DATA EXCHANGE MODEL IN THE INTERNET OF THINGS CONCEPT
Iryna Afanasieva, Nataliіa Golіan, Oleksandr S. Hnatenko, Yana Daniiel, Kostiantyn Onyshchenko · Telecommunications and Radio Engineering · 2019
Proposed Data exchange model that combines MQTT and Modbus, is based on the Observer pattern to organize interaction between the system components in the Internet of Things concept. Modbus is used as the local interface for interacting with devices and MQTT is responsible for organization of global connections between the components of the system. In this case, Internet gateways support both protocols that ensure the stability of the systems. The QoS of MQTT were investigated, their main advantages and disadvantages were determined. The QoS 2 of MQTT, which uses the four-step verification procedure for message delivery was selected. The smart device emulator and the system prototype in the Internet of Things concept were developed. The proposed Data exchange model was compared to HTPPS in 3G and Wi-Fi networks. The research results showed that the bandwidth of the HTTPS protocol is 93 times smaller than the proposed combination of MQTT and Modbus protocols. Using the second level of quality, the MQTT protocol ensures 100% delivery of messages, unlike the HTTPS protocol, that delivers from 20% to 50% of all messages.