Taming the densification challenge in next generation wireless LANs: An investigation into the use of dynamic sensitivity control

The IEEE 802.11ax Working Group is aiming to devise ways to improve spectrum efficiency, in particular to enhance the system throughput in highly dense scenarios, frequently referred to as Overlapped Basic Service Set (OBSS). Several techniques are being considered to achieve these objectives. In this paper we explore receiver sensitivity adaptation, one of these techniques, as a potential lever for accomplishing the above mentioned objectives. In particular, we propose a practical method of adapting receiver sensitivity and highlight findings from a comprehensive simulation based study conducted using the network simulator ns3. Findings from this study indicate that the proposed method significantly outperforms the baseline technique currently being considered in the 11ax working group. The proposed method achieves this without requiring any changes to the hardware, the existing infrastructure and the WLAN standard. Moreover, STAs employing the proposed technique can co-exist with legacy devices that do not employ such adaptation. Findings also highlight that the traditional conservative approach of using a static CCA threshold (no sensitivity adaptation) may not always yield the best performance and that identifying the optimal CCA threshold at design time is a non-trivial problem.