Unfortunately, there is some modem setup necessary before it will work wireless and for that, you have to be connected by wire. I assume the modem came with a CD for installation. Mine did.

Once you've done the setup it will work wireless unless at some later date you need to do the setup again.

The modem I got was a Netgear, when my previous modem stopped working. The installation CD was pretty self explanatory but I was a computer geek so maybe it wasn't for non-computer geeks. There was a phone number to call for assistance so if you have problems, call them.