- Initialism of Telecommunications Device for the Deaf.
- (computer science) Initialism of Test Driven Development.
tdd - Computer Definition
- Time-Division Duplex. A means of providing bidirectional communications in digital wireless networks, such as cellular networks.TDD typically is used in conjunction with frequency-division duplex (FDD), with the forward and backward time division multiplexed (TDM) channels riding over separate frequency channels. Further, the time slots are staggered so the frequency-specific transceivers are not asked to transmit and receive at the same exact moments in time. See also cellular, digital, FDD, TDM, time slot, and transceiver.
- Telecommunications Device for the Deaf. In the United States, a printing telegraph service widely used by those with hearing or speech impairments. Also generically known as TTY (TeleTYpewriter), textphone in Europe, and minicom in the United Kingdom. TDDs use the Baudot code, also known as International Telegraph Alphabet #2 (ITA #2). See also Baudot code, telegraph, and teletype.
(1) (Telecommunications Device for the Deaf) See TDD/TTY.
(2) (Time Division Duplexing) A transmission method that uses the same channel for the uplink and downlink (transmit and receive), but separates them by time slots. In 1/1 TDD, downlink slots are interleaved equally with the uplink; a 2/1 TDD gives the downlink twice as many slots as the uplink. However, in a wireless application, power is a critical factor. For example, mobile phone antennas transmit less power than the cell tower antennas, and even a 1/1 TDD yields a lower uplink speed to the tower than the downlink speed from the tower. Contrast with FDD.