Cross-Layer Optimization of Multipoint Message Broadcast in MANETs

Multipoint-to-multipoint message broadcast is a demanding application scenario in ad-hoc networks. Adaptive management of wireless resources is necessary to support such applications in a safety critical context. In this work we study adaptation of transmission rate and power to varying densities of ad-hoc nodes. Our approach is to construct a cross-layer model building on existing models for physical and link layers. To enable optimization in relation to metrics of end-to-end delay and message reception probability a model of flooding broadcast is proposed as a part of the cross-layer model. In a simulation study we show that adaptation of transmission power and rate can be necessary to achieve delay requirements and maximize message reception probability. Compared to simulation our cross-layer model based optimization approach generates slightly more conservative parameter settings. It is further shown how correlated losses have a significant impact on the robustness of the broadcast technique.