MDS 05-3301A01, Rev. C
MDS 9810 Installation and Operation Guide
11
4. Multiple MDS 9810 systems can co-exist in proximity to each other
with only very minor interference as long as they are each assigned
a unique network address. Each network address has a different hop
pattern.
5. If constant interference is present in a particular frequency zone, it
may be necessary to “lock out” that zone from the radio’s hopping
pattern. The radio includes built-in software to help users identify
and remove blocked frequency zones from its hopping pattern. Refer
to the discussion of
ZONE DATA
(Page 49) and
SKIP
(Page 46) com-
mands for more information.
6. If interference problems persist even after removing blocked zones,
try reducing the length of data streams. Groups of short data streams
have a better chance of getting through in the presence of interfer-
ence than do long streams.
7. The power output of all radios in a system should be set for the low-
est level necessary for reliable communications. This lessens the
chance of causing unnecessary interference to nearby systems.
3.4 Antenna & Feedline Selection
Antennas
The equipment can be used with a number of antennas. The exact style
used depends on the physical size and layout of a system. Contact your
MDS representative for specific recommendations on antenna types and
hardware sources.
In general, an omnidirectional antenna (Figure 10) is used at the master
station site in an MAS system. This provides equal coverage to all of the
remote sites.
NOTE:
Antenna polarization is important. If the wrong polarization is
used, a signal reduction of 20 dB or more will result. Most
systems using a gain-type omnidirectional antenna at the
master station employ vertical polarization of the signal; there-
fore, the remote antenna(s) must also be vertically polarized
(elements oriented perpendicular to the horizon).
When required, horizontally polarized omnidirectional
antennas are also available. Contact your MDS representative
for details.
