Direct sequence is a method of
spread spectrum radio communications which spreads
data over several bands of
radio frequency. This can accomplish
one of
two things: firstly, this can be used in the same manner as
RAID striping mode; that is, each
channel may be used to send different
data, and the
receiver may be forced to put it all together at the end. Secondly, it may be used in the same manner as
RAID mirroring; that is to say that each
channel may have the same
data transmitted, and the
receiver must decide, from all the
symbols received, what the
transmitter was trying to send.
Both of these methods require multiple
tuners and
transmitters, making them expensive. Neither is more secure than standard singleband
radio communications. Redundant method can be more
interference-resistant than
frequency-hopping, but still is nowhere near as secure. Striped method can be as many times faster than
frequency-hopping or redundant method as there are
tranceivers. This makes excellent use of limited RF
bandwidth, but is extremely vulnerable to
interference.
see also:
frequency-hopping.