This article demonstrates how to run a tower scan in a PMP 450 deployment.
Support team requests to provide spectrum analyzer results to investigate issues like degraded performance, slow speeds, and link drop to name a few. This purpose is to understand if the source of interference impacts the uplink or downlink.
Solution: Run a Tower scan
Every transmitter displays the transmission properties as displayed below:
Let us consider a 360-degree tower with four 90-degree sectors using ABAB channel reuse.
In this case, when the spectrum analysis is started on one sector the remaining 3 sectors will continue to transmit. The resulting analysis would display skewed results.
Here is a sample of spectrum analysis run individually vs simultaneously (both scans are from the same tower):
Individual scans run at different times.
Simultaneous scans: We can observe lower noise levels in this scan compared individual scans shown in the previous image.
The scans above are a clear indication of the accuracy of the results when individually vs run simultaneously. Hence, performing a tower scan when troubleshooting interference is always suggested.
To perform the tower scan, login to all the involved APs through the web browser, set the display to Averaging, set min and max to full scan, scan duration to 180 seconds, and click on start timed spectrum analysis.