Just finished installing a Force 425 in a noisy environment in the 5.8 GHz band. My performance (200 Mbps agg) is in the predicted range using LP. I set the interference at -81 dBm in a 40 MHz channel based on a spectrum sweep. The link is 7 miles crossing a city with a pop. of 100,000. According to LP the RSSI should be -44 to -52 dBm. The actual RSSI is -66 dBm. Any input on this would be greatly appreciated. The customer is happy with the up and down speeds but I’m not happy with the rec pwr. Thanks in advance!
Scott
Senglish,
Welcome to the Cambium community!
The RSSI discrepancy is normally due to LP’s handling of clutter. Since LP does not know the actual height of the buildings, trees, and any other obstacle on the ground (you tell LP how high to treat each clutter classification), but does know the terrain very well, 6-10 dB discrepancy at 7 miles is probably OK.
For your link, the question would be the stability of the link…if the RSSI is steady at -66 for the most part (there will be fading) - your installation is probably good. If the stability is poor, then you likely have a Fresnel zone issue somewhere in the link.
Hope this helps, Dave.
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Thank you, Dave. I have found that the clutter function in LP is unreliable to say the least. I have used good, solid links to test it and LP will fail the good working link when “use clutter” is selected.
Fresnel zone may be skimming a tree top or two. Looking out with binos, I have at least 10 feet of clearance. The RSSI is steady at -66. The customer wanted at least 100 megs aggregate, and seeing it’s double that, I think I’ll call it good. Thanks again!
it would be curious to see what cnHeat says for that link, assuming good lidar maps are available for your area.