Cirronet HopNet 10 Series, User Manual

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Guidelines for Reducing Interference
800281 Rev. B HopNet Family of Products 77
Guidelines for Reducing Interference
Introduction
The transceivers share the same frequency spectrum with other services and other
Part 15 devices in the US. Because of this, you may not achieve 100 percent error free
communications in a given location. You should also expect some level of
interference. However, the flexible design of the radio and the hopping pattern
should allow for adequate performance as long as care is taken in choosing station
location, configuration parameters of the transceivers, and protocols techniques.
Use the following guidelines to reduce interference in your HopNet system.
Guidelines for Setting Up the Network
In general, the following points should be followed when setting up a network:
•
Systems installed in rural areas are least likely to encounter interference.
•
If possible, use directional antennas at remote sites. The directional antennas
confine the transmission path and reception pattern to a comparatively narrow
lobe, which minimizes interference from stations located outside the pattern.
•
Multiple HopNet systems can co-exist in close proximity to each other with very
minor interface as long as they are assigned a unique network address. Each
network address has a different hop pattern.
•
If interference is suspected from a similar operating system, change the antenna
polarization. This will provide an additional 20dB of attenuation to interference.
•
For indoor applications, set all transceivers for the lowest level necessary for
reliable communications. This lessens the chance of interference from nearby
systems.
Guidelines for Selecting Your Site
Use these guidelines to select a proper site for the master remote stations. Suitable
sites must provide the following:
•
An adequate and stable source of primary power.
•
Antenna location that provides an unobstructed transmission path in the direction
of the associated units.
•
Proper antenna selection, data access, and feedline cabling
•
A clear line-of-sight. Microwave radio signals travel primarily by line-of-sight, and
obstructions between the sending and receiving stations will affect system
performance.