Energy-efficient transmission with data sharing

In a wireless system, when multiple applications can share data transmitted by rate-adaptive wireless devices, there exists a trade-off between transmission redundancy and energy efficiency. This paper conducts the first theoretical analysis on such a trade-off. We formulate the problem as a bi-objective optimization problem to simultaneously minimize the transmission redundancy and the energy consumption. In the offline setting that the full information is known in advance, we provide optimal algorithms for the bi-objective optimization problem. In the online setting, we provide an online algorithm with proven performance bound to approximate the optimal solution without relying on any assumed distribution or future information. The proposed online algorithm is proved O(ln T)-competitive with respect to transmission redundancy and also O(ln T)-competitive with respect to energy consumption, where T is the number of time slots. That is, the output of the algorithm always approximates the optimal solution within a logarithmic factor over all possible inputs. Our simulation results further validate the efficiency of our online algorithm.