Monitoring QoS in Wireless Ad Hoc Networks
Date of Award
Doctor of Philosophy in Information Systems (DISS)
Graduate School of Computer and Information Sciences
Francisco J. Mitropoulos
Wireless ad hoc networks allow spontaneous collaboration and exchange of information using streaming multimedia applications without any wired infrastructure. To do so, streaming video or audio applications require QoS methods that ensure minimal jitter, delay, dropped packets, and maximum throughput during periods of congestion. Standard mobile ad hoc network (MANET) routing protocols do not consider QoS in their algorithms; therefore, these routing protocols do not provide QoS guarantees during periods of congestion. Past research had proposed routing protocols that consider a single QoS parameter such as battery-life, bandwidth capacity, or link quality. However, routing protocols that consider bandwidth or link quality are not able to identify mobile nodes that are experiencing congestion or high resource utilization. Thus, mobile nodes that cause or experience congestion may not have adequate resources to provide routing services. This work proved that updating the MANET Dynamic Source Routing (DSR) protocol to monitor and route based on resource utilization levels improved certain aspects of QoS for streaming multimedia applications. This work modified the Network Simulator 2 program to implement the protocol update and thereby enabled mobile nodes to monitor for congestion using defined thresholds related to jitter, queue capacity, and battery level. Violations of these thresholds indicated congestion and resulted in the use of multi-path routing and route admission control in an effort to manage and avoid congestion. This work compared the simulation results of the updated DSR protocol with the standard DSR protocol, and used simulation scenarios to test basic operations and performance of the protocol update in typical MANETs. The performance metrics of throughput, average end-to-end delay, dropped packets, and jitter were measured using both DSR protocols. The results indicated that the updated DSR protocol consistently produced higher throughputs. Additionally, the updated DSR protocol frequently produced superior jitter values, comparable end-to-end delays, and comparable packet loss at the expense of generating additional routing packets. Finally, this work recommended that future research: explore the impact of battery consumption as related to multi-path routing; explore the monitoring of other resource utilization parameters; and evaluate the use of multi-path routing amongst other MANET routing protocols.
Randy L. Melton. 2008. Monitoring QoS in Wireless Ad Hoc Networks. Doctoral dissertation. Nova Southeastern University. Retrieved from NSUWorks, Graduate School of Computer and Information Sciences. (721)