User's Manual

Glossary
4Motion 920 System Manual
PICMG The PCI Industrial Computers Manufacturer's Group is a consortium of over 450
industrial computer product vendors. PICMG's charter is to develop specifications for
PCI-based systems and boards for use in industrial computing applications. PICMG
2.x series is a specification for PCI-based equipment that combines the power of low
cost PCI silicon and software with the rugged Eurocard packaging.
PIM Protocol Independent Multicast. A protocol-independent multicast routing protocol.
PIM sparse mode routes to multicast groups that might span wide-area and
interdomain internets. PIM dense mode is a flood-and-prune protocol.
PIU Power Interface Unit
PKM Privacy Key Management. The key management protocol used in 802.16 to obtain
the needed authorization to use the media. PKM protocol operates in two phases:
AK (Authorization Key) phase, and TEK (Traffic Encryption Keys). AK represents the
secret key used to obtain TEK in the exchanges between MS and BS in subsequent
phases.
PSU Power Supply Unit
PUSC Partial Usage of Sub-Channels
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.
RET Remote Electrical Tilt
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.