ThaMan419 has your answer. That's what I use.
I have limited cell coverage on my property, and nearly none inside the house. Zero cell coverage in my basement where my office is. So now my Verizon internet router is in my basement office, and provides excellent WIFI coverage through my whole house. I turned on the 'Use WIFI for Phone Calls' on my family's cell phones, and we all have 100% cell call use anywhere in the house including the basement. When we use our phones outside we lose WIFI signal and pick up cell tower coverage. I wasn't sure how this would work at first, but after struggling with cell usage for years I gave it a try. I was completely satisfied, even using my cell phone for business, so I dropped my land line. When you turn on WIFI for calls, you can enter the address you want to use as a locator in case you need to dial 911 while using your home's WIFI.