Sleep Scheduling Mechanism For Mobile Delay Tolerate Networks

Recent years, with the popularity of mobile communications terminal equipment used in the Delay Tolerant Network (DTN), the mobile characteristic of DTN become more prominent, and then DTN develops into Mobile Delay Tolerant Network (MDTN). Considering mobility and portability, the equipment usually uses the batteries with limited capacity, which makes the equipment energy limited. Because of the fact that the lifetime of the equipment affect the lifetime and performance of MDTN, energy efficiency optimization of the equipment become more and more significant.To begin with, the energy saving mechanisms of wireless network are studied in this dissertation, introducing the classification and basic working principle. Then the features shown in the mobile devices communication process is applied to the device energy management mechanism. The distribution features of inter-contact time of four real dataset have been fine-grained analyzed and they show some volatility in densely distributed value area, while they also bear some certain attenuation characteristic. The characteristic that the inter-contact time of the devices obeys power-law distribution is added to the energy-saving mechanism of MDTN nodes. Making use of the Pareto distribution which belongs to the power-law distribution, this dissertation designs node sleep scheduling mechanism based on a power-law distribution by controlling the scanning process to achieve the sleep and wakeup state transition of devices. Next, the performance of sleep scheduling mechanism is analyzed and studied by simulation experiments using the ONE simulation tool. By comparison with asynchronous wakeup mechanism, the result shows that the sleep scheduling mechanism can do better in energy saving on condition that it hardly affects the data delivery.