Worst-case access delay of HomePlug Green PHY (HPGP) for delay-critical in-vehicle applications

The increasing complexity of automotive electronics has put considerable pressure on automotive communication networking to accommodate in-vehicle information flows. The use of power lines has been a promising alternative to in-vehicle communications because of elimination of extra data cables. In this paper, we focus on the latest HomePlug Green PHY (HPGP) which has been promoted by major automotive manufacturers for green communications with electric vehicles, and study its worst-case access delay performance in supporting delaycritical in-vehicle applications using both theoretical analysis and the simulation. Specifically, we apply Network Calculus as a deterministic modeling approach to evaluate the worst delay and further verify its performance using the OMNeT++ simulation. Evaluation results are also supplemented to compare with legacy methods and provide useful guidelines for developing HPGP based vehicular power line communication systems

Techniques for Reducing Redundant Unicast Traffic in HSR Networks

High-availability seamless redundancy (HSR) is a seamless redundancy protocol for Ethernet networks. HSR provides seamless communication with fault tolerance based on the duplication of every unicast frame sent in a ring topology. HSR is very useful for mission- and time-critical systems such as substation automation systems (SASs). However, the main drawback of HSR is to generate excessively redundant network traffic in HSR networks. This drawback would unnecessarily waste network bandwidth and hence could degrade network performance in HSR networks. Several traffic reduction techniques for HSR networks have been proposed to improve the network performance in the networks. These techniques can be classified into two main groups: traffic filtering-based and dual paths-based techniques. In this chapter, we provide a description and comparison of these HSR traffic reduction techniques. This chapter describes these traffic reduction techniques and compares their network performance. The operations, advantages, and disadvantages of these techniques are investigated and summarized

Delay analysis and time-critical protocol design for in-vehicle power line communication systems

With the emerging automated tasks in vehicle domain, the development of in-vehicle communications is increasingly important and subjected to new applications. The use of vehicular power lines has been a promising alternative to invehicle communications because of elimination of extra data cables. In this paper, we focus on the latest HomePlug Green PHY (HPGP) and explore its opportunity to support timecritical in-vehicle applications. Specifically, we apply Network Calculus to evaluate the worst access and queuing delay of various priority flows in vehicle bus networks. In order to maximize the bandwidth utility and satisfy the end-to-end hard delay requirements, we further propose a bandwidth efficient fair rate scheduling and delay sensitive traffic shaper. Performance evaluation supplemented by numerical and simulation results is also provided to show the advantage of HPGP and the proposed traffic shaper over the existing industry solutions

Impact analysis of time synchronization error in airborne target tracking using a heterogeneous sensor network

This paper investigates the influence of time synchronization on sensor fusion and target tracking. As a benchmark, we design a target tracking system based on track-to-track fusion architecture. Heterogeneous sensors detect targets and transmit measurements through a communication network, while local tracking and track fusion are performed in the fusion center to integrate measurements from these sensors into a fused track. The time synchronization error is mathematically modeled, and local time is biased from the reference clock during the holdover phase. The influence of the time synchronization error on target tracking system components such as local association, filtering, and track fusion is discussed. The results demonstrate that an increase in the time synchronization error leads to deteriorating association and filtering performance. In addition, the results of the simulation study validate the impact of the time synchronization error on the sensor network.This work was supported by Innovate UK funding (grant number 10012306)

Aikakriittisen Ethernet-verkon toteuttaminen hyödyntäen Time-Sensitive Networking -tekniikkaa

