PERFORMANCE ANALYSIS OF INDOOR WLAN MOBILITY MOHD. DANI BABA, MOHAMAD IBRAHIM, ABDULMUKTI AHMAD Faculty of Electrical Engineering Universiti Teknologi MARA 40450 Shah Alam, Selangor MALAYSIA Abstract :- In the new era of wireless communication, Wireless Local Area Network (WLAN) has emerged as one of the key players in the wireless communication family. There are many obstacles when deploying WLAN, which demands seamless indoor handover. While the access point, should have the appropriate coverage suitable to the propagation characteristic of the building. The wireless network planner needs a comprehensive tool to implement efficient WLAN network. In this paper, we have developed a mathematical path loss model using OPNET 10 simulation design tool. By using this simulation program, WLAN planner will be able to setup the access point for the optimum propagation coverage. Key-Words:- Wireless communication, mobility, propagation, handover, indoor path loss, mobile node 1 Introduction WLAN products may exhibit the limitation in coverage when performing in crowded office or building due to the propagation loss, transmits power, receive power, fading and other basic obstacles. If the user needs a higher data rate for the WLAN, the burden to create seamless coverage becomes crucial. The network designers need a comprehensive method to locate the Access Point (AP) at the correct angle of the building. If more APs have been deployed, it may increase the cost unnecessary, however if less APs may jeopardize the coverage area. In other words the network planner need to have a first hand experience with the Radio Frequency (RF) characteristic of the facilities. This paper attempts to provide a helpful method to measure the propagation characteristic for indoor environment using the OPNET 10 simulation software. For the indoor environment, there are two types of elements; namely static and dynamic elements. The static elements such as natural and man made materials. The dynamic element comprises of moving objects [1]. Both terrain contour and human made structures strongly affect the received mobile signal strength. In an indoor environment, additional parameters must be considered, such as reflection, wall penetration, how fast the channel changes and etc. The complexity of these parameters make nearly impossible to derive a generic formula to accurately describe indoor propagation [2]. The capability of OPNET 10 to simulate this indoor environment scenario close to the real situation condition motivates us to employ this software to further the study on RF indoor characteristics [3]. Wireless LAN OPNET 10 Module permits mobile node to move from one place to another using trajectory attribute. We have done the simulation using this method and found that the mobile node stunned where no throughput occurs when mobile node switch from one access point to another access point. This model uses a distance method when a mobile node is far away from the access points by scanning phase and reauthentication phase with the new AP [4]. The propagation model employed in the Wireless LAN OPNET Standard is more on free space or Line of Sight (LOS) model rather than for an indoor environment. 2 Indoor Propagation Overview Indoor propagation mechanism needs to overcome three specific main electromagnetic wave phenomena,