基于动力学模型的下一代HBDP网络拥塞控制系统研究

With the rapid development of Gbit networks, wireless sensor networks,IOT(Internet of Things) and satellite networks, traditional network congestion control mechanisms are unsuitable for the High Bandwidth-Delay Production (HBDP) networks. Therefore, congestion control algorithm in HBDP networks becomes one of the hotspots in the next generation Internet research field. This project focus on the stability, nonlinear dynamics and optimal control methods of congestion control system in the HBDP networks with complex wired/wireless network environment and multi-sources and multi-links network topology. Stability and nonlinear dynamics (bifurcaiton and chaos) of network congestion contorl models whose parameters are variable will be studied by use of the Lyapnov stability theorem and Homotopy Analysis Method (HAM) , and the Sliding Mode Controller (SMC) and Nonlinear Random Feedback Controller (NRFC) are used to increase the stable region of the models' parameters. Moreover, several wireless, high speed TCP algorithms and routing algorithms are compared with respect to their performance, and some appropriate congetion control algorithms of the HBDP networks will be developed, considering stability, TCP-friendly and fairness. This project belongs to interdiscipline of communications, networks control and mathmatics. It will help the growth of analysis model of high speed network congestion control algorithms, and development of the theory support for congestion control algorithm suitable for the HBDP networks. This project can give a new theoretic explanation of why the network is congestion, a new method for the research of nonliearity of congesiton control system and a new route for the development of new congestion control algorithms in HBDP networks, therefore it has tremendous importance in theoretical and practical significance.

随着吉比特网络、无线网络、传感器网络、物联网和卫星网络的不断普及，HBDP网络的拥塞控制成为下一代互联网研究的新热点之一。本课题关注HBDP网络复杂环境和拓扑结构下拥塞控制系统的稳定性、非线性动力学行为及其优化控制方法，探索适应HBDP网络的拥塞控制协议。在HBDP网络TCP改进协议和路由协议参数不确定性动力学模型的基础上，利用Lyapnov稳定性定理和同伦分析法(HAM)研究拥塞控制协议模型的稳定性及其动力学行为，如分岔、混沌；并利用滑模控制（SMC）等优化控制方法，扩大系统的稳定性；比较各种TCP改进协议及路由协议的拥塞控制性能，设计兼顾稳定性、友好性、公平性的适合HBDP网络拥塞控制算法。本项目属于通信、控制和数学的交叉学科，为揭示拥塞发生的本质原因提供新的理论依据，为研究HBDP网络拥塞系统非线性提供新方法，为设计HBDP网络拥塞控制算法提供新思路，具有十分重要的理论和实践意义。

本项目采用非线性动力学方法，探索适合HBDP网络的拥塞控制算法，所得出的理论和方法能够较好地应用到实际中去，为正确地分析、准确地设计和控制复杂的实际网络拥塞控制系统提供有效的手段和工具。本项目取得了以下研究成果：建立了HBDP网络拥塞控制系统动力学模型、稳定性条件和复杂非线性动力学现象的存在性；无线网络拥塞控制模型的Hopf分岔的周期解的稳定性和方向；HBDP网络拥塞控制系统一阶离散模型的稳定性；TCP WestwoodLog/RED模型的非线性动力学行为分析及控制；带时延反馈的无线接入网络拥塞系统的Hopf分岔的控制；网络拥塞控制系统对偶模型的分岔控制问题；分数阶小世界网络模型的Hopf分岔的控制；CTCP/RED网络拥塞控制系统的稳定性及分岔控制；复杂网络时延小世界网络中的分岔控制的问题；评估社交网络的社会相关强度问题等。本项目所研究的问题完善和发展了目前互联网拥塞控制系统的理论模型，揭示了网络拥塞控制系统存在非线性现象的本质，具有重要的理论意义和实用价值。