Authors: S. Reddy Vamshidhar Reddy; Sanjay Dhar Roy
Addresses: Department of Electronics & Communication Engineering, National Institute of Technology, Durgapur, West Bengal, India ' Department of Electronics & Communication Engineering, National Institute of Technology, Durgapur, West Bengal, India
Abstract: In this paper, we consider the overlapping of two adjacent radio cells coverage of access points (APs) of Wireless Local Area Network (WLAN). The number of handoffs, decision delay, call drops and optimum overlapping ratios are estimated as the mobile terminal (MT) moves from the centre of AP1 towards the AP2. Previous publications have derived the minimal required overlapping of adjacent radio cells by considering the signal averaging (low-pass filtering) and a hysteresis margin. But they do not consider the shadow fading effect. In this paper, we propose an effective method to support the handoff requests from rapidly moving subscribers in shadow fading environment. We present the optimum required overlapping ratio of adjacent coverage areas of APs for interrupt-free handoff, minimum handover delay and zero call drops based on Received Signal Strength (RSS). We evaluate the performance of designed network model in terms of average number of handoffs, handoff decision delay, call drops and overlapping ratio.
Keywords: handoff algorithm; seamless handover; decision delay; RSS; received signal strength; WLANs; optimisation; overlapping ratios; adjacent radio cell coverage; wireless LANs; local area networks; WLAN access points; call drops; shadow fading effect.
International Journal of Wireless and Mobile Computing, 2014 Vol.7 No.6, pp.599 - 607
Received: 21 Sep 2013
Accepted: 30 Jun 2014
Published online: 30 Oct 2014 *