624 Int. J. Mobile Communications, Vol. 12, No. 6, 2014 Copyright © 2014 Inderscience Enterprises Ltd. Performance analysis of WIMAX–WLAN overlay networks using modified dynamic speed sensitive call admission control V. Bharathi* Department of ECE, Sri Manakula Vinayagar Engineering College, Puducherry, India E-mail: bharathime@rediffmail.com *Corresponding author L. Nithyanandan Department of ECE, Pondicherry Engineering College, Puducherry, India E-mail: nithi@pec.edu Abstract: The efficient call admission control (CAC) plays an important role in effective utilisation of integrated heterogeneous networks such as IEEE 802.11/wireless local area networks (WLANs) and IEEE 802.16/wireless microwave access (WiMAX). In this paper, modified dynamic speed sensitive CAC (MDSSCAC) is proposed and analysed for loose, tight and hybrid ring- based WiMAX–WLAN overlay networks. MDSSCAC effectively utilises available resources by admitting calls to proper network and enhances Quality of Service by dynamically varying bandwidth reservation for handoff calls based on traffic prediction. MDSSCAC assigns preference for the calls to admit either in WiMAX or in WLAN network based on velocity, location and service type of call. MDSSCAC avoids unnecessary handoff initiated by high-velocity users and effectively balances load between WiMAX and WLAN networks. MDSSCAC yields better performance compared with the existing speed sensitive CAC (SSCAC) and dynamic SSCAC (DSSCAC). The hybrid coupling provides better performance compared with other coupling. Keywords: CAC; call admission control; WiMAX; wireless microwave access; WLAN; wireless local area network; heterogeneous networks; QoS; quality of service; bandwidth reservation; vertical handoff; overlay network. Reference to this paper should be made as follows: Bharathi, V. and Nithyanandan, L. (2014) ‘Performance analysis of WIMAX–WLAN overlay networks using modified dynamic speed sensitive call admission control’, Int. J. Mobile Communications, Vol. 12, No. 6, pp.624–641. Biographical notes: V. Bharathi received her Bachelor of Engineering from the University of Madras in 1999, Master of Technology in 2003 and pursuing PhD in Pondicherry University. She is working as an Associate Professor of Electronics and Communication Engineering, Sri Manakula Vinayagar Engineering College, Puducherry, India. She has more than 14 publications in national/international conferences and journals. Her areas of interest include wireless networks, wireless communication and signal processing.