Abbreviation for Fahrenheit. Measure of temperature where pure water freezes at 32° and boils at 212°.

Abbreviation for tera. One trillion or 1012.

Abbreviation for Watt. A linear measurement of optical power, usually expressed in milliwatts, microwatts, and nanowatts.

Half-duplex Transmission: bidirectional link that is limited to one-way transfer of data, i.e., data cannot be sent both ways at the same time. Also referred to as simplex transmission.