一种新的基于分区的多媒体代理协作管理策略

A NOVEL PARTITION-BASED MULTIMEDIA PROXY CACHE COOPERATION MANAGEMENT SCHEME

多媒体代理缓存是提高媒体流化质量和减轻网络负载的重要手段 .将基于协作的多媒体代理缓存技术引入无线网络 ,提出一种新的分区缓存管理模型 (partition- based caching m anager,PBCM) .通过对系统中各个代理的部分缓存空间 (称为静态分区 )采取集中式管理 ,可以合理配置缓存资源 ,降低缓存的冗余度 ,从全局角度优化系统的整体性能 .具体地 ,PBCM中制定了一种全局对象放置策略来管理静态分区缓存的内容 .该策略被模型化为一个优化问题 ,并采用改进遗传算法来求解 .仿真实验表明该模型及算法是有效可行的 .

Multimedia proxy cache is an efficient technique to improve the quality of service of streaming multimedia and reduce network traffic. In this paper, a cooperated multimedia proxy cache architecture, MobileCache, is proposed for cell-based wireless environment. The proxies cooperate to provide seamless streaming for mobile clients. In order to improve the efficiency of MobileCache, a novel cache cooperation management scheme based on partition is proposed. Parts of each proxy's physical cache space are organized in a large logical cache pool and managed centrally, which can take full advantage of the system cache resources and reduce the duplicates among proxies. To optimize the efficiency of the whole system, a global object placement strategy is introduced to manage the logical cache pool. The strategy can be modeled as an optimal problem and a modified genetic algorithm is presented to solve it. Simulation proves that the scheme and algorithm above improves the QoS of multimedia streaming, while startup latency and network transmission cost are notably reduced.