| Wireless local area networks (WLAN) are one of the most widely used technologies in our daily lives. Instead of being limited to the range of wired equipment, users can communicate freely. However, since wireless networks are based on communication within radio channels, WLANs are susceptible to malicious attempts to block the channel. One of the most frequently used attacks is a Denial of Service (DoS) attack known as a jamming attack. Jamming attacks interfere with the transmission channels by constantly sending useless packets in order to disturb the communication between legitimate nodes. In real wireless networks where users communicate constantly, a jamming attack can cause serious problems. Because of this, a study of jamming attacks and how to prevent them is necessary. In this thesis, the jamming attacks were simulated in WLAN using OPNET Modeler, in order to provide a better understanding of jamming attacks. This study will be helpful for future research and development of a practical, effective way to avoid jamming attacks. The objectives of this thesis were to simulate client-server and ad-hoc networks and different jammers; launch jamming attacks in order to test how much influence different jammers have in WLAN communications; and to compare the performances of different ad-hoc routing protocols. |
