Ethernet - a survey on its fields of application

During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

Modeling and Analysis of Automotive Cyber-physical Systems: Formal Approaches to Latency Analysis in Practice

Based on advances in scheduling analysis in the 1970s, a whole area of research has evolved: formal end-to-end latency analysis in real-time systems. Although multiple approaches from the scientific community have successfully been applied in industrial practice, a gap is emerging between the means provided by formally backed approaches and the need of the automotive industry where cyber-physical systems have taken over from classic embedded systems. They are accompanied by a shift to heterogeneous platforms build upon multicore architectures. Scien- tific techniques are often still based on too simple system models and estimations on important end-to-end latencies have only been tightened recently. To this end, we present an expressive system model and formally describe the problem of end-to-end latency analysis in modern automotive cyber-physical systems. Based on this we examine approaches to formally estimate tight end-to-end latencies in Chapter 4 and Chapter 5. The de- veloped approaches include a wide range of relevant systems. We show that our approach for the estimation of latencies of task chains dominates existing approaches in terms of tightness of the results. In the last chapter we make a brief digression to measurement analysis since measuring and simulation is an important part of verification in current industrial practice

Real-time wireless networks for industrial control systems

The next generation of industrial systems (Industry 4.0) will dramatically transform manyproductive sectors, integrating emerging concepts such as Internet of Things, artificialintelligence, big data, cloud robotics and virtual reality, to name a few. Most of thesetechnologies heavily rely on the availability of communication networks able to offernearly–istantaneous, secure and reliable data transfer. In the industrial sector, these tasks are nowadays mainly accomplished by wired networks, that combine the speed ofoptical fiber media with collision–free switching technology. However, driven by the pervasive deployment of mobile devices for personal com-munications in the last years, more and more industrial applications require wireless connectivity, which can bring enormous advantages in terms of cost reduction and flex-ibility. Designing timely, reliable and deterministic industrial wireless networks is a complicated task, due to the nature of the wireless channel, intrinsically error–prone andshared among all the devices transmitting on the same frequency band. In this thesis, several solutions to enhance the performance of wireless networks employed in industrial control applications are proposed. The presented approaches differ in terms of achieved performance and target applications, but they are all characterized by an improvement over existing industrial wireless solutions in terms of timeliness, reliability and determinism. When possible, an experimental validation of the designed solutions is provided. The obtained results prove that significant performance improvements are already possible, often using commercially available devices and preserving compliance to existing standards. Future research efforts, combined with the availability of new chipsets and standards, could lead to a world where wireless links effectively replace most of the existing cables in industrial environments, as it is already the case in the consumer market

A holistic approach to ZigBee performance enhancement for home automation networks

Wireless home automation networks are gaining importance for smart homes. In this ambit, ZigBee networks play an important role. The ZigBee specification defines a default set of protocol stack parameters and mechanisms that is further refined by the ZigBee Home Automation application profile. In a holistic approach, we analyze how the network performance is affected with the tuning of parameters and mechanisms across multiple layers of the ZigBee protocol stack and investigate possible performance gains by implementing and testing alternative settings. The evaluations are carried out in a testbed of 57 TelosB motes. The results show that considerable performance improvements can be achieved by using alternative protocol stack configurations. From these results, we derive two improved protocol stack configurations for ZigBee wireless home automation networks that are validated in various network scenarios. In our experiments, these improved configurations yield a relative packet delivery ratio increase of up to 33.6%, a delay decrease of up to 66.6% and an improvement of the energy efficiency for battery powered devices of up to 48.7%, obtainable without incurring any overhead to the network.Postprint (published version

Protecting an Industrial AC Drive Application against Cyber Sabotage

Vuonna 2010 havaittua, erittäin kehittynyttä tietokonevirusta nimeltä Stuxnet on kuvailtu myös ensimmäiseksi kybersodan aseeksi, koska eri lähteiden mukaan se tuhosi vähintään 1 000 uraania rikastavaa kaasusentrifugia Iranissa. Tämä kybersabotaasi suoritettiin tunkeutumalla teolliseen ohjausjärjestelmään, kytkemällä sentrifugeja ohjaavien taajuusmuuttajien suojatoiminnot pois päältä ja pyörittämällä niitä niin suurilla nopeuksilla, että keskipakoisvoimat aiheuttivat roottoreiden repeämisen. Dekantterit ovat toisenlaisia sentrifugeja, joita käytetään erottamaan kiinteät aineet nestemäisistä useilla eri teollisuudenaloilla, kuten esimerkiksi vedenkäsittelyssä ja kaivostoiminnassa. Dekantterisentrifugit, eli tarkemmin kiinteärumpuiset, ruuvipurkuiset lingot, käyvät usein epätahtikoneilla ja taajuusmuuttajilla. Olettaen, että Stuxnet-tapauksen kaltainen tuho voidaan estää sopivilla turvajärjestelmillä, toimenpiteitä dekantterilingon suojelemiseksi tutkittiin käyttäen kirjallisuutta ja nykyistä tietoturva- ja henkilöturvaominaisuustarjontaa seuraavilta uudenaikaisilta taajuusmuuttajilta, joissa on Ethernet-pohjainen kenttäväyläyhteys: ABB ACS880-01, Rockwell Allen-Bradley PowerFlex 755 ja Siemens SINAMICS S110. Rajoitetun arvioinnin tuloksena taajuusmuuttajien pahin kyberturvallisuuteen liittyvä haavoittuvuus on tyypillinen monille kenttäväyliä käyttäville automaatiolaitteille: täysivaltainen asetusten muutos on mahdollista oletusarvoisesti ilman minkäänlaista käyttäjähallintaa. Kuitenkin toiminnallisen turvallisuuden asetukset voidaan suojata salasanalla, joten standardoitu turvafunktio nimeltä turvallisesti rajoitettu nopeus on toteuttamiskelpoinen ratkaisu dekantterilingon suojelemiseksi kybersabotaasilta. Liitteenä olevaa tarkistuslistaa seuraamalla dekanttereissa käytettävät taajuusmuuttajat voidaan konfiguroida mahdollisimman hyvin kyberturvallisuuden kannalta.Discovered in 2010, the highly advanced computer virus called Stuxnet, also described as the first weapon of cyber warfare, reportedly destroyed at least 1,000 gas centrifuges enriching uranium in Iran. This kind of act of cyber sabotage was conducted by compromising the industrial control system, disabling protection functions of AC drives running the centrifuges, and making them spin at such high speeds that centrifugal forces caused their rotors to rupture. Decanters are another type of centrifuges used to separate solids from liquids in many industries including water treatment and mining for example. Also known as solid-bowl, scroll-discharge centrifuges, decanters are commonly powered by induction motors and AC drives. Assuming havoc similar to the Stuxnet case can be prevented with suitable safety systems, a review was conducted on the protection methods for decanter centrifuges based on literature and the current security and safety features of the following modern AC drives with Ethernet-based fieldbus connectivity: ABB ACS880-01, Rockwell Allen-Bradley PowerFlex 755, and Siemens SINAMICS S110. As a result of the limited assessment, the worst vulnerability related to cybersecurity of the AC drives is typical to many automation devices using fieldbuses: total configuration is possible remotely without any authentication by default. However, the functional safety configuration can be protected by means of a password, therefore allowing a standardized safety function called safely-limited speed (SLS) to become a viable solution for protecting the decanter centrifuge against cyber sabotage. By following the supplied checklist, it is possible to configure AC drives used with decanters optimally in terms of cybersecurity