delay is equivalent to the reference delay, and relative delays are
equivalent to envelope-delay distortion.
Moreover, the primary delay is
equivalent to the secondary delay.
Primary delay = maximum initial line
delay - minimum initial line delay. Average
delay =
(5) Calculating relative delays.
Assume that the maximum initial
line delay is 1.675 ms at 600 Hz and the minimum is 0.325 ms at 2,000 Hz.
What are the primary delay, average delay, and relative delay?
Note that the upper relative delay is positive because it is larger
than average, while the lower relative delay is negative because it is
smaller than average.
The total variation permitted is established by
limits of the parameter () from average for the intended type of service.
(6) Calculating envelope-delay distortion.
The equalizing process
adds delay to make all delays at least equal to the longest initial line
delay (1.675 ms before equalization), and most of the time the process
causes all delays to be higher. For example, assume that after equalization
the maximum final line delay is 2.025 ms and the minimum is 1.975 ms. What
is the secondary delay, reference delay, and envelope-delay distortion?
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