Cache Discovery Policies of MANET

In situations where establishing a network infrastructure is impossible, Ad-hoc networks are considered particularly important. Most of the previous research in Ad-hoc networks concentrated on the development and enhancement of dynamic routing protocols, which could efficiently discover routes between two communicating nodes. Although routing strategies is an important topic in MANETs, other topics such as data access are also crucial since the final goal of using Ad-hoc networks is to provide data access to mobile nodes. One of the most attractive techniques used to improve the data access performance in MANET environment is cooperative caching; which means multiple caching nodes share and cooperatively manage the cached contents. It is lead the research to important questions, what data should be cached, where, when, and how? A cooperative caching addressed into two basic issues: cache discovery and cache management, in other words, how to find requested data efficiently and how to manage an individual cache to improve the overall capacity of a cooperated cache. In this paper we have made a review of the existing cache discovery algorithms to address four stages after application request and before server response, using an historical file to record the previous data requests, and proposed cluster architecture with data cluster head election to store efficient information for future use and reducing the cost of flooding. In addition, this paper suggests some alternative techniques for cache discovery. Finally, the paper concludes with a discussion on future research directions. Keywords-Mobile Ad-hoc networks (MANETs); Cooperative caching; Cache discovery.