Deployment considerations for mobile data offloading in LTE-femtocell networks

Deployment of femtocells to facilitate mobile data offloading from macro/micro cell is considered in 4th Generation (4G) and beyond broadband wireless systems, specifically in Long Term Evolution (LTE). Traffic offloaded to the femtocells reduces spectrum usage of the macro/micro cell. The macrocell bandwidth saved in this way can be used to add extra new users into the system. The co-channel deployment of femtocells increases the frequency reuse by several folds; thereby improving overall Area Spectral Efficiency (ASE). In this work, the capacity increase in macro/micro cell due to femtocell deployment is analyzed for co-channel macro/micro-femto cell network. Performance variations of a LTE-Femtocell network with the number of femtocells and their Radio Access Network (RAN) parameters, namely, load and transmit power, is also presented which provide operational guidelines for heterogeneous network. The guidelines are derived with the system deployment objectives of maximizing sum-cell-throughput and maximizing total number of users in the system subject to satisfaction of a minimum throughput for each user. The congruity of the two objectives is also discussed. The analysis is done following International Telecommunication Union (ITU) recommended channel models for testing LTE systems.