User's Manual

05-4446A01, Rev. C Mercury Reference Manual 155
strength, it might be necessary to mount the station antennas higher, use
higher gain antennas, select a different site, or install a repeater station.
To prepare the equipment for an on-the-air test, follow the general
installation procedures given in this guide and become familiar with the
operating instructions found in the
CHAPTER-2 TABLETOP EVALUA-
TION AND TEST SETUP
on Page 19.
5.1.6 A Word About Radio Interference
The transceiver shares the radio-frequency spectrum with other
3650 MHz services and other Part 15 (unlicensed) devices in the USA.
Completely error-free communications might not be achievable in a
given location, and some level of interference should be expected. How-
ever, the radios flexible design and hopping techniques should allow
adequate performance as long as you carefully choose the station loca-
tion, configuration of radio parameters, and software/protocol tech-
niques.
In general, keep the following points in mind when setting up your com-
munications network:
¥ Systems installed in rural areas are least likely to encounter interfer-
ence; those in suburban and urban environments are more likely to
be affected by other devices operating in the license-free frequency
band and by adjacent licensed services.
¥ Use a directional antenna at remote sites whenever possible.
Although these antennas may be more costly than omnidirectional
types, they confine the transmission and reception pattern to a com-
paratively narrow lobe, minimizing interference to (and from) sta-
tions located outside the pattern.
¥ If interference is suspected from a nearby licensed system (such as a
paging transmitter), it might be helpful to use horizontal polarization
of all antennas in the network. Because most other services use ver-
tical polarization in this band, you can achieve an additional 20 dB
of attenuation to interference by using horizontal polarization.
Another approach is to use a bandpass filter to attenuate all signals
outside the 3650 MHz band.
¥ Multiple Access Point units can co-exist in proximity to each other
with no interference. The APs should be configured to operate in
TDD Sync Mode, where their transmissions are synchronized to
GPS timing.
See Protected Network Operation using Multiple
Access Points on Page 14
. For additional isolation, separate direc-
tional antennas with as much vertical or horizontal separation as is
practical.
¥ 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.