AT&T Archives: Advanced Mobile Phone Service (AMPS), a 1978 film on cell phones

For more from the AT&T Archives, visit techchannel.att.com/archives
Using simple graphics, this film, made in 1978, illustrates the concept of cellular telephony in easily-understood terms, which are instructive even today, since the basic idea of dividing a service area into a pattern of small cells remains the same.
As the film points out, the concept of using these small cells was developed at Bell Labs, and it was this idea that constituted the giant leap from earlier, less efficient mobile phone systems to today's modern cell service. What the film does not mention: the year the cellular idea was first proposed at the Labs, which was 1947.
In 1946, AT&T had introduced the first commercial mobile telephone service in St. Louis, Missouri. The equipment weighed nearly 80 pounds and was installed in a subscriber's motor vehicle. A single transmitter on a central tower provided service to the entire area, and only a handful of channels had to be shared by all subscribers. Before long, more channels were needed for mobile service to continue to grow. That's when Bell Labs engineer, D.H. Ring, proposed a solution.
In his 1947 memorandum, Ring outlined a hexagonal grid system composed of multiple low-power transmitters with automatic call handoff from one hexagon to another. The scheme would enable reuse of frequencies within a given area, dramatically increasing the mobile network's capacity. But at the time, the technology to implement Ring's proposal did not yet exist, and it would be another few decades before this scheme would be revisited by AT&T Bell Labs engineers Richard Frenkiel and Joel Engel. Their work would provide the basis for an AT&T proposal in 1971 to the Federal Communications Commission (FCC) for a cellular network. The FCC would later grant AT&T permission in 1977 to start conducting trials of a cellular system in the United States. The first commercial cellular system in the U.S., in Chicago, followed in 1983.
Footage Courtesy of AT&T Archives and History Center, Warren, NJ

[@johnopalko5223]

I worked on the AMPS project when I was at Bell Labs. Wow, that was a fun job! I guess I'm just an old softie, but this video brought tears to my eyes. I left the Labs shortly after Divestiture and went on to work for McCaw Cellular. That was fun, too, and it got me to Seattle. No more Chicago winters!

[@BadBoyBobby85]

@Director HFerreira amps has been shut down for a while, even cdma is getting the boot at the end of the year and att has abandoned gsm

[@mybigfatpolishlife]

Thank you for your work

[@bayareanewman1566]

Thank you John !!

[@charlesroberts3650]

​@Director HFerreira No more brain cancer, right? If that were so I would start using mobile phones again. Right now, I use cellphones very seldom, try to use only Landlines. I personally know of three people (computer hacker cyber criminals) that overused transceiver devices that use RADAR RANGE frequencies (800 MHz) and they have MASSIVE brain tumors, RIGHT BEHIND THEIR RIGHT EARS (the antennas are located on the right ear phone). It serves them right. Any more than an hour or two of daily usage can cause physiological damage. That goes for WIFI enabled devices also, SPECIALLY headsets.

[@80sCompaqPC]

I’d love for AMPS to come back. I’d love to use one of my Motorola DynaTACs, MicroTACs or bag phones! It obviously never will, but it’s a fun thought, none the less. I like these old phones a lot. Can’t beat some good old analog technology!

[@voiceofjeff]

My first "mobile phone" was an Aerotron MTS phone that went through an operator. My unit number was 2707. I was on the 150mhz band and could talk from just about anywhere in my area. It was a minimal monthly service charge. Loved that system until it was shut down! Yes, the sound quality was much better than most cell phones with their digital artifacts!

[@carlospulpo4205]

Wow this brings back memories of the real phone hacking before rooting and jail-breaking became a thing. I had a old Motorola "bag" phone that was totally modified via hardware and change of EPROM code so I could do almost anything I wanted on a network, basically without going in to great detail I had low level control over all the transceiver and data operations on the phone, use your imagination! . I made a serial connection to a PC and wrote the accompanying software to control it. I gave the phone the nickname "superphone" and the good times with that.

[@theoneTMoney]

please go into great detail, i am interested

[@yuriythebest]

now THIS is worthy of a youtube video

[@jamesb8305]

Ah yes... I had a copy of the Motorola Bible, a high powered bag phone, a scanner, and a cell tower less than a 1/4 mile away from my house. Teen mischief ensued.

