This article investigates the power consumption of LTE-M and NB-IoT devices using u-blox SARA-R422S modules complying with the standards of two French operators. Our findings suggest that under certain conditions, these technologies can achieve a 5-year operational lifespan. The size of transmitted data does not have a significant impact on power consumption under favourable coverage conditions, but can quickly affect the battery life under harsh coverage conditions. This article offers insights into the power consumption of LTE-M and NB-IoT devices and provides useful information for those considering the use of these technolgaies in IoT.

The Internet of Things (IoT) has succeeded to be one of the important future communication technologies. The evolution of IoT has accelerated along with the emergence of 5G considered as a leading IoT service provider. In this context, the low power wide area network (LPWAN) has recently attracted attention as it provides an impeccable infrastructure for massive Machine-Type Communications (mMTCs). Long range wide area network (LoRaWAN) is one of the most adopted LPWAN technologies in the world. However, an efficient integration of LoRaWAN technology into the 5G system (5GS) is required. In this article, we review briefly related work trying to integrate LoRaWAN into the 5GS. Then, we present our solution for the integration and we detail the adopted network architecture. We propose new authentication methods based on the extensible authentication protocol (EAP) providing secure access, and an adaptation function to attain seamless and efficient integration. In addition, we evaluate our solution in terms of performance and security. Moreover, a comparison of our solution with related work confirms the efficiency of our solution.

Techniques that improve interfacing between power-line communication (PLC) systems and LED-based visible light communication (VLC) systems start to gain attention in recent years. Indeed, this hybrid system is able to provide simultaneously power, lighting, and data transmission. Contrariwise, if the integration between PLC and commercial LED bulbs is done unintentionally, the risks of PLC data leakage by commercial LED bulbs must be carefully analyzed. Thus, in this paper, the risks of eavesdropping on the PLC network via commercial LED bulbs are studied. The impact of the LED driver on PLC data leakage through LED bulbs is explained. The electrical-optical channel transfer function for different LED bulbs and the power spectral density of the signal received through the LED bulbs when two commercial powerline modems are plugged into the same power line are measured. Afterwards, pseudo random binary sequence signals are injected into the electrical-optical channel in order to assess quantitatively the possibility to extract information from the received signal. Finally, simple LED driver modifications that foster and increase the leakage are analyzed.

The integration of powerline communication (PLC) with visible light communication (VLC) has attracted the attention of many researchers. Cascading these two techniques offers the possibility of performing a wired transmission over existing powerline infrastructure and a last-mile energy-efficient wireless transmission through pre-installed LEDs for indoor illumination. Therefore, VLC should be deeply analyzed to optimize its integration with other systems. So far, most research has only modeled the channel and modulation bandwidth of the VLC system. However, the electrical and optical aspects are rarely taken into account and there is no explicit expression of the received signal as a function of that emitted. So in this paper, An explicit expression is proposed allowing a direct calculation of the photo-current as a function of the transmitted current taking into account the optical, electrical, and frequency behavior of the VLC system. This expression is validated using measurement results.

This paper explores the possibility of having confirmed traffic in LoRaWAN networks under channel-oblivious jamming. Our results show that a LoRaWAN cell can handle up to 500 end-devices with a relatively good message success probability (∼ 0.8) if the network is strongly jammed (60% of the time) by using a maximum of 16 re-transmissions. We have also proved that, using a channel for downlink transmissions operating in the lowest SF is a major weakness in the LoRaWAN specification. Indeed, our results suggest that for a LoRaWAN cell with 600 end-devices the network goodput can be decreased by ∼ 53.06% when ACK transmissions on the second receive window are allowed. This was done by using an open-source network simulator that allows to evaluate many scenarios that can help LoRaWAN operators to better scale their networks in order to be more resilient against jamming attacks before actual deployments.

In this article, we consider the mobility of an end device (ED) in low-power wide-area networks (LPWANs) and we focus on the continuity of the ED session with the application server when this ED is moving from the coverage of one operator to that of another one. One of the methods to achieve the continuity of the session after roaming is the use of an IPv6-based scheme. As LPWAN is characterized by a fixed message rate and very small bandwidth as well as asymmetric communication, an efficient header compression scheme is required. Recently, the Internet Engineering Task Force LPWAN working group has proposed a static context header compression (SCHC) to compress IPv6 into LPWAN through a rule-based mechanism. In this article, we first extend the SCHC scheme to support session continuity and the new scheme is called mobile SCHC (MSCHC). MSCHC consists of several contexts, instead of the static context for SCHC and we also improve the use of the memory by dividing the rules into layers. Then, we investigate the mobility of the ED to show how the continuity of the session can be achieved while transmitting and receiving data when the ED is roaming between different operators. The proposed solution is based on the use of light mobile IPv6 messages compressed with MSCHC. Finally, the proposed mechanism is implemented in the popular LoRaWAN technology, evaluated and compared with the existing solutions provided by the LoRaWAN v1.1 standard.

