State-of-the-Art Data Replication Techniques in IoT-Based Sensor Systems

Internet of Things (IoT) is an emerging technology aimed at bridging the gap between physical and digital worlds. IoT envisions to provide a seamless and efficient way of interacting with real-world physical objects through the Internet which highly impacts modern day life. Wireless Sensor Networks (WSNs) are primarily responsible for turning physical objects into communicating entities that can be remotely accessed and controlled, thus, providing the basis for smart solutions to all the human needs. To realize the concept of IoT, efficient data generation, collection, and presentation through WSNs are crucial issues. However, WSNs face numerous challenges mainly because of the resource-constrained and unreliable nature of nodes which may result in loss of valuable sensed data. Data replication is a promising solution to facilitate efficient data management in IoT-based sensor systems. This paper presents a survey of state-of-the-art data replication protocols for IoT-based sensor systems. To the best of our knowledge, our study is the first one that presents a detailed analysis and comparison of the existing solutions by classifying them into sub-categories of data retrieval, query balancing, system robustness, and data availability. We conclude by highlighting potential future research directions.