Could cellphones be created in the 1920s and mass produced from the 30s on?

[Gukpard]

Now, something I never understood quite right why cellphones showed up so late. I remember watching a mid 1970s anime and one of the characters took a small radio that worked exactly like a modern cellphone, but still the cellphone only became widespread on the late 90s or even the 2000s in third world countries.

Could a mobile phone with radio signal be created in the mid-late 1920s and as the world recover from the great depression such device explodes on the market? The idea is for it to be a mobile telephone, it does not needs a camera neither needs to be small like a modern one, but you need to have a wireless comunication.

 

[Protagoras]

Assigning non-conflicting frequencies to a large number of devices simultaneously to enable each to communicate only with the other device it is supposed to communicate with and not any others is a non-trivial computing task. Well, it's trivial these days, but it is non-trivial in the sense of impossible in the 1920s; cellphones basically appear at the point when the computing power needed to handle frequency assignments and avoid conflicts can fit inside something of reasonable size.

 

[Gukpard]

Assigning non-conflicting frequencies to a large number of devices simultaneously to enable each to communicate only with the other device it is supposed to communicate with and not any others is a non-trivial computing task. Well, it's trivial these days, but it is non-trivial in the sense of impossible in the 1920s; cellphones basically appear at the point when the computing power needed to handle frequency assignments and avoid conflicts can fit inside something of reasonable size.

So what about the late 1950s?

 

[Philip]

They existed in the 1940s. Here is what they looked like:

(Courtesy of Wikimedia)

 

[marathag]

Could a mobile phone with radio signal be created in the mid-late 1920s and as the world recover from the great depression such device explodes on the market? The idea is for it to be a mobile telephone, it does not needs a camera neither needs to be small like a modern one, but you need to have a wireless comunication.

From
http://www.wb6nvh.com/MTSfiles/Carphone1.htm

The first car telephones connected to the Public Switched Telephone Network in the United States were put into service in 1946, as a response to the growing mobility of the American population in the postwar years. Initial design of the mobile telephone itself was undertaken by the Western Electric Corporation, the prime supplier of telephone sets to the nation's Bell System operating companies, while Bell Laboratories itself designed the overall system and set the specifications for the equipment. At the same time, the independent telephone companies were developing their own equipment, to be supplied by Automatic Electric. The Bell System equipment built upon an already existing mobile radio set, Western Electric's 1945 vintage Type 38 or 39 VHF FM police radio equipment, adding a telephone style handset and a selective calling decoder, which rang a bell in the automobile when that phone's unique number was signaled. The selective calling decoder consisted of a small wheel in a glass enclosure, with pins located at certain points around its circumference. The decoder had been developed in the 19th century for railway right-of-way signaling, was later used in ship to shore radio telephone installations in the 1930's, and was a proven concept. This decoder was labeled "102." Western Electric and the Bell companies thus did not draw up an entirely new concept for a car telephone in 1946; they used proven components of other systems to create the new public car telephone service.


Mobile telephone equipment had already been in use internally within the Bell System on an experimental basis, going back before WWII, using mobile radios such as the Western Electric Type 28 VHF equipment. One example was the Emergency Radiotelephone Service established by New York Telephone in December, 1940, which used AM on the 30-40 Megacycle band. Based on the successful tests of that equipment, AT&T announced the creation of the General Mobile Radiotelephone Service on June 29, 1945, and applied to the FCC for authority to establish base stations in Baltimore, Chicago, Cincinnati, Milwaukee, Philadelphia, Pittsburgh, St. Louis, Washington DC, Columbus Ohio, Denver, Houston, New York City, and Salt Lake City. One has to wonder why nothing was initially considered for California.


The FCC and the Bell companies envisioned two forms of mobile telephone service, "HIGHWAY" and "URBAN." Both would be VHF, and both would use FM. The "Highway" service, as its name implies, was intended primarily to serve the major land and water routes that existed across the United States in the 1940's, which would not be served by the "Urban" systems. Highway service was intended for trucks and barges on inland waterways rather than private vehicles. Highway service was allocated 12 channels in the VHF "low band," with the mobile equipment receiving on 35 Megacycle and transmitting on 43 Megacycle frequencies, although not all 12 channels were initially used. The Urban equipment, as its name implies, was intended to serve mobile subscribers whose travels took them primarily within the immediate radius of a major urban center, such as doctors, delivery trucks, ambulances, newspaper reporters and so forth. Urban equipment operated on VHF 152 Megacycles (receive) and 158 Megacycles (transmit,) and the initial FCC allocation in 1946 was for 6 channels. The separation in transmit and receive channels was necessary to provide a "half duplex" communications circuit, and allowed the telephone company base station to remain on the air continuously during the duration of the call. The first Highway system went on the air in August 28, 1946 in Green Bay, Wisconsin, and the first Urban system went on the air in Saint Louis on June 17, 1946.


