Q

 

QAM (Quadrature Amplitude Modulation): QAM is method for encoding data on a single carrier frequency. The modulation encodes data (or bits) as discrete phase plus amplitude changes of a carrier tone. Cable modems and ADSL use QAM. With QAM, the carrier signal is split into two signals, shifted in phase by 90 degrees. Each component is modulated with ASK, using as many as 16 amplitude levels to represent as many as 256 different states (256-QAM).

Qualifying Facility (QF): A cogeneration or small power production facility that meets certain ownership, operating, and efficiency criteria established by the Federal Energy Regulatory Commission (FERC) pursuant to the Public Utility Regulatory Policies Act (PURPA).  [DOE Glossary of Electricity Terms]

Quality of Service (QoS): A parameter specifying the level of performance needed for communications, such as transit delay, priority, accuracy, or reliability.

QuickTime: A video and sound format developed by Apple Computers that has become a standard on the Internet.