Channel quality aware cross-layer design based rate adaptive MAC for improving the throughput capacity of multi-hop ad hoc networks

In this paper we address the goal of achieving higher throughput capacity in multi-hop wireless ad hoc networks than estimated by capacity scaling laws of Gupta and Kumar (2000) [1]. By exploiting the implications pointed in earlier research, a cross-layer design based channel quality aware rate adaptive MAC algorithm CQRA-MAC is proposed to achieve this goal. CQRA-MAC dynamically switches the MAC transmission rate on the basis of channel quality experienced at the physical layer. The proposed algorithm is implemented by modifying the IEEE 802.11 model of Qualnet 4.5 simulator and its performance is evaluated in static and mobile network scenarios following the random access transport capacity approach. Experimental results show that CQRA-MAC achieves higher throughput than DCF and ARF. The achieved throughput capacity is quantified in terms of measurable network parameters and thus validates equations of random access transport capacity framework (Andrews et al., 2010) [9].