You have me a lil confused, you said you laid down cash for high-speed wireless internet. Then you mention wireless cable/dsl, what are you getting. There is wireless internet available (very $$$) and then there is DSL/cable. The way it sounds me is that you have your broadband going into your router and routing the broadbad over wireless inside your house, correct me if I am wrong.
Wireless, the new 802.11b runs at 22mbps, the 802.11a runs at 54mbps IF your in line of sight, throw in walls and floors it drastically reduces signal strength and bandwidth. As far as security goes, you can normally apply some type of encryption for the wireless transmission.
