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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Get In Sync With TSN : A Study of Partially Synchronized TSN Networks

Johansson, Andreas Johansson January 2022 (has links)
Automotive and industrial embedded systems are increasingly dependent on real-time capabilities. TSN aims to offer flexibility of the traffic by providing Ethernet with hard and soft real-time capabilities which allows for integration with other protocols in legacy systems. TSN requires the network to be fully synchronized to achieve high performance. However, there are cases where legacy systems are not able to synchronize with TSN. These systems might nonetheless be able to synchronize with each other through their legacy synchronization mechanisms. In this thesis, we have investigated effects in terms of jitter and clock drift in endpoints by synchronizing them with each other and passing communication through an unsynchronized intermediary TSN switch. Our results revealed that with the introduction of TSN, jitter was reduced, while clock drift between endpoints and the TSN switch was introduced. The results show that negative clock drift leads to packets missing their scheduled TSN windows and positive drift leads to packets being dropped in the switch buffer queues. We proposed two solutions in order to manage the experienced clock drift. In one solution we statically changed the switch cycle, and in the other, we let the receiver node dynamically update the sending period in the sender node. In the static solution, the clock drift was reduced from negative eight microseconds per second to two nanoseconds per second. In the dynamic solution, a packet error rate of one per 100 seconds was reduced to zero errors in 19 hours.
12

Integrating 5G Components into a TSN Discrete Event Simulation Framework

Magnusson, Alexander, Pantzar, David January 2021 (has links)
TSN has for many years been the staple of reliable communication over traditional switched Ethernet and, has been used to advance the industrial automation sector. However, TSN is not mobile, which is needed to fully enable Industry 4.0. The development of 5G and its promised URLLC combined with TSN would give both a mobile and reliable heterogeneous network. The 3GPP has suggested different designs for a 5G and TSN integration. This thesis investigates the different proposed integration designs. Besides the integration design, one of the most essential steps towards validity of the integration is to evaluate the TSN-5G networks based on simulation. Currently, this simulation environment is missing. The investigation in this thesis shows that the most exhaustive work had been done on the Logical TSN Bridge design for simulators, such as the ones based on OMNeT++. Capabilities of the simulator itself are also investigated, where aspects such as the lack of a 5G medium and clock synchronization are presented. In this thesis, we implement the 5G-TSN component that results in a translator which sets different 5G channel parameters depending on the Ethernet packet's priority and its corresponding value. To verify the functionality of the translator that is developed within the simulator, it is tested in a use case inspired by the vehicle industry, containing both TSN and 5G devices. Results from the use case indicate that the translation is performed correctly.
13

Providing a Solution for Configuration of Linux end-hosts in Time-Sensitive Networks / Lösning för konfiguration av Linux-end-hosts i Time-Sensitive Networks

Alonso, Nils, Olsson, Jesper January 2023 (has links)
Time-critical networks of various types are widely used in fields such as industrial automation. Many of these time-critical networking solutions are proprietary and closed, which can make them costly to work with. An alternative to these legacy solutions is Time-Sensitive Networking. Time Sensitive Networking, or TSN, is an open standard for time-critical communication over Ethernet hardware and protocols. Compared to proprietary and closed legacy solutions, a TSN can be easier to set up. There is still however a challenge in configuring a TSN since the configuration process is hardware dependent. This thesis sets out to ease the configuration process, making it more user-friendly by providing a tool for the generation of end-host configurations. Currently, no such readily available tool exists for configuration of Linux end-hosts in TSNs. This is done by implementing extensions to the incomplete TSN configuration middleware DETD to a state where it is a suitable solution to this problem. The extensions made to DETD consist of implementing support for configuring listener streams, adding the ability to configure the TAPRIO queueing discipline, and adding support for an additional network interface card in the form of the Intel I210. To verify the functionality of these extensions a simple testbed using two real-time Linux machines is used.
14

