Trango Broadband Wireless Access5830™ User Manual
User Manual Rev 1
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Summary: The link will work since the calculated system gain is equal
to the required system gain.
Note: Connector and cable losses are incorporated into the antenna gains
above for simplification.
NOTE:
The sensitivity specification of the M5830S radio is specified to be –83
dBm typical for a 1E-6 Bit Error Rate. This specification, however, will vary
with the size of the Ethernet packet being transmitted. For small packets (ex.
64 bytes) such as URL requests, the sensitivity of the receiver section is about
-87 dBm. For large packets (i.e. 1600 bytes), the sensitivity is about –83 dBm
worst case. This characteristic improves the fading margin for smaller packets.
The packet size is determined by the Ethernet MAC layer and cannot be
controlled or fragmented in the radio.
6.5.1.
Free Space Loss (FSL)
Any RF signal will be attenuated as it travels through space according to the
following equation:
Loss
fsl
= 92.4+ 20log(F)+20log(R)
Where:
F= Frequency in GHz
R = range in km
Example:
For a 20 mile path at 5.8 GHz, the free space loss would be:
Loss = 92.4+20log(5.8) + 20log(20/.6) dB
Loss = 138.11 dB
The system gain must be greater than this loss for the link to work.
6.5.2.
Signal Fading Factors
The following factors will add losses to the FSL loss and must be accounted for
by adding fade margin
6.5.2.1.
Fresnel Zone Fading