Tämän kandidaatintyön tarkoituksena on tutkia Time-Sensitive Networking (TSN) -tekniikkaa sekä sitä edeltänyttä Audio Video Bridging (AVB) -tekniikkaa. TSN on joukko IEEE:n 802 Ethernet alastandardeja, jotka mahdollistavat aikakriittisen tietoliikenteen siirtämisen tavallisessa Ethernet-verkossa. Työssä ei käsitellä aivan kaikkia TSN:n standardeja, vaan TSN:n toiminnan kannalta oleellisimmat standardit. Myös TSN:ää edeltänyt AVB käsitellään lyhyesti, koska jotkin TSN:n standardit pohjautuvat AVB:n standardeihin. TSN:n standardeihin perehtymisen lisäksi työssä käydään läpi, mitä TSN:n standardeja tukevia laitteita markkinoilla on jo olemassa tämän työn kirjoittamisen aikana. Viimeisenä osana työtä esitellään työssä toteutettu kokeellinen toteutus, jonka tarkoituksena oli demonstroida TSN:n toimintaa tietoverkossa, joka koostui kahdesta päätepistelaitteesta sekä kahdesta kytkimestä. Markkinoilla olevien TSN:n standardeja tukevien laitteiden löytämiseksi selvitettiin, mitkä teollisuus- ja teknologiayritykset ovat mukana TSN:n kehittämisessä. Tämän tiedon perusteella yrityksien tuotevalikoimia käytiin yksitellen läpi samalla karsien joukosta pois kaikki yritykset, joiden tuotevalikoimassa ei ollut TSN:ää tukevia tuotteita. TSN:n kokeellista toteutusta ei saatu kokonaisuudessaan suoritettua demonstraatiossa ilmenneen lisenssiongelman vuoksi. Työssä kuitenkin saatiin suoritettua TSN:n toiminnallisuuden konfigurointi tietoverkon kytkimiin sekä demonstroitua TSN:n aikasynkronointiominaisuus. Työssä myös osoitettiin, että olemassa olevilla laitteilla ja niiden käyttöön liittyvillä ohjeilla olisi mahdollista toteuttaa kokonainen TSN:n toiminnallisuuksia demonstroiva toteutus. Täten työtä ja sen lähteitä voidaan hyödyntää tulevaisuudessa perinpohjaisempaan TSN:n ominaisuuksien demonstroitiin

A Survey of Clock Synchronization Over Packet-Switched Networks

Clock synchronization is a prerequisite for the realization of emerging applications in various domains such as industrial automation and the intelligent power grid. This paper surveys the standardized protocols and technologies for providing synchronization of devices connected by packet-switched networks. A review of synchronization impairments and the state-of-the-art mechanisms to improve the synchronization accuracy is then presented. Providing microsecond to sub-microsecond synchronization accuracy under the presence of asymmetric delays in a cost-effective manner is a challenging problem, and still an open issue in many application scenarios. Further, security is of significant importance for systems where timing is critical. The security threats and solutions to protect exchanged synchronization messages are also discussed

A Comprehensive Review on Time Sensitive Networks with a Special Focus on Its Applicability to Industrial Smart and Distributed Measurement Systems

The groundbreaking transformations triggered by the Industry 4.0 paradigm have dramati-cally reshaped the requirements for control and communication systems within the factory systems of the future. The aforementioned technological revolution strongly affects industrial smart and distributed measurement systems as well, pointing to ever more integrated and intelligent equipment devoted to derive accurate measurements. Moreover, as factory automation uses ever wider and complex smart distributed measurement systems, the well-known Internet of Things (IoT) paradigm finds its viability also in the industrial context, namely Industrial IoT (IIoT). In this context, communication networks and protocols play a key role, directly impacting on the measurement accuracy, causality, reliability and safety. The requirements coming both from Industry 4.0 and the IIoT, such as the coexistence of time-sensitive and best effort traffic, the need for enhanced horizontal and vertical integration, and interoperability between Information Technology (IT) and Operational Technology (OT), fostered the development of enhanced communication subsystems. Indeed, established tech-nologies, such as Ethernet and Wi-Fi, widespread in the consumer and office fields, are intrinsically non-deterministic and unable to support critical traffic. In the last years, the IEEE 802.1 Working Group defined an extensive set of standards, comprehensively known as Time Sensitive Networking (TSN), aiming at reshaping the Ethernet standard to support for time-, mission-and safety-critical traffic. In this paper, a comprehensive overview of the TSN Working Group standardization activity is provided, while contextualizing TSN within the complex existing industrial technological panorama, particularly focusing on industrial distributed measurement systems. In particular, this paper has to be considered a technical review of the most important features of TSN, while underlining its applicability to the measurement field. Furthermore, the adoption of TSN within the Wi-Fi technology is addressed in the last part of the survey, since wireless communication represents an appealing opportunity in the industrial measurement context. In this respect, a test case is presented, to point out the need for wirelessly connected sensors networks. In particular, by reviewing some literature contributions it has been possible to show how wireless technologies offer the flexibility necessary to support advanced mobile IIoT applications

