is your wireless router also an ADSL modem or just a standard ethernet wan wireless router
you have 2 options:
1st connect the telone modem to the routers wan port and reconfigure the wireless router to use a different lan IP and subnet for dhcp and the router itself - this can be complicated depending on your router setup
2nd - connect the telone modem to one of the other ports on the router, and disable DHCP on the wireless router, and configure it to access point/bridge mode, then the telone modem will handle everything else, usually simpler to achieve than option one
please do take note of Chris Mberi's notes about wifi encryption and make sure its setup for 2 reasons
1) it provides a layer of security for your wireless devices
2) it stops people stealing your internet