reviewed along with a lengthy discussion of how cellular and PCS calls are switched. Circulation Group, Room 3C-417 AT&T Bell Laboratories 600 Mountain Ave. P.O. Box 636 Murray Hill, N.J. 07974-0636 (908) 582-4019 Six times a year. $55 domestic. $11.00 for single copies. They may have two years of back issues available but some editions are sold out. Best to write first for info on back issues and subscribing. Bell Labs News Nicely done tabloid sized, 6 page newspaper that's published bi- weekly. Closed subscriber list. Limited to employees of AT&T . I got a copy from a subscriber but you may want to try the person below: Linda Crockett, Editor Room 3C-420 A AT&T Bell Laboratories 600 Mountain Avenue P.O. Box 636 Murray Hill, NJ 07974-0636 (908) 582-4739 attmail!crockett Blacklisted! 411 "The Official Hacker's Magazine". A nicely done magazine out of southern California. It's well worth looking for. You'll probably want to subscribe if you enjoy 2600 or my magazine. P.O. Box 2506 Cypress, CA 90630 (310) 596-4673 Quarterly. $20 a year. $5.00 for a sample. Cabling Business Magazine "The Only Telecommunications Copper and Fiber Optics Cabling and Wiring Magazine for Voice, Data, and Image." These people seem a little too eager to give you a subscription. Wouldn't even tell me the price of a sample or sub over the phone. They insisted on sending a free copy. In addition, the publication is very practical and interesting. Write for this one! Cabling Business Magazine P.O. Box 496177 Garland TX 754049-6177 (214) 328-1717 Call Center A call center is a place that takes a customer's calls. It might be a catalog sales center or a cable TV company's order department. Interesting enough to check out. "Ten Ways To Foil a Hacker" was a good, non-hysterical article on fraud. Call Center 1265 Industrial Highway Southampton, PA 18966 1-800-677-3435 MCI Mail 627-4700. Monthly. US: 12 issues for $14. Canada: $20. Cellular Business "This rag sucks and doesn't contain much more than fluffy press releases from the manufacturers of phones and accessories. No technical information, and they ran an article on cellular fraud that was grossly inaccurate and belonged in a Sunday newspaper supplement. I subscribed, and then refused to send them the $39 they wanted for a subscription. Just glossy garbage." Your editor, though, thinks that it really is worth a look, they seem to be getting better. Cellular Business Intertec Publishing Corp. P.O. Box 12901 Overland Park, KS 66282-2901 (913) 341-1300 Monthly. $24 a year to qualified subscribers. Call for free sample. Cellular Marketing Another publication that I haven't seen but one that David Crowe recommends. He says it is trying to take on a more technical focus. Write for a sample. Argus Circulation Center P.O. Box 41528 Nashville, TN 37204 $29 for a U.S. sub and $39 for a Canadian or Mexican subscription. Cellular Network Perspectives Expertly done, professional newsletter. David Crowe focuses on networks, protocols and general cellular concepts, rather than on exact technical details. It gives you the big picture without any corporate slant. Cellular Networking Perspectives 2636 Toronto Crescent NW Calgary, AB T2N 3W1 Canada (403) 289-6609 (403) 289-6658 FAX 71574.3157@compuserve.com Monthly. $150 a year for small business and educational customers. $250 otherwise. All back issues available He'll mail or fax you a copy of "IS-41 Explained" if you like. Computer Telephony Driven by ads and corporations. Same folks as Call Center and Teleconnect. Some interesting articles on occasion. A recent article by Mitel predicts the death of PBX's as we understand them. They're giving away subs so you might as well sign up. Computer Telephony 1265 Industrial Highway Southampton, PA 18966 1-800-677-3435 1015032@mcimail.com 70600.2451@compuserve.com Electronic Design A real find. Features articles occasionally on telecom. Goldberg's article on PCS, for example, was a better read than a similar article that ran about the same time in the expensive IEEE Personal Communications. Electronic Design, A Penton Publication Penton Publishing Subscription Lockbox P.O. Box 96732 Chicago, Ill 60693 Supposedly $105 a year. Write for a sample -- you should be able to wrangle a free sub from them. FCC Report Another newsletter from Telecom. Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 $591. They say they don't charge for a sample. People on the phone are sometimes confused. Fiber Optic News Newsletter. "Covers management and marketing of optical fibers and laser technology" Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1-800-777-5006 Weekly. 