Research On Resource Management In Novel Broadband Wireless Access Networks

Broadband wireless access networks have many advantages such as the lower cost, shorter construction period, faster service provision and stronger flexibility, which represent a new trend that can not be ignored. Resource management is one of the key issues in the research on broadband wireless access networks. This dissertation focuses on the efficient resource management and the QoS improvement. An in-depth study on the resource management problem in broadband wireless access network is presented.WiMAX WMNs (Wireless Mesh Networks) is one of the most promising broadband wireless access technologies in the future. However, Due to the broadcast characteristics of wireless media, maximizing network throughput and providing QoS support for data transmission has become one of the key issues in WiMAX WMNs. Theoretically the interference aware link scheduling model with objective of maximizing the entire network throughput is analyzed. A heuristic algorithm to solve the near optimal scheduling length is proposed for link list with fixed sequence. Furthermore, as the performance is much more affected by the sequence of the link list, the link scheduling scheme is proposed to sort the overall network link list.based on genetic algorithm. Simulation results demonstrate that the proposed scheme can converge to the optimal schedule length more rapidly, thus having a better transfer efficiency and a lower implementation complexity than the existing algorithms.As the demand of transfer efficiency of multimedia services has become much higher, undoubtedly, searching the link scheduling scheme to satisfy both throughput and transmission efficiency requirement is of great significance. The relationship between link scheduling and throughput as well as the delay of end to end transmission is analyzed. With the design of the expansion graph model by node decomposition, a unified framework to solve the link scheduling algorithm with single transmission and multiple transmissions is designed. The fast link scheduling algorithm is also proposed to speed up computing in the condition of node decomposition. With the introduction of multi-objective optimization theory, performance evaluation based on Pareto rules for scheduling algorithms is given and the NSGA-Ⅱ based link scheduling algorithm is proposed. Simulation results validate the above claims.Multi-radio multi-channel WMN can significantly enhance the network capacity. However, traditional algorithms merely aim at minimizing the overall network interference, which lead to the reduction of the network connectivity. By analyzing the relationship between channels assignment with the whole interference and connectivity, the corresponding evaluation criteria of node, link and channel selection are defined, and then the node-level oriented and link-level oriented channel assignment schemes based on greedy algorithm are proposed. Furthermore, a link scheduling scheme based on NSGA-II is proposed. Extensive simulation results demonstrate the effectiveness of these approaches.The multimedia applications will become the main part of the network traffic in the future broadband wireless network. As to the time variation, non-linearity and long range dependence in VBR video traffic trace, a novel method of feature based on multi-scale decomposition is proposed. The wavelet packets which have the trait of arbitrary distinction and decomposition are selected. After space partition of wavelet packets, the best wavelet packet basis for feature extraction is picked out. Based on the best basis, it can do fast arbitrary multi-scale WPT (Wavelet Packet Transform). On the basis of LS-SVM and LMS algorithms, the wavelet coefficients prediction is proposed. The long-term prediction of VBR video traffic is obtained through reverse wavelet transformation on the predicted wavelet coefficients. Furthermore, the resource management scheme on the basis of prediction time window is proposed. Numerical and simulation results are provided to validate the claims.Broadband satellite access network has become an important component of next generation networks. Traditional resource request mechanisms lag far behind the increasing traffic, and cannot meet the communication needs in satellite link with long transmission delay. In this dissertation, the resource allocation procedure and time sequence of resource requests in MAC protocol for multimedia satellite network are analyzed systematically. A resource request algorithm combined traffic prediction and recording operator is proposed. The algorithm can decrease the number of request signaling messages and shorten the resource response time. Further, a bandwidth allocation combining free slots allocation and fair allocation is proposed. The simulation results show that the algorithm proposed can greatly improve the bandwidth allocation efficiency, and is superior to other existing resource request algorithms in the adaptability under conditions of high load ability and long peak transmission time.