User's Manual

136 BreezeMAX CPEs Product Manual
Glossary
PPPoE Point-to-Point Protocol over Ethernet. PPPoE relies on two widely
accepted standards: PPP and Ethernet. PPPoE is a specification for
connecting the users on an Ethernet to the Internet through a
common broadband medium, such as a single DSL line, wireless
device or cable modem. All the users over the Ethernet share a
common connection, so the Ethernet principles supporting multiple
users in a LAN combines with the principles of PPP, which apply to
serial connections.
QAM Quadrature Amplitude Modulation. A technique used in wireless
applications to double the available bandwidth by combining two
amplitude-modulated signals. The two combined signals differ in
phase by 90 degrees; this technique doubles the bandwidth by
combining the two signals at the source before transmission,
transmitting digital data at a rate of 4 bits per signal change.
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.
RSSI Received Signal Strength Indicator. A signal or circuit that indicates
the strength of the incoming (received) signal in a receiver.
R&TTE Radio & Telecommunications Terminal Equipment. The R&TTE
Directive 1999/5/EC governs the marketing and use of R&TTE
equipment. With the exception of a few categories of equipment, the
Directive covers all equipment, which uses the radio frequency
spectrum. It also covers all terminal equipment attached to public
telecommunication networks.