Researches On QoS Techniques In Wireless Heterogeneous Networks Environments

Maritime communication environment is composed of several kinds of networks includingshort-wave communication, ultra short-wave communication and satellite communication and soon. The differences between them and the mobility of communication nodes impact theheterogeneity and complexity of network structures and effective communication wayssignificantly. The great heterogeneity and the variability of a heterogeneous networkenvironment result in a series of practical problems, such as the uniform management of theresource, access management, QoS guarantee, and security, etc. The guarantee of QoS as acrucial element for further heterogeneous networks faces many challenges. It mainly includeslacking of uniform QoS classifications, techniques in general and the global QoS optimization.This dissertation mainly deal with the horizontally QoS mapping mechanism and QoS routingalgorithm for the purpose of building a future wireless heterogeneous network with betterperformance. It will establish a sound theoretical basis for the QoS guarantee in wirelessmaritime communication network.A Policy-Based Dynamic Mapping (PBDM) method was proposed, which aims at thehorizontally QoS mapping in the heterogeneous environment. It firstly classifies those differentcommunication services according to the respective characteristics and generates QoS mappingschema among each two heterogeneous networks. The different policy can be chosen accordingto the variability of the network traffics and the flexible adjustment of the mapping cansignificantly improve the resource utilization without obvious variability of the targetapplications’ QoS index. The experimental results show that the QoS of observed services can besatisfied effectively and the performance of the network is improved significantly.An approach on QoS Routing Selection with Reliability Estimation (QRS-RE) in a wirelessheterogeneous environment is also proposed in this dissertation. It can establish the optimalrouting by comparing the resource state of the known routes with the service request and thereliability for the specified routes, and finally calculating the satisfaction index between routesand services. The comprehensive experiment and wide analysis was performed to select thethreshold for the satisfaction index and other parameters. The experimental results show that theproposed approach of QRS-RE can effectively determine an optimal route for a specified taskand improve the utilization of network resource with a better performance.In conclusion, this dissertation proposes two approachs of a PBDM and a QRS-RE, which mainly deals with the horizontally QoS-mapping and QoS routing issues in the wirelessheterogeneous network and were verified effectively in the simulated experimental environments.They provide a theoretical reference for solving the QoS problems in wireless heterogeneousnetwork environment, and are benefit for improving the future maritime communicationnetwork’s QoS.