telecom@ucbvax.ARPA (08/21/85)
From: Moderator <Telecom-REQUEST@MIT-XX.ARPA> TELECOM Digest Monday, August 19, 1985 11:24PM Volume 5, Issue 21 Today's Topics: 976 charges Re: Cellular "air time" Hayes 2400 modems Re: Cellular phone info wanted DOVE ---------------------------------------------------------------------- Date: Fri, 16-Aug-85 19:13:39 PDT From: vortex!lauren@rand-unix.ARPA (Lauren Weinstein) Subject: 976 charges I believe that the "applicable toll charges" are to the 976 serving office, which tends to be in a central city location. True enough, at this time only 976 callers inside the same area code (with the possible exception of pseudo-split codes like 213/818 in the same city) are charged the service fee for the call. I believe this will be changing, however, when a distributed database for such services charging is set up. --Lauren-- ------------------------------ Date: Sat, 17 Aug 85 19:10:44 EDT From: "Richard P. Wilkes" <wilkes@hopkins-eecs-bravo.ARPA> Subject: Re: Cellular "air time" I live in Baltimore and have had a cellular phone in my car for several months now. I love it, and it has certainly changed the way I use my travel time and has helped me stay in touch far better. The service does have a cost, tho. In this area (Balmer/Washington) we have a choice of two services. One, offered by Bell Atlantic Mobile Systems has a ~$100 per month service that includes an hour of prime time and an hour of off-peak. After this time, you pay $0.44 per min prime and $.24 off peak. This seems comparable to the offering of Cellular One, the other service. Cell One offers an NEC phone under a rental program (no obligation except for first month) for $95/mo that includes 100 minutes of air time--prime or off peak. After that it's $.40/$.24. The difference is how they change for usage. Bell charges as soon as the call is placed, in one min increments, regardless of whether the call goes through. 60 no answers is one hour of air time. This adds up right quickly. Cell one does not charge until the party answers. So, I can call my answering machine which answers on 1 ring if there are messages and 4 rings otherwise and not get charged unless I have messages. Ditto for busy numbers. My typical bill runs $130 for roughly 3.5 hours of air time per month. The typical call lasts less than 3 mins. It would cost me far more with Bell. Bell also has a $49.95 "special" which includes a rental phone of lower quality that their prime service and 100 mins of off peak time. HOWEVER, peak time is charged at $.75/min. This is a great option for folks that just want the phone as a status symbol (altho I recommend buying the antenna alone as a cheaper alternative). But, a few unanswered daytime calls will make up the difference quickly. Cell one also has an extremely useful service for me called No Answer Transfer. If I am not in the car or decide not to answer, my call can be transferred to a number I choose. I set up this number by dialing *72 followed by the number. Cost is $5 per month I believe and their is no charge for setting up the individual transfers. I do this when I visit client sites so I can be reached in an emergency without an electronic leash (beeper). Also, this area is considered one calling region. I can place calls from my phone to/from Washington and Annapolis for the same rate. Transfers, too. I do recommend than anyone looking into a phone do some heavy research. There's much competition in this area, and you can often do some bargaining. I'd be happy to answer any specific questions. -r ------------------------------ Date: Thursday, 1 August 1985 06:11-MDT From: "Gary W. Sanders (N8EMR)" <ihnp4!cbosgd!cbdkc1!cbnap!gws@Ucb-Bax.ARPA> Subject: Hayes 2400 modems In article <991@hou2h.UUCP> hhs@hou2h.UUCP (H.SHARP) writes: >I have been trying out a Hayes 2400 modem working with a >Teletype 5420 terminal. >I have noticed that the Hayes modem does not raise Data Set Ready >until it gets answer tone from the remote modem. The Teletype >terminal will not receive data from the modem unless Data Set Ready >is raised. > ...... Try shorting pins 5 to 6 or pins 5 to 8 on the 5420, The 5420 will work (as you have noted) , but not full function. >Another problem I have noticed is using the Hayes to call into >our computer. The computer is using AT&T modems. About three >out of four times I call in, after I get the "Connect 1200" >message (no 2400 bps modems on the other end) I get a line of >garbage on the screen. The computer times out and disconnects the >call. Anyone else notice this problem? What speed is your terminal running? I have a USR2400 modem. If I have my terminal set to 2400baud and I connect to a 1200 baud modem, I get the "Connect 