ABSTRACT
Quality is a moving target. When the role of the telecommunications network was to transport analog voice signals, quality was a relatively simple issue. Good quality meant affirmative responses to the questions: (a) When 1 pick up the telephone do I usually get dial tone? (b) Does the call go through promptly? or (c) When I reach the called party can the conversation be clearly heard? These subjective standards could be passed even under circumstances in which quantitative technical measurements would have shown that significant signal distortion, delay, and noise interference were present.
