User Guide: Technical Reference APPENDIX B GLOSSARY OF TERMS
PRELIMINARY
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B-8
signal.
Path Length
The distance between two ends of a wireless system.
Path Loss
The decrease in signal power experienced when a signal is transmitted between
two points.
Path Profile
A drawing of the terrain including buildings, trees, hills, lakes, etc. along a
transmission path to determine if a given path is viable for the communication link.
Usually done with a computer.
Personal Communication
Services (PCS)
A lower powered, higher frequency competitive technology to cellular.
Point-to-Point Protocol
(PPP)
A method of connecting to a network that provides error checking features.
Polarization
The direction of the amplitude of a radio wave. Polarization is usually horizontal or
vertical.
Power Output
The power produced by a transmitter. Measured in dBm.
Propagation
The transmission of a wave along a given path through a medium.
Pseudo-random Noise
code (PN code)
A high rate digital code that mimics random noise-like properties. It is multiplied
with a lower rate data signal in order to achieve spread spectrum transmission
signals. The receiver then multiplies the same code back into the transmission to
recover the data signal.
Public Switched Telephone
Network (PSTN)
Refers to a worldwide voice telephone network accessible to all those with
telephones and access privileges.
Q
QPSK
Quadrature Phase Shift Keying
R
Radiation
The flow of electromagnetic energy from a transmitter.
Radiation Pattern
An illustration of the energy level radiated by an antenna in every direction.
Radio Frequency (RF)
The frequency at which microwave systems transmit.
Received Signal Strength
Indicator (RSSI)
The RSSI voltage is used to determine the RF Input Level.
Reflection
The sharp change in direction of a wave after hitting an obstruction in its path.