By 1948, Urban service was available in 60 cities in the United States and Canada, with 4000 mobile subscribers, handling 117,000 calls per month. Highway service was in place in 85 cities with 1900 mobile subscribers, handling approximately 36,000 calls per month, with most major highways in the east and Midwest covered.


The Bell System also entered the two-way business and police radio market after the war by offering the rental of entire radio systems including their maintenance and updating. This equipment was marked "Bell System" either in white painted letters or with water-slide decals. Smaller police departments were encouraged to use the "Urban" mobile telephone system as opposed to a traditional dispatch system, which must have been somewhat odd in operation. Most of the equipment rented by the Bell System affiliates was Motorola two-piece "Deluxe" equipment, FMTRU-5V "Dispatcher" and GE one-piece pre-Progress Line radios. It is believed that the Bell System discontinued this practice sometime in the early to mid 1950's.


Map of Mobile Telephone Land Stations in Service or Planned in early 1947:

Map of first "Highway" Mobile Telephone Land Station channel assignments, early 1947:

ORIGINAL URBAN SIX CHANNEL ALPHA-DESIGNATORS:


WJ WR JL JP JR JS


ORIGINAL HIGHWAY ALPHA CHANNEL DESIGNATORS:


ZF ZH ZM ZO ZB ZA ZL


POST-NARROW BANDING ALPHA CHANNEL DESIGNATORS:


(After 1964)


Highway: ZO ZF ZH ZM ZA ZY ZR ZB ZW ZL


Urban: JL YL JP YP YJ YK JS YS YR JK JR


UHF: QJ QA QP QB QR QF QS QH QW QL QX QM


Typical installation of the first car telephone:

WESTERN ELECTRIC 238 and 239 EQUIPMENT AND 41A CONTROL HEAD


The Western Electric house-made equipment consisted of two pieces; the transmitter cabinet and the receiver cabinet. These mounted in the automobile trunk, and a large cable brought forward under the carpet connected to a "control head" under the dash which contained a telephone handset. The control head featured two illuminated lenses--one indicated that the equipment was turned on, and the other would illuminate when the mobile telephone was called. The Western Electric Type 38 was Highway band equipment, i.e. VHF low band, and the Type 39 equipment was Urban, or VHF high band equipment. A complete installation would be prefixed "2"; in other words, type 238 would be a complete Highway mobile telephone, and type 239 a complete Urban mobile telephone. As originally supplied, all equipment was single channel in operation although two channel expansion was possible.

Transmitter shown below

 

[Gukpard]

@marathag now, why this didn't exploded as a consumer good for the public? Could they minituarize this on the ongoing years?

 

[Sam R.]

With the employment structure of 1945—desperately trying to retain degrees trade skilled and trained—employers had not forced day to day flexibility on workers and thus the need for day to day flexibile contact wasn’t required.

Instead they used the bullpen and foremen picked suckers for labour

 

[marathag]

@marathag now, why this didn't exploded as a consumer good for the public? Could they minituarize this on the ongoing years?

Expensive, and since it all went thru AT&T, didn't see it as something many people would want, that fed back into the limited development and stayed with the original frequencies and that limited amount of bandwidth, and the gear hardly modernized thru the '60s where a move to Solid State was done by GE and Motorola, that allowed dialing from the car, and full duplex operation, could speak and hear at same time.
Also a change in bandwidth space, narrowband that allowed 11 open channels from original six

Since it was AT&T, the operator didn't need the FCC licensing and knowledge exam, or the Morse Code requirement that Ham Radio would have needed. All that the User needed to do, was spend the $$$ and manually pick the Channel, and hope the 'Busy' light didn't show so the direct dial could be done
Still large

mid 1970s, the first real portable, mobile Phone

 

[James Ricker]

