User's Manual

MDS 05-6302A01, Rev. A MDS Mercury 16E Technical Manual 63
ered authenticated when it has agreed with the access point on the type
of encryption that will be used for data packets traveling between them.
The process of association causes a station to be bound to an access
point and allows it to receive and transmit packets to and from the access
point. In order for a station to be associated it must first authenticate
with the access point. The authentication and association processes
occur automatically without user intervention.
Portability refers to the ability of a station to connect to an access point
from multiple locations without the need to reconfigure the network set-
tings. For example, a remote transceiver that is connected to an access
point may be turned off, moved to new site, turned back on, and,
assuming the right information is entered, can immediately reconnect to
the access point without user intervention.
PLC—Programmable Logic Controller. A dedicated microprocessor
configured for a specific application with discrete inputs and outputs. It
can serve as a host or as an RTU.
PuTTY—A free implementation of Telnet and SSH for Win32 and
Unix platforms. It is written and maintained primarily by Simon Tatham
Refer to http://www.pobox.com/~anakin/ for more information.
Remote—A transceiver in a network that communicates with an asso-
ciated Access Point.
RFI—Radio Frequency Interference.
Roaming—A station's ability to automatically switch its wireless con-
nection between various access points (APs) as the need arises. A station
may roam from one AP to another because the signal strength or quality
of the current AP has degraded below what another AP can provide.
When two access points are co-located for redundancy, roaming allows
the stations to switch between them to provide a robust network.
Roaming may also be employed in conjunction with Portability where
the station has been moved beyond the range of the original AP to which
it was connected. As the station comes in range of a new AP, it will
switch its connection to the stronger signal. Roaming refers to a station's
logical, not necessarily physical, move between access points within a
specific network and IP subnet.
RSSI—Received Signal Strength Indicator.
RTU—Remote Terminal Unit. A data collection device installed at a
remote radio site.
SCADA—Supervisory Control And Data Acquisition. An overall term
for the functions commonly provided through an MAS radio system.