Estimating the cause of frame losses in 802.11 wireless networks

Abstract

In indoor wireless environments such as warehouses and factories, since radio propagation occurs in complicated ways and there are large moving objects like Automated Guided Vehicles (AGVs), from the perspective of network management, maintaining wireless communication quality is challenging. Because the failures in wireless communications may lead to undesirable delay or even stop in the manufacturing processes, it is desirable not only to detect degradations in link quality, but also to estimate the cause of the frame losses, to recover from the link failures as quick as possible. In this paper, we propose a sensing system that allows comprehensive analysis between physical and Medium Access Control (MAC) layer information, and allows estimation of the cause of the frame losses due to signal attenuation or interference. We implemented a prototype sensor node using an FPGA board and conducted an experiment to investigate the accuracy of the estimation. From the experiment, we confirmed that the prototype sensor node can determine whether the cause is due to attenuation or interference with high accuracy.