Um estudo e avaliação do desempenho de Protocolos de Aplicação para a Internet das Coisas

Abstract

The Internet of Things aims to facilitate automatic interaction and access to industrial, automation and home devices such as sensors and actuators .One of the challenges for IoT development is the growing number and heterogeneity of devices. Proposed software frameworks for IoT, such as FIWARE [1], DOJOT [2], SOFIA [3], OpenIoT [4], usually include support services, and device integration with client application modules. These frameworks feature an Application layer, which includes Application Protocols, oriented to the interaction between processes and devices. Several Application Protocols are established and some standardized, with emphasison HTTP[5], MQTT[6], CoAP [7], AMQP[8], XMPP[9], and WebSocket [10]. This work evaluates the performance of each of those protocols in a Wi-Finet work. For testing of all selected protocols, four "dimensions" were combined: the 6 protocols; 1 quantitative metric (RoundTripTime); 3 scalability metrics (message size, number of sensors and band width available) and 2 qualitative metrics (reliability/QoS) and security layer usage. The tests were performed in an isolated environment. Test applications were developed for sending and receiving messages. This also made it possible to verify the feasibility and viability of using some libraries available for Node MCU devices and Android mobile devices. The results of the performance tests are presented and discussed. Those results allow us to identify the differences in performance and operating characteristics between the Application Protocols that need to be considered according to the application and will use them. Some application scenarios are associated with evaluated parameters of message size, bandwidth and number of devices used.