Multi-user cross-layer optimization for delay-sensitive applications over wireless multihop mesh networks

In this paper, the energy-limited wireless multihop mesh networks are considered. Minimizing the total transmission energy in the network, while satisfying the applications´ delay constraints, is the target of our optimization problem. To achieve this goal, energy-efficient design should be supported across all layers of the protocol stack through a cross-layer design. This paper proposes energy-efficient joint routing, scheduling, and link adaptation strategies that minimize the total transmission energy in the network. The proposed cross-layer energy-aware algorithms allocate resources, dynamically according to channel quality and traffic load so as to minimize the overall transmission energy, while satisfying the given packets delay and bit error rate (BER) constraints. The resources considered are the transmitted power and modulation in the physical layer, scheduling in the link layer and routing in the network layer. In addition to the proposed optimal solution, suboptimum solutions are presented as well. The simulation results show that, under the same conditions, the proposed optimum algorithm has less energy consumption than routing algorithms that consider delay constraints only. Moreover, simulations show that the suboptimum algorithms have performance near to the optimum algorithm with a huge reduction in the complexity.