@article {16782,
	title = {A survey and taxonomy of simulation environments modelling fog computing},
	journal = {Simulation Modelling Practice and Theory},
	volume = {vol 101},
	year = {2020},
	abstract = {In the past ten years, the latest advances in Information and Communication Technology had a significant impact on distributed systems by giving birth to paradigms such as Cloud Computing, Fog Computing and the Internet of Things (IoT). The environments they created are closely coupled in most cases: IoT sensors and devices generate data that have to be stored, processed and analysed by cloud or fog services, depending on the actual application needs. These IoT-Fog-Cloud systems are very complex, and the use of simulations in their design, development and operational processes is inevitable. Nowadays, there are many simulator solutions available to model and analyse these systems depending our research needs, but in many cases it is hard to grasp their differences, and implementing certain scenarios in different tools is time consuming. The goal of this work is to help researchers and practitioners in this regard by proposing a survey and taxonomy of the available simulators modelling clouds, IoT and specifically fogs, which is the latest, currently still forming paradigm. The main contributions of this study are our novel viewpoints for classification including software quality, which is performed by analysing the source code of the considered simulators. We also propose comparison tables for three groups of simulators that reveal their differences and the way they model the elements of these systems. Finally, we discuss the relevant findings of our classifications, and highlight open issues that need further research.},
	keywords = {cloud computing, fog computing, Internet of Things, simulation, Survey, Taxonomy},
	issn = {1569-190X},
	doi = {https://doi.org/10.1016/j.simpat.2019.102042},
	url = {https://www.sciencedirect.com/science/article/pii/S1569190X1930173X},
	author = {Andr{\'a}s M{\'a}rkus and Attila Kert{\'e}sz}
}
@article {16783,
	title = {The Use of MQTT in M2M and IoT Systems: A Survey},
	journal = {IEEE Access},
	volume = {vol 8},
	year = {2020},
	pages = {201071-201086},
	abstract = {Nowadays billions of smart devices or things are present in Internet of Things (IoT) environments, such as homes, hospitals, factories, and vehicles, all around the world. As a result, the number of interconnected devices is continuously and rapidly growing. These devices communicate with each other and with other services using various communication protocols for the transportation of sensor or event data. These protocols enable applications to collect, store, process, describe, and analyze data to solve a variety of problems. IoT also aims to provide secure, bi-directional communication between interconnected devices, such as sensors, actuators, microcontrollers or smart appliances, and corresponding cloud services. In this paper we analyze the growth of M2M protocol research (MQTT, AMQP, and CoAP) over the past 20 years, and show how the growth in MQTT research stands out from the rest. We also gather relevant application areas of MQTT, as the most widespread M2M/IoT protocol, by performing a detailed literature search in major digital research archives. Our quantitative evaluation presents some of the important MQTT-related studies published in the past five years, which we compare to discuss the main features, advantages, and limitations of the MQTT protocol. We also propose a taxonomy to compare the properties and features of various MQTT implementations, i.e. brokers and libraries currently available in the public domain to help researchers and end-users to efficiently choose a broker or client library based on their requirements. Finally, we discuss the relevant findings of our comparison and highlight open issues that need further research and attention.},
	keywords = {cloud computing, Internet of Things, IoT, IoT protocols, ISO standards, Machine-to-machine communications, MQTT, MQTT brokers, Protocols, Quality of service, Reliability, Survey},
	issn = {2169-3536},
	doi = {10.1109/ACCESS.2020.3035849},
	url = {https://ieeexplore.ieee.org/document/9247996},
	author = {Mishra, Biswajeeban and Kert{\'e}sz, Attila}
}
