Santosh Paul Abraham

802.11n MAC design and system performance

We present an overview of the MAC and PHY layer enhancements required to ensure high application layer throughput for IEEE 802.11n. We describe an enhanced scheduled mode operation which is shown, through simulation, to yield an application layer throughput that is greater than 100 Mb/s in practical scenarios. We also demonstrate that the proposed enhancements significantly improve the application layer throughput with EDCA.

Methods for Improving Medium Reuse in IEEE 802.11 Networks

In this paper we identify the mechanisms in the IEEE 802.11 standard which limit medium reuse by not allowing concurrent transmissions even when they are actually possible. To improve medium reuse we propose an interference management protocol, PCONAV, which cognitively enables and disables the virtual (NAV) and physical carrier sensing (CCA) according to the interference environment. We combine this mechanisms with address filtering and capture and demonstrate improved medium reuse. The proposed cognitive mechanisms are further enhanced with a tuning mechanism that adapts the carrier sensing threshold (CST) at each node. Simulations are used to show the improved performance obtained with each of the proposed mechanisms.