Fuzzy-Based Hybrid FAHP-FTOPSIS Algorithm for Enhancing Vertical Handoff RAT Selection in Heterogeneous Wireless Network

<strong>ABSTRACT</strong>: A key element of heterogeneous wireless networks is the existence of many Radio Access Technologies (RATs) within the same service region. Based on the enhancement of vertical handoff RAT selection in HWN, it is desired to maintain uninterrupted connectivity of vertical handoff while maximizing QoS to satisfy user needs. The Main challenging issue in the vertical handoff RAT selection algorithm in an HWN, is the complexity of choosing the most appropriate network when the mobile user seamlessly roams across different RATs based on user context QoS criteria. This study focuses on network selection strategies based on QoS class to enhance vertical handoff between different RATs like LTE, WLAN, and WiMAX. This paper proposed a Fuzzy-Based Hybrid FAHP-FTOPSIS algorithm for Enhancing Vertical Handoff RAT Selection in HWN. The hybrid algorithm was developed by combining the Fuzzy Analytical hierarch process (FAHP) methods for computing weight scores with the Fuzzy Technique for Order Preference by Similarity to Ideal Solution (FTOPSIS) methods for ranking RATs. This hybrid algorithm developed considered the current and the new RSSI threshold and enabled fuzzy inference system IF then rule to monitor the QoS classes. This hybrid algorithm was evaluated and simulated by MATLAB software simulation tool. The simulation result shows that the hybrid algorithms reduce handoff decision delay by 1.49%, 4.5 %, and 5% on conventional, 2 %, 2.51% and 2.98% on interactive, 2.96%, 4.99%, and 7.1% on background, and 2.13%, 6.2%, 7.97% on streaming class. Handoff failure reduced by 1.8%, 2.7%, and 3.2% on conventional, 5.1%, 7.15%, and 9% on interactive, 6%, 9.1%, and 15% on the background, and 3.12%, 7.1%, and 22% on streaming application compared to FTOPSIS, TOPSIS, and SAW algorithms respectively. Finally, the hybrid FAHP-FTPOSIS algorithm enhances vertical handoffs compared to FTOPSIS, TOPSIS, and SAW, algorithms in terms of best network selection by prioritizing user QoS handoff criteria. However, this paper does not consider security and RAT load balance. Therefore, in future work, will consider expanding the hybrid algorithm in this study by adding security and RAT load balancing.