Research Of QoS Routing Protocols Of Ad Hoc Networks And OPNET Simulations

Ad Hoc networks composed of mobile nodes with wireless communication device are typically characterized by their multi-hop, temporary and un-center. With the nodes in Ad Hoc networks moving fast, the topologies of Ad Hoc networks are constantly changing. The traditional routing protocols used in Internet can not adapt to the need of Ad Hoc networks. Adaptive routing algorithms must be designed to solve the routing question in Ad Hoc networks. The researches on the routing protocols and QoS routing protocols are important research issues of Ad Hoc networks.Firstly, this paper introduces the concept and characteristic of Ad Hoc networks. Then it introduces the two kinds of routing protocols of Ad Hoc networks including the table driven protocols and on demand protocols. We research deeply in the routing protocols such as DSDV, DSR, AODV, and TORA. With Ad Hoc networks developing fast, some applications need guarantee of the service quality. The research in the QoS support is just to solve the problem among which the QoS routing protocols are the important factors. This paper introduces the QoS routing protocols and researches deeply in some typical QoS routing protocols. Then the network simulation and OPNET software are presented in detail.This paper puts forward a new protocol, which can provide QoS guarantee. The protocol chooses the QoS routing path based on dynamic delay restriction and link stability factor. Firstly, SDQR chooses the routing path based on dynamic delay restriction. In the request stage, SDQR chooses the routing path, which satisfies the delay restriction. In the maintenance stage, it examines the changes of the current delay and predicts the delay in the future based on the dynamic delay prediction algorithm so as to choose the optimal routing path with best delay performance. Secondly, SDQR predicts the valid routing time due to the mobile information of the moving nodes. It chooses the most stable routing link, which satisfies the delay restriction in order to decrease the routing cost. SDQR chooses the routing pathbased on the above two conditions so as to provide good QoS performance. This paper implements SDQR protocol in OPNET and compares its performance with DSR. The result shows that SDQR decreases the routing cost, increases the packet delivery rate and decreases the end-to-end delay. Finally the conclusions of this paper and suggestions for future research of the field are given.This paper is supported by National Natural Science Foundation of China (90304018).