Consistency of cooperative caching in mobile peer-to-peer systems over MANET

Abstract

Cooperative caching can be used to improve the availability and scalability in data sharing and dissemination as well as to reduce the network traffic and query delay. Caching consistency is an important issue in cooperative caching but it has not been adequately addressed for mobile ad hoc networks (MANETs). In this paper, we proposed a novel approach, called relay peer-based cache consistency (RPCC), to addressing the caching consistency issues in a MANET. With the introduction of relay peers between the source host and the cache nodes, both push-based and pull-based strategies can be employed, which helps to reduce the communication overhead and query latency. The source host pushes the data to the relay peers and the cache nodes pull the data from the relay peers. These operations can be performed asynchronously and simultaneously. Moreover, the proposed RPCC approach is flexible in that it can deal with three kinds of consistency requirements (strong, Δ and weak consistency) adaptively. Simulation results demonstrated that RPCC outperforms the traditional push and pull based strategies by taking their advantages while at the same time avoiding their weakness.

Keywords:

• Cooperative caching
• Mobile computing
• Peer-to-peer
• MANET

Keywords:

• 68P20
• 68M14

Acknowledgements

This work is partially supported by University Grant Council of Hong Kong under the CERG grant B-Q822 (PolyU 5183/04E), the Hong Kong Polytechnic University under the ICRG grant A-PF77, and the 973 Program of China under the grant 2002CB312002.