The desire for communication anywhere, any place has created a proliferation of interest in digital cellular phones. This paper covers the evolution of the worldwide cellular standards from the 1st generation analog cellular standards (such as AMPS, TACS, NMT) to the 2nd generation digital cellular standards (such as GSM, CDMA, TDMA, PDC, and so on) including the PCS standards. Part 1 of the paper covers the basics of the analog and digital cellular telephony. With a brief overview of the analog cellular standards, the paper starts to build upon the 2nd generation digital cellular standards including the transceiver chain budget specification and a representative implementation with a few examples. The paper also gets into the digital modulation technique, forward error correction mechanism, multiple access Scheme (FDMA/TDMA/CDMA), and diversity scheme in today’s digital cellular standards. The readers will get an understanding and insight into the present-day cellular standards, air interface, layer-1 implementation issues, and the future course of the cellular standard.