In the last decade, the research on CPU-FPGA hybrid architectures has become a hot topic. One of the main challenges in this domain consists in efficiently and safely managing dynamic partial reconfiguration (DPR) resources. This paper focuses on the management of the reconfiguration by an hypervisor on an ARM-FPGA platform. Using the virtualization approach, virtual machines (VM) may access resources independently, being unaware of the existence of other VMs. The purpose of our work is to provide an abstract and transparent interface for virtual machines to access reconfigurable resources. The underlying infrastructure of partial reconfiguration management is hidden from the virtual machines, so that software developers do not need to consider the implementation details. We propose a framework where DPR accelerators are presented as virtual devices, which are universally mapped in each VM space as ordinary peripherals. The hypervisor automatically detects VM's requests for DPR resources and handles them dynamically according to a preemptive allocation mechanism. Our custom hypervisor guarantees the independent and isolation of VM domains. We also evaluate the efficiency of our framework by measuring the critical overheads during DPR management and allocations. The results demonstrate that our mechanism is implemented with low overhead.

This paper deals with the implementation of an embedded communication system for vehicle, based on vehicular power line (VPLC) and/or wireless technologies using the USRP platforms. This platform allows a modular design of OFDM based systems. Many configurations of the PHY and MAC layers are studied on real vehicular PLC/RF environments, without developing a specific board. According to the used channels, the radio frequency daughter cards can be used without changing the digital signal processing.

The increasing complexity of communication infrastructures in the automotive domain implies the use of reliable models to assist designers in the development process of networked embedded systems. In this context, transaction level modeling, supported by languages as SystemC, is a promising solution to assess performances of networked architectures with a good compromise between accuracy and simulation speed. This article presents the modeling and performance evaluation of a video transmission system supported by three electronic controller units and based on a specific power line communication protocol. The created model incorporates the various communication layers considered. The simulation of the model allows the evaluation of time properties and memory cost inferred.

Consider a flat-fading Multiple-Input Multiple-Output (MIMO) system. The near-optimum detection problematic has been shown to be efficiently solved through QR Decomposition (QRD)-based detectors. However, this step is demanding, and leads to wasting a large part of the system resource in case of a straightforward multi-carrier extension. In this paper, a solution that provides the QRD output by advantageously considering the correlation between adjacent channels is proposed. Originally, it relies on the matrix perturbation theory and induces a strong complexity reduction. Simulation results show that the proposed solution significantly reduces the implementation complexity while maintaining good performance.

This paper deals with the implementation of a new reconfigurable architecture for the computation of Fast Fourier Transform (FFT) in the context of digital terrestrial television broadcasting (DTTB). The proposed architecture allows more possibilities in the choice of the FFT size. In this paper, two algorithms (Radix algorithm and Winograd Fourier Transform Algorithm (WFTA)) are presented. These may be used to compute a FFT of size 2048 (2K), 4096 (4K), 8192 (8K) or 3780 that are utilized in three of the most important DTTB standards. The reconfigurable architecture is presented. The time performances and resources requirement are provided in comparison with classical architectures.

It has been widely shown that the sphere decoding can be used to find the maximum likelihood (ML) solution with an expected complexity that is roughly cubic in the dimensions of the problem. However, the computational complexity becomes prohibitive if the signal-to-noise ratio is too low and/or if the dimension of the problem is too large. That is why another technique denoted as fixed-complexity sphere decoder (FSD) is an interesting approach. This algorithm needs a preprocessing step, and in this paper the QR-decomposition-based preprocessing technique, which is not inconsequential, will be studied. Two different techniques are exposed, including the classical Gram Schmidt orthonormalization process. Their computational complexities and their impacts on the FSD computational complexity are studied. In the LTE context, the overall computational complexities of the two detection techniques are quantified and are shown to be dependent on the constellation size.

This paper deals with automotive power line communication for high data rate. Today's automobiles contain many complex systems, each one incorporates a large number of electronic control units. These buses increase the number of cables and interferences. In order to reduce the total amount of cables and EMC, a potential solution is power line communications (PLC), using multi-carrier modulation. This technique offers both high data rate and good adequacy with channel properties. In the present work, the PLC techniques has been tested in the automotive environment, and the first results seem to be very promising. An optimized modem has been simulated to reach the expected data rate.

Dynamic reconfiguration of FPGAs enables systems to adapt to changing demands. This paper concentrates on how to take into account specificities of partially reconfigurable components during the high level adequation algorithm architecture process. We present a method which generates automatically the design for both partially and fixed parts of FPGAs. The runtime reconfiguration manager which monitors dynamic reconfigurations, uses prefetching technic to minimize reconfiguration latency of runtime reconfiguration. We demonstrate the benefits of this approach through the design of a dynamic reconfigurable MC-CDMA transmitter implemented on a Xilinx Virtex2.

This article presents the effective implementation of a MC-CDMA modulation scheme. It is shown how the spreading operation and the multi-carrier modulation can be combined in order to carry out computation savings. According to the target component (hardware or software), various structures are proposed. Computation times are also given in the two cases.

This article presents a particular application of the spread spectrum code division multiple access concept (CDMA) based on direct spread spectrum modulation (DS-SSM) for an automotive area network on power-lines. Advantages and related problems to set up the system in a car are discussed. Measurements for the evaluation of the system's performances in terms of the additive noise and the interference caused by the other users are given. Design of this communication system is made taking also into account protection against electromagnetic disturbances.>