A Performance Evaluation of Raspberry Pi Zero W Based Gateway Running MQTT Broker for IoT

The Internet of Things (IoT) has become widely used in recent years in a wide range of applications, such as, weather condition monitoring, transportation, smart homes, smart cities, smart farm, etc. The ecosystem of the IoT is also vast, including from sensor and hardware devices up to cloud-computing. An approach that is getting more and more attention in the IoT ecosystem is the edge-computing and one of its fundamental pieces of equipment is the edge-computing gateway (GTW), which can working as a data-processing device nearer to the things and as a bridge to the Internet, as well. The most important features for these GTWs must be robustness and efficiency and a very popular solution is to use low-cost Raspberry Pi card-size computers. Considering protocol solution, Message Queue Telemetry Transport (MQTT) communication protocol has been considered one of the most applicable to IoT because of its low-power capability. In this context, this paper describes a study about the performance evaluation of a low-power member of the Raspberry Pi family, the Raspberry Pi Zero W, working as an IoT gateway and running MQTT. The experimental results show its performance using as metrics: the processor temperature, the CPU usage level, and rate of MQTT received messages under different Quality of Services (QoS).