Contain your Wi-Fi signal

Reader Mike Waters writes: I am concerned about Wi-Fi security. One of the most basic ways to secure a wireless signal seems like it would be to reduce the strength in "uncontrolled" areas so no signal can be received. I would like to be able to REDUCE the range of my home Wi-Fi network so it just covers my house! As it is I can receive signals almost 2 blocks away! Is there any safe, reliable way to do this? Remove tha antenna from the hub, wear a tinfoil hat?

Sure enough, there is, but not on every router. Hop into your router management system (either through a program you installed when you set up your router initially or by typing the IP address of the router into your web browser), and poke around. Every router is different, but you'll likely find the option to reduce radio transmission power under advanced settings or somewhere else in the wireless configuration section. On Linksys routers, for example, look for "Output Power" under the Advanced Wireless tab. Remember, though, that not all routers include this feature (not even all routers from the same vendor).

Like Mike suggests, lowering the total power output of your router can do a good job at keeping the signal from spreading too far outside your house and down the street. However, this method comes with some caveats. The big one: By lowering signal strength you may inadvertently lower the signal too much so that you don't cover your entire house. Wireless signal is finicky, and the just-fine signal strength on one floor may be barely acceptable a single story up. You may very well drop your connection altogether in the far corners of your home, so experiment before you etch this setting in stone.

The other caveat is that even if your signal doesn't drop out, it will likely slow down throughout your house, even when you are relatively close to the router. As signal strength decreases, the signal-to-noise ratio falls as well, which means you'll lose more data and suffer through more re-transmissions as interference gets worse, lowering the overall speed of the connection. (Neighbor networks may overpower yours, even.) This may not be a big deal, in fact you may not even notice it, or it may have such an impact that it makes your network unusable. Again, you'll have to experiment to find a setting that keeps the network relatively confined to your house while still giving you enough bandwidth to work comfortably in.

Regardless of whether you throttle your wireless radio's power output, don't rely on this as your sole means of Wi-Fi security. Use wireless encryption, set a strong administrator password, and change default settings as described here.