Femtocell-based capacity extension of wireless access infrastructures

The exponential increase in the requests of demanding services has lead current networks to their limits. As a result there is need to handle the increased traffic. This work focuses on the solution of Opportunistic Networks (ONs) which are operator-governed, coordinated extensions of the infrastructure. More specifically a macro base station (BS) is considered that faces congestion issues. A proportion of the macro-terminals will be redirected to nearby femtocells forming an ON. Femtocells are low-power BSs that exploit the backhaul network of the end-user, e.g. an ADSL line, to communicate with the operator. This paper aims at solving the complex optimization problem of resource allocation to femtocells. Thus, an innovative greedy algorithm is proposed, namely the Dynamic Resource Allocation (DRA) algorithm. The algorithm allocates power levels to femtocells in order to cover the most terminals possible but with the minimum transmission power possible. In addition, it utilizes an assignment algorithm to distribute terminals to femtocells and QoS to terminals. Finally, the algorithm is validated through a Java-based platform and is compared with the well-known Simulated Annealing and Tabu Search algorithms.