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Volume 2018, Article ID 3685927, 14 pages
Research Article

Improved Method for Predicting the Performance of the Physical Links in Telecommunications Access Networks

1Department of Telecommunications, Széchenyi István University, Egyetem tér 1, Győr 9026, Hungary
2Széchenyi István University, Győr, Hungary
3Budapest University of Technology and Economics, Budapest, Hungary

Correspondence should be addressed to Ferenc Lilik; uh.ezs@fkilil

Received 29 December 2017; Accepted 22 March 2018; Published 16 May 2018

Academic Editor: Michele Scarpiniti

Copyright © 2018 Ferenc Lilik et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A novel approach is presented which is able to predict the available maximal data transfer rate of SHDSL connections from measured frequency dependent electrical parameters of wire pairs. Predictions are made by a fuzzy inference system. The basis of the operable and tested method will be introduced, then an improved version is shown, in which the problems derived from sampling of continuous functions of electrical parameters are eliminated by wavelet transformation. Also possibilities for simplification of the problem and a way of reducing the dimensions of the applied rule bases are presented. As the set of the measured data leads to sparse rule bases, handling of sparseness is unavoidable. Two different ways—fuzzy interpolation and various membership functions—will be introduced. The presented methods were tested by measurements in real telecommunications access networks.