The term smart cell is used in 4th generation( 4G) and 5th generation( 5G) mobile communications networks for intelligent radio cells. Smart cells are smaller radio cells with a shorter range that can be classified as microcells, picocells and femtocells.
Smart radio cells are designed to provide optimum coverage of a specific reception area in terms of transmission technology. Depending on the indoor or outdoor application, they have different ranges, ranging from a few meters to two kilometers and beyond. Since the range of the base stations depends on the transmitting power and the free- space attenuation, smart cells can transmit indoors with transmitting powers of 100 mW, in the range of pico cells with up to 250 mW at distances of up to 250 meters, and at greater distances in microcells with transmitting powers of up to 5 W. As far as free-space attenuation is concerned, this is much higher for 5G networks than for Long Term Evolution( LTE), since 5G transmits in the frequency range above 3.6 GHz.
The number of subscribers that can be logged in depends on the radio cell size. For example, microcells can be used by several hundred subscribers at the same time, whereas femtocells can only be used by around 20. To increase the connection density in inner-city conurbations, smart cells in 5G mobile networks can be configured to operate with many picocells instead of a few microcells. Such a concept also extends battery life because mobile devices have to use less transmitting power to reach the next base station, which is in the immediate vicinity. Another advantage of networking with many microcells is the ultra-short latency times, which is enormously important for the Internet of Things( IoT) and a prerequisite for ultra-high reliability and low latency communications( uRLLC).