Erlang-based dimensioning for IPv4 Address+Port translation

International audienceAs the IPv4 address pool is being exhausted, it becomes urgent to find a way to migrate IPv4 network architectures to IPv6, or to reduce the use of IPv4 addresses. In this paper, we discuss a strategy known as ''Address + Port'' translation, which consists in several users sharing the same IPv4 address and being distinguished by a range of port numbers. Of critical importance for the feasibility of such a mechanism is the knowledge of the minimum number of ports to allocate to users so that no service degradation is perceived. To that extent, we analyse the port consumption of the most port-consuming Internet applications, web browsing, and present some aggregate port consumption curves for the student population of our campus. Our results suggest that a port range of 1000 ports is totally transparent to users (which would allow to share a single IPv4 address among 64 users),while 400 ports (i.e., 150 users per address) is sufficient for most of users. Finally, the number of users per address could be further improved by benefiting from statistical multiplexing, i.e., using dynamical instead of fixed port range allocation

Simplified Ray Tracing for the Millimeter Wave Channel: A Performance Evaluation

Millimeter-wave (mmWave) communication is one of the cornerstone innovations of fifth-generation (5G) wireless networks, thanks to the massive bandwidth available in these frequency bands. To correctly assess the performance of such systems, however, it is essential to have reliable channel models, based on a deep understanding of the propagation characteristics of the mmWave signal. In this respect, ray tracers can provide high accuracy, at the expense of a significant computational complexity, which limits the scalability of simulations. To address this issue, in this paper we present possible simplifications that can reduce the complexity of ray tracing in the mmWave environment, without significantly affecting the accuracy of the model. We evaluate the effect of such simplifications on link-level metrics, testing different configuration parameters and propagation scenarios.Comment: 6 pages, 6 figures, 1 table. This paper has been accepted for presentation at ITA 2020. (c) 2020 IEEE. Please cite it as: M. Lecci, P. Testolina, M. Giordani, M. Polese, T. Ropitault, C. Gentile, N. Varshney, A. Bodi, M. Zorzi, "Simplified Ray Tracing for the Millimeter Wave Channel: A Performance Evaluation," Information Theory and Applications Workshop (ITA), San Diego, US, 202

Routing and performance for the Smart Grid

The power grid has begun a major evolution in the past decade, laying the foundations of what is known as the Smart Grid. The Smart Grid relies on bidirectional communications in order to enable new functionalities. One of the key components of the Smart Grid is the Advanced Metering Infrastructure that enables the interconnection between users and utilities thanks to a new generation of power meters: the Smart Meter. While Smart Meter deployments have already started worldwide at the instigation of governments, a multitude of choices still remains to be done concerning their technical implementations. Specifically, Smart Meter networking can be based on Power Line Communication (PLC), which is one of the major networking technologies available to utilities. P1901.2, a narrowband PLC has been standardized by the IEEE for usage in the Smart Grid. However, debates are still open for the routing protocol to use for these new high-density, narrowband PLC networks. PLC, being a harsh environment (low bandwidth, noisy, etc.), has most of the characteristics of a Low power and Lossy Network. As a result, the protocol RPL, designed specifically for Low power and Lossy Network, is a prime candidate for routing in IEEE P1901.2 networks. The goal of this thesis is to study RPL¿s behavior in Smart Grid environment and to provide adjustments to its behavior in order to improve the network performance in a narrowband PLC network of Smart Meters.Le réseau électrique a connu récemment une évolution majeure pour se transformer en un réseau électrique intelligent: le Smart Grid (SG). La bidirectionnalité des communications est au c¿ur du SG et permet de mettre en ¿uvre et de prendre en compte un ensemble de nouvelles fonctionnalités. L'Advanced Metering Infrastructure permet d'assurer l'interconnexion entre utilisateurs et opérateurs électrique à l'aide d'une nouvelle génération de compteur: "les compteurs intelligents". Alors que le déploiement de compteur intelligent a déjà commencé dans le monde, une multitude de choix reste encore à faire concernant leur mise-en-¿uvre. Concernant le medium de communication, le Courant Porteur en Ligne (CPL), utilisant les lignes électriques déjà déployées, semble être la solution idéale pour les opérateurs énergétiques. Le standard P901.2 a été standardisé par l'IEEE pour permettre des communication efficaces au sein du SG. Il préconise l'utilisation du protocole IPv6 mais ne donne aucune indication concernant le protocole de routage à utiliser. Le CPL est un environnement extrême de part sa nature (bruits, faibles débits) et peut-être vu comme un Low Power and Lossy Network (LLN). L'IETF a défini le protocole pro-actif RPL spécifiquement pour les LLN et semble, de ce fait, un bon candidat pour les environnements IEEE P1901.2. Le but de cette thèse a été d'étudier le comportement de RPL dans le Smart Grid et d'apporter des améliorations spécifiques pour le Smart Grid afin de garantir un fonctionnement optimal de RPL dans ce type d'environnement

