On Mar 31, 9:29*pm, "Michael R N Dolbear" wrote:

AT&T had radiophones working in St Louis (and later other cities) in
1946, so likely that zero generation technology. I understand that
local calls could be dialed - no operator. I recall a early Ed McBain
where this is a plot point. A radio link to a central exchange just
replaced the normal landline.

The original mobile phone system was strictly manual. An improvement
in the 1960s allowed dialing.

As to "zero generation", I strongly suspect AT&T's experience in
wartime military communications contributed to making mobile phones
practical. They (and others) had to rush to develop improved two-way
radios for tanks and jeeps.

*The concepts of frequency reuse and handoff as well as a number of
other concepts that formed the basis of modern Cell Phone technology
are first described in Patent Number 4152647, issued **May 1, 1979** to
Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada . . ..

The Bell System Technical Journal has an issue devoted to explaining
original cellular technology. As mentioned, the Penn Central
Metroliner train phones had an early method of automatic seamless
handoffs from one tower to the next and selecting an empty channel,
including special provisions for the Baltimore Tunnels.