Wireless Hacks

Aligning Antennas at Long Distances

By working methodically and communicating well, you can easily bring up wireless links several miles apart.

The farther apart your points are, the harder it is to aim your antennas. At distances up to five miles or so, this is rarely a problem. Just so long as you have enough total gain to overcome the path loss, which you should have calculated by now [Hack #81]. At greater distances, getting the antennas pointed directly at each other can be quite tricky. Here is a list of techniques that might help you get your dishes pointed where they need to be:

• Use mobile phones or FRS/GMRS radios [Hack #9] to maintain communications between the two points while you’re aiming the antennas. It helps to have at least two people at each end (one to manipulate the antenna, and another to coordinate with the other end). Radios often work much better in areas where mobile phone coverage is spotty.

• Set up all of your network settings ahead of time, so there aren’t any variables once you get to the remote site. Check all gear, ping each box, and even transfer a file or two to be sure that your equipment works at close range. You don’t want to question it later if you have problems getting the link going.

• Use a tool like the Wavemon [Hack #31], or a good built-in client [Hack #20] to show the signal strength and noise readings in real time. This kind of tool is your best friend, short of an actual spectrum analyzer.

• Work on one end of the link at a time, slowly ...