Towards an Integrated TSN-5G Network for Real-Time Applications

Ragnarsson, Daniel, Nordin, Didrik January 2024 (has links)
This report explores the integration of 5G cellular networks with Time-Sensitive Networks (TSN), focusing on network latencies. While mobile 5G networks offer high bandwidth and low latency, TSN is an IEEE standard-based wired solution used in real-time applications for deterministic data transmission with low latency and high reliability. Integrating TSN with 5G could significantly enhance scalability, particularly in industrial automation, by providing flexibility, efficiency, and responsiveness. When combining 5G capabilities with TSN, seamless communication across wired and wireless domains becomes achievable. 5G supports several Quality of Service (QoS) flows with different priorities that must map to TSN QoS to ensure smooth integration. To meet TSN's requirements for latency and jitter, effective traffic translation and forwarding between the networks are crucial. This thesis aims to address key questions regarding traffic translation, QoS implementation, and latency in both TSN and 5G networks. Through experiments and evaluations, we assess latency and network capabilities. Understanding these metrics is essential for devising effective integration strategies. Our findings indicate that integrating 5G with TSN is feasible for achieving low latencies for packet sizes below 128-bytes. However, as packet sizes increase, latencies and jitter rise significantly. This result indicates that Firecell 5G technology may have difficulties efficiently handling larger packet sizes without latency degradation. Additionally, leveraging QoS functionalities in the current version of OpenAirInterface (OAI), which forms the foundation of the utilized Firecell 5G, is currently unattainable. This thesis highlights the importance of implementing QoS functionalities to maintain low latencies and jitter in targeted network applications. / Denna rapport undersöker den potentiella integrationen av 5G-mobilnät med tidskänsliga nätverk (TSN), med fokus på nätverksfördröjningar. Medan 5G-nät erbjuder hög bandbredd och låg fördröjning, är TSN en IEEE-standardiserad trådbunden teknik som används i realtidsapplikationer för deterministisk dataöverföring med låg fördröjning och hög tillförlitlighet. Att integrera TSN med 5G kan avsevärt förbättra skalbarheten, särskilt inom industriell automation, genom att erbjuda flexibilitet, effektivitet och låg fördröjning. Genom att kombinera 5G med TSN blir tidskänslig kommunikation över trådbundna och trådlösa nätverk möjligt. 5G stödjer flera kvalitetsnivåer för tjänster (QoS) med olika prioriteringar som måste anpassas till TSN:s QoS för att säkerställa en smidig integration. För att möta TSN:s krav på fördröjning och jitter är effektiv datahantering mellan nätverken avgörande. Denna avhandling behandlar centrala frågor kring datahantering, QoS-implementering och fördröjning i både TSN och 5G-nätverk. Genom experiment och utvärderingar får vi fram information om fördröjning och nätverkskapacitet i TSN-5G, vilket är avgörande för att utveckla effektiva integrationsstrategier. Våra resultat visar att integrationen av TSN-5G uppnår låg fördröjning för paketstorlekar under 128 byte. När paketstorleken ökar, ökar också fördröjning och jitter avsevärt. Resultaten visar att Firecell 5G-teknologin har svårigheter att effektivt hantera större paketstorlekar utan ökad fördröjning. Utöver detta är det för närvarande inte möjligt att använda QoS-funktioner i den nuvarande versionen av OpenAirInterface (OAI), vilket är mjukvaran Firecell 5G bygger på. Denna avhandling understryker vikten av att kunna implementera QoS-funktioner för att upprätthålla låg fördröjning och jitter i specifika nätverksapplikationer.
15

TSN Distributed Clock : An analysis of relationships between network configuration parameters and the resulting precision of time synchronization / TSN Distribuerad Klocka : En analys av samband mellan nätverksparametrar och den resulterande precisionen av tidssynkronisering

