We have an Arris TG862 from Comcast. It looks nice and there aren't any problems with the ethernet speed but the wifi range and speed is horrific. Just walk 10 feet away from it (no walls) and you'll get about 15 to 20 Mbps out of the 25 promised and it gets worse even with walls. In my room, which is about 20 feet away, you get about 5 Mbps on a good day. I feel that we need a new Wifi Router so we can hopefully resolve our wifi issues.

Requirements:
- Dual band 2.4Ghz/5Ghz (since my Nvidia Shield so desperately needs less interference when streaming)
- Must be compatible with Comcast (I don't know much about networking equipment, sounds like a stupid question)
- Must have great wifi speeds and range that can penetrate through walls
- Fairly cheap, under $100 is the budget, it can go a bit higher but it's best to keep it under $100

I'm reading around the internet and from just looking at that, we can use our router and put it in Bridge Mode so that it acts like a modem and we can connect a router to the Arris TG862. Is that correct and will it work?