Ejigu Dejene (PhD)Kebede Misganaw2018-06-212023-11-042018-06-212023-11-044/3/2013http://etd.aau.edu.et/handle/123456789/2732The current trend of connectivity anywhere, anytime, and any how brings a new paradigm of accessing multimedia services (voice, video, and text) via MANETs specifically in areas of military, emergency, automotive application e.t.c. However, the available bandwidth for supporting these applications is rather limited, and proper management of the bandwidth is necessary to accommodate the envisaged highbandwidth applications and, thus, provide QoS. In other words it is a must to have QoS support routing protocol that find a feasible path between source/destination pair (i.e. a path that has sufficient available resources capable of satisfying the QoS requirements). In this work, a survey on selected best effort routing protocols (OLSR, DSDV, and AODV) is conducted using qualitative and quantitative multi metrics and shows protocols that work in proactive mode are more suitable for QoS routing than reactive ones. Since routes are maintained, proactive protocols have lower latency where as reactive protocols may have higher latency because a route from source to destination will be found only when sender attempts to send to the receiver. However, proactive protocols can (but not necessarily) result in higher overhead due to continuous route updating. The result finally shows OLSR is a good candidate for QoS improvement. Therefore, reengineering of best effort OLSR proactive protocol using new MPR selection approach is found as the best alternative to add QoS features and the result is a corresponding QoS Aware version of OLSR. Even though a number of variant approaches are available, they are not optimal in selecting MPRs covering 2 hop neighbors and a good quality links. Therefore, we have devised a new selection mechanism that takes in to account the number of MPRs and bandwidth to have a relatively better QoS support. With the help of scenario based simulation analysis, we finally proved that QoS aware OLSR is better than the original OLSR in delivering QoS services. Thus, the algorithm we proposed in architecting QoS Aware OLSR shows improvement to the best effort OLSR in terms of QoS support. Key words: MANETs, Qos Routing, best effort OLSR, QoS Aware OLSR, MPRenManets; Qos Routing ;Best Effort OLSR; Qos Aware OLSR;MPRThesis