Internet of Things: Architectures, Enabling Technologies and Application Protocols

This review summarises the literature on the Internet of Things (IoT), covering architectural visions, enabling technologies, application-layer protocols and the use of IoT in urban services. It draws on widely cited surveys and two protocol specifications (CoAP and MQTT) and compares the two protocols on their stated design goals. It concludes with open issues that the surveys identify, including interoperability and the handling of large data volumes. This is a narrative review; it contains no new data.