Götberg, Jakob, Olsson, Jakob January 2023 (has links)
In real-time systems spanning a network, there is a need for deterministic communication. The best-effort approach which most of the Internets traffic follows is not suitable for this area since it does not guarantee packet delivery within a deadline and there is also no accurate measure of when the packet was sent. The network core and edge entities such as routers and hosts do not have any concept of time in normal networking, making real-time constraints more difficult to enforce. Time Sensitive Networking is a set of standards, all of which are related to solving the problem above. The most central of these standards is IEEE 802.1AS which defines the generic Precision Time Protocol that specifies how all the nodes of a network should synchronize their clocks to one master clock, giving them a common perception of time. This standard is a prerequisite for some of the other standards in the suite, for example, the 802.1Qbv standard defining a Time Aware Sharper which provides bounded latency for time-critical traffic. A common perception of time is also by itself needed by applications that have to orchestrate actions, with temporal relations to each other, across a network. These applications can be found within areas such as industrial automation and vehicular control systems. The problem that this thesis explores is how the precision of time synchronization of a Time Sensitive Networking (TSN) solution depends on variables in the network such as configuration, topology, and external factors. To find the correlation between the parameters and the precision of the time synchronization, several experiments have been conducted. The experiments were performed on a simple network of hardware components constituting a physical test bed and an oscilloscope was used to probe the clocks if its nodes and extract measurements. Our findings indicate several relationships between the tested parameters and the synchronization precision. The biggest conclusion we can make from our study is that the IEEE 802.1AS standard does not rely on the support of other standards to achieve sub-microsecond results when there is a best-effort traffic load on the network. The manipulated configuration of the standard has given results that in general coincide with the expected behavior. Finally, the data gathered on different topologies, that were tested showed no significant trends regarding the precision. / I realtidssystem som kommunicerar över nätverk finns det ett behov av deterministisk kommunikation. Det vanliga tillvägagångssättet som de mesta av internettrafiken följer är inte lämpligt för detta område eftersom det inte garanterar paketleverans inom en deadline och det inte heller finns något exakt mått av när paketet skickades. Nätverkets enheter som routrar och noder har inte någon uppfattning om tid i normala nätverk, vilket gör realtidsbegränsningar omöjliga att upprätthålla. Time Sensitive Networking är en uppsättning standarder, som alla är relaterade till att lösa problemet ovan. Den mest centrala av dessa standarder är IEEE 802.1AS som definierar generic precision Time Protocol som specificerar hur alla noder i ett nätverk ska synkronisera sina klockor till en masterklicka, vilket ger dem en gemensam tidsuppfattning. Denna standard är en förutsättning för några av de andra standarderna i sviten, till exempel 802.1Qbv-standrarden som definierar en Time Aware Scheduler som ger begränsad latens för tidskritisk trafik. En gemensam tidsuppfattning behövs också av applikationer som måste orkestrera operationer, med tidsmässiga relationer till varandra, över ett nätverk. Dessa applikationer finns inom områden som industriell automation och fordonsstyrningssystem. Problemet som denna avhandling undersöker är hur precisionen av tidssynkronisering av en TSN-lösning beror på variabler i nätverket så som konfiguration, topologi och externa faktorer. För att hitta korrelationen mellan parametrarna och precisionen i tidssynkroniseringen har flera experiment genomförts. Experimenten utfördes på ett enkelt nätverk av hårdvarukomponenter som utgör en fysisk testbädd och ett oscilloskop användes för att undersöka klockorna på dess noder och extrahera mätningarna. Våra resultat indikerar flera samband mellan de testade parametrarna och synkroniseringsprecisionen. Den största slutsatsen vi kan dra från vår studie är att IEEE 802.1AS-standaden inte förlitar sig på stöd från andra standarder för att uppnå resultat under mikrosekunder när det finns en annan trafikbelastning på nätverket. Den manipulerade konfigurationen av standarden har gett resultat som i allmänhet överensstämmer med det förväntade beteendet. Slutligen visade de insamlade data om olika typologier som testades inga signifikanta trender vad gäller precisionen.
16

Time-Sensitive Networking in Digital Substations

Johansson, Andreas, Wågbrant, Samuel January 2024 (has links)
With the advancements in the Industrial Internet of Things (IIoT), new networking requirements and demands are introduced to Substation Automation Systems (SAS) within electrical power grids. The possibility of merging Information Technology (IT) and Operational Technology (OT) traffic on the same network to achieve higher productivity, however, presents new challenges in providing real-time guarantees to OT traffic. Time-Sensitive Networking (TSN) can be a promising solution that allows IT and OT traffic to coexist seamlessly while still providing real-time guarantees for critical applications. Substations act as critical nodes within power grids, and their digitalisation is a crucial element in the energy transition. A digital substation handles International Electrotechnical Commission (IEC) 61850 protocol traffic such as Generic Object Oriented Substation Event (GOOSE), Sampled Values (SV), and Manufacturing Message Specification (MMS), which all have strict timing requirements. The integration of TSN into these substations could improve the handling of this traffic and, consequently, the controllability of power grids. This thesis investigates the use of TSN in an IEC 61850 process bus, typically implemented in an SAS. A series of simulated test scenarios were developed to evaluate the impact of TSN compared to traditional networking methods. These included configurations using Ethernet, Ethernet with priority queuing, and TSN with Time-Aware Shaper (TAS) and Credit-Based Shaper (CBS). The results indicate that TSN can meet critical timing requirements, reduce jitter, and manage sporadic traffic effectively under high traffic loads. While the TAS scheduler may increase End-to-End delay for periodic traffic, CBS can reduce it for event-based traffic. Furthermore, robust timing guarantees are ensured for the TSN scenarios by providing a feasible schedule for Scheduled Traffic (ST) and a worst-case response time analysis for Audio-Video Bridging (AVB) traffic. This research highlights TSN’s potential to improve grid controllability and reliability through enhanced network performance, illustrating its role in the future of resilient grid technologies.
17

Security Analysis of OPC UA in Automation Systems for IIoT / Säkerhetsanalys av OPC UA inom automationssystem för IIoT.

