Оцінка достовірності алгоритмів моніторингу для абонентьких пристроїв стандарту 802.11

Abstract

The article investigates the assessment of the reliability of measuring the main parameters of wireless channels using monitoring algorithms based on 802.11 subscriber devices. Also, the measuring capabilities of subscriber devices and the feasibility of their use for technical diagnostics of wireless channels of the 802.11 standard are determined. Based on statistical estimates and Kolmogorov-Smirnov and Shapiro-Wilk criteria, it was found that a normal distribution law can be used to determine confidence intervals. This gives approximate results. Studies based on the Laplace function, Student's coefficient and the distribution of χ2 have shown that the distribution for the measured quantities has the closest approximation to χ2. However, if the fluctuations of the main parameters are taken into account, the reference intervals for the signal power at the receiver input will be no more than ± 0.3 dBm, provided that the observation period is 360 s with a monitoring cycle of 1 s. For information parameters, the process of estimating the confidence intervals showed values of not more than ± 0.04 Mb / s for the effective data rate, and not more than ± 7 MB / s for channel bandwidth. Also, it is established that it is enough to use 50 measurements for information parameters. In this case, the distribution will be closer to χ2, but given the small values of the confidence interval and the peculiarities of packet transmission using 802.11 frames, the difference between the normal distribution will have almost no effect on the final result. The use of the obtained results allows to use them to assess the degree of adequacy of the models and the reliability of the methods of estimating the basic parameters of wireless channels for the stages of design and operation of 802.11 networks