SEA 7157, Operator'S Manual, Page: 46 / 49

GLOSSARY
41
DEFINITIONS
This manual assumes basic VHF radiotelephone knowledge. Below are
definitions of acronyms used in the operating instructions.
ACK : Shorthand for ACK nowledge.
AF : A udio F requency.
B.E.R. : B it E rror R ate is an accuracy measurement for data transmissions.
CCITT : I nternational T elegraph and T elephone C onsultative C ommittee is an
ITU agency which helps define standards.
dB : d eci (1/10) B ell. A logarithmic unit of measurement in relation to one Bell.
DSC : D igital S elective C alling is an advanced signaling system.
DUPLEX : A channel using different transmit and receive frequencies.
F1B : Emission designation for F requency modulation using a single channel of
digital information to modulate the carrier ( 1 ) with telegraphy type information
( B ) for automatic reception. May be followed with FEC for Forward Error
Correction, ARQ for Automatic Repeat reQuest, or TTY for TeleType.
F3E : Emission designation for F requency modulation using a single channel of
analog information to modulate the carrier (
3
) with telephony type information
( E ). This may be followed with SPX for simplex channel or DPX for duplex.
FAX : FA csimile X mission.
FCC : F ederal C ommunications C ommission.
FM : F requency M odulation of the carrier signal.
FSK
: F requency S hift K eying is a method of modulating the carrier.
GMDSS : G lobal M aritime D istress and S afety S ystem.
GMT : G reenwich M ean T ime is the same as UTC located at the prime meridian.
GPS
: G lobal P ositioning System .
ITU : I nternational T elecommunications U nion.
KHz : K ilo (thousand) H ert z .
LCD
: L iquid C rystal D isplay.
LORAN-C : LO ng RAN ge positioning system.
MMSI : M aritime M obile S ystem I dentification. Similar to a telephone number,
this number is unique to every DSC station.
MHz : M ega (million) H ert z . Typically used when referring to the frequency
assigned to a channel such as ‘CH 16’s frequency is 156.8 MHz.’
MODEM : A device for data that is both a MOD ulator and DEM odulator.
NMEA : N ational M arine E lectronics A ssociation.
PPM : P arts P er M illion.