A MAC-PHY Cross-Layer Protocol for Wireless Ad-Hoc Networks

Abstract—Cooperative communications is a promising technol-ogy that tends to change the conventional access and transmission schemes in wireless networks. By enabling additional collabora-tion from nodes that otherwise will not directly participate in the transmission, it enables spatial diversity and dramatically improves the performance of the network. In this paper we propose a cross-layer cooperative protocol based on a MAC protocol called CoopMAC [1]–[3] for ad-hoc wireless networks in order to leverage cooperation in both MAC and PHY layer1. Exploiting physical layer combining at the receiver, this simple yet efficient scheme illustrates a new paradigm for realistic cross-layer cooperative protocol design for next generation wireless ad-hoc networks. We have evaluated the performance of the proposed protocol by extensive simulations in a large scale wireless ad-hoc network. Simulation results show that the new protocol significantly improves the network performance in terms of throughput and delay. Index Terms—Cooperative communications, medium access control, IEEE 802.11, ad-hoc network I