Fast Adaptive Handover using Fuzzy Logic for 5G Communications on High Speed Trains

Abstract

Today, the high-speed train (HST) that operates at a speed of 400km/h or more is being deployed rapidly in various countries as a convenient and fast public transportation that carries tremendous numbers of passengers all over the world every day. Handover (HO) takes place too frequently due to the high speed of the HST. The failure rates of handover increase with the higher moving speed. This is the most crucial issue facing communication systems in high-speed trains, specifically for real-time services. Preserving seamless wireless connectivity on the high-speed train is the key to achieve optimum service quality for the users on board. To accomplish this goal, very high data rates are required as well as the ability to overcome several HO problems including latency, radio link failure (RLF) and ping-pong HO. Integrating the fifth mobile generation (5G) technology in high speed environments could have a beneficial impact on the HST communication. However, the 5G faces many problems due to the small coverage area of the cells. Therefore, a new proposed HST communication scheme that would overcome the previously mentioned problems could be a promising solution to achieve the feasibility of integrating the 5G technology in high speed environments in addition to maintaining seamless connectivity. A lot of research work was done to mitigate some of these problems, however, further work is still needed. In this thesis, we propose two techniques. The first technique is based on the fast target cell prediction. A method by which the upcoming target base station is predicted in advance. In high-speed trains the future trajectory of the train is easily predictable. Keeping the records of the previous handovers will aid in predefining the target base station in advance using the proposed handover cell prediction technique. The second technique is based on a proposed adaptive fuzzy logic algorithm that dynamically adjusts the optimum time to trigger of the handover procedure in order to overcome the radio link failure and the ping-pong handover. The key contribution of this work is realized by integrating the two proposed techniques to preserve seamless connectivity in HSTs. Using Matlab, the system performance is evaluated. The results obtained indicate that the proposed system successfully overcomes the previously mentioned problems. It decreases the latency and reduces the overhead disruption arising from the HO process achieving fast seamless communication in the high-speed environment. Moreover, it dynamically mitigates the ping-pong HO and the RLF simultaneously. It offers a customized solution to control the network performance based on the network operator preferences to achieve optimum network reliability via the proposed fuzzy logic algorithm.