IEEE 802.11 standard for wireless local area network is more popular as it has a very high throughput as well as high data rate but there are fields where one need to have a different set of necessities like low cost, less power consumption, more reliability, low data rate and the less throughput. In order to full fill these requirements, IEEE 802.15. 4 standard was developed for LR-WPAN providing a low cost and less complicated solution. Routing protocols plays a very important role in the direction of utilizing the limited network resources. Routing protocols is responsible for recognizing, creating and sustaining multi hop routes between sending node and destination node when there is no possibility of direct communication between them. This paper takes the reference from the previous work done by the author where he has implemented the AODV routing protocol in True Time 2.0 which is a Simulink based software used in MATLAB. A Path loss is the most important element that effects the design and the analysis of the wireless communication system. Here author has studied the impact of path loss exponent on transmission range and the hop count. Also soft computing technique named Fuzzy logic is used for deciding the optimum path loss exponent.