Optimal throughput analysis of a super dense wireless network with the Renewal Access Protocol

Abstract

As Wireless Local Area Networks (WLANs) become denser and denser recently, the contention-based MAC protocol such as the IEEE 802.11 DCF, the de facto standard for the WLAN, should be modified to handle such dense WLANs. To this end, we consider a recently proposed novel MAC protocol called the Renewal Access Protocol (RAP) in this paper. With the RAP, we consider two strategies for resolving collisions efficiently and achieving high throughput performance in a super dense WLAN: strategies without and with grouping. First, we analyze the asymptotic behavior of the RAP itself (i.e., without grouping) as the number of terminals goes to infinity. We show that the RAP can achieve optimal throughput even in a super dense WLAN and the related optimal access probability of the RAP can be derived in a closed-form from the analysis. Second, we propose a new grouping strategy in the RAP and call it the grouped RAP (G-RAP). While a grouping strategy in the IEEE 802.11ah standard is based on time division, which can cause a waste of channel, our grouping strategy is based on transmission attempts, which does not waste channel resources. From the analysis we show that the G-RAP easily achieves the optimal network throughput performance for any group structure (i.e., unform group size and arbitrary group size) if terminals use the optimal access probability that we derive. Our analytical results are validated by simulation.