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
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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!
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End of TELECOM Digest
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