Small Cells
Encyclopedia
Small Cells are low-powered radio access nodes that operate in licensed and unlicensed spectrum that have a range of 10 meter to 200 meters, compared to a mobile Macrocell
which might have a range of a few kilometres. With mobile operators struggling to support the growth in mobile data traffic, many are using Mobile data offloading
as a more efficient use of radio spectrum. Small cells are a vital element to 3G data off-loading, and many mobile network operators see small cells as vital to managing LTE Advanced spectrum more efficiently compared to using just macrocells.
s, Beamforming
(focusing a radio signal on a very specific area), Picocell
s, Microcell
s and distributed radio technologies that comprise a centralised baseband with remote radio heads. A common factor in all these approaches to small cells is that they are mobile network operator managed.
Small cells provide a small radio footprint, which can range from 10 meters within urban and in-building locations to 2 km for a rural location. Picocells and microcells can also have a range of a few hundred meters to a few kilometers, but they differ from femtocells in that they do not always have self-organising and self-management capabilities.
, TD-SCDMA
, W-CDMA
, LTE
and WiMax
. In 3GPP
terminology, a Home NodeB (HNB) is a 3G femtocell. A Home eNodeB (HeNB) is an LTE femtocell. Wi-Fi is a small cell but does not operate in licensed spectrum therefore cannot be managed as effectively as small cells utilising licensed spectrum.
ABI Research also believes that small cells also help service providers discover new revenue opportunities through their location and presence information, argues ABI Research. If a registered user enters a femtozone, the network is notified of their location. The service provider, with the user's permission, could share this location information to update user's social media status, for instance. Opening up small cells APIs
to the wider mobile ecosystem could enable a Long Tail
effect.
(DAS) which are not low-powered access nodes.
Future innovations in radio access design introduce the idea of an almost flat architecture where the difference between a small cell and a macrocell depends on how may cubes are stacked together. With software-defined radio
, a base station could be 2G, 3G or 4G at the flick of a switch, and the antenna range can easily be tuned.
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...
which might have a range of a few kilometres. With mobile operators struggling to support the growth in mobile data traffic, many are using Mobile data offloading
Mobile data offloading
Mobile data offloading, also called data offloading is the use of complementary network technologies for delivering data originally targeted for cellular networks. Rules triggering the mobile offloading action can either be set by an end-user or an operator...
as a more efficient use of radio spectrum. Small cells are a vital element to 3G data off-loading, and many mobile network operators see small cells as vital to managing LTE Advanced spectrum more efficiently compared to using just macrocells.
Types of small cells
Small cells encompass FemtocellFemtocell
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...
s, Beamforming
Beamforming
Beamforming is a signal processing technique used in sensor arrays for directional signal transmission or reception. This is achieved by combining elements in the array in a way where signals at particular angles experience constructive interference and while others experience destructive...
(focusing a radio signal on a very specific area), Picocell
Picocell
A picocell is a small cellular basestation typically covering a small area, such as in-building , or more recently in-aircraft...
s, 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...
s and distributed radio technologies that comprise a centralised baseband with remote radio heads. A common factor in all these approaches to small cells is that they are mobile network operator managed.
Small cells provide a small radio footprint, which can range from 10 meters within urban and in-building locations to 2 km for a rural location. Picocells and microcells can also have a range of a few hundred meters to a few kilometers, but they differ from femtocells in that they do not always have self-organising and self-management capabilities.
Compatible technology
Small cells are available for a wide range of air interfaces including GSM, CDMA2000CDMA2000
CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
, TD-SCDMA
TD-SCDMA
Time Division Synchronous Code Division Multiple Access or UTRA/UMTS-TDD 1.28 Mcps Low Chip Rate , is an air interface found in UMTS mobile telecommunications networks in China as an alternative to W-CDMA. Together with TD-CDMA, it is also known as UMTS-TDD or IMT 2000 Time-Division .The term...
, W-CDMA
W-CDMA
W-CDMA , UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G mobile telecommunications networks. It is the basis of Japan's NTT DoCoMo's FOMA service and the most-commonly used member of the UMTS family and sometimes used as a synonym for UMTS...
, LTE
3GPP Long Term Evolution
3GPP Long Term Evolution, usually referred to as LTE, is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using new modulation techniques...
and WiMax
WiMAX
WiMAX is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. The 2005 WiMAX revision provided bit rates up to 40 Mbit/s with the 2011 update up to 1 Gbit/s for fixed stations...
. In 3GPP
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
terminology, a Home NodeB (HNB) is a 3G femtocell. A Home eNodeB (HeNB) is an LTE femtocell. Wi-Fi is a small cell but does not operate in licensed spectrum therefore cannot be managed as effectively as small cells utilising licensed spectrum.
Purpose
Small cells can be used to provide in-building and outdoor wireless service. Mobile operators use small cells to extend their service coverage and/or increase network capacity. With small cells, mobile operators can offload traffic as much as 80% during peak times. ABI Research estimates that by 2015, 48% of mobile data traffic will be offloaded from the macro network. No individual technology will dominate offloading.ABI Research also believes that small cells also help service providers discover new revenue opportunities through their location and presence information, argues ABI Research. If a registered user enters a femtozone, the network is notified of their location. The service provider, with the user's permission, could share this location information to update user's social media status, for instance. Opening up small cells APIs
APIS
APIS may refer to:*Advance Passenger Information System*Armour Piercing Incendiary Shells...
to the wider mobile ecosystem could enable a Long Tail
Long tail
Long tail may refer to:*The Long Tail, a consumer demographic in business*Power law's long tail, a statistics term describing certain kinds of distribution*Long-tail boat, a type of watercraft native to Southeast Asia...
effect.
Umbrella term
The most common form of small cells are femtocells. Femtocells were initially designed for residential and small business use, with a short range and a limited number of channels. Femtocells with increased range and capacity spawned a proliferation of terms: metrocells, metro femtocells, public access femtocells, enterprise femtocells, super femtos, Class 3 femto, greater femtos and microcells. The term small cells is frequently used by analysts and the industry as an umbrella to describe the different implementations of femtocells, and to clear up any confusion that femtocells are limited to residential uses. Small cells are sometimes, incorrectly, also used to describe Distributed Antenna SystemsDistributed Antenna System
A Distributed Antenna System, or DAS, is a network of spatially separated antenna nodes connected to a common source via a transport medium that provides wireless service within a geographic area or structure...
(DAS) which are not low-powered access nodes.
Future mobile networks
Small cells are an integral part of future LTE networks. In 3G networks, small cells are viewed as an offload technique. In 4G networks, the principal of heterogeneous network (HetNet) is introduced where the mobile network is constructed with layers of small and large cells. In LTE, all cells will be self-organizing, drawing upon the principles laid down in current Home NodeB (HNB), the 3GPP term for residential femtocells.Future innovations in radio access design introduce the idea of an almost flat architecture where the difference between a small cell and a macrocell depends on how may cubes are stacked together. With software-defined radio
Software-defined radio
A software-defined radio system, or SDR, is a radio communication system where components that have been typically implemented in hardware are instead implemented by means of software on a personal computer or embedded computing devices...
, a base station could be 2G, 3G or 4G at the flick of a switch, and the antenna range can easily be tuned.