Balancing Sensor Communication Performances With MQTT/CoAP and Data Security With TLS/DTLS in Invasive Cardiac Internet of Medical Things

Abstract

Security is a critical concern in the Internet of Medical Things (IoMT), where protecting sensitive patient data and the integrity of device communication are paramount. Medical devices such as pacemakers and defibrillators must ensure the confidentiality and authenticity of the data while maintaining efficient communication in resource-constrained environments. Lightweight protocols such as MQTT (Message Queuing Telemetry Transport) and CoAP (Constrained Application Protocol) are widely used in IoMT to support secure and efficient data transmission. This paper evaluates the performance of MQTT and CoAP in terms of latency, efficiency, and energy consumption under varying packet sizes, considering the impact of security mechanisms such as Transport Layer Security (TLS) for MQTT and Datagram Transport Layer Security (DTLS) for CoAP. The results show that CoAP, with its lightweight UDP-based design, achieves 20 to 35% lower latency and 15 to 25% higher efficiency compared to MQTT in packet sizes ranging from 50 to 500 bytes. When security layers are added, CoAP-DTLS outperforms MQTT-TLS by consuming 20–30% less energy while maintaining comparable latency and efficiency. These findings suggest that CoAP-DTLS is the preferred protocol for energy-constrained IoMT devices, ensuring real-time performance and extended battery life while supporting robust security.