1200" message at 2400 baud but then the modem switches to 1200 baud and the terminal must be switched manualy to 1200 in order to converse with the computer.. tnx Gary W. Sanders (N8EMR) ihnp4!cbnap!gws AT&T Bell Labs (Columbus,Oh) ------------------------------ Date: 18 Aug 1985 21:29-PDT Subject: Re: Cellular phone info wanted From: the tty of Geoffrey S. Goodfellow <Geoff@SRI-CSL.ARPA> In reply to the questions Steve Vance asks: Q. Do I have to buy the hardware and the service together? A. No, but it is the simplest way to "one stop shop" for a phone if you buy the phone, have it installed and initiate the service at one place. That way, if problems occur, you don't have any finger pointing. Q. The cellular services around here are still charging $1000-$2500 for a cellular phone, depending if it has 10-number memory and a battery or not, but I have heard rumors that you can get a cellular phone of some kind at a discount for under $500. Does anyone know where? Is it a good idea for me to try to do this? A. One place here in The Bay Area is selling the E. F. Johnson (aka Western Union dial in base) unit for $688 + $140 for installation. That's pretty cheap. Most are charging around $225-$250 to install phones (especially in foreign cars) and around $1500 to $2500 for the phones. I think the best place to buy a phone is through one of the two carriers providing the service in your area. Carriers usually buy many more phones than an independent dealer could and are able to offer them at better prices. Again, if there are problems, you are not dealing with a "cellular reseller" but direct with the carrier. Some carriers also offer attractive lease/purchase plans. Some allow you to get on very cheaply, for something like $200 down and $100/mo you get a phone installed in your car, service on the carrier, some minutes of "free" air-time each month, maintenance and insurance on your equipment and after 3 years you own the phone. Others are making it as cheap as $50/mo which includes the phone installed in your car, service, rental of equipment and free air-time. Shop around with your carriers and see what `packages' they might offer. Q. After I have my own unit, can I call any of the 800 numbers I hear on the radio who advertise cellular service, and have them hook me up? Or do some charge more than others, and I should shop around? A. In any given area there are two types of carriers; I would recommend calling them both and comparing monthly rate packages, manner of charging air-time (see below), coverage, service and roaming agreements with other carriers (handy if you plan to travel with your phone). In each market there is the `ability' for two carriers to exist. One potential provider will be known as a WIRELINE. The WIRELINE designation specifically refers to a local utility currently providing landline telephone service in the market area that is licensed to offer cellular service. Here in The Bay Area, GTE and Pacific Bell were the two existing wireline/landline telephone companies. GTE (thru a series of negotiations) took a majority stake in the bay area in trade for Pac*Bell taking a majority stake in the Los Angeles system. Hence, our provider of cellular service on the WIRELINE block is GTE. The other potential provider of cellular service in a market area is designated as the NON-WIRELINE carrier. Unlike wireline applicants, the NON-WIRELINE applicant doesn't necessarily have to have a local presence in the market area where they are filing for a cellular license. In many markets, NON-WIRELINE applicants have been established radio common carriers, a consortium of communications (or other) industry firms, or virtually any applicant that does not fit into the wireline category. NON-WIRELINE systems are usually designed, engineered, owned and operated locally; WIRELINE systems are usually designed, engineered, owned and operated by remote control. The GTE system for the Bay Area, for example is controlled from Houston, TX. Q. I have heard that it costs $40/mo plus "air time". Is this a typical rate? Does the "air time" jazz mean that I am charged something when people call me, too? A. The typical air-time rates in most markets started out around the $30-$50 per month charge "for service", plus $.30-$.50 cents per minute for peak-time use and $.20-$.35 for non-peak use. Peak use in "most" markets has been 7am-7pm weekdays; non-peak being 7pm-7am weekdays, all weekend long and holidays. However, BEWARE of the various `methods' of charging for air-time, there are three of them: Method 1-- Air-time is applied from the time the called person answers the phone and is only applied to calls that actually `complete'. This is like we're all used to with long