Scheduling the Data Transmission Interval in IEEE 802.11ad: A Reinforcement Learning Approach

The IEEE 802.11ad Wi-Fi standard enables communications in the unlicensed mm-wave band at 60 GHz. Propagation at such frequencies accounts for increased path loss and sensitivity to blockage when compared to the traditional sub-6-GHz Wi-Fi frequencies. To cope with these phenomena, directional transmissions through beamformed links are needed. Many new features have been introduced with IEEE 802.11ad in order to realize directional communications in this band. One of the most crucial changes compared to legacy Wi-Fi communication paradigms is the introduction of a hybrid Medium Access Control (MAC), which enables contention-free and contention-based channel access. The increased complexity associated with hybrid channel access at the MAC layer must be addressed through the development of a resource scheduling algorithm. This paper proposes two novel resource scheduling mechanisms for IEEE 802.11ad. The first approach serves as a baseline for the development of a more advanced strategy based on Reinforcement Learning (RL). Indeed, the second scheme exploits RL to successfully find the optimal duration of each contention-free access period. Our performance evaluation shows that the policy based on RL provides the same level of expected throughput and delay performance while preserving more transmission time to be devoted to other traffic in order to enhance the network efficiency

Anemone : a ready-to-go testbed for IPv6 compliant intelligent transport systems

International audience

Doing it right-Recommendations for RPL in PLC-based networks for the Smart Grid

International audienceNarrowband powerline communications are one of the core technologies for the evolution of the power grid enabling the dialogue between the power meters and the utilities. The new environment, traffic patterns and application requirements make the choice of network protocols in these networks nontrivial. In this paper, we analyse the behavior of the Contiki RPL stack, the most popular and open implementation of the IETF RPL standard. We provide evidence why the state-of-art implementations do not behave in an optimal way for Smart Grid applications and propose mechanisms and parameter selection politics that lead to improved performance during the route formation phase of the network

IEEE 802.11bf DMG Sensing: Enabling High-Resolution mmWave Wi-Fi Sensing

IEEE 802.11bf amendment is defining the wireless Local Area Network (WLAN) sensing procedure, which supports sensing in license-exempt frequency bands below 7 GHz, and the Directional Multi-Gigabit (DMG) sensing procedure for license-exempt frequency bands above 45 GHz. In this paper, we examine the use of Millimeter-Wave (mmWave) Wi-Fi to enable high-resolution sensing. We first provide an introduction to the principle of sensing and the modifications defined by the IEEE 802.11bf amendment to IEEE 802.11 to enable mmWave Wi-Fi sensing. We then present a new open-source framework that we develop to enable the evaluation of the DMG sensing procedure accuracy. We finally quantify the performance of the DMG sensing in terms of the velocity/angle estimate accuracy, and its overhead on the communication link. Results show that the DMG sensing procedure defined in IEEE 802.11bf is flexible enough to accommodate a wide range of sensing applications. For the bistatic scenario considered, the velocity accuracy is in the interval 0.1 m/s to 0.4 m/s, while the angular accuracy is between 1$^{\circ }$ and 8 degrees depending on the sensing parameters used. Ultimately, the overhead introduced by sensing is limited with a sensing overhead below 5.5% of the system symbol rate

Generating Realistic Smart Grid Communication Topologies Based on Real-Data

Today’s electricity grid must undergo substantial changes in order to keep pace with the rising demand for energy. The vision of the smart grid aims to increase the efficiency and reliability of today’s electricity grid, e.g. by integrating renewable energies and distributed micro-generations. The backbone of this effort is the facilitation of information and communication technologies to allow two-way communication and an automated control of devices. The underlying communication topology is essential for the smart grid and is what enables the smart grid to be smart. Analyzing, simulating, designing, and comparing smart grid infrastructures but also optimizing routing algorithms, and predicating impacts of failures, all of this relies on deep knowledge of a smart grids communication topology. However, since smart grids are still in a research and test phase, it is very difficult to get access to real-world topology data. In this paper we provide a comprehensive analysis of the power-line communication topology of a real-world smart grid, the one currently deployed and tested in Luxembourg. Building on the results of this analysis we implement a generator to automatically create random but realistic smart grid communication topologies. These can be used by researchers and industrial professionals to analyze, simulate, design, compare, and improve smart grid infrastructures