The development of metal-oxide-semiconductor (MOS) large-scale integration (LSI) technology, information theory and cellular networking led to the development of affordable mobile communications. The first call on a handheld mobile phone was made on April 3, 1973 by Martin Cooper, then of Motorola to his opposite number in Bell Labs who were also racing to be first. Bell Labs went on to install the first trial cellular network in Chicago in 1978. This trial system was licensed by the FCC to ATT for commercial use in 1982 and, as part of the divestiture arrangements for the breakup of ATT, the AMPS technology was distributed to local telcos. The first commercial system opened in Chicago in October 1983. A system designed by Motorola also operated in the Washington D.C./Baltimore area from summer 1982 and became a full public service later the following year. Japan's first commercial radiotelephony service was launched by NTT in 1979.