Research On Cross-layer Optimization Technology Of Wireless Ad Hoc Networks Based On The QoS Assurance

Due to the existing Internet service model can not be directly applied to Ad hoc network,a suitable model for QoS needs to be designed from the characteristics of Ad hoc network.The QoS model,including the architecture and framework for service assurance,will be provided for Ad hoc network,and the existing Internet architecture needs to be taken into account,to achieve seamless connectivity with the Internet,from the business applications of Ad hoc network in the future.A key question for the design of QoS model is Ad hoc network needs to provide what level of service quality standards.It will affect the QoS model and all other elements of QoS assurance.The major challenge in this paper is how to provide user acceptable quality of service flexibly,by the dynamic network environment and limited resources,if only discusses a separate aspect of QoS,does not gain a clear distinction between them,it will be difficult to understand and evaluate the performance of the system as a whole.This article discusses the QoS architecture,QoS signaling,the various control strategies,including resources support and business in wireless Ad hoc network,then points out that all levels of QoS control strategy are independent of each other,local optimization and redundant strategy,similar to the multi-repeat,limit the performance of Ad hoc network.The program of blurring the boundaries between layers and cross-layer design will be the tendency of wireless network.Next it gives a viable cross-layer QoS model.Adaptive feedback and adaptive scheduling strategy affect the protocol stack at all levels,to reduce the complexity and redundancy of the original IP QoS,optimize overall performance and increase service quality assurance level in wireless Ad hoc network.This article,based on the existing framework of the Ad hoc network QoS basic service model,gives the specific design of functional components, mainly related to the areas of cache management,admission control,QoS routing,service level mapping,so as to arrive at the issue of main QoS architecture in wireless Ad hoc network.This cross-layer QoS mechanisms framework,based on wireless Ad hoc network QoS assurance,combines the three(forecast,coordination and adaptation) mechanisms at different levels with adaptive mechanism,then provides the assurance of QoS to improve the overall system capacity and reflect the thinking of the cross-layer. Finally,we use mathematical models and network simulation software OPNET for performance analysis of the cross-layer QoS mechanism,and compare with traditional mechanisms to estimate the improvement of mechanism performance in the three areas of the average access delay,packet loss rate,throughput.The simulation results show that the packet loss rate and throughput get more significantly improved.