Have you setup wireless encryption on your router yet? If so, what type are you using (WEP, WPA, WPA2)?
-If you don't know wtf I'm talking about, go to your command prompt (start > type cmd.exe) and type ipconfig and make note of your default gateway
-It should be 192.168.1.1 or 192.168.0.1
-Type that number into your web browser and it'll take you to your router's login, where you can fuck with its options. The default login should be Admin/Password (or no password at all) but you may have to check Google for that.
Order of security, lowest to highest:
nothing
WEP
WPA
WPA2
Order of connection speed, slowest to fastest:
WPA
WEP
WPA2
nothing (assuming your neighbors aren't using your shit)
Securing your connection slows it down a bit because the data has to be boxed up with pretty little ribbons and that bogs the connection speeds from 5-30%. Since you have a Wireless-N model, I would take advantage of the connection speed if you haven't already. However, if you are broadcasting with encryption/speeds your phone (or laptop etc) doesn't have the hardware for, you may have connectivity issues and will need to tone down the broadcast speed to 54mbps in your router settings. I've had trouble with that myself and can only use WPA encryption.