移动Ad Hoc网络下协作缓存策略研究

Research on Cooperative Caching Strategy in Mobile Ad Hoc Networks

缓存是提高数据访问效率的一种常用技术。协作缓存技术,在多节点间实现缓存数据的共享,发掘缓存技术的潜能。移动Ad Hoc网络中缓存的基本问题是:缓存放置、缓存发现以及缓存替换。根据两种基本缓存的优点,结合Ad Hoc网络环境的动态变化,提出一种效率更高的Adaptive缓存放置策略。同时由于Ad Hoc网络资源有限性,文中对现有的COOP缓存发现策略引入了核心节点概念,提出一种改进的E-COOP策略。仿真结果表明,相比其他现有的缓存方案,Adaptive缓存放置策略配合改进的E-COOP缓存发现策略,在查询延迟、能量损耗、数据吞吐量等方面具有显著优势。

Caching is a common technique to improve the performance of data access.Cooperative caching,which allows the sharing and coordination of cached data among multiple nodes,can further explore the potential of the caching techniques.The basic issues of caching in mobile Ad Hoc networks are about cache placement,cache discovery and cache replacement.For this,we propose an efficient adaptive cache placement strategy based on the advantages of two basic caches and the dynamic changes of Ad Hoc networks environment.At the same time,due to the limited resources of Ad Hoc networks,the existing COOP cache discovery strategy is introduced into the core node concept,and an improved E-COOP strategy is proposed. Then,the adaptive cache placement is combined with the improved E-COOP cache discovery scheme in a caching system compared to the existing caching scheme. Simulation shows that the proposed schemes can significantly reduce the query delay,energy consumption and improve network throughput.