They are called "femocells" and require broadband and GPS. I have a Sprint version and have been using it for over a year and love it. Sprint version operates at 1900mhz which is sprints native band and Verizon one at 800mhz or their native band. They need GPS data so system knows how to map them and do hand offs. My current one provides 3g coverage too. I get full signal in house and excellent battery life.
The Verizon version requires a broadband connection and a GPS signal, but there are full active repeaters that don't.
You missed a "t" in the word "femtocell".
I'm familiar with the technology- I don't want one that requires an internet connection for obvious reasons (the internet fails when power goes out). I'm looking for a "true" RF-based cell phone repeater like a Wi-Ex or a ZBoost, but need to know which brand and model generates the least consumer complaints (not necessarily restricted to those two brands- they were just two I found for sale on eBay). I surfed a few consumer review sites, but they all seem to review units that are no longer being produced.