Small Cell is an umbrella term for low-powered radio access nodes that operate in licensed and unlicensed spectrum that have a range of 10 meter to several hundred meters. These contrast with a typical mobile macrocell which might have a range of up to several tens of kilometers. The term covers femtocells, picocells, microcells and metrocells.
Small cells provide improved cellular coverage, capacity and applications for homes and enterprises as well as metropolitan and rural public spaces. Small cells also facilitate a new breed of mobile service that exploits the technology’s ability to detect presence, and connect and interact with existing networks.
A femtocell is a low-power, short range, self-contained base station. Femtocells are targeted to be used for improving in-building coverage (both residential and small business applications). A femtocell allows service providers to extend service coverage indoors or at the cell edge, especially where access would otherwise be limited or unavailable.
Picocells are typically used as low power compact base stations, covering a small area, such as in-building (offices, shopping malls, train stations, offices, etc.). Picocells are also used to extend coverage to indoor areas where outdoor signals do not reach well, or to add radio capacity in areas with very dense phone usage. The term ‘Picocell’ is sometimes also used to encompass outdoor small cells as well.
Microcells are outdoor short-range base station aimed at enhancing coverage for both indoor and outdoor users where macro coverage is insufficient. The range of a microcell is less than two kilometers wide. Microcells are occasionally installed indoors to provide coverage and capacity in areas above the scope of a picocell.
Metrocell is a term that has been used to describe small cell technologies designed for high capacity metropolitan areas. Such devices are typically installed on building walls or street furniture (e.g. lampposts and CCTV poles). This category can include technologies such as femtocells, picocells and microcells where they meet these deployment criteria.