NETWORK TRAFFIC FORCASTING IN INFORMATION-TELECOMMUNICATION SYSTEM OF PRYDNIPROVSK RAILWAYS BASED ON NEURO-FUZZY NETWORK

• Main Author: V. M. Pakhomovа
• Format: Article
• Language: English
• Published: Dnipro National University of Railway Transport named after Academician V. Lazaryan 2016-12-01
• Series: Nauka ta progres transportu
• Subjects: forecasting; network traffic; volume; neuro-fuzzy network; hybrid system; term; membership function; set; adequacy; error
• Online Access: http://stp.diit.edu.ua/article/view/90485/86966

Purpose. Continuous increase in network traffic in the information-telecommunication system (ITS) of Prydniprovsk Railways leads to the need to determine the real-time network congestion and to control the data flows. One of the possible solutions is a method of forecasting the volume of network traffic (inbound and outbound) using neural network technology that will prevent from server overload and improve the quality of services. Methodology. Analysis of current network traffic in ITS of Prydniprovsk Railways and preparation of sets: learning, test and validation ones was conducted as well as creation of neuro-fuzzy network (hybrid system) in Matlab program and organization of the following phases on the appropriate sets: learning, testing, forecast adequacy analysis. Findings. For the fragment (Dnipropetrovsk – Kyiv) in ITS of Prydniprovsk Railways we made a forecast (day ahead) for volume of network traffic based on the hybrid system created in Matlab program; MAPE values are as follows: 6.9% for volume of inbound traffic; 7.7% for volume of outbound traffic. It was found that the average learning error of the hybrid system decreases in case of increase in: the number of inputs (from 2 to 4); the number of terms (from 2 to 5) of the input variable; learning sample power (from 20 to 100). A significant impact on the average learning error of the hybrid system is caused by the number of terms of its input variable. It was determined that the lowest value of the average learning error is provided by 4-input hybrid system, it ensures more accurate learning of the neuro-fuzzy network by the hybrid method. Originality. The work resulted in the dependences for the average hybrid system error of the network traffic volume forecasting for the fragment (Dnipropetrovsk-Kyiv) in ITS Prydniprovsk Railways on: the number of its inputs, the number of input variable terms, the learning sample power for different learning methods. Practical value. Forecasting of network traffic volume in ITS of Prydniprovsk Railways will allow for real-time identification of the network congestion and control of data flows.