Time division duplex
Time division duplex
(also TDD)
Time division duplex definition
Time division duplex (TDD) refers to a wireless communication technology that allows for the transmission of both upstream and downstream data on the same frequency channel, using different time slots.
Time division duplex is similar to other telecommunication techniques such as time division multiplexing (TDM) and frequency division duplex (FDD) but they differ in how they allocate bandwidth for upstream and downstream communication. TDD uses time slots on a single frequency channel, TDM uses time slots on a shared transmission line, and FDD uses separate frequency channels for upstream and downstream communication.
See also: time-division multiplexing
Types of time division duplex:
- Synchronous TDD. The time slots for upstream and downstream data transmission in synchronous TDD are fixed and synchronized across all devices in the network. This helps prevent interferences between the upstream and downstream data transmissions, as each device knows when it is supposed to transmit and receive data.
- Asynchronous TDD: Here, the time slots for upstream and downstream data transmission are not fixed or synchronized across all devices in the network. Instead, devices transmit and receive data whenever they have data to send, and the time slots may vary depending on network traffic and other factors.