Adaptive Handoff Initiation Algorithm using Fuzzy Logic in Wireless Communication

Abstract

Handoff is a mechanism of transferring an ongoing active call from one cell to another or from one Mobile Switching Centre (MSC) to another or one channel to another as a user moves through the coverage area of a cellular system. The initiating time of any handoff is one of the criteria that determines whether the handoff will be successful or not. Conventional handoff uses fixed values of parameters and can only perform well in a specific network environment. The prominent problems of this algorithm are handoff delay and system overload due to unnecessary handoff. In this paper, an enhanced adaptive handoff initiation algorithm using fuzzy logic is proposed. The proposed method exploits the capability of soft computing to handle the unpredictable nature of the radio propagation. The algorithm dynamically changes the handoff threshold and hysteresis values as the Throughput, User Velocity, Signal-to-Noise ratio (SNR), and Mobile transmitting Power change. When the SNR, M.T.P., Velocity and Throughput, are 35dB, 20dBm, 0Km/h, 100% respectively, the handoff threshold and hysteresis are -106dBm and 9.43dBm respectively. Also, When the SNR, M.T.P., Velocity and Throughput, are 22.5dB, 26dBm, 65Km/h, and 50% respectively, the handoff threshold and hysteresis are -76.7dBm and 4.94dBm respectively. With this work, unnecessary handoff, handoff delay, Call termination due to handoff initiation and network overload due to Ping-Pong effect were eradicated which greatly improved the Quality of Service (QoS)