Varadarajan, Vaishnavi January 2022 (has links)
Establishing secured communication among the different entities in an industrial environment is a major concern. Especially with the introduction of the Industrial Internet of Things (IIoT), industries have been susceptible to cyber threats, which makes security a critical requirement for the industries. Prevailing industrial communication standards were proven to meet the security needs to some extent, but the major issue which was yet to be addressed was interoperability. To achieve interoperability, Open Platform Communication Unified Architecture (OPC UA) was introduced as a communication protocol. OPC UA helped bridge the gap between Information Technology (IT) and Operational Technology (OT) security needs, but this also gives rise to new attack opportunities for the intruder. In this thesis, we have analysed the security challenges in OPC UA and the impact of two different cyberattacks on the OPC UA. First, we have implemented an OPC UA Network with the help of Raspberry Pis and open62541, an open-source implementation of the OPC UA client and server. Following this, to evaluate the performance of the network, we performed three cybersecurity attacks, Packet Sniffing, Man in the Middle Attack (MITM) and Denial of Service attack. We assessed the impact these attacks have on the OPC UA network. We have also discussed the detection mechanism for the same attacks. This analysis has helped us recognize the threats faced by OPC UA in an IIoT environment with respect to message flooding, packet sniffing and man in the middle attack and the countermeasures to this attack have been discussed / Att etablera en säker kommunikation mellan de olika enheterna i en industriell miljö är en stor utmaning. Speciellt efter introduktionen av Industrial Internet of Things (IIoT) har industrier varit mottagliga för cyberhot vilket gör cybersäkerhet en prioritet. Rådande industriella kommunikationsstandarder har visats att till viss del uppfylla säkerhets- behoven, men en av de största problemen var bristen på interoperabilitet. För att uppnå interoperabiliteten skapades Open Platform Communication Unified Architecture (OPC UA) som kommun- ikationsprotokoll. OPC UA hjälper till att överbrygga gapet mellan säkerhetsbehoven av information- steknologi (IT) och Operational Technology (OT), men detta ger också upphov till nya attackmöjligheter för inkräktare. I detta examensarbete har vi analyserat säkerhetsutmaningarna i OPC UA och effekten av två olika cyberattacker på OPC UA. Först har vi implementerat ett OPC UA Network med hjälp av Raspberry Pis och open62541 som är en öppen källkodsimplementering av OPC UA klient och server. Efter detta utförde vi tre cybersäkerhetsattacker för att utvärdera nätverkets prestanda, packet sniffing, Man in the Middle Attack (MITM) och Denial of Service attack. Vi bedömde vilken effekt dessa attacker har på OPC UA-nätverket. Vi har också diskuterat detektionsmekanismen för samma attacker. Denna analys har hjälpt oss att känna igen de hot som OPC UA står inför i en IIoT-miljö med avseende på dataflöde, packet sniffing och Man in the Middle attack och även försvar mot dessa attacker har diskuterats.
18

Security Analysis of OPC UA in Automation Systems for IIoT / Säkerhetsanalys av OPC UA inom automationssystem för IIoT.

Varadarajan, Vaishnavi January 2022 (has links)
Establishing secured communication among the different entities in an industrial environment is a major concern. Especially with the introduction of the Industrial Internet of Things (IIoT), industries have been susceptible to cyber threats, which makes security a critical requirement for the industries. Prevailing industrial communication standards were proven to meet the security needs to some extent, but the major issue which was yet to be addressed was interoperability. To achieve interoperability, Open Platform Communication Unified Architecture (OPC UA) was introduced as a communication protocol. OPC UA helped bridge the gap between Information Technology (IT) and Operational Technology (OT) security needs, but this also gives rise to new attack opportunities for the intruder. In this thesis, we have analysed the security challenges in OPC UA and the impact of two different cyberattacks on the OPCUA. First, we have implemented an OPC UA Network with the help of Raspberry Pis and open62541, an open-source implementation of the OPC UA client and server. Following this, to evaluate the performance of the network, we performed three cybersecurity attacks, Packet Sniffing, Man in the Middle Attack (MITM) and Denial of Service attack. We assessed the impact these attacks have on the OPC UA network. We have also discussed the detection mechanism for the same attacks. This analysis has helped us recognize the threats faced by OPC UA in an IIoT environment with respect to message flooding, packet sniffing and man in the middle attack and the countermeasures to this attack have been discussed. / Att etablera en säker kommunikation mellan de olika enheterna i en industriell miljö är en stor utmaning. Speciellt efter introduktionen av Industrial Internet of Things (IIoT) har industrier varit mottagliga för cyberhot vilket gör cybersäkerhet en prioritet. Rådande industriella kommunikationsstandarder har visats att till viss del uppfylla säkerhets- behoven, men en av de största problemen var bristen på interoperabilitet. För att uppnå interoperabiliteten skapades Open Platform Communication Unified Architecture (OPC UA) som kommun- ikationsprotokoll. OPC UA hjälper till att överbrygga gapet mellan säkerhetsbehoven av information- steknologi (IT) och Operational Technology (OT), men detta ger också upphov till nya attackmöjligheter för inkräktare. I detta examensarbete har vi analyserat säkerhetsutmaningarna i OPC UA och effekten av två olika cyberattacker på OPC UA. Först har vi implementerat ett OPC UA Network med hjälp av Raspberry Pis och open62541 som är en öppen källkodsimplementering av OPC UA klient och server. Efter detta utförde vi tre cybersäkerhetsattacker för att utvärdera nätverkets prestanda, packet sniffing, Man in the Middle Attack (MITM) och Denial of Service attack. Vi bedömde vilken effekt dessa attacker har på OPC UA-nätverket. Vi har också diskuterat detektionsmekanismen för samma attacker. Denna analys har hjälpt oss att känna igen de hot som OPC UA står inför i en IIoT-miljö med avseende på dataflöde, packet sniffing och Man in the Middle attack och även försvar mot dessa attacker har diskuterats.
19

