Ad-hoc, Mobile, and Wireless Networks

The Industrial Internet of Things tends now to emerge as a key paradigm to interconnect a collection of wireless devices. However, most industrial applications have strict requirements, especially concerning the reliability and the latency. IEEE802.15.4-TSCH represents currently a promising standard relying on a strict schedule of the transmissions to provide such guarantees. The standard ISA-100.11a-2011 has proposed the concept of duocast, where a pair of receivers are allocated to the same transmission opportunity to increase the reliability. In this paper, we generalize this approach to involve k different receivers, and we explore the impact of this technique on the performance of the network. We propose an algorithm assigning several receivers for each transmission to increase the probability that at least one device receives correctly the packet. By exploiting a multipath topology created by the routing layer, we are able to reduce the number of transmissions while still achieving the same reliability. We consequently increase the network capacity, and reduce significantly the jitter. Our simulation results highlight the relevance of this k-cast technique in TSCH for the Industrial Internet of Things.

IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) is a distance vector routing protocol especially designed for the Internet of Things (IoT). RPL uses broadcast DODAG Information Object (DIO) messages to build a Destination Oriented Directed Acyclic Graph (DODAG) toward a root. Each node selects a parent node toward the root using a common Objective Function (OF). However, the use of a single route can affect the network reliability and the end-to-end latency. In this study, we propose to employ the Packet Replication and Elimination (PRE) principles to use parallel paths toward the DODAG root, over the IEEE 802.15.4 Time-Slotted Channel Hopping (TSCH) as a medium access. To this aim, we propose number of algorithms to select the second or the alternative parent in RPL. Furthermore, we study the advantages of using overhearing feature over correlated paths. Our simulation campaign conducted over Cooja, the simulator of Contiki OS, demonstrate that the use of overhearing in conjunction with PRE in RPL considerably improves the robustness of a wireless network by providing greater opportunity to a packet to reach its destination.

Multiple heterogeneous communication technologies offer great opportunities in Smart grid network by using wire, wireless and optic fiber. Most of future smart meters will use Powerline Communication (PLC) technology in addition to one or more wireless interfaces to tackle the physical constraints and failure of the PLC network. When a smart meter is connected using two different technologies, choosing the best relay node and the best link to transmit the message is a key decision to provide a good quality of service and increase the reliability of the communication network. In this paper, we propose an algorithm to manage multiple interfaces at the routing level (using RPL), and a re-transmission scheme to improve the reliability of the network when a PLC interface fails.

As we move towards autonomous vehicles, a reliable Vehicle-to-Everything (V2X) communication framework becomes of paramount importance. In this paper we present the development and the performance evaluation of a real-world vehicular networking testbed. Our testbed, deployed in the heart of the City of Bristol, UK, is able to exchange sensor data in a V2X manner. We will describe the testbed architecture and its operational modes. Then, we will provide some insight pertaining the firmware operating on the network devices. The system performance has been evaluated under a series of large-scale field trials, which have proven how our solution represents a low-cost high-quality framework for V2X communications. Our system managed to achieve high packet delivery ratios under different scenarios (urban, rural, highway) and for different locations around the city. We have also identified the instability of the packet transmission rate while using single-core devices, and we present some future directions that will address that.

Industry is experiencing a new evolution phase where manufacturing is going through a process of digitalization, with every step of the production chain becoming smart. The emergence of IoT technologies and the fasted-paced evolution in advanced computing capabilities enable a pervasive monitoring and rapid data processing, unleashing new applications, e.g., real-time error-correction and fault-detection, remote robot control, intelligent logistics. The flexibility and low cost of wireless solutions makes them appealing with respect to wired connections, but current wireless technologies operate at sub-6-GHz bands and are not able to meet the reliability, latency, and data rate demands of novel applications. In this paper, we give an overview of the main limits of current technologies and discuss the role that mmWaves may play in guaranteeing ultra reliable and low latency wireless communication in smart industry. We especially focus on the IEEE 802.11ad and 802.11ay standards for communication at 60 GHz. A factory work-cell is used as an illustrative example to explore the potential of mmWaves and how they could contribute to the realization of a resilient smart factory.

