User's Manual

Glossary
BreezeMAX Modular Base Station System Manual 287
QoS Quality of Service. Measure of performance for a transmission
system that reflects its transmission quality and service availability.
QPSK Quadrature Phase Shift Keying. A data transfer technique used in
coaxial cable networks that sends data using modulating signals.
Four different phases represent data, with each signal's information
determined by the signal before it. For example, if a phase stays the
same from one signal to the other, the information has not changed.
RADIUS Remote Authentication Dial-In User Service, an authentication and
accounting system used by many Internet Service Providers (ISPs).
When you connect to the system you must enter your username and
password. This information is passed to a RADIUS server, which
checks that the information is correct, and then authorizes access to
the system.
RF Radio frequency. An AC signal of high enough frequency to be used
for wireless communications.
RFC Request For Comments. The name of the result and the process for
creating a standard on the Internet. New standards are proposed
and published on the Internet, as a Request For Comments. The
proposal is reviewed by the Internet Engineering Task Force.
RoHS Restriction of the use of certain Hazardous Substances in electrical
and electronic equipment, reference EC Directive 2002/95/EC of 27
January 2003.
RS-232 A serial interface published by the EIA (Electronic Industries
Association) for asynchronous data communication over distances
up to a few hundred feet. Characterized by a single-ended (not
differential) physical layer, it uses one signal wire for transmission,
another for reception, and a common wire (ground), plus some
timing and control signals.
RS-422 RS-422 is a serial interface standard in which data is sent in a
differential pair (two wires, or twisted pair cable), which allows
greater distances and higher data rates than non-differential serial
schemes such as RS-232.