TDD
Time Division Duplex
A general method for two-way communication where devices at each end of a connection "take turns" transmitting on the same channel.
In radio networks like cellular phone networks, this means taking turns transmitting on the same radio frequency. Typically, the "turns" are so rapid - hundreds or thousands per second - that a human could not possibly notice them during a voice phone call, for example.
TDD was once rare for phone networks, but has become more common, particularly with newer, higher frequency bands.
The alternative to TDD is FDD, where two separate frequencies are used for communication in each direction.
See: FDD
FDD requires paired radio spectrum.
See: Paired Band
Last updated Sep 8, 2022 by Rich Brome
Editor in Chief Rich became fascinated with cell phones in 1999, creating mobile web sites for phones with tiny black-and-white displays and obsessing over new phone models. Realizing a need for better info about phones, he started Phone Scoop in 2001, and has been helming the site ever since. Rich has spent two decades researching and covering every detail of the phone industry, traveling the world to tour factories, interview CEOs, and get every last spec and photo Phone Scoop readers have come to expect. As an industry veteran, Rich is a respected voice on phone technology of the past, present, and future.
