Re: [Telecom] Analog cell-phone network going off air

wrote

The earliest >cell phones were mounted in cars,

Not really.

The earliest "mobile phone" service used transceivers (made to look like a phone) mounted in cars, but that service was not "cellular".

A "nit" to be sure but significant in some contexts! ;-)

IIRC, the "transition" was something like what is going on now. That is, notice was given a LONG time in advance that the original service was going to die and the users were pretty much left to find their own solution.

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

As the former owner of a Motorola TLD-1000A, I can attest to the dramatic difference between the old and new systems. The IMTS control head was the thing most people though of as the "phone": it had a dial, a handset, eleven channel-select buttons, and some other buttons for various things (such as using the car's horn to signal an incoming call). IIRC, it was about seven inches high, ten across, and about five deep, plus a mounting bracket and cables.

The control head, however, was small compared to the actual radio: it was about twenty-four inches long, about 15 wide, and five or six inches high. It could only be mounted in a trunk, and I could see the headlights dim when I keyed the PTT button!

The transition to cellular was much less painful for me than for others: I sold the unit long before cellular started.

Bill Horne Temporary Moderator

Reply to
Ken Abrams
Loading thread data ...

Actually I was speaking of _cellular_ phones, not the predecessor system. When cellular phones first came out, IIRC, they were generally available only as car mounted units. They were certainly smaller than the predecessors, but still bulky. The portable "bricks" were rare. The alternative was a bag phone which was cumbersome. But it didn't take long for portable models to shrink down and car installed models (and installation centers) ceased.

As other noted, the early cellular units were far more powerful than later handsets. Presumably the number of cells within a region was relatively small and the cells themselves relatively large. As demand increased, they kept adding more towers and shrinking the cells.

I recall watching a rerun of the TV show "90210" and the character was talking on his car cell phone, a handset connected by cord to the dashboard. This at first seemed very strange to me until I realized the episode was old and dated from the time cellphones were new and a novelty.

Before cellular phones it was called "mobile" telephone service because it was mounted in cars, as described elsewhere. This dated from about 1948. At that time similar units were installed in deluxe passenger trains.

A pioneer cell phone effort was the Metroliner train phones introduced in 1969. These used a pioneer automated cell switching arrangement and handoffs so that service was provided seamlessly between Jersey City and Washington, even within the Baltimore tunnels (but not the NYC Hudson tunnels). Previous posts discussed this in detail.

Others mentioned competing mobile telephone service _within_ Bell System territories. I was not aware of that. Did those system _seamlessly_ connect with the Bell Telephone network as did Bell mobile phones? (The later generation of mobile phones had direct dial in both directions.) So, users in the competing system had their own direct phone numbers? This would represent a rare crack in the Bell System monopoly.

I would've thought under the old Bell System mobile telephone users would've rented the radio set, as did other subscribers of Bell System services. People had to buy the radio set?

Do you remember anything about the tarrifs for the old system in terms of rates charged?

Would you recall how many watts the mobile unit put out?

I believe the old arrangement was that Motorola furnished the mobile radio sets while the Bell System provided the service per an agreement between the two companies. I don't know who provided the mobile base stations or switching gear interfaces. This was a rare instance of the Bell System using equipment not provided for by Western Electric, although WE built plenty of mobile radios for the military. Motorola got its start making car radios that were shielded from interferance from the car's ignition system; at the time that was a big innovation (thus the name "Motor").

I presume the old Bell mobile service was supported by the regular Bell System personnel, not a separate subsidary? When I got my first Bell Atlantic cell phone, I presumed it was supported that way but I quickly found out the cell phone business was entirely separate. The store personnel were clearly not the caliber of regular Bell System people, none of that Vail tradition for them.

Reply to
hancock4

I know the few that I saw that were mounted in GTE company vehicles had a phone number from their local switch or an office the IMTS equipment installed. We could dial out and call most of the time, but in a couple of areas you had to call the MTS operator and she would make the call, I don't think they used the phone number, but a signaling system much like the pagers of the time. It took me a bit of getting used to not having dial tone when I first stated using a cell phone, but then having worked in the CO I know that dial tone was not really needed, just to let the caller know they could make a call, I learned that when we lost our rial tone generators and we still could make calls.

Reply to
Steven Lichter

The Bell System and other telco mobile phone service had 11 VHF channels urban), and about the same Low Band (rural) and UHF metropolitan) channels. The Radio Common Carriers (RRC) had 7 VHF channels and I don't recall the UHF channels. Because they were different channel sets, they did not work with each other.

In Texas, the deployment of Bell towers was kind of random, where the RCCs were population density deployed.

With my Motorola Mocom and a Secode control head, I installed my own channel sets and the Secode could decode both the MTS/IMTS telco signalling format and the 2805 Hz RCC format.

Southwestern Bell Mobile didn't charge for the unit rental. I could be wrong and it was simply buried in with the $25 per month fee.

I believe I was paying $25 a month for unlimted calls and full roaming. Other states, like California charged by the minute. The RCCs had a similar rate plan.

Bell originally used a modified Motrac with a tube power amplifier and around 1976 they started using solid state units. I want to say they were putting out 25 watts into the antenna. That means the transmitter output was around 50 watts as there was a antenna duplexer. As many times I connected a Bird to the sets, I simply just don't remember.

I did come across a few mobile sets a Weco tag, but both Motorola and GE made the units. I recall both Moto and GE in the racks at the base stations.

All of this is going from memory thirty years back.

I do know for a fact that if you plugged in your mobile to the coax running down the tower from a 6 dBd antenna, you could light up base stations 400 hundred miles away.

Reply to
DTC

Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.