# Internet of Things: A Scientometric Review
## 5 Conclusions  
A scientometrics review about Internet of Things was performed over a data set of 19,035 documents published during a period of 15 years (2002-2016) from two databases (Clarivate Web of Science and Scopus). A Python script called ScientoPy was developed to make a quantitative analysis of this data set, providing insight into research trends by investigating primary author's country affiliation, most published authors, and prevalence of various research topics. Using authors' keywords, the top research topics for IoT were found, including applications, communication protocols, software processing, hardware, and operating systems. Analysis by country affiliation of the primary author shows a major increase in the number of publications for IoT in countries where the government has possibly implemented polices that  
Figure 9: Internet of Things top trending topics based on authors’ keywords, with average growth rate (AGR) for different times periods (2011–2012, 2013–2014, and 2015–2016). improve the development of IoT. Similarly, this increase has shown in countries where private initiatives could have launched commercial low cost IoT networks (such as LoRa, Sigfox, etc.). In addition, prototype IoT infrastructure on small test environments, such as universities, creates microcosms that foster investigations for different IoT applications. From 2014 to 2016, there was a sharp growth of smart environments including smart city, home, grids, and other surfaces with technology incorporating Big Data and cloud computing into IoT devices. Nevertheless, security [91; 92; 93] and privacy [103; 106; 107] are major concerns for many applications such as smart home and grid. Cyber-Physical Systems is an application that, when powered by the IoT, enables the targets fixed by Industry 4.0 [111]. Trends in communications protocols have changed in the last few years. The RFID publications sigmoid growth is on a stationary phase, while other media layer protocols such as BLE, WiFi, and 5G are on sigmoid growth exponential phase. Host layer protocols show a high growth rate for CoAP and MQTT. Software data processing demonstrates that the techniques designed to work with Big Data are growing on the sigmoid exponential phase for IoT data processing environments. For operating systems, Android has become the most used OS for scientific researchers on IoT. This OS has been used for IoT gateways [238; 239; 240; 241] and user interface in IoT devices [270; 271]. Contiki is growing in a sigmoid exponential phase with its integrated protocol stack and WSN simulator, Coja. Similarly, in IoT research, Raspberry Pi and Arduino are the most popular platforms for learning and development. In addition, the combination is widely used wherein Raspberry Pi is an IoT gateway [255; 256; 257] and Arduino boards serve as edge monitoring devices [262; 263; 264]. Similarly, smartphones exhibit their versatility being used as gateway [265; 266; 267], user interface [270; 271], and sensing [265; 266] IoT devices. Meanwhile, FPGAs have exhibited a sigmoid exponential phase growth in the last two years, with applications such as data encryption [273; 274; 275], routing algorithms optimization [276], and parallel networks simulation [277]. Top trending topics demonstrate that cloud integration with IoT devices is enabling the implementation of smart environments. Nevertheless, security and privacy in these environments are important growing concerns for IoT researchers and industry. WSNs are one of the most utilized technologies enabling the IoT. Furthermore, Fog computing has emerged as a promising edge device to decentralize data processing, decrease latency, and bring more reliability for WSN in IoT. Likewise, research on Software Defined Networks (SDN) grew rapidly during the last year, offering more efficient nodes, mobility, resources management, and improved security of IoT networks. The related trending topics offer unique opportunities for IoT innovations and start-ups in pursuit of an efficient, secure, and reliable IoT environment.