50 times a year. 10 pages. $697 a year. $37.50 for a sample. Full Disclosure Glen Roberts puts out this interesting, newspaper like publication. It deals with many electronic privacy issues but it has some nice telephone articles from time to time. I see it only rarely on newsstands. Ask your magazine dealer to order it through Fine Print Distributors. First Amendment Press, Inc. 8129 N. 35th Ave., Suite 134 Phoenix, AZ 85051 Monthly. $29.95 for 12 issues. Canadian subscriptions add $15.00. For all other countries add $25.00 per twelve issues. Global Telephony Another one from Intertec. I haven't called for prices yet. Intertec Publishing Corp. P.O. Box 12901 Overland Park, KS 66282-2901 (913) 341-1300 IEEE Communications Magazine Occasionally interesting telephone pieces. I read it from time to time at a university libary. IEEE Service Center 445 Hoes Lane Piscataway, N.J. 08855-13311 (908) 981-0060 j.milizzo@ieee.org Monthly. $23 to members, $135 to non-members, single issue copies are $10 to members and $20 to non-members. IEEE Personal Communications "The Magazine of Nomadic Communications and Computing" Winter 1994 edition had lots of stuff on the development of PCS protocols. Cutting edge information if you can understand it or afford it. IEEE Service Center 445 Hoes Lane Piscataway, N.J. 08855-13311 (908) 981-0060 e.wilber@ieee.org Quarterly. $80 a year to non-members. A single copy to non-members costs $20. Innovations This is Protel's own quarterly newsletter. They're the largest COCOT maker in the country. It's small (4 pp) but well done and it's free. Greg Hogan, National Accounts Manager, does a good job explaining the NANP or North American Numbering Plan in issue 7. Send a postcard requesting it to: Teresa Frueh Blocher Protel Inc. 4150 Kidron Rd. Lakeland, Fl 33811-1274 BTW, she wants your name, company name, and your daytime phone number. Yeah, right. ISDN News Another expensive newsletter from Phillips. Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1-800-777-5006 25 times a year for $597 a year. $35 for a sample. They'll send you a free brochure on it if you want one. Land Mobile Radio News Newsletter. They'll send you a free brochure on it. Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1-800-777-5006 Weekly. 50 times a year. 12 to 14 pages an issue. $597 a year. $35 for a sample. Local Competition Report Another newsletter from Telecom. Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 $425 yearly. Comes out every two weeks. They say they don't charge for a sample. Local Telecom Competition Newsletter. They'll send you a free brochure about it if you want it. Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1-800-777-5006 Bi-weekly. 25 times a year. 12 to 14 pages an issue. $597 a year. $35 for a sample. Microwave Journal " . . . I get more technical info about the direction and technology of cellular from one issue of RF Design News or Microwave Journal than I could from a whole year of Cellular Business." Horizon House Publications, Inc. P.O. Box 850949 Braintree MA 02185-0949 (617) 356-4595 Monthly. Domestic, one year, $67.00, two year $110, foreign $120 one year, two year subscriptions $230, back issues (if available) and single copies, $8.00 domestic and $17.00 foreign. Microwaves & RF Heavy duty publication for the radio engineer. Microwaves and RF A Penton Publication 1100 Superior Avenue Cleveland OH 44197-8101 (216) 696-7000 Monthly. $60 for US subscriptions. Free to qualified individuals. Mobile Communications International Magazine. Haven't seen it. Central House 27 Park Street Croydon CRO 1YD +44 (0)81 686 5654 Monthly. 40 pounds UK, overseas 60 pounds ($120) per year. Mobile Data Report Another newsletter from the folks at Telecom. Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 $597. Every two weeks. They say they don't charge for a sample. Mobile Phone News Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1-800-777-5006 Newsletter. Weekly. 50 times a year. $597 a year. $35 for a sample. They'll send you a free brochure on it if you want one. Mobile Satellite News Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1-800-777-5006 Newsletter. Weekly. 