Database caching in MANETs based on separation of queries and responses

This paper proposes a model for caching database data in mobile ad-hoc networks through caching the queries and their responses. The approach makes a distinction between the queries and their responses and caches them on separate mobile nodes. This method is driven by the fact that queries do not become invalid unless when the design of the database entities changes while data changes depending on the application that feeds information into the database. The architecture we use is hierarchical and employs three types of designated nodes: a query directory (QD), service manager (SM), and caching node (CN). The one or more QDs are responsible for caching the queries and are assigned and supervised by the SM that also oversees the mobility activities and the availability of nodes in the network and makes "managerial" decisions accordingly, including appointing backup nodes. With this model, any node that joins the ad hoc network will either contribute services to other nodes (willingness to become an SM, a QD, or a CN) or consume services offered by other nodes. This model attempts to coordinate the query executing and query caching mechanisms in a seamless manner while maintaining minimal communication among nodes. We present preliminary results of a model that was simulated using the NS-2 software and show the viability of the proposed approach.