Picocell
Encyclopedia
A picocell is a small cellular basestation typically covering a small area, such as in-building (offices, shopping malls, train stations, stock exchanges, etc.), or more recently in-aircraft. In cellular networks, picocells are typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network
Cellular network
A cellular network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver known as a cell site or base station. When joined together these cells provide radio coverage over a wide geographic area...

 capacity in areas with very dense phone usage, such as train stations. Picocells provide coverage and capacity in areas difficult or expensive to reach using the more traditional Macrocell
Macrocell
A macrocell is a cell in a mobile phone network that provides radio coverage served by a high power cellular base station . Generally, macrocells provide coverage larger than microcell. The antennas for macrocells are mounted on ground-based masts, rooftops and other existing structures, at a...

 approach.

In cellular wireless networks, such as GSM, the picocell base station is typically a low cost, small (typically the size of a ream of A4 paper), reasonably simple unit that connects to a Base Station Controller (BSC). Multiple picocell 'heads' connect to each BSC: the BSC performs radio resource management and hand-over functions, and aggregates data to be passed to the Mobile Switching Centre (MSC) and/or the Gateway GPRS Support Node (GGSN).

Connectivity between the picocell heads and the BSC typically consists of in-building wiring. Although originally deployed systems (1990s) used PDH
Plesiochronous Digital Hierarchy
The Plesiochronous Digital Hierarchy is a technology used in telecommunications networks to transport large quantities of data over digital transport equipment such as fibre optic and microwave radio systems...

 links such as E1/T1 links, more recent systems use Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

 cabling. Aircraft use satellite links.

More recent work has developed the concept towards a head unit containing not only a picocell, but also many of the functions of the BSC and some of the MSC. This form of picocell is sometimes called an access point base station or 'enterprise femtocell
Femtocell
In telecommunications, a femtocell is a small cellular base station, typically designed for use in a home or small business. It connects to the service provider’s network via broadband ; current designs typically support 2 to 4 active mobile phones in a residential setting, and 8 to 16 active...

'. In this case, the unit contains all the capability required to connect directly to the Internet, without the need for the BSC/MSC infrastructure. This is potentially a more cost effective approach.

Picocells offer many of the benefits of "small cells" (similar to femtocells) in that they improve data throughput for mobile users and increase capacity in the mobile network. In particular, the integration of picocells with macrocells through a Heterogeneous Network can be useful in seamless handoffs and increased mobile data capacity.

Picocells are available for most cellular technologies including GSM, CDMA, UMTS and LTE from manufacturers including ip.access
Ip.access
ip.access Limited is a multinational corporation that designs, manufactures, and markets picocell and femtocell technologies and infrastructure equipment for GSM, GPRS, EDGE, and 3G...

, ZTE, Huawei and Airwalk.

Typically the range of a microcell
Microcell
A microcell is a cell in a mobile phone network served by a low power cellular base station , covering a limited area such as a mall, a hotel, or a transportation hub. A microcell is usually larger than a picocell, though the distinction is not always clear...

 is less than two kilometers wide, a picocell is 200 meters or less, and a femtocell
Femtocell
In telecommunications, a femtocell is a small cellular base station, typically designed for use in a home or small business. It connects to the service provider’s network via broadband ; current designs typically support 2 to 4 active mobile phones in a residential setting, and 8 to 16 active...

is on the order of 10 meters., although AT&T calls its product, with a range of 40 feet (12.2 m), a "microcell".
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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