Main article: History of mobile phones Analog Motorola DynaTAC 8000X Advanced Mobile Phone System mobile phone as of 1983.
In 1908, U.S. Patent 887,357 for a wireless telephone was issued in to Nathan B.
Stubblefield of Murray, Kentucky. He applied this patent to "cave radio" telephones and
not directly to cellular telephony as the term is currently understood. Cells for mobile phone base stations were invented in 1947 by Bell Labs engineers at AT&T and further developed by Bell Labs during the 1960s. Radiophones have a long and varied history going back to Reginald Fessenden's invention and shore-to-ship demonstration of radio telephony, through the Second World War with military use of radio telephony links and civil services in the 1950s, while hand-held cellular radio devices have been available since 1973. A patent for the first wireless phone as we know today was issued in US Patent Number 3,449,750 to George Sweigert of Euclid, Ohio on June 10, 1969.
In 1945, the zero generation (0G) of mobile telephones was introduced. Like othertechnologies of the time, it involved a single, powerful base station covering a wide area, and each telephone would effectively monopolize a channel over that whole areawhile in use. 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 U.S. Patent 4,152,647, issued May 1, 1979 to Charles A. Gladden and Martin H. Parelman, both of Las Vegas, Nevada and assigned by them to the United States Government.This is the first embodiment of all the concepts that formed the basis of the next major step in mobile telephony, the Analog cellular telephone. Concepts covered in this patent (cited in at least 34 other patents) also were later extended to several satellite
communication systems. Later updating of the cellular system to a digital system credits
this patent.Martin Cooper, a Motorola researcher and executive is widely considered to be the
inventor of the first practical mobile phone for hand-held use in a non-vehicle setting.
Cooper is the inventor named on "Radio telephone system" filed on October 17, 1973 with
the US Patent Office and later issued as US Patent 3,906,166.[4] Using a modern, if
somewhat heavy portable handset, Cooper made the first call on a hand-held mobile phone
on April 3, 1973 to a rival, Dr. Joel S. Engel of Bell Labs The first commercial citywide cellular network was launched in Japan by NTT in 1979.
Fully automatic cellular networks were first introduced in the early to mid 1980s (the 1G
generation). The Nordic Mobile Telephone (NMT) system went online in Denmark, Finland,
Norway and Sweden in 1981.
Personal Handy-phone System mobiles and modems used in Japan around 1997-2003In 1983,
Motorola DynaTAC was the first approved mobile phone by FCC in the United States. In 1984, Bell Labs developed modern commercial cellular technology (based, to a large extent, on the Gladden, Parelman Patent), which employed multiple, centrally controlled base stations (cell sites), each providing service to a small area (a cell). The cell sites would be set up such that cells partially overlapped. In a cellular system, a signal between a base station (cell site) and a terminal (phone) only need be strong enough to reach between the two, so the same channel can be used simultaneously for separate conversations in different cells.
Cellular systems required several leaps of technology, including handover, which allowed a conversation to continue as a mobile phone traveled from cell to cell.
This system included variable transmission power in both the base stations and the telephones (controlled by the base stations), which allowed range and cell size to vary. As the system expanded and neared capacity, the ability to reduce transmission power allowed new cells to be added, resulting in more, smaller cells and thus more capacity. The evidence of this growth can still be seen in the many older, tall cell site towers with no antennae on the upper parts of their towers. These sites originally created large cells, and so had their antennae mounted atop high towers; the towers were designed so that as the system expanded—and cell sizes shrank—the antennae could be lowered on their original masts to reduce range.
