Easy as ABC: A Lightweight Centrality-Based Caching Strategy for Information-Centric IoT

In Information-Centric Networking (ICN), the ability to cache content at multiple points in the network is one of the most important factors in the speed and reliability of content delivery. However, in the constrained environment of the Internet of Things (IoT), memory is often a scarce resource, which means that particular focus needs to be placed on how to use the available memory for caching. Previous research has shown that caching heuristics that take network topology into account have great promise, but are often not feasible for use in the IoT as they typically incur high overheads or require extensive knowledge of the topology. We introduce a simple content caching strategy called Approximate Betweenness Centrality (ABC), which makes use of the topology-based heuristics of existing strategies, but requires no knowledge of the network and incurs no communications overhead. We compare this new strategy to several existing ICN caching strategies and evaluate its effectiveness using real IoT devices in a large physical testbed. We show that our lightweight approach can deliver results that are comparable to those of more expensive strategies while incurring almost no additional costs.