Cooperative Cross Layer Solution for Performance Improvement in Wireless OFDMA Network

Wireless OFDMA networks enable new and exciting applications but also pose significant technical challenges due to the need for decentralized control, dynamic topology and the characteristics of the wireless channel. Cooperative cross-layer design is a promising method to satisfy the network requirements. In wireless OFDMA networks working in an ad hoc model, link asymmetry exists because of the heterogeneous transmission range of network clients and network routers. In such networks, several challenges, including the unidirectional link problem, heterogeneous hidden problem and heterogeneous exposed problem, can dramatically degrade network performance. In this paper, we develop a cooperative cross-layer approach for wireless OFDMA networks to simultaneously address these challenges and improve network performance. The main ideas of our approach are to eliminate the unidirectional link at the network layer and design novel handshake and resource allocation mechanisms at the medium-access control (MAC) layer using topological information collected in the network layer.