The great breakthrough in the Mobile Internet of Things (IoT) has led to a wide range of application domains but has also raised new challenges, especially for routing protocols. In fact, the IoT devices’ mobility leads to routes instability which increases the packet error rate. Additionally, the energy shortage of IoT devices accentuates the routing protocol problems since routing is one of the most important sources of energy whereas the IoT devices suffer from the energy shortage. In this paper, we propose FOLLOWER: Fog-based routing protocol for mobile IoT devices. FOLLOWER exploits the proximity of fog nodes to mobile IoT devices to offer a robust routing protocol that can ensure energy and time-efficient routing while handling IoT objects’ mobility. FOLLOWER divides the IoT network into clusters. Each cluster is led by a fog node. The main routing tasks are done using the fog nodes that are using the Chord protocol for efficient lookup. The performance evaluation has proved that FOLLOWER managed to save time and energy and to handle efficiently IoT nodes mobility.

The technological progress of miniaturized sensors has led to the invasion of IoT in our lives through multiple applications, specifically in the healthcare domain where security and privacy are paramount concerns. This evolution has given rise to the Internet of Medical Things (IoMT). Despite the promising role of Blockchain technology in ensuring traceability and privacy for IoT systems, integrating it into IoMT poses challenges due to the IoMT devices resource shortage that cannot bear the blockchain heavy tasks. To bridge this integration gap, numerous Blockchain-based solutions have been proposed, either by modifying core Blockchain properties which reduces its efficiency and security level or by relying on intermediary parties. This paper introduces a novel lightweight solution, allowing IoMT devices to directly interact with the Blockchain network. Specifically, we advocate for the development of a lightweight Web3 interface embedded within IoMT devices. This interface facilitates secure authentication, efficient resource utilization, and efficient interaction with decentralized applications powered by blockchain technology. We provide all technical choices and implementation details of the proposed solution, leveraging the ESP32 microcontroller platform. Furthermore, we provide rigorous security and performance evaluations to demonstrate the credibility and efficiency of our solution.

We are currently living in the era of the Internet of Things (IoT) where numerous smart objects are surrounding us and reporting various information about our environment. The main challenge of these IoT devices is energy consumption since the lifetime of each device is tightly related to its limited battery capacity. For this reason, it is beneficial to keep the IoT nodes in sleeping mode and to wake them up only when they are required. Wake-up-based wireless sensors present nowadays a leading technology that shapes well this requirement. However, despite their important impact on extending the network lifetime, these sensors present a real obstacle for IoT routing protocols. Effectively, routing in IoT networks should be time efficient, whereas these sensors require additional time to wake up and to be prepared for data reception and forwarding. In this paper, we give a general overview of the wake-up-based sensors and detail the most important challenges facing these sensors in the scope of the routing protocols. We also survey and propose a taxonomy of the most important and recent routing protocols that have used these sensors.

The outstanding progress in the smart devices as well as the noticeable reduction in their cost has led to the invasion of the Internet of Things (IoT) in our real lives. The multiplicity of the IoT applications and the diversity and heterogeneity of the IoT devices present a real challenge in the IoT development. There is hence a need to have an intermediate layer between the physical layer including the smart devices and the application layer to facilitate the integration and the usage of the IoT devices in the IoT applications. This layer is the middleware layer. Most of the existing middleware are suitable for small-scale IoT networks including limited number of smart things. The performance of these middleware is reduced when the number of IoT devices increases. The main reason of the performance deterioration is the unsuitable middleware architecture that is unable to bear the increasing number of IoT devices. We present in this paper a distributed middleware architecture based on Chord protocol. Our architecture transforms any centralized middleware to a distributed one which improves its performance and makes it scalable. The performance evaluation have shown that our proposed approach has the ability to cope successfully with the increasing number of IoT devices and requests.

Wake-up Receiver (WuRx) is one of the most trivial and effective solutions for energy-constrained networks and a promising solution for monitoring various phenomena in the sense of the Internet of Things (IoT). The most important and challenging issue in WuRx-based networks is the time efficient routing process in an energy efficient manner. Effectively, awaking each node needed in the routing process recursively requires a lot of time which is not suitable for time-critical applications. In this paper, we propose a novel Wake-up Receiver based routing protocol called Time Efficient WuRx-based Routing (TEW) that ensures energy optimised and time efficient routing in indoor scenarios. In our proposed approach, the network is divided into clusters at which each Fog Node manages the routes for data transmission in an asymmetric manner. When the Sink requires data from a specific set of nodes of a particular cluster, the Sink transmits a DataPts request to the corresponding Fog Node. In addition, the Fog Node sends instructions by means of a single Request (REQ) packet informing the corresponding nodes how often they should act as relays before switching to the sleeping mode. The measurement results show that our proposed approach has higher energy efficiency and achieves significant performance improvements in data delivery delay.

