The main problems of current cellular network are the expensive deployment cost of network infrastructure as well as Low signal strength received from an outdoor BS inside a building.
Some studies on wireless usage show that more than 50% voice calls and more than 70% data traffic are originated indoor. So, efficient strategy will be higher data rate and reliability for subscribers (User) and reduced amount of traffic on expensive macrocell network (Operator).
Fig. FemtoCell [see the attachment]What is Femtocell ?
Femtocell originally known as an Access Point Base Station is a small cellular base station. It is low-power wireless access points that operate in licensed spectrum to connect standard mobile devices to a mobile operator’s network using residential DSL or cable broadband connections.
It is typically designed for use in a home or small business. It connects to the service provider’s network via broadband (such as DSL or cable). Typically it supports 2 to 4 active mobile phones in a residential setting. A femtocell allows service providers to extend service coverage indoors, especially where access would otherwise be limited or unavailable. Although much attention is focused on WCDMA, the concept is applicable to all standards, including GSM, CDMA2000, TD-SCDMA and WiMAX solutions.Femtocell Properties:
Femtocell is implemented in IEEE standard 802.16e (mobile WiMAX) and 802.16m(). It uses 2.3 GHz or 2.5GHz as carrier frequency. Channel Bandwidth could be 8.75MHz or 10MHz. Convolution Coding or Convolution Turbo Coding is used for channel coding. Different kinds of modulation techniques are used for uplink and downlink such as QPSK, 16QAM, 64QAM etc. It is a small network of 5 active users.Benefits of Femtocells
1. Due to short transmit-receive distance it shows better coverage and capacity
2. Some of the attracting features are:
• Lower transmit power
• Prolong handset life
• Higher SINR
• Higher spectral efficiency
3. It also improves macro reliability because BS can provide better reception for mobile users. Traffic originating indoors can
be absorbed into femtocell networks over IP backbone
4. Cost Benefit -- $60,000/year/marcrocell vs. $200/year/femtocell
5. Enhanced home coverage will reduce motivation for users to switch carriers i.e. other operators.
In a word, Femtocell is a powerful candidate technology for Home Network QoS-guaranteed wireless gateway for Home & Enterprise.Applications of Femtocell:
• It improves indoor coverage extension using Femtocell instead of repeater. It needs DSL or cable. Femtocell has
easy installation and convenience for customer. It also reduces bandwidth load in the macrocell network.
• It provides high quality & low cost voice service
• We can use Femtocell as a Home Gateway also. For example, it can use in
– Multi-mode Wireless Gateway
• WCDMA, WiBro + WLAN, WPAN AP
• Cost-saving techniques : SDR BS, Cognitive Radio
– Home Networking Gateway
• Wireless Connectivity to all Home devices
• Mobile Communication service + wireless broadband Internet access + Home networking + mobile IPTV
• It also constructs Mobile Intranet solution with IP backhaul connectivity for Enterprise