History Of Mobile Phones

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From The Old Mobile Service Area System To…

Advanced Mobile Phone Service (Cell Phones)

 

Having a phone in your car isn’t new. It goes back to the 1930’s beginning with something called the “Mobile Service Area.”

The system used one broadcast (access) point and required a mobile operator to help place the call and – she kept track of the channel being used – then, reassigned that (radio) channel when the call was completed. So, another channel then opened – then – someone else could use the network.

Range was about 20-30 miles – give or take.

At first – hand-sets used a transmit button – push to talk, let go – listen.  And – originally – there  were 21 channels allocated to the MSA service, rising to 33. The problem, MSA’s only got a portion of those channels assigned – so say for Los Angeles proper – you’d have – at the most – 16 channels available for everyone.

The reason was interference. You had to have a 100-mile separation between assigned channels.

Why 100 miles – when the range is 20 -30 you say? You never know with radio. Weather conditions can cause distant propagation on those VHF and UHF bands.

This brings up an interesting point: something called frequency re-usage. Engineers came up with a plan – “Advanced Mobile Phone Service” that took the best advantage of limited spectrum.

This new scheme – enabled smaller, tighter MSA’s with corresponding  “cells” –  so  – you can more control channel re-usage and signal.

This 1978 video takes us through the mobile phone beginnings – into this new scheme – and – lets us know real-world testing is underway.

“Advanced Mobile Phone Service” (AMPS)  gave way to just cell phone. I kind of like the sound of having an AMPS phone!

https://www.youtube.com/watch?v=ZTkUdHNYFRo

 

 

Author

Gary West

Historian Gary West built his first website in 1998 with www.pophistorynow.com. That addressed now forwards to www.mrpopculture.com - an amazing pop culture/news database with 25,000 pages, covering the years 1955-2014. He's also the author of www.technologynewstimeline.com - covering consumer technology from 1952 to the present. West has been a contributor to numerous books, radio-TV shows, CNN & USA Today & the History Channel.

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