This field test compared two LTE CAT-M devices running in parallel on the same drive route with known out-of-service zones. The graph shows RSRP (signal strength) over time and reveals an unexpected truth.
DUT 1 (blue): Stronger signal, often 20 dB higher
DUT 2 (red): Weaker signal, but less time out of service.
Insight: Strong RSRP doesn’t guarantee better real-world coverage. The out-of-service bars, below the graph tell the real story.
Scripted with TeraTerm
Visualized with Python + Matplotlib
Collected in a known weak coverage zone
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