Testovací modul pro vybranou část standardu IEEE 802.1Q / Tester for chosen sub-standard of the IEEE 802.1Q

Avramović, Nikola January 2019 (has links)
Tato práce se zabývá analyzováním IEEE 802.1Q standardu TSN skupiny a návrhem testovacího modulu. Testovací modul je napsán v jazyku VHDL a je možné jej implementovat do Intel Stratix® V GX FPGA (5SGXEA7N2F45C2) vývojové desky. Standard IEEE 802.1Q (TSN) definuje deterministickou komunikace přes Ethernet sít, v reálném čase, požíváním globálního času a správným rozvrhem vysíláním a příjmem zpráv. Hlavní funkce tohoto standardu jsou: časová synchronizace, plánování provozu a konfigurace sítě. Každá z těchto funkcí je definovaná pomocí více různých podskupin tohoto standardu. Podle definice IEEE 802.1Q standardu je možno tyto podskupiny vzájemně libovolně kombinovat. Některé podskupiny standardu nemohou fungovat nezávisle, musí využívat funkce jiných podskupin standardu. Realizace funkce podskupin standardu je možná softwarově, hardwarově, nebo jejich kombinací. Na základě výše uvedených fakt, implementace podskupin standardu, které jsou softwarově související, byly vyloučené. Taky byly vyloučené podskupiny standardů, které jsou závislé na jiných podskupinách. IEEE 802.1Qbu byl vybrán jako vhodná část pro realizaci hardwarového testu. Různé způsoby testování byly vysvětleny jako DFT, BIST, ATPG a další jiné techniky. Pro hardwarové testování byla vybrána „Protocol Aware (PA)“technika, protože tato technika zrychluje testování, dovoluje opakovanou použitelnost a taky zkracuje dobu uvedení na trh. Testovací modul se skládá ze dvou objektů (generátor a monitor), které mají implementovanou IEEE 802.1Qbu podskupinu standardu. Funkce generátoru je vygenerovat náhodné nebo nenáhodné impulzy a potom je poslat do testovaného zařízeni ve správném definovaném protokolu. Funkce monitoru je přijat ethernet rámce a ověřit jejich správnost. Objekty jsou navrhnuty stejným způsobem na „TOP“úrovni a skládají se ze čtyř modulů: Avalon MM rozhraní, dvou šablon a jednoho portu. Avalon MM rozhraní bylo vytvořeno pro komunikaci softwaru s hardwarem. Tento modul přijme pakety ze softwaru a potom je dekóduje podle definovaného protokolu a „pod-protokolu “. „Pod-protokol“se skládá z příkazu a hodnoty daného příkazu. Podle dekódovaného příkazu a hodnot daných příkazem je kontrolovaný celý objekt. Šablona se používá na generování nebo ověřování náhodných nebo nenáhodných dat. Dvě šablony byly implementovány pro expresní ověřování nebo preempční transakce, definované IEEE 802.1Qbu. Porty byly vytvořené pro komunikaci mezi testovaným zařízením a šablonou podle daného standardu. Port „generátor“má za úkol vybrat a vyslat rámce podle priority a času vysílaní. Port „monitor“přijme rámce do „content-addressable memory”, která ověřuje priority rámce a podle toho je posílá do správné šablony. Výsledky prokázaly, že tato testovací technika dosahuje vysoké rychlosti a rychlé implementace.

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