Author(s):
Chi-Hua Chen^a, Ming-Shan Yeh^b, Yi-Hsin Lin^c, Chin-Chieh Huang^d, Shau-Sheng Tung^e, Wen-Hsien Chiang^f, Moa-Tai Chen^g, Kuen-Rong Lo^h

Author Affiliation:
Telecommunication Laboratories, Chunghwa Telecom Co., Ltd., No. 99, Dianyan Rd., Yangmei District, Taoyuan City 32661, Taiwan, R.O.C.

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Recently, Internet of Things (IoT) has become more and more popular. Several applications for IoT devices have been designed and developed to detect environmental changes and send instant updates to a cloud computing server farm via mobile communications and middleware for big data analyses. Multiple international organizations such as oneM2M have established specifications of M2M (Machine to Machine) communication and provided some use cases across multiple disciplines including energy, enterprise, healthcare, public services, residential, retail, transportation, among many others. Some middleware techniques which are defined by oneM2M include Representational State Transfer (REST), Constrained Application Protocol (CoAP), and Message Queue Telemetry Transport (MQTT) for transmission. However, the analyses and comparisons of these middleware techniques have not been discussed and investigated. Therefore, this study designed and implemented two transmission scenarios to compare the performance of each protocol. The experimental results showed that the response time of using MQTT protocol is the shortest. However, the transmission cost of using CoAP is the lowest. Therefore, the adaptable middleware technique can be selected and adopted in accordance with various IoT applications. Finally, two practical case studies including smart home and Intelligent Transportation System (ITS) in Taiwan are illustrated to discuss and to analyze the applications of these middleware techniques.

KEYWORDS:
Representational state transfer; constrained application protocol; message queue telemetry transport; internet of things; oneM2M