[@Open_DoorMedia]

@@jamesb8305 lolz

[@mystica-subs]

I love how they call "small cells" something starting out at 4-mile radius (before going maybe down to 1 mile)! That term has changed so much in ~40 years. In a city, 1 mile is often way too large for a single cell. Suburbia loves 1 mile cell radii however, much to the chagrin (and slow datarates) of the hundreds of customers within each sector...

[@Gannett2011]

Music used: 'Flying High' by James Clarke, from the album 'Music Pictorial' KPM 1972.

[@anthonym612]

kzbin.info/www/bejne/iqKwfJyAgL6WZpo

[@MsJamiewoods]

The "recently allocated frequency frequency band" (13:38) was actually UHF TV channels 70 through 83. Until about 1984/85 most TVs were sold with UHF tuners going up to channel 83. However, channels 70-plus were never actually used by the FCC for commercial or educational TV.

[@Cjaiceman]

If you were lucky enough to have a TV that could tune that high, and with some small adjustments of the "Fine Tune" knob on the back, you could pick up people's calls, usually the tower side only though.

[@krisstarring]

There were a few TV stations in the United States and Canada on 70+ channels, but they were all defunct or reallocated to another channel by the mid 70's.

[@tresdeazucar]

The script of this video seems written by engineers. Too technical for ordinary people. In any case, I find it fascinating that AT&T had already been working on mobile phones for civilian use since 1946, and in 1977 had already created a cell phone system similar in essence to the one we use today.

[@truthbydesign5146]

I remember it was around $1.00 a minute when my cousin got a mobile phone in 1984 ... Probably even more expensive in ‘78, when I was born.

[@prfo5554]

Oddly, despite being obsolete I occasionally still see payphones/phone booths in some rest areas.

[@AureliusR]

Payphones aren't obsolete -- yet.

[@christophers.8553]

A lot of those graphics were 15 years old in 1978. Looks like they are out of the Flintstones.

[@marcfield1234]

The very basis of how cell, and smart phones work today. Very fascinating indeed. Besides how else could we text and drive?

[@spankyharland9845]

real nice tech to allow you to be in touch with others- but also a way the government can track you and know every place you have been to thanks to the cell sites tracking every move you make.

[@MrWolfTickets]

Sweeeeeet. Thanks for keeping these awesome videos coming.

[@steadfastcoward]

You may not realize that the growing need for both cellular and emergeny communications will turn your television service on it's head in the next two years, as the FCC 'repacks' the band and eliminates most channel about channel 38. In addition to any new stations seeking to air, existing stations will be moved and eve combined (piggybacked) with other program services/licensees as well. Your antenna TV is about to get crazy.

[@luisreyes1963]

Thanks for the heads-up.

[@johnsiders7819]

I got my first cell phone in 1984 they were called car phones had that big box in the back of the truck behind the seat on the cab back wall had the handset on the dash with the keypad and mic speaker a heavy coiled cord to the cradle that held it was a Motorola full 4 watt system the antenna took a 3/4 inch hole in the roofs center and it cost like almost 4 K ! For the system and installation I was working for the wild well people and it demanded instant finding of us when a call came in of a blowing or burning oil or gas well it was a dollar a minute to use and out side your home area it had a roaming charge of 3 dollars per day on top of the air time and if you traveled out of that area you got hit with roaming again ! Of course before all we had were these big pagers that only beeped no texting or voice if it went off you called the office out in public people would stare at you like you were some kind of big shot to have a pager and using the car phone going down the road other cars people pointed at you like wow that’s a rich man he’s got a phone ! LOL we were just oil field trash . Doing a important job .

[@johnsiders7819]

@D that’s why I used it it was a big deal back then . At our main office when we were hired to put out and shut it in a blowing/burning oil or gas well that was a million just to get us organized and equipment with the crew going to it not a lot of money when you think how much of the customers oil or gas was going up in smoke every 24 hours .

[@AureliusR]

My god, how do you read what you wrote without using punctuation? It's like one giant sentence.

