Cooperative Caching in Mobile Ad Hoc Networks

Abstract

Mobile ad hoc network (MANET) presents a constrained communication environment due to fundamental limitations of client’s resources, insufficient wireless bandwidth and users’ frequent mobility. MANETs have many distinct characteristics which distinguish them from other wireless networks. Due to frequent network disconnection, data availability is lower than traditional wired networks. Cooperative caching helps MANETs in alleviating the situation of non availability of data. In this paper, the authors present a scheme called global cluster cooperation (GCC) for caching in mobile ad hoc networks. In this scheme, network topology is partitioned into non-overlapping clusters based on the physical network proximity. This approach fully exploits the pull mechanism to facilitate cache sharing in a MANET. Simulation experiments show that GCC mechanism achieves significant improvements in cache hit ratio and average query latency in comparison with other caching strategies.

Cache Replacement in Mobile Adhoc Networks

“…If it is a cache hit, but the value is obsolete (i.e., the TTL has expired), the cache manager initiates a cache discovery process. Cache discovery process is same as proposed in Chauhan, Awasthi, Chand, Misra, and Joshi (2010) that is when a client suffers from cache miss, the client looks the required data from cluster members. When the client does not find data in cluster members, it will request the cache state node (CSN) which keeps the global cache state and maintains the information about the node in the network which has copy of desired data item.…”

“…The proposed replacement scheme (PBR) has been implemented on Global Cooperative Caching (GCC) (Chauhan, Awasthi, Chand, Misra, & Joshi, 2010). In GCC, the network topology is divided into predefined equal sized geographical grids called clusters.…”

“…The simulation area is assumed of size 1500 m x 1500 m. The clients move according to the random waypoint model (Bettstetter, Resta, & Santi, 2003). Performance comparison of GCC using PBR has been performed with GCC scheme (Chauhan, Awasthi, Chand, Joshi, & Misra, 2011). The node density is changed by choosing the number of nodes between 50 and 100 in a fixed area.…”

“…MANETs do have applications in sensor networks also, where sensors are used to study or analyze the properties of an area. In MANET which is demand based infrastructureless network, being resource poor, caching plays a vital role in making such network a success (Hara & Madria, 2009;Chauhan, Awasthi, Chand, Misra, & Joshi, 2011). This being a multi-hop environment, the request from a requesting node or the reply from a responding node will traverse to either direction through multi-hop connections.…”