Smart Home Connectivity: Identifying the Best IoT Application Layer Protocols

The Internet of Things (IoT) bridges the physical and digital worlds by utilizing sensors, actuators, communication technologies, computing power, and data analytics to enable precise monitoring and control of the surrounding environment. Leveraging the data derived from IoT can lead to optimal decision-making for system management. In smart homes, IoT has ushered in a new generation known as connected homes. Given the diverse range of protocols available for the IoT application layer, selecting the appropriate protocol to connect smart home devices (based on their specific requirements) to the internet gateway is a critical issue. This paper first identifies the key factors influencing the choice of application layer protocols in smart homes. Then, it examines and analyzes some of the most commonly used IoT application layer protocols, including HTTP, MQTT, CoAP, WebSocket, DDS, XMPP, AMQP, STOMP, LwM2M, Zigbee, Z-Wave, BLE, and 6LoWPAN, based on these factors. Finally, recommendations for protocol selection in various sections of a smart home are provided based on the analysis conducted.