دانلود رایگان مقاله انگلیسی جلوگیری از اطلاعات Decision-aware در شبکه های حسگر بی سیم برای برنامه های ردیابی هدف - اشپرینگر 2017

Abstract

Target tracking applications of wireless sensor networks (WSNs) may provide a high performance only when a reliable collection of target positions from sensor nodes is ensured. The performance of target tracking in WSNs is affected by transmission delay, failure probability, and nodes energy depletion. These negative factors can be effectively mitigated by decreasing the amount of transmitted data. Thus, the minimization of data transfers from sensor nodes is an important research issue for the development of WSN-based target tracking applications. In this paper, a data suppression approach is proposed for target chasing in WSNs. The aim of the considered target chasing task is to catch a moving target by a mobile sink in the shortest time. According to the introduced approach, a sensor node sends actual target position to the mobile sink only if this information is expected to be useful for minimizing the time in which target will be caught by the sink. The presented method allows sensor nodes to evaluate the usefulness of sensor readings and select those readings that have to be reported to the sink. Experiments were performed in a simulation environment to compare effectiveness of the proposed approach against state-of-the-art methods. Results of the experiments show that the presented suppression method enables a substantial reduction in the amount of transmitted data with no significant negative effect on target chasing time.

5 Conclusions and future work

State-of-the-art data suppression methods aim at obtaining a predetermined accuracy level of the collected information for an entire period, when a monitoring task is executed. In target tracking applications, the required accuracy of collected target position information varies significantly in time. A reduced accuracy is often sufficient for making optimal sink decisions. The proposed suppression approach exploits the above insight to decrease the amount of data transmitted in WSN. Instead of suppressing transmissions of sensor readings that are not necessary to accurately estimate target position, the introduced method suppresses those sensor readings that are not useful for selecting optimal movement direction by the mobile sink.

According to the proposed approach, at each time step of the tracking procedure the mobile sink has to minimize its distance to a location in which the target can be caught. The data describing actual target position are useless and should be suppressed, if there is a high probability that the above mentioned distance will be minimized when the sink will move towards a recently reported target position instead of the actual target position.

Results of the simulation experiments clearly show advantages of the proposed approach. When comparing with stateof-the-art algorithms, the decision-aware suppression allows the data communication costs (packet rate and hop count) to be significantly reduced without decreasing performance of target tracking. Furthermore, the decision-aware suppression enables a beneficial trade-off between the tracking performance (time to catch) and the data communication cost. The negative effect of communication failures on the tracking performance can be effectively mitigated for this approach by using the ARQ method.