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(solid-state physics)



(1) (Metal Oxide Semiconductor) See MOSFET.

(2) (Mean Opinion Score) The quality of a digitized voice line. It is a subjective measurement that is derived entirely by people listening to the calls and scoring the results from 1 to 5. Toll quality audio is generally considered to have a MOS rating of 4 and above.

The MOS is an average of the numbers for a particular codec. Because MOS testing requires carefully prepared and controlled test conditions, the best way to get a MOS test done is to have it outsourced. See codec.

An Objective Model
The E-Model is another rating system that provides an objective measurement of quality based on packet loss, jitter and delay. The E-Model reports results as R-values. Following is an approximate relationship between MOS and E-Model quality ratings.

Subjective Interpretation         MOS  R

 Perfect                           5.0 100

 Excellent - almost all satisfied  4.5  90

 Very good - most are satisfied    4.0  80

 Good - some are dissatisfied      3.6  70

 Fair - many are dissatisfied      3.1  60

 Poor - most are dissatisfied      2.6  50

 Bad - not recommended             1.0   0
References in periodicals archive ?
This leads up to the current state and prospects of MOS 251A.
What remains to close out is MOS 254A, Signal Systems Support Technician and MOS 255Z, Senior Signal Systems Technician; both created in 2000 though not effected MOS until April 2003.
A temporary suspension of the language requirement for promotion eligibility for all MOS 97E Soldiers at all grades.
Only a limited number of MOS 97E Soldiers will reclassify to MOS 97B until the MOS 97E strength is at or near 90 percent.