Internet of Things (IoT) communications have significant impact on our social life due to the exponential growth of many objects and devices creating a fully interconnected world. Due to the high performance requirements of 5G IoT applications, enhancements are needed to support the weighty uplink (UL) traffic produced by Machine-to-Machine (M-M) and Human-to-Human (H-H) communications. In this paper, we present a radio resource management (RRM) approach based on Quality of Service (QoS) requirements of the UL IoT flows. The proposed scheme provides best scenarios that aim to provide a tradeoff between the two types of traffic by guaranteeing the network performance, maximizing the bandwidth utilisation rate and avoiding flow starvation.

Due to the growth explosion of Machine-to-Machine (M2M) and Human-to-Human (H2H) communications traffic, the majority of the mobile network operators (MNOs) recently start the deployment of heterogeneous network (HetNet) including femtocells. HetNet is a promising solution for next generation networks to meet the increasing of data rate demand. Whereas, femtocell selection scheme plays a critical role in improving the benefit of this technology. In this paper, we have developed and then evaluated a Dynamic Joint Resource Allocation and Femtocell selection for 5G HetNet (J5G-RAS). Besides, our work aims to enhance the resource utilization by dividing the resources of each station in static and dynamic resources. Significant simulation results, show the improvements of the system model performances in terms of resource utilization ratio, dropped request probability, and total average throughput of the system.

When a disaster strikes, communication infrastructure such as cellular network may get destroyed, which makes rescue operations more challenging. Short range-based opportunistic communications using daily mobile devices such as smartphones present a promising solution to support infrastructure failure. In a previous work, we have proposed COPE, a cooperative opportunistic alert diffusion solution useful for trapped survivors during disasters to ease and speed up their rescue and assistance. It targets to maintain mobile devices alive as long as possible for a maximum network coverage until reaching proximate rescuers. COPE leverage mobile devices that come with multiple network technologies and aims to perform a systematic network interface selection. We have implemented a proof-of-concept of COPE for android smartphones using two network technologies: Bluetooth and Wi-Fi. This work presents a benchmark analysis of performances of smartphones based on COPE. Testing experiments have been carried out to measure the performance of smartphones in terms of energy consumption, clock synchronization and transmission range. We believe that such experimental results can support technological choices for rescue operations but also for many other applications relying on smartphone performances.

The security issues of devices, used in the Internet of Things (IoT) for example, can be considered in two contexts. On the one hand, these algorithms can be proven secure mathematically. On the other hand, physical attacks can weaken the implementation. In this work, we want to compare these attacks between them. A tool to evaluate and compare different physical attacks, by separating the theoretical attack path and the experimental parts of the attacks, is presented.

This demonstration defines a small IoT wireless network that uses TI CC2538-OpenMote as hardware platform and state-of-the-art IETF network standards such as 6LoWPAN, RPL, and CoAP implemented by ContikiOS. The IoT nodes are controlled from outside the IoT network using end-to-end connectivity provided by IPv6-CoAP messages. We implement a man-in-the-middle attack that disrupts the normal behavior of the system. Our attack leverages on the inherent hierarchical routing topology of RPL-based IoT networks. The demonstration aims at highlighting the need for end-to-end source-authentication and authorization enforcement of information even inside a trusted IoT network. We also provide some insights on how these services can be offered in a IoT-friendly way.

One of the most important issues in wireless sensor networks is energy autonomy. Thereby wireless communication leads to excessive demands of energy. In this paper, a fuzzy based energy aware unequal clustering algorithm is presented. The network is partitioned into certain number of rings. An energy analysis model is proposed to measure the optimal radius of each cluster. This enables to vary the size of clusters from one ring to another, which ensures the load balance of the network. Then, a fuzzy logic system is employed to select suitable cluster head. The fuzzy set relies only on three parameters; residual energy, number of neighboring nodes and centrality of node among its neighbors. The proposed algorithm outperforms other clustering approaches, like LEACH, DUCF and MCFL in terms of energy efficiency and network lifetime.

