Does anyone remember the IMTS System? [telecom]

In the early 1970s, a friend of mine worked for a VIP who had a mobile phone in his car. My friend would call me or I would call him on it occasionally. We kept our calls brief as it was expensive.

Operationally, it worked like a regular telephone; the mobile set had a rotary dial and a ringer.

Certain elite passenger trains, like the 20th Century Limited, Broadway Limited, and Congressionals had on-board mobile telephone service, though I believe it was the older manual type.

Metroliner service, introduced in 1969, had a modern on-board mobile phone, with automatic handoff between radio bases, and Touch Tone coin telephone sets. If memory serves, a call was priced at $3.00 for three minutes, high in its day, but not outrageous. (FWIW, when I rode a Metroliner train in 1973, no one used the phone.)

One thing we must remember is that that service was actually an _automobile_ telephone--one could only use it in their car. It seems that a great many cell phone users today would find that restriction extremely limiting. (Ironically today, such use while driving is illegal in some places.) Also, the phone took up space, both the dashboard unit and a unit in the trunk.

When cellular phones first came out, they were automobile- oriented, and cell phone stores had a garage to physically mount the phone in the car.

We also must remember that capacity was extremely limited, there was room for only a few conversations at time. The Bell System regularly sought more radio channels, but was denied by the FCC.

"The crossbar tandem system was used to serve these mobile and other special service lines directly--a function it could perform since it could receive and send dial pulses."

"Significant use of private mobile radio systems dates back to 1921, beginning with the Detroit police department. Over the years, the Federal Communications Commission has granted additional radio spectra to increase private licenses to over eight million users (and another eight million on CB). These systems for the most part do not connect to the telephone network. Beginning in 1946, the Bell System inaugurated a three-channel system in St. Louis. Over the succeeding years, additional frequencies were allocated, improvements were made in changing service from manual to automatic, and trunking was added between mobile units and available channels. However, only 143,000 customers are served by Bell and the radio common carriers (RCC). There are tens of thousands of held orders for carrier-connected mobile telephone systems, even though the tariff is ten to twenty times that of residential telephone service. Because the waiting time is so long, there are many others who need this type of service but have not bothered to add themselves to the waiting list."

[evolution to cell service] "Since 1947, the Bell System has expressed to the Federal Communications Commission, in a number of review dockets, its interest in a large-scale mobile telephone system. In docket 19262, Bell introduced in 1971 a new version of the cellular system, which reuses a basic group of frequencies in nonadjacent hexagonal cells. As the mobile unit roams from cell to cell, its connection is moved from transceiver to transceiver under control of a central office switching system. No. 1 ESS was chosen to be the mobile telephone switching office (MTSO), since it has the software capability to allocate cells and frequencies as a call is "handed off" from cell to cell. In addition, the MTSO has to locate the cell for originations and provide additional conveniences for mobile customers. Initially the intent was to combine local and mobile services in the same switching office. In 1975, the FCC gave the Bell System the go-ahead for a development field trial of the cellular system but the switching office would be limited to handling only calls to and from mobile units. A No. 1 ESS, located in Oakbrook, Illinois was set up to operate a few cells and mobile units. Success of the trial is expected to lead to a larger service test and, with FCC approval, commercial service. "

I went to a church camp on an island off the coast of New Hampshire where for many years the only phone was an IMTS phone installed in a phone booth in the lobby. To call in, you'd dial 0, ask for the mobile operator in Dover NH, then ask the operator for JS8-3445. (The phone had a dial but my recollection is that they never automated that mobile site.) Calls were expensive and limited to three minutes.

When IMTS shut down one of the campers who was an engineer in real life put an antenna on the roof with line of sight to a church steeple on the mainland and set up a remote phone repeater, which gave us a pair of normal phones with normal phone numbers, albeit somewhat hissy sound. Since then I gather they arranged to run a cable to an adjacent island where the Coast Goard had run a cable out to their lighthouse from the mainland, and now they have not just phone but Internet. The campers, of course, just use their cell phones to cell sites on the mainland since radio waves propagate easily across salt water.

