Data Caching and Prefetching Using Collaborative Caching and Prefetching Algorithm in Wireless ADHOC Networks

Prefetching the information is a prominent strategy that enhances information availability in wired or remote systems. However, in wireless ad hoc networks, improvement in access latency and cache hit ratio may diminish because of the mobility and limited cache space of hosts. The proposed scheme uses a Collaborative Caching with Data Prefetching (CCDP) which is a method that prefetches the image based on association among data items. The scheme prefetches highly related data items and considers confidence of association rules. Whenever a node issues a request, the cache request processing module first logs this request into record and checks whether the desired data item is available in local cache of that node or in any of the node in the cluster. If it is a cache hit, the cache manager still needs to validate the consistency of the cached item with the copy at the original server. To validate the cached item, the cache manager checks the validation of data item from its TTL value. If the data item is verified as being upto date, it is returned to the node immediately. If it is a cache hit, but the value is obsolete, the cache manager sends an uplink requests to the server and waits for the data broadcast. When the requested data item appears, the cache manager returns it to the requester and retains a copy in the cache. The simulations are done using both MATLAB and Network Simulator 2 tool and the performance metrics like throughput, packet loss and delay will be compared with previous schemes.