【作者】 方红雨；

【导师】 李晓辉；

【作者基本信息】 安徽大学 ， 电路与系统， 2006， 硕士

【摘要】 随着Internet的发展，出现了如视频点播、电视会议、远程学习、计算机协同工作等新的业务。用传统的点到点通信方式，不仅浪费大量的网络带宽，而且效率很低。一种有效地利用现有带宽的技术就是多播技术。多播是一种点到多点(和多点到多点)的通信方式，即多个接收者同时接收一个源发送的相同信息。以实时多媒体应用(如网络会议、网上直播和网络教室等)为代表的新型网络应用对网络服务质量要求较高，从而对应用广泛的多播通信技术也提出了迫切的要求，在不同的应用领域出现了多种多播路由协议和算法。 大多数路由算法使用的是基于单个服务质量指标的多播树优化方案，得到的是一棵树路由。本文提出了将多播路由的选择过程模型化为一个多指标优化问题，使用多目标遗传算法进行求解。基于多目标优化的遗传算法是最近出现的解决多指标优化问题的崭新方法，它运用Pareto优胜关系来处理多个相互冲突的待优化指标。 本文在分析多棵树路由问题的基础上，提出一种基于不同树策略的路由算法来同时优化多种服务质量指标，以多棵树路由作为多播通信方案来获得较低的综合代价，达到平衡网络负载的功效。由于多播路由的最优选择问题在多项式时间内难以求解，因此利用了遗传算法原理来优化多个指标。仿真结果表明多树策略的使用可降低网络的整个链路代价，这种路由算法具有较好的性能。 传统的多播技术处理的都是针对固定节点的情况，如要在移动IP网络中实现多播，不仅要考虑到动态的成员关系，还要考虑到成员的动态的位置关系。随着移动IP的逐渐成熟和完善，在该网络模型下如何较好地实现多播，成为人们迫切要解决的问题。更多还原

【Abstract】 With the development of Internet, a lot of new operations have emerged, such as video-on-demand, videoconferencing, long-distance learning, computer coordinated work, and so on. The traditional communication mode, point-to-point, not only wastes a great deal of network bandwidth, but is of very low efficiency. A new technique, which takes efficient advantage of existing bandwidth, is called multicast. multicast is a point-to-multipoint (as well as multipoint-to-multipoint) communication mode, i.e. many receptors receiving simultaneously the same information from one resource. The new type of network application, typically real-time multimedia (e.g. net conferencing, living broadcast on line, classroom on line, etc.), requires high-quality network services, thus demands urgently the widely-used multicast communication technique, resulting in various multicast route protocols and algorithms in different application areas.Most route algorithms take use of multi-tree optimizing project, which is based on a single targeting for service quality, and achieve the one-tree route. This article puts forward the way in which the selection-process model is converted into a multi-targeting optimization problem, which seeks solution by the multi-targeting heredity algorithm. Dependent on optimizing multi-targeting, the heredity algorithm is a new method solving the problem of optimizing multi-targeting. This algorithm, taking advantage of Pareto superior relation, disposes of a number of conflicting indices to be optimized.On the basis of analyzing the multi-tree route problem, this article presents another route algorithm depending on different-tree strategy in order to optimize many types of service quality indices simultaneously. And this algorithm adopts the multi-tree route as a strategy for multicast communication, so that a relatively synthetic cost can be更多还原