A large number of researchers found their interest in addressing the issue of capacity scaling for wireless ad hoc networks. This paper aims to provide a comprehensive overview of the development of capacity scaling laws in wireless networks, highlighting the problem of scaling as one of the basic challenges in their research. The review began with the definition of the notion of bandwidth of random networks, which were taken as a reference model of consideration when determining more advanced strategies for improving throughput capacity. Based on these strategies, other factors that have an impact on capacity scaling laws have been identified and elaborated. Finally, the capacity of hybrid wireless networks, ie networks in which at least two types of nodes functionally exist (ad hoc nodes/infrastructure nodes / auxiliary nodes), was partially investigated.

Internet of Things (IoT) is the inter-networking paradigm based on many processes such as identifying, sensing, networking and computation. An IoT technology stack provides seamless connectivity between various physical and virtual objects. The increasing number of IoT applications leads to the issue of transmitting, storing, and processing a large amount of data. Therefore, it is necessary to enable a system capable to handle the growing traffic requirements with the required level of QoS (Quality of Service). IoT devices become more complex due to the various components such as sensors and network interfaces. The IoT environment is often demanding for mobile power source, QoS, mobility, reliability, security, and other requirements. Therefore, new IoT technologies are required to overcome some of these issues. In recent years new wireless communication technologies are being developed to support the development of new IoT applications. This paper provides an overview of some of the most widely used wireless communication technologies used for IoT applications.

Abstract IoT (Internet of Things) is a new paradigm which provides a set of new services for the next wave of technological innovations. IoT applications are nearly limitless while enabling seamless integration of the cyber-world with the physical world. However, despite the enormous efforts of standardization bodies, alliances, industries, researchers and others, there are still numerous problems to deal with in order to reach the full potential of IoT. These issues should be considered from various aspects such as enabling technologies, applications, business models, social and environmental impacts. In focus of this paper are open issues and challenges considered from the technological perspective. Just for clarification, we put in light different visions that stand behind this paradigm in order to facilitate a better understanding of the IoT's features. Furthermore, this exhaustive survey provides insights into the state-of-the-art of IoT enabling and emerging technologies. The most relevant among them are addressed with some details. The main scope is to deliver a comprehensive overview of open issues and challenges to be tackled by future research. We provide some insights into specific emerging ideas in order to facilitate future research. Also, this paper brings order in the existing literature by classifying contributions according to different research topics.