3
rd
Generation Rack-
Mount RDMS™
65
Quasonix, Inc.
•
Bright green
–
Best signal; this signal has the highest data quality of all correlating signals, and its quality
is directly reflected in the BCS quality bar
•
Green
–
Good signal; this signal correlates sufficiently to the best signal to participate in best-channel
selection, but its data quality is not highest
•
Red
–
Bad signal; this signal does not correlate sufficiently to the best signal to participate in best-channel
selection
•
Grey
–
Disabled signal; the BCS is set to Off
The preceding descriptions may seem to imply a static state for each channel. In reality, channel dynamics including
noise, may cause fairly rapid changes in BCS state. The BCS indicator shows a snapshot of the current status
multiple times per second, but may not reflect every state transition in a highly dynamic environment. In addition,
Signal Quality updates are not necessarily synchronized. Thus, as channel conditions change, there may be brief
times when Combiner data quality appears to exceed BCS data quality. On average, BCS data quality will always
equal, or exceed, Combiner (and Channel 1 and Channel 2) data quality.
In general, the Combiner is expected to be the best channel. However, many conditions may lead to selection of
Channel 1 or Channel 2 as the best channel. One common condition is multipath. Another common
—
and less
intuitive
—
condition is absence of any signal impairment. In this case, all
channels have essentially “perfect” signal
quality, so the BCS cannot distinguish one that is “best” and will simply stick with its current selection until
something changes. Similarly, if no signal is present, the BCS may pick any channel as “best” thoug
h none are good.
When the BCS status display indicates the Combiner is the best signal, the BCS and Combiner Signal Quality bars
indicate equal quality for the BCS and for the Combiner. When the BCS status display indicates Channel 1 or
Channel 2 is the best signal, the BCS Signal Quality bar indicates better data quality for the BCS than for the
Combiner. This difference highlights the improvement provided by the BCS relative to Combiner data alone.
Figure 96 illustrates a good signal for Channel 1 and Channel 2, with the best signal being selected from the
Combiner.
Figure 96: Best Channel Indicator-Combiner
Figure 97 illustrates a good signal for the Combiner and Channel 2, with the best signal being selected from Channel
1. This is an
example of all channels being essentially “perfect.”
