It is predicted that mobile traffic, mainly taking place indoors, will increase up to 1000 times in the next decade. Future smart buildings/cities will be connected through wireless communication systems. High capacity and reliable wireless communications will play a very important role in future smart building/city. In telecommunications, a femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. It allows service providers to extend service coverage indoors or at the cell edge, especially where access would be limited or unavailable. Since its first commercial deployment by Sprint Nextel Corporation in 2008, femtocell has continued to gain momentum with mobile network operators in Amer...