43.33 Km LOS with USB WiFi stick
Is it possible?
Hard to say, so before attending the real location some calculation with the help of the software is essential. Curiosity was the main reason, and if there is just a marginal possibility it's worth to give a try. All experiments and measurements are done randomly without notices to any parties to scan the real situation on the field.
As you can find out from the software calculation, radio link between two identical WiFi stations is possible with the standard equipment. In this case standard means cheap, easy available WiFi equipment with following characteristics:
TX power : 0,02 W
RX sensitivity : 5uV (-93 dBm)
Antenna gain : 15dBi
Line loss : 1dB
Propagation over the water, continental temperature and some other details not visible on the picture are also considered. For the antenna height I chose 5m as average on both sides.
Limited with already
mentioned parameters, the only factor that we can play around is location of
the antenna-equipment. I choose the hill 250 meters ASL with clear horizons to
Line Of Sight is essential in
this case, clear sky, nice weather and we are ready to roll. Distance between
my location and
WiFi equipment used on my side was really marginal. RF hardware - Simple USB 802.11b WiFi adapter with original antenna. Whole adapter was mounted in the focus of the Deep Dish Cylindrical Parabolic antenna. The design found on the web was easy to build (copy). As this is just quick and dirty approach, whole antenna was ready in 30 minutes. Aluminum food foil, hard paper, polystyrene, scotch tape and the cutter is all you need to fabricate this antenna. Looks too simple to work, produce some gain, but I was surprised with the results I get. Many people already experienced same results but this antenna just overcame all my expectations. The real gain was not measured but simple comparing this antenna with the barefoot USB adapter in the local city network was good enough to take this ''State of art'' on the remote location. Just to mention that signal level jump from poor 20% to good stable 40% with this antenna. IT hardware – 5 meters of the USB connection cable ant notebook.
Aftermath showed that WiFi equipment used on the other side was not a ''Rocket science'', antenna sector 15dBi, AP senao 3054cb3 (PrismGT chipset 802.11g). The fact that the sector antenna was not pointed in my direction give us a plenty room for better signals on both sides.
After the initial Site Survey, immediately pops up the SSID on the Ch 5 with 20% of signal level. Attempt to point my antenna more accurately did not give me better signal that 20% from the initial try. Considering all before mentioned facts this was good enough for me. Calculated distance between this to sites is 43.33 km. Cost of wireless equipment used on my side together with 5m of USB cable is 26 Euro. Calculation gives us funny ratio of 60 Eurocents/km.
Any questions, feel free to contact me on