Wireless industrial applications require high level of Quality of Service (QoS) such as low-delay and jitter performances, low-power operations as well as end-to-end reliability close to 100%. However, considering the large number of wireless networks operating in 2.4 GHz, the radio technologies are more prone to the external interference, which eventually may negatively affect the reliability, the delay and the goodput performance due to collisions and retransmissions. To tackle the previously detailed issues, Time-Slotted Channel Hopping (TSCH) Medium Access Control (MAC) protocol emerged with IEEE 802.15.4-2015 as an alternative to the industrial standards such as WirelessHART and ISA100.11a. TSCH is based on frequency hopping to avoid the interference, while the medium access is based on a scheduler (i.e., slotframe) that repeats periodically to avoid the collisions. Yet, the majority of the proposed TSCH schedulers are based on traditional collision detection and retransmission in the following slotframe, which essentially increases the end-to-end delay performance. In this poster, we consider allocating consecutive timeslots for a single data transmission, to allow thus, to retransmit the data packet within the slotframe in case of losses. We study the potential trade-offs, reliability and delay versus energy consumption, when considering the over-allocation approach.

In this demo, we present a framework to retrieve data from an electric vehicle platform and publish it through an embedded wireless network. We developed driver programs to read the car’s data (such as speed, battery level, etc.), and we built a IEEE802.15.4-TSCH network with a (CoAP) server to make it available to other devices. We also developed a dashboard, including a CoAP client, and multiple displays, to show the relevant information in real time to the driver.

LoRa’s long-range and low-power features have made it an attractive candidate for IoT devices in various fields. In this work, we present an enhanced LoRaWAN protocol. LoRaWAN MAC protocol is characterized by the restrictive use of the channel, limited by the regulatory authorities to a 1% duty cycle per cycle (i.e., 36 s per hour) per node. This regulation penalizes the nodes which require a channel access time greater than the limited duty cycle to occasionally transmit a large amount of data such as video surveillance or access control information in applications like smart school surveillance. However, some other nodes like environment sensors sharing a same LoRaWAN server may send very small amounts of information (e.g. temperature, humidity, ...) and under-use the authorized activity time of 1% duty cycle. Hence the idea of implementing an activity time sharing mechanism among nodes that allows devices to borrow additional activity time from a device or set of devices that have completed the transmission of their packets and do not need the remaining time of the corresponding duty cycle. Our work extends and improves the activity time sharing mechanism initially proposed in [1]. Instead of FIFO sharing-time allocation based on a global activity time, which may lead to the starvation of the nodes that are others than that in the head of FIFO line, we propose a new time allocation algorithm based on the classification of the different requests according to their needs in terms of their QoS requirements. It allows to satisfy a larger number of nodes requiring extra time, with less control overheads while ensuring fairness. Our time-sharing algorithm has been implemented and tested on the wasp-mote chip of libelium, showing the performance improvement and its practical usability.

The Internet of Things and particularly energy constraint object revealed these last years some radio frequencies technologies which allow to realize wireless transmissions at long range and with low energy. This change of paradigm makes tip over the problems of multi-hop networks to multi-channel MAC networks. The technology arises from this sphere of influence by using the spread spectrum to reach the expected performances. This physical layer is very original compared with the physical layers used for a long time with the IEEE 802.15.4 standard. This article highlights the specificities of the physical layer to design new MAC layers for the ad hoc Internet of Things.

Following the trend of the Internet of Thing, public transport systems are seen as an efficient bearer of mobile devices to generate and collect data in urban environments. Bicycle sharing system is one part of the city’s larger transport system. In this article, we study the “Internet of Bikes” IoB-DTN protocol which applies the Delay Tolerant Network (DTN) paradigm to the Internet of Things (IoT) applications running on urban bike sharing system based sensor network. We evaluate the performances of the protocol with respect to the transmission power. Performances are measured in terms of delivery rate, delivery delay, throughput and energy cost. We also compare the multi-hop IoB-DTN protocol to a low-power wide-area network (LPWAN) technology. LPWAN have been designed to provide cost-effective wide area connectivity for small throughput IoT applications: multiyear lifetime and multikilometer range for battery-operated mobile devices. This work aims at providing network designers and managers insights on the most relevant technology for their urban applications that could run on bike sharing systems. To the best of our knowledge, this work is the first to provide a detailed performance comparison between multi-hop and long range DTN-like protocol being applied to mobile network IoT devices running a data collection applications in an urban environment.