distance calls via AT&T. Method 2-- has the air-time "clock" start at the time you are allocated a voice channel, but are only charged on `completed' calls, as above. With this method, you are paying, when the call completes, for the time it takes the telephone company to switch the call and for the person on the other end to answer it. Method 3-- starts the air-time clock at the time you are allocated a voice channel AND bills you for it regardless of call completion! Many of the Bell Cellular Companies are using this @i<evil> (please excuse the comment) method of charging for air-time. Hence, with this method, you get billed for calls which don't answer, return busy, or perhaps reach a disconnected number or out of service number! As you can see, there are many different ways of charging for air-time -- be sure to read the small print and ask your local carrier which method they are using. With respect to incoming calls, you're charged air-time, the only difference being between the methods above. With method--1 your charged from the time you take the phone off-hook to answer the call. With method--2 you're charged from the time you're allocated the voice channel and ringing starts, but not for calls you don't answer (after ringing times out). With method--3 you pay for air-time REGARDLESS of whether you answer the call or not IF your phone is on an acknowledges the incoming call and is allocated a voice-channel (ringing is sent over the voice channel as a command to your mobile unit). The only way to avoid paying air-time for unanswered calls with method 3 is to turn your off! As a side note: an interesting development with respect to shifting the burden for incoming call air-time charges is currently afoot at two carriers in conjunction with their local landline telephone company will bill air-time to the person calling the mobile instead of the mobile customer (as has been traditionally done all these years). A couple of other things with respect to cellular calls: Some carriers bill in 6-second increments; some 30 and others the standard full minute. One of the neat things all cellular carriers i'm aware of are providing is that of "coverage area local dialing". Meaning, calls which originate anywhere within the approximate coverage area of the system can terminate to any point and not incur a toll charge. Example being if you're a Bay Area customer on the GTE Mobilnet system, and even tho your home NPA-NXX of your mobile number is Palo Alto based, you can call numbers in San Francisco, San Jose, etc. and they are not charged as toll calls as they would be if you were calling from a landline phone. In some areas of the country (Los Angeles being one of them) it's cheaper say to hop in your car and make a cellular call than it would be to pay intra-lata landline rates! Q. I haven't seen any articles in Consumer Reports on which cellular phones are best--has anyone seen a comparative report anywhere? Specific recommendations are welcome. A. Personal Communications Magazine has featured various types of phones from time to time, but as far as I know Consumer Reports or any other type of "non-biased" magazine hasn't done a study yet. In buying your phone, one of the most important questions to ask i think is: is the company in it for the long haul? Can i expect to get service if my unit breaks down? What if my unit breaks down when I'm out of town? Q. How long before I can get one the size of Captain Kirk's (plus car cigarette lighter cord)? A. As of this writing, only Motorola and GE have true portables out. They cost around $3K each and have adapters which provide them with external antenuation and power from the car. I think you will see the cellular portable market develop much like the portable computer market: they will get smaller, more featureful and cost less as time goes on. The portable I paid $4K just over a year ago now sells for around $3K, and in some areas I have seen them selling for as cheap as $2495. As an aside, i think the portable is the only way to go: people don't want to talk to cars (homes or offices) they want to talk to PEOPLE. Many cellular systems were not designed to support portable users although portable will work, you may have trouble using them in buildings until the carrier adds more cell sites and sector- izes its gain receive antennas. I hope I have adequately answered your questions; I would be happy to answer any additional questions you or the readership may have concerning cellular radio (which is just in its infancy). Geoff Goodfellow ------------------------------ Date: Monday, 19 August 1985 13:34-MDT From: Skeet Steffey TWS-S <csteffey@wsmr05.arpa> Subject: DOVE I did the following analysis of the current