【作者】 朱龙杰；

【导师】 方旭明；

【作者基本信息】 西南交通大学 ， 通信与信息系统， 2006， 硕士

【摘要】 呼叫允许控制(Call Admission Control,CAC)技术是无线蜂窝网资源管理的主要内容之一,它通过接纳或者拒绝一个用户的服务请求,来保持系统的正常运行,是平衡用户服务满意度与系统资源最大化利用矛盾的主要手段。随着无线蜂窝网3G技术的到来,话音、视频、数据等多媒体综合业务将成为网络的主流业务。在一个综合业务的无线蜂窝网中,由于变速率业务的存在,使该系统的CAC难度增大。同时,由于分组交换技术正逐渐成为未来无线通信网络的核心技术,而在分组网络中CAC面对的对象将不再是连接而是分组,所以传统的基于连接的CAC方案将不能满足需求。本文在对综合业务CDMA无线蜂窝系统建模的基础上,仿真分析了基于连接的CAC方案,以及基于分组的CAC方案。通过设置联合接入判决准则以及合理地降低优先级较低的业务用户服务速率,降低了系统溢出率及阻塞率,提高系统性能。在对基于分组的CAC方案的研究中,提出了用户连接允许控制与用户分组允许控制协作的CAC机制,以及一种基于优先级的改进CAC方案,通过仿真与分析说明该方案提高了系统性能与网络QoS,针对下一代无线多媒体网络具有参考意义。 本文第一章介绍了研究背景、论文的研究内容与组织结构。然后在第二章介绍了无线蜂窝网中的CAC技术,以及研究多媒体无线蜂窝网CAC技术的方法,其中包括多媒体业务建模与系统仿真平台。第三章研究了基于连接的多媒体无线蜂窝网CAC技术,在仿真分析基于优先级的CAC方案的基础上,提出了基于优先级的改进CAC方案与基于剩余容量的自适应CAC方案。本文第四章针对基于分组的多媒体无线蜂窝网CAC技术进行了仿真研究,通过仿真结果分析验证了基于分组的CAC方案对系统性能改善的显著作用。 最后总结了全文,并提出了未来的工作方向。更多还原

【Abstract】 Call admission control (CAC) is one of the most important parts of resource management in wireless cellular networks. It keeps the system work stable through accepting or rejecting users’ service requests. CAC solves the conflict between the service satisfaction of user and system resource utilization. With the emergence of the 3rd generation of wireless cellular networks, multimedia traffics, such as voice, video, data, etc., become the leading services provided by networks. The presence of variable bit rate traffics makes the CAC be more complicated for the system in the multi-traffics wireless cellular networks. On the other hand, since the packet switching is becoming the primary technology in future wireless communication networks and the CAC in the packet switching networks are not facing user’s connection but every single packet, conventional CAC schemes will not satisfy the system requirement. In this thesis, the simulation and performance analysis of connection odentied CAC schemes and packet odentied CAC schemes are given out with the foundation of modeling multi-traffic CDMA wireless cellular system. New connection odentied CAC schemes are proposed to decrease system outage probability and blocking probability for better system performance, through setting combined admission criterions and decreasing the service bit rate of lower-priority user reasonably. Based on the simulation and analysis, connection odentied CAC schemes in multi-media wireless cellular networks are investigated in the 3rd chapter. An advanced priority based CAC scheme and an adaptive residual capacity based CAC scheme are proposed with the foundation of simulation and analysis on the priority based CAC scheme. In the 4th chapter of thesis, packet orientied CAC schemes in multi-media wireless cellular networks are studied, and it’s proved that, packed orientied CAC scheme improves the system performance significantly, by the simulation and analysis results.Finally, the thesis is summarized and the future work is brought forth.更多还原