System for digital cellular service that increases capacity by multiplexing, or time-slicing, a radio signal. TDMA improves cellular calling capacity by 300%, and improves security because it cannot be picked up :in the clear” by an ordinary radio. Note: The U.S. cellular industry has endorsed TDMA as its choice for cellular upgrades, and some TDMA systems are being installed in major markets. All these TDMA systems are “dual standard” equipment, so analog phones, cell sites, and switches work in TDMA networks.