We consider a realistic wireless local area network (WLAN) consisting of a number of access points (APs) and a number of clients of heterogeneous types (IEEE 802.11 b/g/n). Although, activating APs using only non-overlapping channels (NOCs), which is very limited, can help us achieve interference-free environment, but the achievable throughput may not be optimized. So, partially overlapping channels (POCs) may be used along with NOCs in the most optimized manner, in order to improve the achievable throughput up to certain extent while satisfying the interference criteria. We present an effective greedy algorithm that makes the most desirable configuration by appropriately selecting a subset of APs for activation using NOCs as well as POCs and associating the clients with the selected APs in the most optimized way. Our simulation results show a significant improvement of the aggregate throughput obtained by using NOCs as well as POCs, over using NOCs only.