Proximity Detection with Single-Antenna IoT Devices

Providing secure communications between wireless devices that encounter each other on an ad-hoc basis is a challenge that has not yet been fully addressed. In these cases, close physical proximity among devices that have never shared a secret key is sometimes used as a basis of trust; devices in close proximity are deemed trustworthy while more distant devices are viewed as potential adversaries. Because radio waves are invisible, however, a user may believe a wireless device is communicating with a nearby device when in fact the user’s device is communicating with a distant adversary. Researchers have previously proposed methods for multi-antenna devices to ascertain physical proximity with other devices, but devices with a single antenna, such as those commonly used in the Internet of Things, cannot take advantage of these techniques. We present theoretical and practical evaluation of a method called SNAP – SiNgle Antenna Proximity – that allows a single-antenna Wi-Fi device to quickly determine proximity with another Wi-Fi device. Our proximity detection technique leverages the repeating nature Wi-Fi’s preamble and the behavior of a signal in a transmitting antenna’s near-field region to detect proximity with high probability; SNAP never falsely declares proximity at ranges longer than 14 cm

Demo: Simulating the Impact of Communication Performance on Road Traffic Safety at Intersections

ABSTRACT Performance evaluation of communication protocols is usually carried out using typical network metrics as delay, jitter, or goodput. However, recent studies in the context of InterVehicle Communication (IVC) have shown that using these metrics is not sufficient for evaluating vehicular safety applications. To highlight the importance of safety metrics and their applicability, we extended our existing simulation framework Veins to visualize these metrics live while the road traffic and network simulation are running in parallel. In particular, we demonstrate the impact of communication on intersection assistance applications. To simulate different intersection approaches, we implemented a simulation model that resembles different kinds of driver behavior and enables crashes at intersections. The resulting situations are displayed in the road traffic simulator and give the visitor insights on the current state of endangered vehicles. Furthermore, an autonomous controller has been implemented which tries to avoid accidents and hence shows the real-world impact, i.e., accidents can be avoided using advanced beaconing techniques. To increase interactivity of the demo, visitors will have the possibility to interact with and take control over endangered vehicles

Multi-Technology Cooperative Driving: An Analysis Based on PLEXE

Cooperative Driving requires ultra-reliable communications, and it is now clear that no single technology will ever be able to satisfy such stringent requirements, if only because active jamming can kill (almost) any wireless technology. Cooperative driving with multiple communication technologies which complement each other opens new spaces for research and development, but also poses several challenges. The work we present tackles the fallback and recovery mechanisms that the longitudinal controlling system of a platoon of vehicles can implement as a distributed system with multiple communication interfaces. We present a protocol and procedure to correctly compute the safe transition between different controlling algorithms, down to autonomous (or manual) driving when no communication is possible. To empower the study, we also develop a new version of PLEXE, which is an integral part of this contribution as the only Open Source, free simulation tool that enables the study of such systems with a modular approach, and that we deem offers the community the possibility of boosting research in this field. The results we present demonstrate the feasibility of safe fallback, but also highlight that such complex systems require careful design choices, as naive approaches can lead to instabilities or even collisions, and that such design can only be done with appropriate in-silico experiments

Organic 6G Networks: Vision, Requirements, and Research Approaches

Building upon the significant number of already published 6G position papers, we are concentrating on the immediate next steps toward turning the research vision of software-centric networks into reality. This is accomplished, by summarizing and assessing the various requirements documents and providing a significant number of specific research directions and approaches in order to fulfill them. This article complements the existing body of work, by focusing on future core networks and their infrastructures, yet maintaining a system-level perspective and progressing in the direction of scoping key technology elements and providing high-potential research approaches for them. Additionally, we rigorously discuss the impact that different technological advancements have on the other parts of the system, to provide a coherent, end-to-end network understanding. This is in strong contrast to current approaches, where from the challenges, each research direction becomes independent and, thus, its advances are potentially cancelled out by the next technology in the chain. By maintaining this system perspective, the adoption of the different technologies becomes easier, as they are developed in unison. To address the requirements in a coherent, holistic, and unified way, we extend our high-level architecture concept named “Organic 6G Networks” towards a comprehensive end-to-end system. A holistic software-centric system, adapting the latest software development advancements from the IT industry. The Organic 6G network provides support for building a streamlined software network architecture and offers the next step on the path towards the development and specification of future mobile networks

