Figure 4-2 Mapping Overlapping Coverage Zones - Clear-Com ECLIPSE DIGITAL WIRELESS User Manual

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• The RSSI (signal strength) number will fluctuate, ranging from 0 to 55, as
you walk through the coverage area, and may even fluctuate as you stand
still. As a rule-of-thumb, you will obtain best system performance when the
signal strength remains at 30 or above. If the signal strength falls below 30,
you may start losing audio. This is the limit of the coverage zone.
• The ERR (error rate) number indicates packets of audio which are lost or
corrupted. When this number exceeds a few percent you may start hearing
audible audio breakup.
A beltpack can transmit to an antenna outdoors at an average distance of 125
meters when the beltpack has an unobstructed "line-of-sight" path to the
antenna. In ideal conditions, the range may be as high as 250 meters. Indoors,
a beltpack can transmit to an antenna at an average distance of 50 meters.
5. Draw a map of the coverage zone for the antenna. The coverage zone is the
area where the signal strength, as a rule-of-thumb, is 30 or above and the error
rate is below a few percent.
6. Repeat this process, one antenna at a time, for as many antennas as necessary
to cover the required area. Overlap coverage zones so that there is no area
where the signal strength is below 30, and no area where the error rate is above
a few percent.
7. You will need to adjust antenna placement to get the best coverage.
Zone A
1 User
Figure 4-2: Mapping overlapping coverage zones
In some environments you may observe that despite having a high signal
strength, the beltpack consistently reports a high error rate.
This could be due to two things:
• In-band interference from an RF source broadcasting in the DECT area of
the spectrum. This can be verified using a DECT band monitor (which
can be purchased from Vitec Group Communications), or by using a
Spectrum Analyser.
• Long Delay Spread Multipath, where the signal is bounced off a number of
reflective surfaces, such as metal ceilings, gantries, walkways or other large
structures. This problem is greatest where the reflective surface is large and
exists at a range of distances from the antenna. To resolve this problem,
consider siting the antenna where it cannot "see" the reflective surface,
installing a reflector close to the antenna between it and the reflective
surface, or purchasing directional antennas. Contact VGC customer
support for more information.
Zone C
Zone B
4 Users
5 Users
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