Abstract: This paper deploys P2P system in mobile campus network and then presents an effective cooperative caching strategy. Access control strategy uses “threshold value” and relationship of location between two nodes to select the data to be cached. Cache replacement strategy chooses the data which will be replaced by the “Cost” function that is decided by three factors: data popularity, data size and distance between two regions. Data consistency strategy combines benefits of Plain-Push and Pull-Every-time and then makes improvements. Two sets of simulation experiments show that cooperative caching strategy achieves better performance in terms of reducing latency, decreasing overhead of network communication and improving the hit ratio.

Key words: mobile P2P network, cooperative caching, access control strategy, cache replacement strategy, data consistency strategy

摘要： 在移动园区网环境中部署了P2P系统并提出了一种协同缓存策略。接入控制策略利用“阈值”和节点的位置关系选择缓存的数据。缓存替换策略利用价值函数“Cost”选择要替换掉的数据，该函数考虑了数据的被访问频率、大小及区域之间的距离这三个因素。数据一致性策略结合了Plain-Push和Pull-Every-time方案的优点并做了改进。通过两组模拟实验验证了这种协同缓存策略在降低时延、减少网络通信开销、提高缓存命中率方面具有较好的性能。

关键词: 移动P2P网络, 协同缓存, 接入控制策略, 缓存替换策略, 数据一致性策略