A literature review on collaborative caching techniques in MANETs: issues and methods used in serving queries

Collaborative cache management in Mobile Ad Hoc Networks (MANETs) environment is considered as an efficient technique to increase data accessibility and availability, by sharing and coordination among mobile nodes. Due to nodes’ mobility, limited battery power and insufficient bandwidth, researchers addressed these challenges by developing many different collaborative caching schemes. The objective of this paper is to review various collaborative caching techniques in MANETs. Collaborative caching techniques are classified by methods used in serving queries, such as: hop-by-hop discovering, broadcasting messages, flooding, and query service differentiation. This review reveals that techniques utilizing hop-by-hop methods have better performance compared to others, especially techniques using additional strategies

MELOC - memory and location optimized caching for mobile Ad hoc networks

The advancement of Mobile ad hoc networks (MANET) is tremendous in the field of social and military applications. Caching and Replication are the two common techniques used to improve data access efficiency in Mobile Ad hoc networks. Caching favors data access efficiency by bringing data closer to the source. Existing caching approaches are deficient in reducing the number of cache locations, thus reducing the number of copies, which is needed for many mission critical applications considering safety and security. Conversely, reducing the number of caches should not affect the efficiency of data access. We design an efficient broker based caching model named Memory and Location Optimized Caching (MELOC) , which reduces the number of cache locations, and at the same time preserves data access efficiency. Our caching model mostly chooses centrally located nodes as cache location. In addition, we cache only essential data closer to the source, saving memory. Hence our approach bears the name Memory and Location Optimized caching (MELOC) . Our initial MELOC model suits only small MANET topology of 30 nodes. We further extend our initial caching model to suit large MANET topology of 100 nodes by overcoming certain disadvantages pertaining to large network topology --Abstract, page iv

Alternative Topology Construction for Cooperative Data Distribution in Mobile Ad Hoc Networks

Ad hoc networks of mobile nodes can be used to extend or improve connectivity, and cooperative data distribution represents the basis of this approach. Cooperation in such networks can be improved by providing nodes with information on network dynamics and topology changes. This paper proposes a proactive approach to handling mobility-induced network topology changes. The approach uses signal strength trends to predict the future locations and connectivity between the network nodes. Our research is aimed towards the creation of an alternative topology in each node, where a node would keep other nodes suitability for cooperation in the data distribution. In this paper we present the initial algorithm and test the prediction method using a simulation. The algorithm is then applied in an experimental testbed where its performance was tested using real moving nodes executing a real data distribution process. The performance results show a significant improvement in terms of file transfer delay

On Improving the Robustness of Partitionable Internet-Based Mobile Ad Hoc Networks

Recent technological advances in portability, mobility support, and high speed wireless communications and users' insatiable interest in accessing the Internet have fueled to development of mobile wireless networks. Internet-based mobile ad hoc network (IMANET) is emerging as a ubiquitous communication infrastructure that combines a mobile ad hoc network (MANET) and the Internet to provide universal information accessibility. However, communication performance may be seriously degraded by network partitions resulted from frequent changes of the network topology. In this paper, we propose an enhanced least recently used replacement policy as a part of the aggregate cache mechanism to improve the information accessibility and reduce the access latency in the presence of network partitioning. The enhanced aggregate cache is analyzed and also evaluated by simulation. Extensive simulation experiments are conducted under various network topologies by using three different mobility models: random waypoint, Manhattan grid, and mo -di -fied random waypoint. The simulation results indicate that the proposed policy significantly improves communication performance in varying network topologies, and relieves the network partition problem to a great extent