Rede sensível ao tempo: um estudo do mapeamento sistemático

The time sensitive network (TSN) is a technology that aims to provide a whole new level of determinism. It is made up of a set of standards, which are still being developed by the IEEE 802.1 working group. Its goal is to provide a network with extremely small packet loss in addition to calculable latencies and jitter. Because it is fairly recent, there is a certain di culty nding relevant materials for conducting research or developing it. Based on this problem this problem, the objective of this work is to perform a survey, gathering the important information about this new technology. The TSN is a set of several mechanisms. Each of them belongs to the 802.1 standard group. The work done here, talks about eight of the main mechanisms. In this way, a reader who has some level of information about networks, is able to understand the most relevant mechanisms and therefore can understand how the time sensitive network works, and its full potential.A rede sensível ao tempo (TSN) é uma tecnologia que visa fornecer um nível de determinismo totalmente novo. Ela é formada por um conjunto de padrões, os quais ainda estão sendo desenvolvidos pelo grupo de trabalho IEEE 802.1. Eles visam fornecer uma rede com perda de pacotes extremamente pequena alem de latências calculáveis e jitter limitado. Por ser razoavelmente recente, ha uma certa dificuldade de encontrar materiais relevantes para a realização uma pesquisa ou para o desenvolvimento da mesma. Visando essa problemática, o objetivo deste trabalho é realizar um mapeamento sistemático reunindo as informações importantes sobre esta nova tecnologia. A TSN é um conjunto de vários mecanismos. Cada um deles pertence a um padrão do grupo 802.1. O trabalho realizado aqui, fala sobre oito dos principais mecanismos. Deste modo o leitor, que possua algum nível de informação sobre redes, é capaz de compreender os mecanismos mais relevantes e por conseguinte entender como a rede sensível ao tempo funciona e todo o seu potencial

Design and management of image processing pipelines within CPS: Acquired experience towards the end of the FitOptiVis ECSEL Project

Cyber-Physical Systems (CPSs) are dynamic and reactive systems interacting with processes, environment and, sometimes, humans. They are often distributed with sensors and actuators, characterized for being smart, adaptive, predictive and react in real-time. Indeed, image- and video-processing pipelines are a prime source for environmental information for systems allowing them to take better decisions according to what they see. Therefore, in FitOptiVis, we are developing novel methods and tools to integrate complex image- and video-processing pipelines. FitOptiVis aims to deliver a reference architecture for describing and optimizing quality and resource management for imaging and video pipelines in CPSs both at design- and run-time. The architecture is concretized in low-power, high-performance, smart components, and in methods and tools for combined design-time and run-time multi-objective optimization and adaptation within system and environment constraints

Design and management of image processing pipelines within CPS : Acquired experience towards the end of the FitOptiVis ECSEL Project

Cyber-Physical Systems (CPSs) are dynamic and reactive systems interacting with processes, environment and, sometimes, humans. They are often distributed with sensors and actuators, characterized for being smart, adaptive, predictive and react in real-time. Indeed, image- and video-processing pipelines are a prime source for environmental information for systems allowing them to take better decisions according to what they see. Therefore, in FitOptiVis, we are developing novel methods and tools to integrate complex image- and video-processing pipelines. FitOptiVis aims to deliver a reference architecture for describing and optimizing quality and resource management for imaging and video pipelines in CPSs both at design- and run-time. The architecture is concretized in low-power, high-performance, smart components, and in methods and tools for combined design-time and run-time multi-objective optimization and adaptation within system and environment constraints.Peer reviewe