[@jasonreedrn]

13:29 How funny! The lady almost cuts off the car coming up behind her. Don't forget to check your blind spot! lol Then the passenger picks up the phone... Love it!

[@ronaldmcdonald6793]

The first mobile phone, as in a hand set was in 1978. It was gigantic. I want to use one, just to see how it works.

[@christophers.8553]

Works like a phone. Dial the number, push "send". My Mom kept hers in he glove compartment for years after everyone else had moved on. One advantage to the analog phones is that you might get static, but you could still converse. Digital phones just drop out. The sound quality was quite good on the oldphones. It was big, but it wasn't "gigantic" even compared to cordless home phones at the time. The big ones were the phones you mounted in your car trunk and just had the handset up by the driver. On the better ones, you could unlock the box from the trunk mount, attach a battery pack to the side, and take it out of the car with the handset like a briefcase. They were always advertised showing a man on the golf course, a driver on his shoulder using the phone. Those bigger phones were a whole lot more powerful than the handheld ones. Look up Radio Shack 17-1002 for an example.

[@christinadouglas3975]

I always wondered why they call them "cell" phones. Now I know why

[@xaenon]

Ha! An AMC Pacer! Just when I though I'd forgotten those things!

[@pimpingmrli]

I thought it was a Gremlin. It' s been so long since I saw either one...I forgot what they looked like. You are talking about the white car at the end right? With the 2 ladies in it?

[@XMguy]

I used CDMA AMPS on phones I had between 2001-2004(?). Whenever the Analog network was shut down.

[@billyfowler9423]

Tropospheric ducting most common late at night during areas of high pressure still caused issues with amps along with intermodulation (crosstalk), but it wasn't as big of an issue as with the older systems on the lower frequencies.

[@BenHelweg]

I was wondering that.

[@sbreheny]

Hmmm, have you experienced that? I haven't seen an AMPS-capable phone since around 2005 and most carriers stopped handling AMPS calls before 2010.

[@WhatALoadOfTosca]

8:57 Get out! It's going to blow!

[@garyarlen]

Driving a Pacer (~13:37)!! How futuristic!!! And wired handset in the car!!!

[@jamesb8305]

The phone and service cost more than the car...

[@prfo5554]

i just realized that on top of the fact that AMPS is divided into 666 channels, its logo is made up of hexagons. As most people know a hexagon is a six sided figure. The logo has six hexagons surrounding the center hexagon. The six exterior hexagons are in two alternating colors. This means there are three exterior hexagons in each color or 6-6-6.

[@OALM]

The mark of the beast

[@ryanleclaire3948]

Good eye. Only makes sense considering where we are today with mobile communications and everyone being a slave to it.

[@TuomasLevoniemi]

Interesting information about AMPS. However, it can be said AMPS was technically pretty old-fashioned when it was released. Compared to NMT (=Nordic Mobile Telephone / 1G) by Nokia and Ericcson. Also, ARP (Autoradiopuhelin, "car radio phone") had been widely used in Finland in the from the start of 1970.

[@daveking3161]

Interesting, so what were the differences between AMPS and NMT?

[@oussematrabelsi9429]

that's not true. AMPS was actually more advanced and did very well especially in cities like chicago. AMPS had political difficulties unlike the NMT due to FCC regulations and disputes with other companies. That's why it was implemented too late. It was still relatively successful and alot of countries used AMPS and not NMT

[@americanspirit8932]

AT&T owned 51% of Erickson at that time I found that out just a couple years ago very interesting

[@QuaaludeCharlie]

This makes me Happy :) QC

[@benjaminnunez8273]

El aspecto viejuno y las pintas de la peña le dan un tufillo al vídeo absolutamente delicioso.

[@robertodelmar1869]

De acuerdo. Me relaja tanto verlo. Lo pongo seguido. Es una joyita

[@JJVernig]

Why does the car from 8:00 onwards look like the flintstones?

[@MsJamiewoods]

Hand off -- when your call drops. While this still occurs, it's getting less frequent. I've been using cell phones since late 1998. Remember the days of Roaming charges?

