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Glossary of broadband terminology: Q to R

Quadrature Amplitude Modulation: A modulation technique used by modems and DSL equipment in which a carrier's amplitude and phase are simultaneously modulated by the digital traffic.
Radio Frequency Interference: Radio frequency is the electromagnetic spectrum from 3 KHz to 300 GHz.
RADSL: Rate Adaptive ADSL
Rate Adaptive Digital Subscriber Line: A version of DSL where the modems test the line at start up and adapt their operating speed to the fastest the line can handle.
ADSL modems that are able to adjust to varying lengths and qualities of lines are said to be rate adaptive. Unlike fixed rate ADSL modems, these modems will connect over varying lines at varying speeds, making them a good choice for service providers attempting to deploy ADSL past 18,000 feet. Modems can be designed to select their connection speed at train up, during a connection, or upon signal from the central office.
Reed Solomon: A forward error correcting code that is used to offset the effects of bit error bursts in the receive-bit stream.
Regional Bell Operating Company: An all-inclusive term for each of the seven telephone companies which were created after AT&T's divestiture.
Remote Terminal: Local loop terminates at remote terminal intermediate points closer to the service user to improve service reliability.
Remote Termination Unit: A device installed at the service user site that connects to the local loop to provide high-speed connectivity. Also referred to as the ATU-R.
Resource Reservation Protocol: A reservation setup protocol for the Internet.
Reverse ADSL: A term for a DSL stream that is asymmetrical in the upstream direction; that is, a reverse ADSL link has a small downstream and large upstream communications path.
RJ-11: Six-conductor modular jack used with four-wire cabling. Most common phone jack in the world and is used commonly on phones, modems, and fax machines.
RJ-45: Eight-pin connector used to attach data transmission devices to standard telephone wiring. Commonly used in 10Base-T connections.
Router: The device that connects multiple computer networks by reading layer three addressing on incoming and outgoing packets. Packet information is read and the packets are then forwarded to the appropriate end station.