Femtocells are small indoor basestations or Access Points that connect to the internet through the enterprise or home LAN. They bring multiple benefits to the cellular operators, for example they:

  • Are purchased, installed and maintained by the end user
  • Offload the operator’s costly backhaul network from bandwidth consuming data services used by smart phones
  • Improve greatly the in-building coverage and represent a low cost solution to remove cellular holes
  • Reduce the users’ phone bill when communicating from the Femtocell
  • Allow new services such as Femtozone and Connected Homes services
  • May use any air interface such as GSM, EDGE, CDMA1x, CDMA EV-DO, WCDMA, HSPA, WiMAX or LTE.

Their capacity and cell size will vary from 4 users in a 150 meter cell in the home to 32 users in a 1000 meter cell in the enterprise, campus, airport, shopping mall.

In the enterprise they allow business users to use a single smart phone with integrated contacts to serve both as a business phone in the office and as a cellular phone outside.

The main differences with Small Cell Basestations are:

  • The RNC or BSC functionality is embedded in the Femtocell with the Modem, therefore Layer 1 (or physical layer) Layer 2 (MAC, RLC) and Layer 3 (RRC) reside in the same piece of equipment. This is also called a collapsed architecture. This is meant to reduce latency and traffic on the Cellular Network which was never designed to support millions of small basesations.
  • They can be installed by anyone and don’t require the expertise of a network planner to specify its location and frequency bands.
Femtocells diagram

Go to UMTS Enterprise Femtocell Access Point, Octasic's Wireless Applications.