In low power wide area networks (LPWAN), a packet transmitted by a device can be received and decoded by all surrounding base stations (BS). If at least one of the base stations decodes the packet, the latter is delivered to the system. This scheme is called selection combining (SC) macro diversity and has been studied in the literature. However, the existing research only cares about the average packet-loss probability over the entire networks. In this paper, we consider as the main performance indicator the outage probability, which better takes into account the real availability of the service in any part of the area: the outage probability. Given an outage probability constrain, we study the minimum required BS spatial density of SC macro diversity based LPWAN. The numerical results show that if both target packet loss rate and outage probability are 10%, the minimum BS spatial density required by SC macro diversity is at most half of that required by traditional BS attach method. The performance gain is more significant when the network load increases.

In this article we introduce authentication preambles as a mechanism to mitigate battery exhaustion attacks in LPWAN networks. We focus on the LoRaWAN technology as an exponent of industrial LPWANs. We analyze the impact of DoS attacks in Class B deployments and implement authentication preambles to limit attacker options when forcing nodes to overhear class B beacons. The article presents realistic results demonstrating significant energy savings (91% energy saving when a network is attacked) versus a 4% energy overhead of the mechanism in normally operating networks.

During this last decade, Unmanned Aerial Vehicles (UAV) are receiving more attention and are being useful in harvesting area and for many applications and for different critical scenarios. In this paper, we focalize our investigation on the military domain for land inspection. In this context, this paper describes state of the art related to technologies and communication systems that handle cooperation and traffic exchange between Unmanned Aerial Vehicles and Ground Control Station (UGS). Accordingly, we propose a holistic architecture that involves Multi-UAVs, wireless sensor network, cellular network, terrestrial control node and satellite for recovery to get more reliable solutions. Furthermore, this paper details information flows between UAVs and UGS.

In the midst of Internet of Things development, a first requirement was tracking and identification of those mentioned “things which could be done thanks to Radio Frequency Identification. However, since then, the development of RFID allowed a new range of applications among which is remote sensing of environmental values. While RFID can be seen as a more efficient solution than traditional Wireless Sensor Networks, two main issues remain: first reading collisions and second proficient data gathering solution. In this paper, we examine the implementation of two applications: for industrial IoT and for smart cities, respectively. Both applications, in regards to their requirements and configuration, challenge the operation of a RFID sensing solution combined with a dynamic wireless data gathering over multihops. They require the use of both mobile and fixed readers to cover the extent of deployment area and a quick retrieval of tag information. We propose a distributed crosslayer solution for improving the efficiency of the RFID system in terms of collision and throughput but also its proficiency in terms of tag information routing towards one or multiple sinks. Simulation results show that we can achieve high level of throughput while maintaining a low level of collision and a fairness of reader medium access above \(95\%\) in situations where readers can be fix and mobile, while tag information is routed with a data rate of \({\approx }97\%\) at worst and reliable delays for considered applications.

We present a receiver for low frequency underwater acoustic communications addressing the Doppler shift that occurs during the transmission of frames at a very low data rate. The receiver handles constant or variable (linearly and nonlinearly) Doppler shift patterns. The waveform supported by the receiver is adapted to difficult underwater channel conditions, such as the ones present in long range under-ice Arctic communications. The bandwidth is extremely narrow (less than six Hz). Redundancy is very high (300%). Our main contributions are in an aspect of the receiver that handles arbitrary types of Doppler shifts. We use the idea of signal tracking function. It follows the progression of a carrier during the reception of a frame. Evaluation results are reported using our GNU Radio implementation.

In this paper, we propose an IP-based mobility management protocol named Fast handover Proxy Mobile IPv6 for Sensor networks (FPMIPv6-S). FPMIPv6-S provides network-based mobility support for 6LoWPAN WSN when a sensor node moves between two Personal Area Networks (PANs). It is an improved version of the Proxy Mobile IPv6 (PMIPv6) protocol proposed for mobility management in IPv6 networks. We compared via simulations FPMIPv6-S with other well-known mobility protocol namely Mobile IPv6. Performance results show that our proposed protocol achieves reduction of packet loss by as much 70% and improve the network throughput by over 25% compared to MIPv6. Further, we implemented our proposed protocol and MIPv6 with NS3 simulator and made extensive simulations runs to compare both protocols.

The design of fast and effective coordination among sensors and actuators in Cyber-Physical Systems (CPS) is a fundamental, but challenging issue, especially when the system model is a priori unknown and multiple random events can simultaneously occur. We propose a novel collaborative state estimation and actuator scheduling algorithm with two phases. In the first phase, we propose a Gaussian Mixture Model (GMM)-based method using the random event physical field distribution to estimate the locations and the states of events. In the second phase, based on the number of identified events and the number of available actuators, we study two actuator scheduling scenarios and formulate them as Integer Linear Programming (ILP) problems with the objective to minimize the actuation delay. We validate and demonstrate the performance of the proposed scheme through both simulations and physical experiments for a home temperature control application.

