The most practical way to accomplish this would be to just validate your RF model assumptions and then apply them to the fixed wireless propagation. As you mentioned there is no practical way to test 22 foot CPE install heights let alone the additional gain that a fixed CPE antenna provides as compared to some sort of radio you could practically have on a mobile platform. While you could go out and spot check with a push up mast that can be time consuming when it comes to gathering a significant number of sample points.
The easier method would be to run an RF propagation with CPE parameters of a device you can install on a mobile unit and drive around with. You could then drive the areas that you predicted this coverage for and gather that data in a text file. Ideally you would do the same drive multiple times and under various climate conditions and seasonal changes. This would give you sample points that you can compare the measured to the predicted. I would do this in a GIS platform and create a delta table and map showing variations between predicted versus measured. I would also have the data for each clutter/tree class. This would allow me to investigate to see if there are consistent delta differences and if they only appear to be variations with certain clutter or if they predictions are off consistently for the whole predicted area. This would then point me in the proper direction to make changes in my RF tool, system wide would mean change the percentage numbers in the mode of variability (fade margin), major differences in the delta for various clutter classifications would tell me I need to adjust my clutter/land cover file settings. Once the model is tuned to your satisfaction you can then run your fixed CPE propagations with a lot better confidence factor. One thing to look out for though is the land cover data being used. I have both the latest and the next oldest clutter data for North America. There was some sort of formula change to the data in the latest release that created some decent sized changes in various parts of the country, this means your predicted coverage may be assuming trees or lack of in areas that the reality is different than the land cover data. You can get a Google Earth file that shows the current vintage land cover map/classification but I am not sure you can do the same for older versions. I am fortunate enough to have all of the data on a hard drive and can easily switch between the two and compare differences. Sometimes the old version is better, sometimes it’s the newer version, it depends on your location. Sometimes there are clutter classifications for an area such as Urban that you would not expect and thus your model is applying losses for a clutter class you are not seeing in real life. I have attached a Google Earth file with three separate areas in the US that have a new and old clutter map version for the same spot, you can turn them on and off at will while looking at the aerial imaging to see what the differences may be. Thank You, Brian Webster www.wirelessmapping.com www.Broadband-Mapping.com -----Original Message----- From: Af [mailto:[email protected]] On Behalf Of Adam Moffett Sent: Thursday, February 04, 2016 12:11 PM To: [email protected] Subject: [AFMUG] Drive Testing I was thinking about this during my drive to work today, and the towercoverage.com thread just reminded me. Is there a realistic way to do drive testing for fixed wireless? I've plotted coverage using a 22' subscriber height, and I can't drive around with a 22' high mast (vehicles and loads have a 13'6" height limit in NY State). So rather than collecting data as I drive --which would be relatively painless-- I'd have to stop, deploy a mast, record coord and reading, un-deploy mast, move to next test point, repeat. I think I could set a drone to a 22' flight ceiling. I'd still have to drive the drone to different places because it will only work within range of the controller. Or maybe forget about drive testing.....is there a realistic way to validate your coverage map other than attempting installations and seeing which ones work? If you're wondering why, I've been asked by some officials "how do you validate this coverage projection?" All I've really got is that we attempt installs and they usually work where they're supposed to.
