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K
KA Band
Satellite
communications systems transmit signals from earth stations to satellites
located in space. Antennas located on the earth are pointed at the
geostationary satellite (also called geosynchronous) and microwave signals
are sent up to the satellite (uplink) where the satellite repeats the
signal and sends it down (downlink) to a remote receiving antenna. There
are three frequency ranges that satellite systems use, C band (4GHz
downlink, 6GHz uplink), KU band (11GHz downlink, 14GHz uplink) and KA band
(20GHz downlink, 30GHz uplink).
KU Band
See KA
band above.
Kbps
The bit rate is
the number of bits transmitted per second (bps). For instance, commonly
used rates for modem speeds are 300bps, 1200bps, 9600bps, 14,400bps, and
19,200bps. Another way of writing 19,200bps is 19.2Kbps. Kbps stands for
kilobits per second which would mean 1000 bits transmitted per second times
19.2. 1.544Mbps is the T1 rate and is 1,544,000 bps.
Kermit
Kermit is a once
popular asynchronous PC file transfer protocol used for communications
between PCs and from PCs to mainframes. It has been superseded by other
protocols such as ZModem.
Keyboard Control Characters
Control
characters are ASCII characters such as carriage return (CR) and line feed
(LF). They are non-printable characters used for control of the flow of
data or the format of data. They are entered from keyboards by holding down
the control key while simultaneously pressing another key. For instance
holding down the control key and pressing M and J keys produces the
carriage return and line feed control characters.
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