A Review of Application Layer Communication Protocols for the IoT Edge Cloud Continuum

The IoT technological paradigm has become widespread and has found its place within industries such as smart cities, smart grids, smart homes, physical security, e-health, asset management, and logistics. Around 50 billion various devices will soon be connected to the Internet. A hot topic within the IoT field is edge computing, which adds extra computing capacity to the edge allowing to perform computationally intensive operations like execution of Deep Neural Networks possibly requiring specialized devices equipped with Graphical Processing Units. Optimal construction of solutions that span the IoT, edge, and cloud computing layers is still an open research area, and it is believed that edge computing is in its infancy. This article reviews application layer protocols that can be used to interconnect entities belonging to the three previously mentioned layers.