Efficient MAC protocols optimization for future high density WLANS

Recently, the High Efficiency WLAN or simply HEW study group was created within IEEE 802.11 working group. This study group considers the improvement of spectrum efficiency to enhance the system’s area throughput in high density scenarios. Subsequently, this led to the creation of a new task group called 802.11ax, which is expected to deliver the next Wi-Fi generation. A key perspective considered by the recent discussions is increasing the spatial reuse using Physical Carrier Sensing (PCS) adaptation.

While Transmit Power Control (TPC) has always been the chosen technique when targeting spatial reuse improvements, this work investigates the weakness points in TPC especially outside centralized network architectures. On the other hand, the incentives behind adopting the PCS approach are discussed. Accordingly, a new algorithm is proposed to adapt the PCS dynamically. The performance of this proposal is compared to that of TPC using OPNET simulations. For a dense IEEE 802.11n network topology, simulation results show that PCS outperforms TPC (120% versus 66% of throughput gain respectively). Particularly, the PCS approach is more robust when there are some nodes that are not implementing the PCS nor the TPC adaptation.