2.4GHz 14dBi Yagi Antennas Don’t Cut It
…through 6.5 miles (~10.5km) devoid of “line of sight” landscape, that is! Doug and I are trying to get a wireless link up between our houses. Six years ago, before the days of DSL and when we had apartments near each other, we had a wireless link. Using 915MHz WaveLAN cards and Linux, we were able to link up and play Quake against each other. Back then, our apartments were only a couple hundred feet away from each other, and we utilized some low sensitivity patch antennas. As long as we aligned the antennas out our windows just right, we could establish a connection. Now, we’re 8 miles away from each other, and we’re wondering if we can do the same thing.
Thanks to Google Maps, this is a satellite picture of the land between my house (right marker) and Doug’s (left marker). Unfortunately, I don’t have a topography map at the moment, which would really help with determining geographical obstacles. At any rate, we have to shoot our wireless link through LOTS of vegetation, some houses, and a (gulp) mountain pass. So, the odds are stacked against us… but it is still a possibility. With the right frequency, the right antennas, and the right power… it might be possible to link up.
For our first test, we tried 14dBi yagi antennas using 802.11g and the 2.4GHz range. I hooked my Linksys WRT54G to the yagi antenna. I am using the Alchemy firmware on my router, which lets me boost my output power from 28mW to 251mW, and select an antenna connector (left or right) in the back. (By the way, “left” and “right” are designated by looking at the router from the back.) On Doug’s side, he connected his yagi to a Lucent Orinoco Silver PC Card plugged into a laptop. Doug ran NetStumbler to see if he could spot my WRT54G.
The long of the short is: no connection! I’m not surprised, anyway… the odds are against us! 2.4GHz has a lot of trouble going through obstacles, as opposed to 900MHz or 5.8Ghz. Next, though, is to try more sensitive antennas, such as the 24dBi Primestar dish / BiQuad antenna. Also, another possibility — digging the 915MHz WaveLAN cards out of the basement and using a dish with a BiQuad feed.