50 times a year. $597 a year. $35 for a sample. They'll send you a free brochure on it if you want one. Monitoring Times Grove Enterprises, Inc. P.O. Box 98, 300 S. Highway 64 West Brasstown, North Carolina 28902-0098 Monthly. $21.95 in the U.S. and $32.00 elsewhere. Newsstands. Nuts and Volts Arguably better than Popular Electronics at its height. Great ads and even better articles. Damien Thorn's cellular articles were especially good. I usually find Nuts and Volts at a ham radio store. Write for a sample. Nuts and Volts Magazine 430 Princeland Court Corona, CA 91719 (909) 371-8497 74262.3664@compuserve.com Monthly. 3d class: $17.00 a year or 2 years for $31. 1st class: $34.00 for one year in the USA. $5.00 for back issues. On the Line "The National Publication of the California Payphone Association". A regional publication that does cover national issues. Another resource for COCOTs. No reader service cards but worth getting. California Payphone Association c/o On the Line 2610 Crow Canyon Rd., Suite 150 San Ramon, CA 94583 (510) 855-3880 Six times a year. $25 a year. Send $5.00 and you'll get a sample. Or call them up and use your social engineering skills. . . Outside Plant Outside plant is an old telephone term for everything outside of the switching center. It's a nice publication but I doubt you are going to get a free sub -- I'm still working on them to give me a discount or to trade subs. Practical Communications, Inc. P.O. Box 183 Cary, Illinois 60013-0183 One year $30 domestic, one year for Canadian addresses is $64 US. Phone + Another COCOT related magazine. A good place to get more information on a hard to research topic. Write or call for a free sample. Phone + Box 5400 Scottsdale, AZ 85261-5400. (602) 990-1101 15 times a year for $50.00 Popular Communications The "Telephones Enroute" column written by Tom Kneitel (K2AES) is very good. Mostly product announcements regarding cellular equipment but analyzed by someone who knows what they're talking about. CQ Publications 76 N. Broadway Hicksville, NY 11801 (516) 681-2926 Monthly. Domestic rate is $21.50 You can get it from any magazine dealer. Premier Telecard Magazine Another telecard magazine. I haven't seen it. I'd send at least five dollars for a sample. Or call first BJE Graphics and Pub., Inc. P.O. Box 2297 Paso Robles, CA 93447 (805) 547-8500 A $30 subscription gets you the mag, two telecards and a telecard calendar for 1995. private line "A journal of inquiry into the telephone system" Okay, you didn't think that I'd leave mine out, did you? The finest, self indulgent nonsense about the telephone system in print today. private line 5150 Fair Oaks Blvd. #101-348 Carmichael, CA 95608 privateline@delphi.com. $24 a year for six issues. Goes up to $27.00 July, 1. $4.00 for a sample. Back issues $5.00. Text of back issues are on line at: etext.archive.umich.edu/pubs/Zines/PrivateLine Public Communications Magazine A hoot. COCOTs and more. The November, 1994 issue featured an article on how raising a local payphone call to $.35 will benefit everyone. Really. I got a free sample by calling the 800 line. My sample came with a form for a free subscription which they did give me. Public Communications P.O. Box 6246 Syracuse, NY 13217-7920 1-800-825-0061 Radio Communications Report "For cellular phone information, my favorite is a weekly tabloid called Radio Communications Report. It has every thing that Phillips newsletters have (plus a lot more) at 1/10 the price. It's also a lot better than the glossies like Cellular Business for following current events in the business." RCR Publications Inc. 777 East Speer Blvd. Denver, C0 80203 1-800-678-9595 Semi-monthly. 1 year $39; 2 years - $59. Wouldn't tell me the sample price -- insisted on mailing me a free copy. RBOC Update Worldwide Videotext P.0. Box 138 Babson Park, Boston MA (508) 477-8979 Monthly newsletter. $150 a year Report on AT&T Newsletter. "Reports on all activities of AT&T" Focuses on "AT&T and its bloody turf battles." Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 Twice a month. $697 a year with a fax alert. They say they will send you a free sample if you are interested. Satellite Times Grove Enterprises, Inc. P.O. Box 98, 300 S. Highway 64 West Brasstown, North Carolina 28902-0098 (704) 837-9200 grove@mercury.interpath.net Bi-monthly-- $19.95 in the U.S. and $26.00 elsewhere . State Telephone Regulation Report Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 Twice a month newsletter. $535 a year. They say they will send you a free sample if you are interested. TeleCard World "America's Leading Magazine for the Telephone Card Industry" Very interesting. Your place to find O.J. calling cards. They'll send you an old issue as a free sample. Telecard World P.O. Box 6246 Syracuse, NY 13217-7920 1-800-825-0061 $36.00 yearly for US subscriptions. Telecom Gear "The National Marketplace To Buy & Sell Telecommunications Equipment" They focus more on used PBX and office equipment, rather than telco equipment which Telephone International covers. 