Practical_modern_SCADA_protocols_-_dnp3,_60870-5_and_Related_Systems

402 Practical Modern SCADA Protocols: DNP3, 60870.5 and Related Systems
G Giga (metric system prefix – 109).
Gateway
G.Lite
GMSS
GPRS
Ground
GSM
A device to connect two different networks which translates
the different protocols.
Most common ADSL standard based on ITU-T G.992.1
Geostationary Mobile Satellite Standard, a satellite air
interface developed from GSM.
General Packet Radio Service.
An electrically neutral circuit having the same potential as the
earth. A reference point for an electrical system also intended
for safety purposes.
Global System for Mobile communications, a.k.a.
Groupe Speciale Mobile. Mobile system that operates in the
900 or 1800 MHz band.
H.323 The UTU-T standard for Packet Based Multimedia
Communication Systems (VoIP).
Half-duplex
Hamming distance
Handshaking
HDLC
HDR
HDS
Hertz (Hz)
Hex
HFC
HLR
Host
HUMAN
Transmissions in either direction, but not simultaneously.
A measure of the effectiveness of error checking. The higher
the Hamming Distance (HD) index, the safer is the data
transmission.
Exchange of predetermined signals between two devices
establishing a connection.
High Level Data Link Control. The international standard
communication protocol defined by ISO to control the
exchange of data across either a point-to-point data link or a
multidrop data link.
High Data Rate a.k.a. 1xEV. A wireless Internet access
technology based on CDMA.
High-speed Digital Subscriber Line.
A term replacing cycles per second as a unit of frequency.
Hexadecimal. Numbering system to Base 16. 4-bit binary
numbers are represented by digits 0–9, A–F.
Hybrid Fiber Coax.
Home Location Register.
This is normally a computer belonging to a user that contains
(hosts) the communication hardware and software necessary to
connect the computer to a data communications network.
High speed Unlicensed Metropolitan Network.