When you say remote location, I assume you have no network access, only RF.
Looping 25W back into our receiver would be a bad idea. :) Looping the modem would just tell you the processor is running.
Do you mean more of a digipeater mode where received packets are stored then re-transmitted? We could disable checksum to guarantee a response for analysis locally.
As part of the Hi-Speed effort, we are building a channel sounder for testing purposes. This is a PN generator designed for analysis.
The easiest thing to do would be to put the remote UDR in sounder mode and use your local UDR to analyze the received data which includes RSSI and BER. Constellation is an internal design tool at this time, but we will provide the hooks to some enterprising WebGL folks for display.
The results could be logged locally. We could also run sounder as a chron job (telemetry or beacon) then you'd get results even if you couldn't successfully talk to the remote unit. A few second burst hourly would be interesting.
Great topic. What if you had several internet connected UDRs receiving results for comparison?
I'd like more input, I think this topic has a lot of merit.
Bryan - K7UDR