Since my last post I learned that the radios nominally use the 80 GHz band, but since it’s a full-duplex link, there are two diffferent frequencies in use: around 80 GHz in one direction and around 72 GHz in the other direction. Consequently, the signal strength in one direction isn’t the same as the signal strength in the other direction. The graph I posted previously was for the stronger of the two.
Since my last post our vendor has repositioned the radios again and wrung out another 3 dB, which is great. Unfortunately, the link is dropping at -66 dBm, whereas the spec says it won’t drop until somewhere in the -69 to -72 range. And according to Bridgewave, our radios tested to -69 in the factory before they were shipped. So we still have a problem.
Here is the signal strength graph from yesterday when in rained starting around noon and continued at varying intensities for the next 24 hours:
In all of that we had only one drop lasting around 30 seconds at 3:39 pm. You can’t see the excursion below -65 because the monitoring system is on the other end of the link. (The monitor needs the link to be up to grab the signal strength from the other end.)
Now, one 30 second drop doesn’t sound to bad considering it’s been raining for 24 hours. But the problem is, if we had staff working here yesterday, every phone call in progress at 3:39 pm would have been dropped. Most likely every Shelby session would also have been dropped. That doesn’t seem good enough to me. What do you think?
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