generated noise. The ground plane forms an integral part of such an antenna, hence it has to be
in a safe distance (several metres) from any electronic equipment as well as the antenna itself. A
metallic plate used as shielding against interference must not form a part of the antenna.
incorectly
correctly
Powersupply
RTU
Fig. 3.8: Antenna mounting
• Do not underestimate ageing of coaxial cables, especially at higher frequencies. Designing a 900
MHz site with 30 m long antenna cable run outdoors would certainly result in trouble two years later.
• We recommend to use vertical polarization for all radio modem networks.
3.8. Recommended values
To check individual radio link quality run Ping test with these settings: Ping type - RSS, Length [bytes]
equal to the longest packets in the networks. Use Operating mode Bridge, when Router, ACK set to
Off. Switch off all other traffic on the Radio channel used for testing. The test should run at least hours,
preferably day(s). The values below should guarantee a reliable radio link:
• Fade margin
Min. 20 dB
Fade margin [dB] = RSS (Received Signal Strength) [dBm] – RX sensitivity [dBm].
Respective RX sensitivity for different data rates can be found in Section 4.4.1, “Detailed Radio
parameters”.
41© RACOM s.r.o. – RipEX Radio modem & Router
Network planning
To Next Page
Loading...