In-depth Study of RNTI Management in Mobile Networks: Allocation Strategies and Implications on Data Trace Analysis

International audienceThe advance of mobile network technologies and components heavily relies on data-driven techniques. This is especially true for fifth generation (5G) and the upcoming sixth generation (6G) networks, as the optimization of network components and protocols is expected to be fueled by artificial intelligence (AI) based solutions. When using real-world radio access measurement traces, the identity of individual users is not directly accessible because at runtime operation Base Stations (BSs) assign Radio Network Temporary Identifiers (RNTIs) to users. RNTIs are not bound to a user but are reused upon expiration of an inactivity timer, whose duration is operator dependent. This implies that, over time, multiple users are mapped to the same RNTI. In fact, the allocation of RNTIs to users is implemented in diverse and proprietary ways by operators and equipment vendors. Distinguishing individual users within the RNTI space is a non-trivial task and key to analyze traffic traces properly. In this paper, we make the following contributions: i) we propose and validate two complementary methodologies to identify the RNTI inactivity threshold, and we characterize ii) the RNTI allocation process of network operators, and iii) the user traffic patterns given the specific RNTI allocation process. Our study is based on a large dataset we collected from production BSs of several mobile network operators across five different countries. We find that there exist heterogeneous strategies for RNTI allocation that BSs dynamically use depending on the traffic load and daytime. We further observe that the RNTI expiration threshold is in the order of minutes, and demonstrate how using thresholds around 10 seconds, as in the vast majority of the literature, can bias subsequent analyses. Overall, our work provides an important step towards dependable mobile network trace analysis, and lays solid foundations to research relying on traffic traces for data-driven analysis

A Vehicular Networking Perspective on Estimating Vehicle Collision Probability at Intersections

Abstract-Finding viable metrics to assess the effectiveness of intelligent transportation systems (ITSs) in terms of safety is one of the major challenges in vehicular networking research. We aim to provide a metric, i.e., an estimation of the vehicle collision probability at intersections, that can be used for evaluating intervehicle communication (IVC) concepts. In the last years, the vehicular networking community reported in several studies that safety-enhancing protocols and applications cannot be evaluated based only on networking metrics such as delays and packet loss rates. We present an evaluation scheme that addresses this need by quantifying the probability of a future crash, depending on the situation in which a vehicle is receiving a beacon message [e.g., a cooperative awareness message (CAM) or a basic safety message (BSM)]. Thus, our criticality metric also allows for fully distributed situation assessment. We investigate the impact of safety messaging between cars approaching an intersection using a modified road traffic simulator that allows selected vehicles to disregard traffic rules. As a direct result, we show that simple beaconing is not as effective as anticipated in suburban environments. More profoundly, however, our simulation results reveal more details about the timeliness (regarding the criticality assessment) of beacon messages, and as such, they can be used to develop more sophisticated beaconing solutions. Index Terms-Vehicle safety, vehicular ad hoc networks, wireless communication