From
http://www.wb6nvh.com/MTSfiles/Carphone1.htm

The first car telephones connected to the Public Switched Telephone Network in the United States were put into service in 1946, as a response to the growing mobility of the American population in the postwar years. Initial design of the mobile telephone itself was undertaken by the Western Electric Corporation, the prime supplier of telephone sets to the nation's Bell System operating companies, while Bell Laboratories itself designed the overall system and set the specifications for the equipment. At the same time, the independent telephone companies were developing their own equipment, to be supplied by Automatic Electric. The Bell System equipment built upon an already existing mobile radio set, Western Electric's 1945 vintage Type 38 or 39 VHF FM police radio equipment, adding a telephone style handset and a selective calling decoder, which rang a bell in the automobile when that phone's unique number was signaled. The selective calling decoder consisted of a small wheel in a glass enclosure, with pins located at certain points around its circumference. The decoder had been developed in the 19th century for railway right-of-way signaling, was later used in ship to shore radio telephone installations in the 1930's, and was a proven concept. This decoder was labeled "102." Western Electric and the Bell companies thus did not draw up an entirely new concept for a car telephone in 1946; they used proven components of other systems to create the new public car telephone service.


Mobile telephone equipment had already been in use internally within the Bell System on an experimental basis, going back before WWII, using mobile radios such as the Western Electric Type 28 VHF equipment. One example was the Emergency Radiotelephone Service established by New York Telephone in December, 1940, which used AM on the 30-40 Megacycle band. Based on the successful tests of that equipment, AT&T announced the creation of the General Mobile Radiotelephone Service on June 29, 1945, and applied to the FCC for authority to establish base stations in Baltimore, Chicago, Cincinnati, Milwaukee, Philadelphia, Pittsburgh, St. Louis, Washington DC, Columbus Ohio, Denver, Houston, New York City, and Salt Lake City. One has to wonder why nothing was initially considered for California.


The FCC and the Bell companies envisioned two forms of mobile telephone service, "HIGHWAY" and "URBAN." Both would be VHF, and both would use FM. The "Highway" service, as its name implies, was intended primarily to serve the major land and water routes that existed across the United States in the 1940's, which would not be served by the "Urban" systems. Highway service was intended for trucks and barges on inland waterways rather than private vehicles. Highway service was allocated 12 channels in the VHF "low band," with the mobile equipment receiving on 35 Megacycle and transmitting on 43 Megacycle frequencies, although not all 12 channels were initially used. The Urban equipment, as its name implies, was intended to serve mobile subscribers whose travels took them primarily within the immediate radius of a major urban center, such as doctors, delivery trucks, ambulances, newspaper reporters and so forth. Urban equipment operated on VHF 152 Megacycles (receive) and 158 Megacycles (transmit,) and the initial FCC allocation in 1946 was for 6 channels. The separation in transmit and receive channels was necessary to provide a "half duplex" communications circuit, and allowed the telephone company base station to remain on the air continuously during the duration of the call. The first Highway system went on the air in August 28, 1946 in Green Bay, Wisconsin, and the first Urban system went on the air in Saint Louis on June 17, 1946.


By 1948, Urban service was available in 60 cities in the United States and Canada, with 4000 mobile subscribers, handling 117,000 calls per month. Highway service was in place in 85 cities with 1900 mobile subscribers, handling approximately 36,000 calls per month, with most major highways in the east and Midwest covered.


The Bell System also entered the two-way business and police radio market after the war by offering the rental of entire radio systems including their maintenance and updating. This equipment was marked "Bell System" either in white painted letters or with water-slide decals. Smaller police departments were encouraged to use the "Urban" mobile telephone system as opposed to a traditional dispatch system, which must have been somewhat odd in operation. Most of the equipment rented by the Bell System affiliates was Motorola two-piece "Deluxe" equipment, FMTRU-5V "Dispatcher" and GE one-piece pre-Progress Line radios. It is believed that the Bell System discontinued this practice sometime in the early to mid 1950's.


