Cisco Prisma II Installation Manual page 172

Glossary
O
OMI
optical modulation index, expressed in decimal or percentage notation.
OPM
optical pluggable module.
P
PLL
phase lock loop. An electronic servo system controlling an oscillator to maintain a constant
phase angle relative to a reference signal.
Q
QAM
quadrature amplitude modulation. An amplitude and phase modulation technique for
representing digital information and transmitting that data with minimal bandwidth. Both
phase and amplitude of carrier waves are altered to represent the binary code. By
manipulating two factors, more discrete digital states are possible and therefore larger binary
schemes can be represented.
R
RF
radio frequency. The frequency in the portion of the electromagnetic spectrum that is above
the audio frequencies and below the infrared frequencies, used in radio transmission systems.
RMA
return material authorization. A form used to return products.
RT
remote terminal. Remote equipment of a supervisory system.
RX
receive or receiver.
S
SBS
stimulated Brillouin scattering. The easiest fiber nonlinearity to trigger. When a powerful
lightwave travels through a fiber, it interacts with acoustical vibration modes in the glass.
This causes a scattering mechanism to be formed that reflects some of the light back to the
source.
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