Caching transient data in Information-Centric Internet-of-Things (IC-IoT) networks: A survey

The Information-Centric Internet-of-Things (IC-IoT) will connect billions of devices to the Internet, which allows for many remarkable applications like smart homes, smart grids, smart transport, and digital health to become a reality. However, such a massive number of connections are certain to generate huge amounts of data and present a real challenge to the network. Caching is one key solution to this problem; however, traditional caching solutions are ineffective in dealing with IoT-produced content due to its transient nature. As such, research on developing caching solutions for transient IC-IoT data has been gaining momentum. This paper aims to provide context for the research efforts in the field, highlight the significance of freshness-aware solutions, demonstrate the contributions of current works, and identify areas for future developments. As such, this article first provides a high-level overview of IC-IoT, caching principles, and data freshness. We then thoroughly examine the state-of-the-art cache placement, cache replacement, and cache coherence policies for transient IC-IoT data. After that, the surveyed works are analyzed from four perspectives: (1) cache deployment, (2) service model, (3) evaluation tools, and (4) evaluation metrics and baselines. Lastly, we conclude this paper by outlining what we believe to be the most promising six research directions for caching transient data in the IC-IoT domain.