Map of Mobile Telephone Land Stations in Service or Planned in early 1947:

Map of first "Highway" Mobile Telephone Land Station channel assignments, early 1947:

ORIGINAL URBAN SIX CHANNEL ALPHA-DESIGNATORS:


WJ WR JL JP JR JS


ORIGINAL HIGHWAY ALPHA CHANNEL DESIGNATORS:


ZF ZH ZM ZO ZB ZA ZL


POST-NARROW BANDING ALPHA CHANNEL DESIGNATORS:


(After 1964)


Highway: ZO ZF ZH ZM ZA ZY ZR ZB ZW ZL


Urban: JL YL JP YP YJ YK JS YS YR JK JR


UHF: QJ QA QP QB QR QF QS QH QW QL QX QM


Typical installation of the first car telephone:

WESTERN ELECTRIC 238 and 239 EQUIPMENT AND 41A CONTROL HEAD


The Western Electric house-made equipment consisted of two pieces; the transmitter cabinet and the receiver cabinet. These mounted in the automobile trunk, and a large cable brought forward under the carpet connected to a "control head" under the dash which contained a telephone handset. The control head featured two illuminated lenses--one indicated that the equipment was turned on, and the other would illuminate when the mobile telephone was called. The Western Electric Type 38 was Highway band equipment, i.e. VHF low band, and the Type 39 equipment was Urban, or VHF high band equipment. A complete installation would be prefixed "2"; in other words, type 238 would be a complete Highway mobile telephone, and type 239 a complete Urban mobile telephone. As originally supplied, all equipment was single channel in operation although two channel expansion was possible.

Transmitter shown below

I can see that thing becoming a very valuable antique

 

[marathag]

I can see that thing becoming a very valuable antique

Not all that much, you can find MTS gear on Ebay for not horrible amounts of $$$, if you find stuff listed as 'Old Tube Amp' for people not knowing what it is. Other people list stuff with high prices since 'They know what they got' There are not as many collectors any more

 

[bsmart]

@marathag now, why this didn't exploded as a consumer good for the public? Could they minituarize this on the ongoing years?

It wasn't until cheaper integrated circuits that could stand the abuse consumer devices get that cell phones were even possible

then the problem was having enough transmitting poser without having a huge (and heavy) battery. That was solved by creating a web of towers that would receive the signal from nearby devices and retransmit it to the intended destination (after figuring out where the recipient was and sending the data over landlines to a transmitter near that location. this all required a fair amount of computing power, which again had to wait for cheaper computers. After that it was just a matter of signing up enough users to justify the infrastructure.

Even in the '70s most field technicians and service people depended on a one way pager and a pocket of dimes or quarters (I used to buy two rolls of quarters a week to keep in my car). These weren't even digital pagers. They were run by a central dispatch which would field customer (and other) calls and contact us to let us know we had a message. They gave out a tone (That was what switched yours on) and gave a voice message to you. It was usually 'call dispatch' or 'Code W' (call your wife) or some short prearranged message. You would then find a phone (not that hard in most areas) to get details. Digital pagers took sentral dispatch out of the equation.

Even after cell phones came out I kept my pager. I joked that I had a 'dial out only' cell phone and coworkers begged me to tell them how to get one. I told them 'just don't give out your number. I tell people to call the pager and I'll call them back. I knew which numbers needed an immediate response and which could wait (and a few that never seemed to come through clearly )

 

[Blue cat]

Expensive, and since it all went thru AT&T, didn't see it as something many people would want, that fed back into the limited development and stayed with the original frequencies and that limited amount of bandwidth, and the gear hardly modernized thru the '60s where a move to Solid State was done by GE and Motorola, that allowed dialing from the car, and full duplex operation, could speak and hear at same time.
Also a change in bandwidth space, narrowband that allowed 11 open channels from original six

Since it was AT&T, the operator didn't need the FCC licensing and knowledge exam, or the Morse Code requirement that Ham Radio would have needed. All that the User needed to do, was spend the $$$ and manually pick the Channel, and hope the 'Busy' light didn't show so the direct dial could be done
Still large

mid 1970s, the first real portable, mobile Phone

From reading relevant publications in the mid to late 1980's / early 90's my understanding was that the VHF radio telephone system had been popular enough that the system had long been essentially over subscribed in at least some major metropolitan areas in the U.S.

So in some ways I would say it was very successful.

I also recall seeing advertisements (in the mid to late 1980's) for hand held VHF radio telephones that were similar in size to early handheld cellualar phones.

I recall using VHF radio telephones in parts of Canada well into the late 1990's.

Parts of Canada also had UHF system(s) that had more channels.

Much fun