Boost cell phone signals by using a signal repeater, installing a femtocell or taking advantage of the Wi-Fi calling feature available on some smartphones through certain carriers. Previously inhabiting a legal gray area, these devices have since gained legal status under regulations adopted by the Federal Communications Commission in 2013.
A cellular signal repeater acts as a relay between the cell tower and any phones within its signal range. It takes the weak signal it receives in an area then amplifies and rebroadcasts that signal to dramatically improve reception in its immediate vicinity. Cellular carriers offer signal repeaters in building, vehicle and individual-device configurations.
A femtocell, on the other hand, does not require an existing signal from a nearby cellular tower to function. Instead, it acts as a mini cell tower and transmits cell phone calls and data to the carrier through a broadband connection. This allows it to function in areas where cellular signals are too weak for a regular signal repeater to function.
Wi-Fi calling also transmits calls to the carrier through a broadband Internet connection and may be used as an alternative to a femtocell, which can be quite expensive. However, unlike femtocells, which broadcast signals to nearby phones over standard cellular signal frequencies, Wi-Fi calling works exclusively over Wi-Fi networks, eliminating the need to install any additional equipment aside from a regular wireless router.