I have the same exact set up and am sure you have the same issue I had. I did not have a strong signal on the far end of my home. I purchased the Nighthawk and am beyond impressed. I now have signal throughout my entire home and even for several feet off of my property. Be sure to turn WiFi off on your Arris modem in the settings and set up the Nighthawk with the same exact network name and password, your devices will automatically connect to the Nighthawk without an issue.