In this work we propose a novel handover (HO) algorithm, that considers system performance from both user and network perspective, in the context of heterogeneous networks (HetNets), i.e., networks composed of BSs with asymmetrical transmission power. In such an environment, conventional HO algorithms that consider only the user perspective, e.g., received signal strength (RSS)-based, might offer suboptimal performance, since they mainly push users to cells with high transmission powers. Thus, new algorithms that take into account also the network perspective, e.g., cell load, are needed. In this work, a load-aware algorithm is proposed considering the service delay that a user experiences from the network. In addition, an implementable framework based on Software Defined Networking (SDN) architecture is sketched to support the algorithm. The proposed algorithm is compared with the traditional one we meet in long-term evolution (LTE) systems and a distance-based one. Extracted cell assignment probability and user service delay performance results show that the load-aware approach outperforms both of them.