SMC Networks D3USG Manual De Usuario
ANSI C63.17-2006
Methods of Measurement of the Electromagnetic and Operational Compatibility of UPCS Devices
not exceed 50 ppm, not including a shift of the mean. Each EUT that further divides access in time shall
maintain a frame-repetition rate whereby three times the standard deviation of the frequency stability shall
not exceed 10 ppm, not including a shift of the mean.
maintain a frame-repetition rate whereby three times the standard deviation of the frequency stability shall
not exceed 10 ppm, not including a shift of the mean.
6.2.3
Table 9
Frame period and jitter
A demodulating spectrum analyzer, modulation analyzer, or frequency- and time-interval analyzer is
configured as follows in Table 9 for frame period and jitter measurements.
configured as follows in Table 9 for frame period and jitter measurements.
—Measurement system configuration for frame period and jitter test
Y axis
Time
Center time
Frame period
Time span
Span large enough so that the full waveform is greater
than 50% but less than 100% of the display scale.
than 50% but less than 100% of the display scale.
X axis
Time
Time setting
Approximate frame period × 100
Measurement time interval
(gating time)
(gating time)
< Frame period (must be able to measure time interval
between rising edge of one pulse to the rising edge of the
next pulse within a resolution of 100 ns)
between rising edge of one pulse to the rising edge of the
next pulse within a resolution of 100 ns)
Number of measurements
100 000 frames total accumulated
Compute the histogram of the frame period distribution with small or negligible latency time between
measurements.
When the accumulated number of measurements reaches 100 000, record the peak-to-peak, mean, and
standard deviation values.
The mean value shall be the frame period and shall be 20 ms or 10 ms/X, where X is a positive integer.
Three times the standard deviation value of the jitter shall not be greater than 12.5 µs. Alternatively, jitter
can be measured by using the analyzer to obtain the time duration between rising edges; use a computer to
compute the difference between two consecutive frame periods. The difference between any two
consecutive frame periods, measured over 100 000 frames, shall not exceed 25 µs.
Deviation of the mean frame period from 20 mS or 10 mS/X shall be subtractive from the allowable jitter.
7.
7.1
Monitoring tests
Introduction
The spectrum sharing rules require that EUTs monitor their intended channel (time and spectrum window)
prior to transmission to sense RF energy in the channel. If there is RF energy above the monitoring
threshold,
prior to transmission to sense RF energy in the channel. If there is RF energy above the monitoring
threshold,
the EUT must either defer transmission until the channel is clear or select another clear
channel. The monitoring tests in this subclause verify that the monitor levels, monitor timing, and deferral
operation are in accordance with the spectrum sharing rules.
operation are in accordance with the spectrum sharing rules.
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See the calculation in 7.2.1 for details.
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