To protect your wireless network, make sure you’ve activated security settings at the highest level that all of your devices support:

1) Use either WEP (Wired Equivalency Protocol) or WPA (Wi-Fi Protected Access).

2) Make sure that both your router or access point and all of the clients on your network share the same encryption key. Write down the key and put it in a safe place.

3) Also use any other means to lock down the wireless network that your access point offers, such as restricting the Media-Access Control (MAC) addresses that are allowed to access the wireless network.

4) Limiting the number of DHCP leases handed out to the number of computers you own. This can typically be done using the management interface of your wireless broadband router. These settings are usually under the Advanced or Security menus.