GE MDS iNET Series, Reference Manual

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Passive Scanning —Scanning is a process used by stations to detect other access points on network to which
it may connect if it needs to roam. Passive scanning is a slower process in which it listens for information
offered by the access points on a regular basis. Active scanning is a faster process in which the station sends
out probe message to which the access points respond. Passive scanning can be done while maintaining the
current network connectivity. Active scanning affects the RF configuration of the radio and therefore, at
least temporarily, disconnects the station from the access point.
PING— Packet INternet Groper. Diagnostic message generally used to test reachability of a network device,
either over a wired or wireless network.
Point-Multipoint System —A radio communications network or system designed with a central control sta-
tion that exchanges data with a number of remote locations equipped with terminal equipment.
Poll —A request for data issued from the host computer (or master PLC) to a remote radio.
Portability —A station is considered connected when it has successfully authenticated and associated with
an access point. A station is considered 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 authentica-
tion 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 settings. 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 main-
tained primarily by Simon Tatham Refer to http://www.pobox.com/~anakin/ for more information.
Remote —A transceiver in a network that communicates with an associated Access Point.
RFI —Radio Frequency Interference
Roaming —A station's ability to automatically switch its wireless connection 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 pro-
vided through an MAS radio system.
SNMP —Simple Network Management Protocol
SNR —Signal-to-Noise Ratio. A measurement of the desired signal to ambient noise levels.This measure-
ment provides a relative indication of signal quality. Because this is a relative number, higher
signal-to-noise ratios indicate improved performance.
SNTP —Simple Network Time Protocol
SSL —Secure Socket Layer