Cache management in mobile ad hoc networks

Cache management tackles with the issue of maintaining data consistency between the cache client and data source. Data consistency refers to the freshness of the data in cache client. The process of maintaining cache consistency becomes difficult as the nodes are resource-constraint. Three types of cache consistency algorithms are available: Push-based algorithm, Pull-based algorithm, Hybrid algorithm. In Push-based algorithm, server helps in maintaining data consistency by sending the updated information to client. In Pull-based algorithm, client request the server for the updated information to maintain data consistency. In Hybrid algorithm either server or client involves in maintaining cache consistency. Smart Server Update Mechanism (SSUM) is an efficient push-based cache invalidation method in which server adjusts the cache update rate, according to data request rate in order to reduce the network traffic. Distributed Cache Invalidation Method (DCIM) is an efficient pull-based cache invalidation method compared to other methods in which strong cache consistency is ensured by implementing adaptive TTL, piggybacking, and prefetching. Piggybacking reduces the traffic in the network and prefetching reduces the query delay.

Solution in NS2

  • The framework of these three algorithms can be simulated and their performance can be evaluated using NS2.

  • Xgraph for performance metrics such as query delay, consistency ratio and network traffic can be generated.

  • Limitation of the Cache Invalidation Methods can be reduced using effective solution and cache invalidation can be enhanced to improve its performance.

  • Performance of the Enhanced Cache Invalidation Methods can be compared with the existing methods using NS2.

Related Titles:

  • Kassem Fawaz, Student Member and Hassan Artai “DCIM: Distributed Cache Invalidation Method for Maintaining Cache Consistency in Wireless Mobile Networks” IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 12, NO. 4, APRIL 2013.

  • Khaleel Mershad and Hassan Artail, “SSUM: Smart Server Update Mechanism for Maintaining Cache Consistency in Mobile Environments” IEEE TRANSACTIONS ON MOBILE COMPUTING, VOL. 9, NO. 6, JUNE 2010.