A cross-layer optimization for ad hoc networks

The lack of an established infrastructure and the hostile nature of the wireless channel make the design of ad hoc networks a challenging task. The cross-layer design methodology, which has been strongly advocated in recent years, essentially aims to overcome the sub-optimality introduced by designing each layer in isolation. This paper explores one aspect of such optimizations, namely using multiple antennas at each node for receiving and transmitting data using directional beams. By jointly analyzing both the MAC layer parameters and choosing a suitable routing protocol afterwards, improvements over earlier published schemes are obtained. We also perform in-depth simulations to characterize the better performance of various scenarios.