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OID nodes Object Identifier Nodes. These are the individual nodes in an MIB.
See SNMP and MIB.
Orthogonal An adjective that refers to the way the many carrier waves in a
OFDM system affect each other. The carriers are spaced in such
a way that the center frequency of each signal lies in the null spot
of its neighbors. This minimizes interference.
Overhead Anything that reduces the payload capacity of a system is overhead,
even if it is useful. Link monitor data determines transmission
statistics, but it reduces the message-carrying capacity of the sys-
tem and is considered overhead.
P
Path Loss The total loss from one end of the path to the other. This includes
propagation losses, cable losses, and any other losses that affect
the system performance.
Ping A method of testing a link. Executing the ping command sends a
signal to the remote station. The station returns the signal. If the
signal comes back on time and intact, the link works.
See Also
FTP .
Polarization The orientation of the radiating element of an antenna with respect
to Earth. The polarization of antennas is usually described as ver-
tical, horizontal, or circular.
PN Pseudo-random noise. A code used to change a narrowband signal
into a spread spectrum signal.
Point-to-Multipoint A wireless system with one base unit communicating with many
remote units. In the BWS system, the AP is the base and the CPEs
the remotes.
Point-to-Point The simplest wireless system, consisting of a base and a remote.
Polling The AP unit handles multiple CPEs by contacting them in the order
they appear in the polling list. When an AP polls a CPE, they ex-
change data. The CPE cannot exchange information with the AP
until it is polled again.
Polling List The order in which the AP contacts the CPEs in its sector.
Propagation Loss The weakening of a signal as it travels through the air. Expressed
in dB.
Q
QAM Quadrature Amplitude Modulation. A kind of modulation that
varies signal amplitude.
R
Reed-Solomon A way of accomplishing Forward Error Correction. Reed-Solomon
describes a data block in such a way that errors in the data block
can be detected and repaired without retransmission.
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Appendices