Microwave Data Systems MDS entraNET 900, System Manual

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106 MDS entraNET 900 System Guide (Preliminary) MDS 05-4055A01, Rev. A
signal strength that may occur from time-to-time. RSSI can be measured
with a terminal connected to the
COM1
Port or with a HTTP browser to
the
LAN
(Ethernet) connector. ( See “Antenna Direction Optimization”
on Page 97 for details.)
5.1.4 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 5-4 ) is used at the Access
Point station site. This provides equal coverage to all of the Remote
Gateway 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
Access Point station employ vertical polarization of the signal;
therefore, the remote antenna(s) must also be vertically polar-
ized (elements oriented perpendicular to the horizon).
When required, horizontally polarized omnidirectional
antennas are also available. Contact your MDS representative
for details.
Invisible place holder
Figure 5-4. Typical Omnidirectional Antennas
At Remote Gateway sites and units in point-to-point LANs, a directional
Yagi (
Figure 5-5 ) antenna is generally recommended to minimize inter-
ference to and from other users. Antennas are available from a number
of manufacturers.
High-gain Type
Unity-gain Type