Wi-LAN Hopper Plus 120-24 Installation And Configuration Manual page 173

overhead
Anything that reduces the payload capacity of a system is overhead, even if it serves a
useful function. The link monitor data is used to determine transmission statistics, but it
reduces the message carrying capacity of a wireless link 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 impact the system performance.
PN
Pseudo-random noise. A code used to change a narrowband signal into a spread
spectrum signal.
polarization
The orientation of the radiating element of an antenna with respect to earth. The
polarizaiton of antennas is usually described as being vertical, horizontal or circular.
point-to-multipoint
A wireless system where one base unit communicates with many remote units. The base
unit polls all the remotes and data passes between units to complete the network.
point-to-point
The simplest wireless system consisting of a base and one remote.
polling
The base unit in a Hopper Plus 120-24 point-to-multipoint system handles multiple
remotes by polling each one sequentially. When a base polls a remote, data exchange
between that remote and the base takes place. The remote cannot exchange information
with the base until it is polled again.
propagation loss
The signal loss experienced as it travels through the air. Expressed in dB.
R
RF
Radio Frequency. A system of communication using electromagnetic waves propagated
through space. Because of varying characteristics, radio waves of different lengths are
used for different purposes and are usually identified by their frequency.
remote unit
A unit that can communicate with a base station or other remote units. A remote unit
forms a wireless link between a network segment and a base station.
repeater base
A repeater base rebroadcasts packets received from a remote unit to other remote
units. Remote units that cannot see each other (do not have LOS) can communicate
through a repeater base.
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