The Internet of Medical Things (IoMT) represents a network of implantable or wearable medical devices that continuously collect medical data about the patient’s health status. These data are heavy, sensitive and require high level of security. With the emergence of blockchain technology, researchers are focusing on using blockchain strategies to bring security to healthcare applications. However, such integration is very difficult and challenging due to the different requirements in these two technologies. We present in this paper a technical review of existing solutions applying blockchain technology on IoMT. We analyze these studies, discuss the proposed architectures and how they managed the integration challenges. The open issues regarding the application of blockchain over IoMT are also specified.

The rapid proliferation and miniaturization of the wireless and embedded devices has led to the invasion of the Internet of Things in many domains and has reached the healthcare sector to form what is called the Internet of Healthcare Things (IoHT) . The growing number of the applications in the Internet of Healthcare Things as well as the overwhelming number of heterogeneous medical devices that should interact in this network has put the researchers and developers in front of lot of challenges: How to facilitate the implementation of the various healthcare applications? And how to ease the integration of new devices and make their interoperation a transparent task for the developers? To fulfill these requirements, lot of middleware have been proposed. In this paper we provide a complete study on the existing middleware for IoHT and specify their applications, we propose a taxonomy for them and we present their main advantages and drawbacks.

The interest in indoor localization systems has grown outstandingly in recent years given the variety of fields of application. In certain technologies, the indoor localization platforms consist of a set of wireless nodes deployed inside the building and others attached to the mobile targets. These wireless nodes collect the required data for localization and send them to a central unit for processing because of their limited power and computation capabilities. The main goal of these systems is to provide the position of the targets in a timely fashion. However, when the number of smart objects increases in larger networks, the delay becomes significant and the lookup process of the target's position becomes challenging. In such a situation, there is a tradeoff between the lookup time efficiency and the central unit storage capabilities. The fog computing presents a promising solution for high computational and storage applications. It is a distributed architecture that brings both computational power and large storage capability to the edge level via distributed and interconnected fog nodes. We present in this paper a new lookup algorithm basedon chord protocol that permits to provide the current location of a specific target in an extended fog-based indoor localization platform within the shortest delays and without the need for strong nodes capabilities.

Many Wireless Sensor Networks (WSN) protocols such as lot of localization protocols rely on the accuracy of the Received Signal Strength Indicator (RSSI). This RSSI metric is sensitive to different factors which lead to its disturbance. Other works have already proved that temperature and humidity have important impact on RSSI in outdoor environment. It is evident that temperature and humidity vary more importantly on outdoor than on indoor. In this paper, we aim to answer at this question: Does the slight modification of temperature and humidity in indoor environment have a significant impact on RSSI value? We have conducted various experiments to study this impact.

The significant progress in smart devices has lead to the shifting of actual Internet to the Internet of Things (IoT). Internet of Things is invading our real lives. In this new Internet vision, trillions of smart dynamic objects and areas will be connected to the Internet and interact between each others to achieve common applications. This new Internet vision requires suitable IoT infrastructure that offers the main Internet of Things functionalities to facilitate the development of IoT applications. Middleware is the software layer between technological and application layers. It is mainly used to afford common services and functions to applications and to abstract implementation details to ease more complex application development. In this paper, we review the main challenges facing Internet of Things middleware and survey the most well known middleware that have been proposed in this field.

Radio communications are the most important sources of energy consumption in Wireless Sensor Networks (WSN). Optimizing the sensors transmitting power with keeping the required nodes average degree preserves significantly the sensors energy. In this paper, we analyze the optimal transmitting power needed by each sensor to reach a given average node degree in heterogeneous WSN. The problem that we aim solving in this paper is the following: given a set of heterogeneous sensors having various capabilities: weak nodes and strong nodes that are scattered randomly in a field according to a Poisson Point Process with densities λ1and λ2respectively. What is the optimal transmitting power needed by each sensor to ensure k-average degree? We investigate also a related problem: What has the most important effect on weak nodes transmitting power: The quantity of the strong nodes or their quality in terms of energy supply? Our analytical study has been validated with Monte-Carlo simulations.