[@johnkern7075]

follow me roam

[@Hot80s]

0:15 Cougar with a Cougar

[@Aaronhouston33]

I’d think this would be a magnet for car thief’s back then

[@jalexgans932]

cool

[@Mr_Chris77]

All this technology now and you still a can't get a cell phone call to sound as good as a landline

[@johnnyblaze9217]

Idk where you at india? Cause my stuff sounds just about as clear as you can get tbh

[@brycmtthw]

HD calling over VoLTE are much clearer than POTTS calls. Most “landlines” now a days are VOIP anyway. 🤷‍♂️

[@James_Knott]

I have to chuckle at how, when describing the cell network, they always show an array of perfect hexagons. Not quite reality. And how do they get the signal to stop right at the cell boundaries? 😀

[@PremiumFuelOnly]

They dont try to stop it. Thats why they dont reuse the frequency unless its several cell sites away depending on the size of the cell. The signal strength determines if the call should be handed over to neighboring site on a different frequency.

[@James_Knott]

@@PremiumFuelOnly I guess you missed the 🙂in my comment.

[@therongperson]

And this is why money never sleeps, pal!

[@bayareanewman1566]

MK Barton you know the scene where he’s walking on the beach w/ the phone.. I’ll bet he didn’t even have coverage! The model phone he had needed to be charged for 8 hours just for 30 minutes of talk time!

[@alsehl3609]

2 antennas on the car! They must have spent no time on a duplexer.

[@couchetard1984]

Where is the gd side view mirror on the vehicle at the end? They're on a highway ffs!

[@brycmtthw]

A lot of cars didn’t have passenger side view mirrors in the 70s.

[@johnkern7075]

Mobile phone in that VW van.

[@OALM]

So that’s why they’re called cell phones!!!

[@darthsatanus]

INTERESTING. v-e-r-y interesting indeed!

[@gakster29]

Hm. This 5G thing is more confusing than I thought.

[@johnnyblaze9217]

Lol just imagine that was just 1g

[@torquemada1971]

This describes the precursor to what we call a cellular network, and really has nothing in common with it.

[@richardhz-oi8px]

Has a lot in common with today's cellular network, the only difference it that the channels are now digitally multiplexed, just like comparing N-carrier to T1-carrier, both multiplex signal so many calls can go along one cable pair, one converts to radio signals, the other(T1) digitally multiplexes the signal. Same concept, different execution. The system described here, AMPS was in use into the early-mid 2000s, the direct digital successor still is.

[@Gannett2011]

Yes, the principles in the film still apply, just in a more modern, digital form.

[@finaltransconfigurat]

@@Gannett2011 I emplore you to initiate a call from a handset made after circa 1985. It will work. ^_^

[@MaxPower-11]

Not really. The basic concept of a “cell-based” network whereby the end-user mobile radio terminal is handed over from cell to cell is still pretty much the same. That’s why we still call them “cellphones”. What’s changed is the introduction of digital encoding and compression technologies and fancy RF modulation schemes which allows the network to handle a lot more users and use available spectrum much more efficiently.

[@TheRosemontag]

5:31 the DEVIL >:D

[@Jeeppeeps]

The Readers Corner it’s funny how 33 and 666 are the reoccurring numbers allll satanic numbers

[@krisstarring]

3:43 - "666 Channels!" LOL!

[@tonysolar284]

And that thing ran off your cars 12v battery.

[@jameslawrence6260]

Won't let me subscribe.

[@Michael_Livingstone]

They still use AMPS in Saskatchewan due to the sparsely populated rural nature of the province.

[@hansonsux]

666 lol

[@gordonarchibald4777]

hansonsux Well, it is AT&T after all.

[@markarca6360]

AMPS is deprecated in the late 90s to early 2000s and replaced by GSM (1G).