With the emerging of Internet of Things (IoT) concept, we are recently assisting to the proliferation of Wireless Sensor Networks (WSNs) around us in our daily life. However, such WSNs can be deployed far away from infrastructures to supervise unreachable areas such as countries’ borders and natural preserves. Besides, the deployment of dedicated transport networks, the use of satellite communications or mobile 3G/4G networks can be expensive and complex to install in such areas. With the exponential development and ubiquity of smartphones, having powerful communication and computation capabilities, the concept of data muling can be beneficial by using these devices to provide low-cost and efficient communications for providers having WSNs deployed in infrastructreless areas.

This paper proposes a novel architecture providing data muling as a service where a set of data muling agents deployed on smartphones can be used to collect and forward sensing data from WSNs, deployed in infrastructureless areas, to remote servers. We design a QoS-aware game theory model to select best efficient data mulling agents to perform data muling tasks with acceptable costs and adequate technical capabilities. Such a model encourages highly reputable and reliable agents to participate in data muling tasks by rewarding and updating their reputations. A simulation is also conducted to assess the efficiency of the proposed model.

A Wireless Sensor Network (WSN) is an important wireless technology that is widely used in the Internet of things and that has wide variety of applications. In fact, a WSN consists of independent sensors, communicating with each other in a distributed way to monitor the environment. In this network, most of the existing distributed algorithms are designed without referring to a computations model. As a consequence, the study, the comparison and the proof of these algorithms become a difficult task. In this paper, we propose a new computations model based on local interactions. This model relies on Graph Relabelling System (GRS), a graph transformation model suitable for encoding distributed algorithms. We show that using our model simplifies the specification and the proof of distributed algorithms for WSN. We illustrate our proposed model through an example of distributed algorithm for WSN. Proofs are given in this paper to demonstrate the correctness of the selected algorithm.

Internet of Things (IoT) technology has the potential to revolutionise several domains of everyday life, including the healthcare sector. In order to reach its full potential, IoT technology needs to be evaluated in the real world, beyond controlled environments, such as laboratories and test-beds. SPHERE is an experimental sensing platform for healthcare in a residential environment. Unlike other similar smart home health systems, SPHERE is deployed in a large number of properties of volunteers. Based on our experiences and lessons learned from SPHERE’s large-scale deployments, this paper focuses on the challenge of effectively managing the sensor installation overhead, aiming at supporting our deployment technicians with achieving a satisfactory deployment throughput. In this context, this paper presents the SPHERE Deployment Manager: an open-source tool that facilitates the deployment of bespoke IoT networks by technicians that are not experts in IoT technology. We believe that the SPHERE Deployment Manager is a tool that can accelerate future IoT research deployments of similar nature and scale.

Testbeds are a key element in the evaluation of wireless multi-hop networks. In order to relieve researchers from the hassle of deploying their own testbeds, remotely controllable testbeds, such as the FIT/IoT-LAB, are built. However, while the IoT-LAB has a high number of nodes, they are deployed in constraint areas. This, together with the complex nature of radio propagation, makes an ad-hoc construction of multi-hop topologies with a high number of hops difficult. This work presents a strategic approach to solve this problem and proposes algorithms to generate topologies with desired properties. The implementation is evaluated for the IoT-LAB testbeds and is provided as open-source software. The results show that preset topologies of various types can be built even in dense testbeds.

F-Interop allows implementors of IoT protocols to test compliance and interoperability of their implementation by connecting to a remote server in the cloud which contains and runs testing tools for different IoT standards. This paper provides an overview of the F-Interop Platform and the tools. Nowadays testing tools for CoAP, 6TiSCH, OSCORE and LoRaWAN standards are already available.

The F-Interop project, which has started as a H2020 project funded by the European Commission, is now supported by a large community of standard development organizations, small/large companies, academic institutions, and protocol designers and implementors. They all see the benefits of adopting the new Interoperability approach proposed by F-Interop, which allows to validate IoT implementation faster, reducing time to market, and standardization.