22-09-2016, 09:21 AM
1455604326-pptonfemtocell150203082220conversiongate02.pptx (Size: 1.16 MB / Downloads: 18)
Introduction
A femtocell is a small cellular base station designed for use in residential or small business environments
It connects to the service provider’s network via broadband (such as DSL or cable) and typically supports 2 to 5 mobile phones in a residential setting
A femtocell allows service providers to extend service coverage inside of your home - especially where access would otherwise be limited or unavailable - without the need for expensive cellular towers
It also decreases backhaul costs since it routes your mobile phone traffic through the IP network
A femtocell is sometimes referred to as a “home base station”, “access point base station”, “3G access point”, “small cellular base station” and “personal 2G-3G base station”
History On Femtocell
The first interest in femtocells started around 2002 when a group of engineers at Motorola were investigating possible new applications and methodologies that could be used with mobile communications.
A couple of years later in 2004, the idea was beginning to gain some momentum and a variety of companies were looking into the idea.
With the idea gaining momentum, and many more companies investigating femto cell technology, the Femto Forum was set up in July 2007. Its aim was to promote the wide-scale adoption of femtocells. With mounting industry pressure to be able to deploy femto cell technology, the Femto Forum also played a coordinating role in ensuring that the standards were agreed and released as fast as possible.
Why Femtocell ?
Technical motivation
Reduced separation distance between transmitter and receiver
Interference is isolated by building structure
Limited number of users
Business motivation
Half of voice calls and a majority of data traffic originate indoor
Operators expand network capacity and coverage without much investments on infrastructure.
Subscribers get better radio service at low price
Features of Femtocell
Operates in the licensed spectrum
Uses fixed broadband connection for backhaul
It is managed by the NAP
The backhaul service provider may be different from NAP/NSP
Principally intended for home and SOHO
Lower cost than PicoBS
Smaller coverage (low power) than PicoBS
Smaller number of subscriber (ten or less) than PicoBS
Higher density
Advantages Of Femtocell
Low Device Cost:
efficient, low-cost power amplifiers, highly sensitive receivers, flexible channel bandwidth, reliable RF filters; low cost and low power implementation; etc.
System Interference Management:
minimize interference to macro (and vice versa); minimize interference to adjacent femtos; coping with unplanned rollouts; coverage estimation, interference cancellation; etc.
Femtocell Capacity Maximization:
link and access management (handover, admission control, resource management, load balancing and flow control); dynamic bandwidth allocation and sharing; etc.
Backhaul Issues:
wired or wireless backhaul, reducing signaling load, QoS provisioning and traffic priorization, joint access and backhaul design; etc.
Viable System Architecture:
control & data planes, access control, authentication, local breakout, efficient forwarding, seamless mobility, zero-config, etc.
Conclusion
Femtocell extends the high-data rate service coverage of UMTS to indoor environment
Higher spectral efficiency due to short range and well isolation
With massive deployment, a solution for ubiquitous mobile broadband access
A range of case studies verify CSG femtocell operation
Interference locally distributed
Flexible spectrum scheme is efficient to reduce uplink outage rate
Mobile teletrauma use case:
With a certain level of femtocell penetration ratio, the service can be delivered with sufficient low outage rate
At least an order of magnitude reduction in service outage rates when femtocells are utilized, compared with macrocell only case
Downlink direction study is also interesting and beneficial to complete the use case study. In the long term, the research direction is LTE femtocell.