DOVE offerings a couple of years ago, and the overall picture hasn't changed much since then. We currently have a large number of buildings served by DOVE which communicates with the Computer Center(s) via high speed modems and in several cases, via T-1 (1.544 megabits) over twisted pairs. We are VERY well satisified with this technology, and we thank our lucky stars for its availability. *************************************************************** Background The proliferation of Computer remote terminals and other devices in support of Workplace Automation has taxed existing in-house cabling to the point that adequate and satisfactory data communication support cannot be provided. In-house conduit systems are inadequate to accomodate additional cables. External conduits/raceways can be installed; however, this solution is not cost affective. The USACC White Sands solution to this problem is to use "Voice-plus-data" (frequency Division Multiplexing) technology for "in-house" data communications. The highlights of the technology are as follows: Simultaneous data/voice transmission over a single cable pair Data transmission totally transparent to normal telephone usage Eliminates additional cabling requirement for data transmission Voice operation unaffected during power failure Eliminates line driver requirement Meets FCC, Part 68 General Descriptions Voice - plus - data technology provides a cost effective, high performance Data/Voice Multiplexing system. Voice - plus - data technology is designed to reduce intrafacility data communication costs by sharing the existing telephone lines for both voice and data transmission. The Voice - plus - data technology consistes of a Terminal Unit and a Central Unit. The Terminal Unit combines voice and data at the telephone end and transmits it to the Central Unit were they are demultiplexed again. The voice/data mulitplexing operation has been designed to be totally transparent to the normal telephone usage. The quality of voice and the audible tones used by the voice system remains unaffected after the installation of Voice - plus - data hardware. Operation To understand the operation of Voice - plus - data technology, we need to examine the frequency bands between the telephone and the PABX or the central end of the voice distribution system. With the introduction of a Terminal Unit and a Central Unit between the two ends of a telephone cable pair, the information exchange takes place on three separate frequency bands. The voice transmission is maintained on the normal 0-4 kHz band. Typically 68-76 kHz band carries up to 19,200 bps of async data to the Central Unit and a 160-76 kHz band carries up to 19,200 bps of async data to the Terminal Unit. Thus, by utilizing Frequency Division scheme, a full-duplex async data link is established between the Terminal and Central Units, without affecting the normal voice communication. Office Shuffling Made Easy Moving a terminal from one office to another (without the Voice - plus - data technology) can be a tedious task. In many cases it may require installation of a brand new cable. With Voice - plus - data technology, the office shuffle can be handled by moving the terminal unit to the new office and utilizing the existing phone line. Eliminate Line Driver The Voice - plus - data technology can drive over 6000 feet, eliminating the need for line drivers. In this case the smaller additional system cost for the Voice - plus - data technology makes it an even more attractive local communication device. Reduced Campus Communications Costs In a campus-like setting with several small buildings, Voice - plus - data technology can be used to bring data lines to a central point in each building. The campus can then be interconnected by multiplexed high speed data links between the buildings, at a reduced overall system cost. Optimize Data and Voice Communications Cost The voice PABXs are optimized for voice communication while the data PABXs are designed to switch data most efficiently. The only argument for integrating the voice and data communication is the ability to share existing wiring in a building. An optimum solution to both voice and data communication can be achieved by sharing the wiring through Voice - plus - data technology, but maintaining separate switching systems for voice and data. ANALYSIS OVERVIEW MICOM embarked on the Voice - plus data technology project as a local distribution adjunct to MICOM's Micro600 at a time when TELTONE was the only manufacturer with a similiar product. Since that time, SIESCOR and COHERENT have developed like products. All three of these companies have a strong background in telecommunications products but are not as strong