Hirschmann BAT 11b, Руководство по управлению

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Glossary
116
BAT 11b
Release 1.0 03/04
• ESS
The Extended Service Set refers to several BSS (several access
points) which form a single virtual wireless network.
• FHSS, Frequency Hopping Spread Spectrum
Frequency spread is attained in a FHSS system by means of con-
tinuously changing frequencies, which are altered according to
specific hopping patterns. In contrast to DSSS systems, there are
no fixed frequencies, but definable hopping patterns. The fre-
quency is frequently changed within one second.
• Firmware
Software code which contains all functions of a device. This code
is written in a PROM (Programmable Read-Only Memory) and is
stored there even after switching off the device. The firmware can
be upgraded by the user if a new software version is available
(firmware upgrade).
• IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a
worldwide cooperation of engineers. It is continuously develop-
ing and improving standards to ensure the connectivity and
interoperability of the most diverse devices.
• IEEE802.11b
One of the IEEE standards for wireless network hardware. Prod-
ucts corresponding to the same IEEE standard are able to commu-
nicate with each other, even if they were produced by different
hardware manufacturers. The IEEE802.11b Standard specifies
data rates of 1, 2, 5.5, and 11 Mbps, a working frequency in the
range of 2.4 to 2.4835 GHz, and WEP encryption. IEEE802.11 wire-
less networks are also referred to as Wi-Fi networks.
• Infrastructure Mode
A network in the infrastructure mode is a network which contains
at least one access point as communications and control center.
In a network in the infrastructure mode, all clients will exclusively
communicate with each other over access points. There is no
direct communication between the individual clients. Such a net-
work is also referred to as BSS (Basic Service Set). A network
which consists of several BSSs is called ESS (Extended Service
Set). Most wireless networks work in the infrastructure mode to
set up connections to the wired network.