Performance Evaluation of Wireless Standards 802.11g and 802.11b on HTTP Application over AODV Protocol using OPNET

ABSTRACT: Mobile ad hoc network (MANET) is a wireless network that does not contain an infrastructure. Nodes in this network are mobile and can join or leave out from the network in time. This feature can be used in many applications like collecting data. In addition to this mobile devices associated with stations are subject to change and continuity, which has led to many changes in the network topology. However, the problem with this network is that it is easily penetrated by hackers trying to break in, and therefore it should increase its efficiency using routing protocols. It is used to find the path between stations or update existing ones. Routing protocols are classified, as a proactive protocols (e.g., OLSR), reactive protocols (e.g., AODV and DSR), and hybrid protocol (e.g., TORA). The IEEE 802.11 wireless LAN, also known as Wi-Fi, has been classified into several standards including 802.11a, 802.11b and 802.11g. In this thesis, we used HTTP application to compare between IEEE 802.11b and 802.11g with different data rates. The routing protocol is used ad hoc on demand distance vector (AODV) protocol in this simulation. Performance of these routing protocols is analyzedby metrics; number of hops per route, HTTP page response time, HTTP object response time, route discovery time, media access delay, retransmission attempts(packet) and throughput.OPNET Modeler version 17.1 is used for modeling and simulatingad hoc network. It is demonstrated from the simulation results that; the media access delay of 802.11b with 11Mbps is greater than 802.11g in all used network cases of clients number. Average retransmission attempts of 802.11g is decreased by increasing the data rates (11Mbps, 24Mbps, and 54Mbps) of network, additionally, the peak value of retransmission attempts is where 24 clients are communicating with server for both standards 802.11b and 802.11g. Throughput of the network for 802.11g is greater than 802.11b for 11Mbps data rate. Additionally, throughput of both standards are increased by increasing the number of nodes that are communicating with the server. Keyword: MANET, AODV, HTTP, IEEE 802.11, OPNET. …………………………………………………………………………………………………………………………