in data communications. These products are the adaptation of "pair gain" voice subscriber carrier systems or telegraph carrier systems. GANDALF has recently announced a Pacxnet local networking using several other manufacturers' equipment in conjunction with their PACX switchers. One of these other products is SIESCOR IDVC-9600, which GANDALF has called Line Miser. TELTONE TELTONE manufacturers two forms of their Data Carrier System, the DCS-2A with integral T1 multiplexor and the DCS-2A basic system. The differences between the DCS-2A and DCS-2B are in the central card file. The station unit is the same for both systems. Features: Terminal: Single Station Loopback Switch Central: Dual Channel Card 8-channel EIA with Integral Power Supply 32-channel EIA 32-channel Multiplexed Output Composite: Voice band: 0-4000 Hz Transmitted Data: 36-40 kHz Received Data: 72-80 kHz Weaknesses: High Distortion No Central Loopback Testing No Data Indicators 23-inch Rack-Mount More noise-prone, likely to have data errors when telephone rings Strengths: Low Price Greater Range Comments: TELTONE has been selling since early 1981. SIESCOR SIESCOR, a sub-division of RAYTHEON that is located in Tulsa, Oklahoma, makes an Integrated Data/Voice Carrier (IDVC-9600) Systems. They also make a digital Voice/Data System for alternate voice and synchronous or asynchronous data, called Panda II. Other product include 2- and 8-channel Voice Subscriber Carrier Frequency Division Multiplexing System. Features: Terminal: Single Station Central: Single Channel Card 24 channels per shelf Composite: Voice band: ? Transmit Data: 36-48 kHz Receive Data: 96-84 kHz Weaknesses: No Central Loopback No Data Indicators Telephone Industry Packaging Strengths: Greater Range Comments: Has entered an agreement with GANDALF. COHERENT COHERENT Communications Systems Corp. is a five to ten million dollar company based in Hauppauge, New York. They are manufacturers of low/medium speed modems, frequency shift multiplexing systems, telephone signalling equipment as well as data communications equipment. None of their modems have been registered. In 1981 they introduced a voice, a 2400 bps and a 75 bps multiplexer -- SPMT-9 (possibly derived from the telegraph system) which offered voiczue, plus up to 8 TTY channel at 50-75 bps. They are currently offering a Linemate 96 plus which is also labeled SPMT-10. Features: Terminal: Single Station Optional Synchronuous Operation TD, RD, CD and PWR Indicators Central: Unknown Composite: Voice band: 0-3000 Hz Channels probably <50 kHz Weaknesses: High Price Strengths: Add on Synchronous Capability Comments: Very preliminary information. Will update as more becomes available. Pricing: Approximately $400 per circuit end. GANDALF GANDALF Technologies Inc of Ottawa, Ontario, Canada is a provider of a wide range of data communications equipment. They announced on September 30, 1982, two Data-Over-Voice Products. One of these is Line Miser which is manufactured by SEISCOR. This is probably a repackaging of the SEISCOR IDVC-9600. The second product is probably SEISCOR's Panda II since GANDALF manufactures the Integrated Services Unit and Computer Data Unit of Panda II according to Datapro newsletter of December 1981. As packaging and pricing information becomes available a complete analysis will be included. MICOM The MICOM Instalink has two basic components, a Terminal Unit for the telephne and a Central Unit for the PABX or the central wiring termination end. The Terminal Unit is packaged in a small enclosure, that fits under the telephone. The terminal and the telephone, are both plugged into the Terminal Unit via standard RS-232-C and RJ11 connectors. A second RJ11 connector is used to connect to the telephone wiring, which is used to transmit data and voice signals. The Terminal Unit is equipped with a loopback button to allow diagnostic loops and a connect button to provide manual toggling of controls. The Central Unit consists of two modules, a chassis to house the power supply and a set of logic modules designed to provide various multiplexing functions. Features: Terminal: Single Station Loopback Switch Connect/Control Central: 8,16,24,32,48 Channel Composite: Voice Band 0-4000Hz Transmit Data 68-76 kHz Receive Data 160-168 khz Weaknesses: Presently Limited to 2000 ft. (will be 18000 ft soon) Strength: Low Cost High Reliability Easy Installation Data Rates to 19.2 kbps ************************************************************** I will be happy to answer any questions (if I can), and anybody is welcome to come and see and get "hands-on" experience. Will also be willing to train installers! ------------------------------ End of TELECOM Digest *********************