15400 Knoll Train Suite 500 Dallas, TX 75248 (214) 233-5131 Monthly 3d class: $31 a year. They sent me a free sample when I wrote for information. Telecommunications: Americas' Edition The best corporate telecom magazine that I've seen. Same group that publishes Microwave Journal. Horizon House Publications P.O. Box 850949 Braintree, MA 02185-0949 telecom@world.com Monthly. $67.00 a year US, $120 foreign, single issues are $8 US and $17 for foreign. Telco Business Report Was Telephone Week. Another expensive newsletter from Telecom. Telecom Publishing Group 1101 King St. Suite 444, Box 1455 Alexandria, VA 22313-20555 1-800-452-8011 Twice a month newsletter. $695 a year. They say they will send you a free sample if you are interested. Telecommunications Policy Academic publication. Policy stuff and more. Explains and comments on technology to non-engineer university types. Uses side margins to footnote! Worth looking at but you'll have to search. Turpin Distribution Services Ltd. Blackhorse Road Letchworth. Herts SG6 IHN. UK Nine times a year. Corporate subscriptions: 270 pounds to UK and Europe, 285 pounds to the rest of the world. Individual: 90 pounds. (Specify Telecommunications Policy when ordering) Teleconnect Teleconnect is more practically oriented than most corporate publications. Available through the Tower chain and at many newsstands. 1265 Industrial Highway Southampton, PA 18966 1-800-677-3435 70600.2451 @compuserve.com 12 issues for $15 -- Canada: $30. Retails for $4.00 a copy. Telemarketing "The Authority on Inbound, Out bound and Customer Service Management" Telemarketing One Technology Plaza Norwalk , CT 06854 1 -800-243-6002 Bi-monthly. $49 in the U.S. Call for a sample. Telephony Some value because it is timely and widely available. Guest editorials are good. Lots of product announcements and self serving press releases. Telephony P.O. Box 12976 Overland Park. Kansas 66282-9940 (312) 922-1408 4944254@mcimail .com Weekly. $45.00 domestic. Single copies are $5.00. Telephone International "Published for buyers and sellers of telecommunications equipment since 1985" This newspaper like publication has display ads and classifieds. Caters to the telco crowd. Small but interesting photos of GTD5s, DMS lOOs, etc. in the ads. This may be your best chance of seeing some inside plant equipment. Fairly easy to get a free sub. Telephone International P.O. Box 3589 -- Hwy. 70 N. Crossville, TN 38557-3589 (615) 484-3685 Monthly. Domestic is $50.00 for two years if mailed first class. Ask for a sample. TeleProfessional "Effective Marketing Via Telecommunications" I think that telemarketing is a terrible thing but the technology involved is fascinating. An easy one to get a free sub from. 209 West Fifth Street Suite N Waterloo, Iowa 50701 -5420 (319) 235-4473 $39 a year. They were running a $10 subscription promo when I called. And they happily sent a sample. Voice Processing Magazine "The source for applications of computer-telephone integration & voice automation" Advanstar Communications 131 W. Birst Street Duluth, MN 55802 $39 for one year or $59 for two years. $4.95 for a sample. Washington Telecom News Phillips Business Information, Inc. 12051 Seven Locks Road Potomac, MD 208564 1 -800-777-5006 Newsletter. Weekly. 50 times a year. 8 to 10 pages an issue. $597 a year. $35 for a sample. They'll send you a free brochure on it if you want one. Wireless "For the corporate user" . Wireless is the future. This magazine covers it well with nice articles on many aspects. Good reader service cards. Circulation Department: Wireless Three Wing Drive, Suite 240 Cedar Knolls NJ 07927-1000 (201) 285-1500 Every two months (bi-monthly). Free to qualified subscribers. $30 to US subscribers and $36 for our Canadian and Mexican friends. They did send me a free sample. STILL LOOKING! AT&T Technology, Common Carrier, Global Telecommunications, Tele-Asia, Telecom and Network Security Review, Telecommunications Journal of Australia, Telesis, World Wide Telecom, Telekom Praxis, Funkschau, Commutations and Refutations, Phillips' Telecommunications Review Ericsson Review, Siemens' Telecom Report Northern Telecom Magazine See you on the net! Tom Farley 5150 Fair Oaks Blvd. #101-348 Carmichael, CA 95608 privateline@delphi.com