FEMTOCELL: OPPORTUNITIES AND CHALLENGES OF THE HOME

CELLULAR BASE STATION FOR THE 3G

Rakesh G Sagar 1SG11EC064

Guided By

Prof. Sudha M S

IntroductionThe topology and architecture of cellular networks are undergoing a major changes voice-centric, circuit switched and towards data- centric, packet switching.The main reason for this is the increase in the consumer demand. By 2015, nearly 1 billion people are expected to access the Internet exclusively through a mobile wireless device.

Traditional methods cannot keep up with the increasing demand.There is an urgent need for new and innovative technologies and cellular topologies that can meet these demands in an energy efficient manner.One such innovative technology is the femtocell.

Femtocells are small, inexpensive, low-power base stations that are generally consumer deployed and connected to their own wired backhaul connection.

Evolution of FemtocellThe first launches from Sprint & Verizon were relatively simple, with a 2.5G service and the rationale of providing simple voice coverage to improve customer retention.The initial technical challenges of implementing the baseband and protocol stack in an integrated device with low power dissipation were essentially solved by 2007.

The year 2009 saw productization of the femtocell and initial launches. It was the year the technology became real to consumers.

Working PrincipleMost operators offer some femtocell service and hardware is available for all common air link protocols including GSM, UMTS, CDMA, cdma2000, and LTE.

The cellular subscriber connects the femtocell base station to his broadband Internet connection (e.g., cable modem or DSL) via Ethernet.Typical femtocell base stations transmit 20 mW, Range is limited to about 30 meters (about 100 feet) but depends on the height of the base station and the local clutter environment.The subscriber must enter the telephone numbers of up to 10 devices that are authorized to access the base station.

The wireless standards organizations publish specifications for femtocells. Such standards vary somewhat by airlink protocol, but all of them have three main elements:•Self-organizing base stations. Unlike macro cell base stations, which require complicated radio resource functions, femtocells configure and optimize themselves, operating nearly autonomously.

•Femtocell gateway:- The gateway provides security functions, enables encrypted IP connections from hundreds of thousands of femtocells, authenticates each femtocell, and interfaces with the mobile telephone switch.•Network management system:- This system allows the network operator to make software updates and run diagnostics using a standard management protocol, TR.069.

Significance and ApplicationBenefits to the user5 bar coverage when there is no existing signal or poor coverage.Consumers benefit from improved coverage since they have a base-station inside their building. As a result the mobile phone achieves the same or higher data rates using less power. They may also get better voice quality. Depending on the pricing policy of the MNO, special tariffs at home can be applied for calls placed under femtocell coverage.

Improved battery life for mobile devices due to reduced transmitter-receiver distance.Femtocells can be used to give coverage in rural areas.

Benefits to the mobile operatorThe attractions of a femtocell are improvements to both coverage, especially indoors, and capacity. Coverage is improved because femtocells can fill in the gaps and eliminate loss of signal through buildings. Capacity is improved by a reduction in the number of phones attempting to use the main network cells. Instead of using the operator's private network the internet is used.

Challenges

There are mainly five challenges faced by the femtocells today.InterferenceLawful interceptionEquipment locationEmergency callsSecurity

Future scope

Research is being done on femtocells that works on 4g network for business enterprises that can handle more calls simultaneously. Since a femtocell hub is primarily used in a home and utilizing an internet bridge it makes sense to eventually use it with other home appliances as well. 

ConclusionFemtocells are a new tool that wireless carriers can use to supplement traditional network upgrades. Femtocells benefit wireless carriers as they improve wireless coverage and offload the wireless networkFemtocells will most likely serve as a stepping stone to improve the performance and reliability of current mobile devices.

References

www.eetimes.comwww.thinksmallcells.comhttp://en.m.wikipedia.org/wiki/femtocell

•Femtocell Security in Theory and Practice by Fabian van den Broek and Ronny Wichers Schreu.•Femtocells: Past, Present, and Future Jeffrey G. Andrews, Holger Claussen, Mischa Dohler, Sundeep Rangan, Mark C. Reed.