[@thetechgenie7374]

1G which was NMT Nordic Mobile Telephone, by Nokia and Ericcson then you had 2G which was GSM, earlier TDMA and FDMA digital, most phase out 2G in the US. Now moving into 5G NR OFDMA. Technically 4G and 5G is data only and voice is done by VoLTE. 4G smartphones could fall back on 2G/3G for voice when VoLTE is not available, but not for 5G. Your smartphone/cellphone is essentially is a radio transceiver that use encryption now a days on a very complex switching level. Like most police and emergency services uses p25 TDMA phase 2 for communications, Back then it was not encrypted and analog as far as the AMP system when. Some use to listen to people talking on that repeater back then with a transceiver, or scanner that was modified to be able to tune to that frequency, which FCC required manufacturers to block that range later on. This video is somewhat inaccurate about people not being able to listen in on the old AMP system. Anyone with little knowledge and a service monitor, or a older, or modified transceiver/receiver could back then. Same with home 800Mhz phones, or baby monitors. Encrypted pretty much stopped that and won't say impossible, but close to it, without getting into classified information. Don't have to worry about the normal Joe listening in.

[@MaxPower-11]

In the USA AMPS was not replaced by GSM but by D-AMPS (aka “TDMA”) or IS-95 (aka “CDMA”). GSM in the USA didn’t come into play until PCS networks were established (these were initially set up in the USA in as greenfield networks the 1900Mhz band where AMPS was never deployed). The first GSM network in the USA was set up by Sprint in the mid-1990 in the DC-Baltimore area. Eventually, AT&T replaced TDMA with GSM.

[@x_x_w_]

@@MaxPower-11 no. It went amps -> gsm or tdma -> edge/cdmaOne -> umts/cdma1xrtt -> hspa+/cdma evdo -> lte

[@MaxPower-11]

@@x_x_w_ That is incorrect. The largest AMPS network in the world, which eventually became Verizon Wireless never used TDMA or GSM. They went straight from AMPS to CDMA. The other huge AMPS network was AT&T Mobility and they first went from AMPS to D-AMPS (aka TDMA) and from there to GSM (AT&T never used CDMA). Verizon Wireless then went from CDMA straight to LTE. AT&T went from GSM to UMTS/HSPA then LTE.

[@dislikebutton1799]

These phones were the devil, with their 666 channels

[@syldamours8831]

je veux retirer att de mon cellulaire je ses que je peut appeller demain matin mes je me demande si je peux pas y arriver ce soir

[@phoneticau]

1G

[@thetechgenie7374]

1G didn't come to later on, which was NMT Nordic Mobile Telephone, then you had 2G which was GSM.

[@Toothily]

@@thetechgenie7374 AMPS was 1G

[@Pisti846]

We lost a great resource when we lost Bell Telephone Laboratories and Western Electric. May "Judge" Harold Green rot in eternal hell.

[@lohphat]

+IstvanN1961 Without breaking the monopoly we'd still have AMPS and expensive Long Distance dial plans. Creating competition has injected innovation and lowered costs.

[@Pisti846]

We could have had every technology we have today and the Bell System. Bell Labs was a tremendous asset to this nation and no amount of low-cost long distance can ever replace that.

[@lohphat]

That asset did great things in its day. No argument. But it had stagnated and other tech in other countries (like GSM) were passing us by. Breaking up the logjam allowed prices to fall -- it also allowed you to buy your own phone instead of having to lease it from ATT.

[@thihal123]

+lohphat Has creating competition really lowered costs? I think phone plans are a lot cheaper in other countries, such as in Korea.

[@lohphat]

Unlimited national calling, unlimited data (t-mobile) -- back in the '80s when I got my first phone -- $300 monthly charges were "normal" -- adjust for inflation and those bills are HUGE by today's standards.

[@XMguy]

Now everyone has a cellphone. More common that’s their primary phone.

[@jameslawrence6260]

🌳🌿🦍

[@MikeDBrnchBannks-eh1ni]

Nv twenty five hundred Wells Fargo Lowe's u haul drivers . The bad drivers adition NTSB gas fuel stations intentional bad deadly drivers n , tte addition near fismms mes hazmat asicste. Miami Florida sunny ISKES area one six three st start wek Tuesday Wednesday. Jan end of the month five o close ck hour.

[@estusflask982]

666 Channels

[@chriscross4994]

Well in 1978 in Europe hate was born

[@randymaatta8824]

AT 3:50 mark. 666 channels. We really were asleep back then.