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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. CPEs are the remote units in the BWS
system.
RF Radio Frequency. RF communication uses 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.
RF Center Frequencies EION Broadband Wireless Access Systems sometimes use two
center frequencies. The AP transmits on one and the CPEs transmit
on another.
RF Station ID This is a configurable number, from one to 2.048, that identifies
an AP or CPE to the network.
RSSI Received Signal Strength Indicator. Strength of received signal
expressed in dB. The Access Point measures RSSI as a fade margin
value.
S
Sensitivity The minimum signal strength required for usable performance,
expressed in dBm.
Shadowing Shadowing is a form of diffraction typically caused by antennas
being mounted too close to a structure, where they lose a portion
of the signal lobe due to reflection. The receiving antenna is in a
shadowed area. To minimize shadowing, mount the antenna
higher.
SNMP Simple Network Management Protocol. A protocol used to re-
motely manage a network element by polling, setting terminal
values, and monitoring network statistics and events. It is the de
facto internet work management standard, designed to provide a
mechanism for exchanging management information in a TCP/IP-
based Internet environment.
SNMP NMS Trap IP Address This is the address to which all the alarms and event messages are
sent.
Spectrum Analyzer An instrument that captures RF energy and displays its amplitude
and frequency on a screen.
Spread Spectrum (SS) Any of a group of modulation formats in which an RF bandwidth
much wider than the signal bandwidth is used to transmit data,
resulting in a greater immunity to noise interference.
Straight-Through Cable A straight-through cable is wired the same at both ends. That is,
pin one connects to pin one, pin two to pin two, and so on. Straight-
through cables are used to connect an IDU to a PC.
System Gain The maximum path loss that the system can support and produce
usable data transmission.
System Image File The Access Point uses system image files to store system config-
uration settings. The default system image file is called the factory
image and is used when the units are first powered up.
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Appendices