HN-291D
Glossary of Terms
Refer to the following list of terms that may be unfamiliar to you. These terms are used
throughout this document.
Term Definition
ARQ
Automatic Repeat Request. The operation in which the radio
will re-send the data until it is received correctly.
asynchronous
A form of communications that uses a start bit at the beginning
of each data word and a stop bit at the end of each data word. It
is called asynchronous because the start of the data word can
occur at any time and does not have to be determined by a clock
signal. However, once transmission begins, the remaining bits
of the data word are sent in time to a clock signal.
bps
Bits-per-second. A measure of information transfer rate of
digital data across a channel.
Decibel
A measure of the ratio between two signal levels. Used to
express either loss or gain.
dBi
Decibels referenced to an ideal isotropic radiator in free space.
Used to express antenna gain.
dBm
Decibels referenced to 1 milliwatt. An absolute unit used to
measure signal power. Transmitter power output or received
signal strength.
DCE
Data Communications Equipment. A device that receives data
in the form of digital signals at its input. The modem side of a
computer-to-modem connection.
DCD
Data Carrier Detect.
DTE
Data Terminal Equipment. A device that provides data in the
form of digital signals at its output. The computer side of a
computer-to-modem connection.
EIRP
Effective Isotropic Radiated Power.
FHSS
Frequency Hopping Spread Spectrum. An RF transmission
technology in which the transmitted signal “hops” from one
frequency to the next in discrete steps. The receiver must be
programmed to follow the transmitter’s frequency hops.
Full duplex
Communications that take place in both directions at the same
time.
©
2000- 2004 Cirronet
™
Inc
50
M-0910-0002 Rev B
