Japan and Korea (and most of Europe) are much more densely populated than the US. That makes wireless that covers most of the population much, much easier and therefore less expensive.
In addition, Europe has good cell phone service/coverage because their wired telephone service is very bad and expensive. When an alternative to the state run telephone services became available everyone flocked to them. That sent huge amounts of money into cellphone services which drove the technology.
I believe it was Motorola that invented the cellphone here in the US.
I believe it was Motorola that invented the cellphone here in the US.It wasn't until the microprocessor and the advancement of frequency synthesizers that that sort of technology was possible. And that has been within the last 35 years (I know; a lifetime for some people).
And Motorola was but only one of several contractors that built the original 'mobile cell phones' used in field trials performed by Bell in the late 70's into the 80's.
The January 1979 issue (Vol. 58, No. 1, Part 3) of "The Bell System Technical Journal" does an excellent job of describing the 'evolution' and development and test and first field trials of the first modern 'cellular system'.
Despite numerous attempts (filings by the Bell System in in 1947, 1949, 1958, 1968), it wasn't until 1971 that Bell addressed an inquiry from the FCC that a positive move towards allocating spectrum for mobile phone use in 1974. In 1975 Illinois Bell Telephone Company made a filing for authorization to test a developmental 'cellular' system in Chicago. This application was granted in March 1977.
The key to the cellular concept is small cells with spectrum re-use; prior to coming to grasp engineering- wise with determining what were accetable C/I issues in the radio link the thought was to assign dedicated frequnecies over a large area and avoide interference. WIth cellular, that interference is managed though something the system RF designers call 'frequency planning', and sometimes mismanaged, leading to problem areas and 'released' (Ericsson terminology) calls.
The "cell" idea was originally generated by a guy working for
Bell, AT&T or affilate thereof. If I remember correctly it was in the 60s or early 70s.