On The QoS-Aware Routing Design And Simulation For Mobile Ad Hoc Network

As an important wireless network, mobile Ad Hoc network consists of a group of mobile nodes, which connect with each other via multiple hop wireless links and formulate an autonomous system without pre-deployed network infrastructure. With the development of the mobile Ad Hoc Network and the emerging data traffic, it is highly desirable to take into consideration of the QoS requirement of different traffic to improve the traffic delivery quality. And the QoS-aware routing protocol design plays an important role in the mobile Ad Hoc Network system.Among different MAC layer performance metrics, node interface buffer queue occupancy is an important indicator to reflect the network payload and congestion status. In this thesis, the interface buffer size based QoS aware routing scheme is proposed to be incorporated into the AODV mechanism to realize the improved AODV-qlen scheme. The simulation through NS2in this dissertation validates that the proposed AODV-qlen can achieve the similar performance like the traditional AODV protocol, when the network payload is not heavy. However, the proposed AODV-qlen scheme can significantly overcome the high packet loss rate problem when the network payload is heavy. And the only problem may be the increased delivery time delay of data traffic.Bandwidth, time delay and packet loss probability are several typical QoS parameters which can characterize the data transfer capability of the mobile Ad Hoc Network. And the available bandwidth is a critical parameter to depict the transfer performance of the mobile Ad Hoc network, which is also an important pre-requisite to realize the QoS-aware routing protocol and the access control. In this dissertation, the passive available bandwidth estimate based AODV protocol is proposed in this thesis to derive the improved AODV-be scheme. The analysis in this paper unveils that, better transfer performance can be achieved when considering fully the transfer capability potential of those intermediate nodes in the routing path selection. It is validated through NS2simulation that the proposed AODV-be scheme outperforms the traditional AODV protocol when the network payload is heavy. When the network payload is light, the AODV-be scheme can realize almost the same performance like the AODV scheme.The related analysis in this thesis disclosed that, in practical mobile Ad Hoc network routing scheme design, both the buffer occupancy status and the statistical idle duration are two indicators which can be exploited in the QoS-aware routing scheme design.