A physical layer experimentation framework for automotive WLAN

Zukünftig werden Automobile mit Kommunikationsmodulen ausgestattet sein, die einen direkten Datenaustausch zwischen den Fahrzeugen ermöglichen. Auf diese Weise können sich Verkehrsteilnehmer koordinieren, um so den Straßenverkehr sicherer, effizienter und komfortabler zu gestalten. Eine der Technologien, die dafür in Betracht gezogen wird, ist IEEE 802.11p, eine an Fahrzeugnetze angepasste Version von normalem Wireless LAN (WLAN). Die Entscheidung WLAN, und damit einen bereits vorhandenen Standard, heranzuziehen, ist im Hinblick auf die Markteinführung sicherlich nachvollziehbar. Gleichzeitig stellt sich allerdings die Frage, ob eine Technologie, die für relativ statische Anwendungen entwickelt wurde, den Herausforderungen dynamischer Fahrzeugnetze gerecht werden kann. Software Defined Radios (SDRs), programmierbare Funksende- und -empfangseinheiten, bieten vollen Zugriff auf alle Aspekte der Kommunikation und sind damit prädestiniert, die Eignung von WLAN zu untersuchen. Um dies zu ermöglichen, haben wir IEEE 802.11p basierend auf GNU Radio implementiert. GNU Radio ist eine SDR-Entwicklungsumgebung, mit der drahtlose Kommunikation prototypisch umgesetzt werden kann. Durch Abbildung des Standards in Software können wir dieselbe Implementierung für Simulationen und Messungen benutzen. Im ersten Teil der Arbeit gehen wir auf unsere IEEE 802.11p-Implementierung ein. Wir untersuchen die Aufwändigkeit der Berechnungen und zeigen die Korrektheit durch Simulationen und Interoperabilitätstests. Darüber hinaus erweitern wir unsere Implementierung durch zeitkritische Funktionen, wie Kanalzugriff und automatische Anpassung der Empfangsverstärkung, ohne die Komplexität merklich zu erhöhen ...Future cars will be equipped with communication modules that allow them to exchange information directly with each other and potentially infrastructure nodes, forming a Vehicular Ad Hoc Network (VANET). Through communication, cars will be able to coordinate and drive cooperatively, which will make transportation safer, more efficient, and more comfortable than ever before. One of the considered technologies for vehicular networks is IEEE 802.11p, a slightly modified version of consumer Wireless LAN (WLAN) that was adapted to better fit the characteristics of vehicular environments. While the decision to rely on readily available technology might ease market introduction, it also raises the question whether a physical layer that was designed for relatively static indoor environments can provide reasonable performance in highly dynamic VANETs. Using Software Defined Radios (SDRs), i.e., fully programmable radios, we are able to address this question, as they allow us to closely examine and modify the physical waveform. We made SDRs accessible for research on VANETs by implementing the first IEEE 802.11p transceiver for GNU Radio, a popular real-time signal processing framework for use in SDRs. Performing all signal processing on a PC, our transceiver is well-suited for rapid prototyping and can be used for simulations as well as real-world experiments, offering a seamless switch from theory to practice. In the first part of the thesis, we detail the design of our IEEE 802.11p transceiver, study its computational complexity, and present results from thorough validations through simulations and interoperability tests. We furthermore show that it is possible to support time-critical functionalities like channel access and automatic gain control without giving up the advantages of a PC implementation ...vorgelegt von Bastian Bloessl ; Betreuer: Prof. Dr.-Ing. habil. Falko Dressler, Gutachter: Prof. Dr.-Ing. habil. Falko Dressler, Prof. Dr.-Ing. Matthias Hollick, Prof. Dr. Renato Lo CignoTag der Verteidigung: 25.06.2018 ; Der Promovend hat zusätzlich zu dem Betreuer weitere Personen angegebenUniversität Paderborn, Dissertation, 201

Benchmarking and Profiling the GNURadio Scheduler

From a technical perspective, GNURadio has two main assets: its comprehensive block library of optimized, state-of-the-art signal processing algorithms and its runtime environment. The latter manages the data flow and turns GNURadio in a real-time signal processing framework. In contrast to the block library, where it is easy to replace blocks with more efficient implementations, the runtime grew organically, which resulted in a complex system that is hard to maintain. At the same time, there are concerns about its performance. To understand the current implementation and explore opportunities for future improvements, we provide benchmarking and profiling results. We, furthermore, compare the performance of GNURadio’s default with a manually optimized configuration to show the potential of a more advanced scheduler