A cellular base station (tower) designed to serve a very small area, such as part of a building, a street corner, or an airplane cabin.
Picocells are usually used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with very dense phone usage, such as train stations.
A picocell is smaller than a microcell, both in physical size and coverage area. Picocells may combine the electronic equipment and antenna in one integrated unit. Picocells are larger than femtocells.