North Queens TV White Space Trials


                           Home PageTerrainCoverageSeasonal VariationInterference

                           RegulationsTest Site 1 ResultsTest Site 2 ResultsLong Term Test



Test 9  *Note this was one of the few tests conducted after the leafs left the trees.

Test site 2 to Pretty Mary Lake

Base 44.37996N -65.0064W antenna 8dBi yagi height 14m, no trees.

Mobile 44.46882N -65.15119W antenna 8dBi yagi height 9m, evergreen trees 15m tall within 50m.

We didn't expect this link to work, it was only undertaken because the tester lives close by, had some time available and was curious to see if was possible to reach the nearest community with some internet availability 15km away  . Computer simulations predicted a signal of -99dBm to low for a link but since the leafs were off the trees we thought it worth a try.

It's a very challenging link not only is it one of the longest we have attempt at 15km but the signal path includes 2 solid objects. We were interested to see how well the equipment perform with a very weak signal and it succeeded in establishing a link with a signal level of -97  to -95dBm and was stable for the 2 hours we ran the test at the -94dBm level, passing data at 0.5Mbs TCP.

It's possible that with a combination of increased antenna height and gain we could pick up another 5-7dBm of signal margin enough to perhaps give us a useable internet connection of over 1.5Mbs but very little fade margin. We would normally not consider such a connection as viable but when the alternative is no internet what do you do?



The link according to Google Earth link distance 15.15km elevation and foliage below.

KML File that opens in Google Earth is available for those wishing to take a detailed look at the terrain and vegetation

Radio Mobile simulated link data using assumed tree height of 20 meters and density of 130
This setting can be found under options- elevation data.


Measured results from Base Station status page


Measured results from Mobile CPE Status page