R's, John

I can't say I "remember" it, but Google certainly responds to the IMTS bait and offers this neat catch (amongst others)

for your delectation :-) . Cheers, -- tlvp

[snip]

They were, of course, Expensive Toys for the Rich and Famous. As such, in the tv show Superman (the real one in the 1950s, accept no imitiation), Perrry White had one. None of the reporters or other staffers did..

P.S.

Some additional early cellular telphone history:

In 1984, the Western Union Telegraph Company, along with its partners, operated cell phone service in Buffalo, Indianapolis, and Milwaukee as the non-wireline carrier. Construction was underway in Cleveland, Detroit, and Toledo. Telephone sets were manufactured by WU's subsidiary, E. F. Johnson.

WU also operated, along with Goeken Communications, Airfone service, with phones in 15 widebody planes, and 100 expected by year end. They handled 150 calls per day. E. F. Johnson also manufactured the Airfone equipment.

In addition, in 1984 WU offered long distance voice service. WU said a six minute daytime call from NYC to L.A. would cost $3.00 via AT&T, $2.83 via GTE, $2.67 via MCI, and $2.64 via WU. WU claimed its voice long distance rates were 25% cheaper than AT&T between points served by WU's microwave system, and 15% cheaper between other points.

In those years, WU was Fighting very substantial rate increases from local telephone companies for local loop access lines to subscribers for data and teletypewriter services. Though WU had been migrating such traffic over to its own lines, a considerable part remained. For instance, after WU acquired AT&T's TWX system, WU had to move all the subscribers over its own lines and switching systems.

--Western Union News, July 1984, August 1984, November 1984.

***** Moderator's Note *****

Western Union's move of TWX to "it's own lines and offices" took a great deal of time: I worked in the Boston-2 test center in the 80's, and we had a "WADS" office there, which was a #5 Crossbar switch that handled TWX. There were contracted TWX and Telex lines right up to the time when I was promoted into NYNEX IS in 1989.

Bill Horne Moderator

I had a number of Motorola IMTS systems in my trucks. Also GE. All on vhf band. I have a GE IMTS phone with Glenayre head that still works.

***** Moderator's Note *****

I take it that there are still service providers for IMTS? How much does the service cost?

By the way, there's an excellent site covering the pre-cellular mobile phones:

Bill Horne Moderator

Here is an old ad:

Here is a Bell Labs Record article on the Metroliner system:

Here is a Bell Labs Record article on the 1953 railroad mobile telephone:

***** Moderator's Note *****

These pages all have a "View" link that brings up a .PDF file showing the actual advertisement.

And ... OMG, is that Pre-Progress Line equipment I see in the picture? I used to fix those!

Bill Horne Moderator

We used to go to a church camp on an island ten miles off Portsmouth NH. The original high-speed communication to and from the mainland was carrier pigeons, which would fly out in the morning to tell the kitchen how many people to expect for lunch on the noon boat. When we started going in the 1960s and 1970s they had an IMTS phone mounted in an old phone booth. You'd call them by dialing the operator, asking for the mobile operator in Dover NH, and asking her for JS8-3445. (I don't think that fairly rural exchange ever implemented IMTS dialing.) The operators never could understand that this phone did not move, and if they weren't answering it was not because they had driven out of range.

At some point one of the engineers who attended the conferences brought out a point to point phone repeater, with the antennae in the top of the island hotel and the steeple of a church on the mainland. That worked pretty well, so the IMTS phone went away in favor of a POTS phone with a normal phone number.

In the 1980s we started bringing out our cell phones and although ten miles from a tower is a long way, line of sight over salt water is ideal for propagation so they worked OK. Around that time the Coast Guard automated the lighthouse on a nearby island and in the process ran a cable out to that island, and let us piggyback on that, so now if you know where to look, there's Ethernet cables in some of the buildings on the island that connect to the Internet.

R's, John

***** Moderator's Note *****

John, if you already had the roost, why not just switch to RFC1149? ;-)

Bill Horne Moderator