RLX2-IHx Series ♦ 802.11a, b, g, n
Glossary of Terms
Industrial Hotspots
User Manual
ProSoft Technology, Inc.
Page 242 of 248
EIRP
Equivalent isotropically radiated power
(EIRP) is the amount of power that would have to
be emitted by an isotropic antenna (that evenly distributes power in all directions and is a
theoretical construct) to produce the peak power density observed in the direction of
maximum antenna gain.
Encryption
Method of scrambling data so that only the intended viewers can decipher and
understand it.
F
Firmware
Firmware is the embedded software code that that runs in hardware containing a CPU
(similar to the BIOS in a personal computer). This is distinguished from the IH Browser
software that is installed on the Configuration PC.
Fresnel Zone
An elliptical area on either side of the straight line of sight that must also be clear for a
long-range wireless network to work.
Full-Duplex
A communications circuit or system designed to simultaneously transmit and receive two
different streams of data. Telephones are an example of a full-duplex communication
system. Both parties on a telephone conversation can talk and listen at the same time. If
both talk at the same time, their two signals are not corrupted.
G
Gain, Antenna
The amount by which an antenna concentrates signal strength in a wireless network.
Gateway
In wireless terms, a gateway is an access point with additional software capabilities such
as providing NAT and DHCP and access to a Wide Area network (WAN), Internet or
other main network.
Guard Interval (GI)
An interval of time between data symbols during transmission. The guard interval time
for 802.11a/b/g systems is fixed at 800 microseconds. 802.11n devices can also use a
400 microsecond guard interval, falling back to 800 microseconds if excessive data
corruption is detected.
H
Half-Duplex
A communications circuit or system designed to transmit and receive data, but not both
simultaneously. CB or walkie-talkie radios are an example of a half-duplex
communication system. Either parties on a radio conversation may talk or listen; but both
cannot talk at the same time without corrupting each other's signal. If one operator is
sending, the other must be receiving to have successful communication.