Time-Sensitive Networking Research Articles

Latency Analysis of Multiple Classes of AVB Traffic in TSN With Standard Credit Behavior Using Network Calculus

Time-sensitive networking (TSN) is a set of amendments that extend Ethernet to support distributed safety-critical and real-time applications in the industrial automation, aerospace, and automotive areas. TSN integrates multiple traffic types and supports interactions in several combinations. In this article, we consider the configuration supporting scheduled traffic (ST) based on gate-control lists, audio–video bridging (AVB) traffic according to IEEE 802.1BA that has bounded latencies, and best-effort traffic, for which no guarantees are provided. This article extends the timing analysis method to multiple AVB classes and proofs the credit bounds for multiple classes of AVB traffic, respectively, under frozen and nonfrozen behaviors of credit during guard band (GB). They are prerequisites for nonoverflow credits of credit-based shaper (CBS) and preventing starvation of AVB traffic. Moreover, this article proposes an improved timing analysis method reducing the pessimism for the worst-case end-to-end delays of AVB traffic by considering the limitations from the physical link rate and the output of CBS. Finally, we evaluate the improved analysis method on both synthetic and real-world test cases, showing the significant reduction of pessimism on latency bounds compared to related work and presenting the correctness validation compared with simulation results. We also compare the AVB latency bounds in the case of frozen and nonfrozen credit during GB. Additionally, we evaluate the scalability of our method with variation of the load of ST flows and of the bandwidth reservation for AVB traffic.

Bandwidth Partitioning for Time-Sensitive Networking Flows in Automotive Communications

Traditional in-vehicle networks are statically deployed and configured during the car manufacturing process. However, the growing need for supporting new in-car traffic flows, e.g., to add new camera-based Advanced Driver Assistant Systems (ADAS) or infotainment applications, generates an increasing demand for bandwidth and requires the ability for re-configuring the bandwidth allocation among flows during the vehicle lifecycle. For this reason, this work proposes a partitioning system for Time-Sensitive Networking (TSN) that allows introducing new flows in the in-vehicle network without affecting the already existing ones. Moreover, the letter presents a simulative assessment of the proposed approach in a realistic automotive scenario.

A scalable factory backbone for multiple independent time-sensitive networks

Convergence of time-sensitive machine control networks as part of the operational technology (OT) with the ubiquitous information technology (IT) networks is an essential requirement for the ongoing digitalization of production. In this paper, we review the fundamental differences between both technologies, the challenges to be solved, existing and upcoming solutions like TSN and their limitations. Furthermore, we introduce an Ethernet extension for a backbone network at factory scale and line rates of 10 - 100Gbit/s. The backbone is intended to carry massive amounts of IT traffic together with the traffic of multiple independent OT networks at the precision of leading-edge field bus technologies in the sub-microsecond range. The backbone remains transparent and does not require changes to the attached OT sub-networks. We prove our claims by prototype measurements, interoperability tests and field trials.

Monitoring of Energy Data with Seamless Temporal Accuracy Based on the Time-Sensitive Networking Standard and Enhanced µPMUs

In the energy sector, distributed synchronism and a high degree of stability are necessary for all real-time monitoring and control systems. Instantaneous response to critical situations is essential for the integration of renewable energies. The most widely used standards for clock synchronisation, such as Network Time Protocol (NTP) and Precision Time Protocol (PTP), do not allow for achieving synchronised simultaneous sampling in distributed systems. In this work, a novel distributed synchronism system based on the Time-Sensitive Networking (TSN) standard has been validated for its integration in an architecture oriented towards the high-resolution digitisation of photovoltaic (PV) generation systems. This method guarantees a time stamping with an optimal resolution that allows for the analysis of the influence of fast-evolving atmospheric fluctuations in several plants located in the same geographical area. This paper proposes an enhanced micro-phasor measurement unit (µPMU) that acts as a phasor meter and TSN master controlling the monitoring system synchronism. With this technique, the synchronism would be extended to the remaining measurement systems that would be involved in the installation at distances greater than 100 m. Several analyses were carried out with an on-line topology of four acquisition systems capturing simultaneously. The influence of the Ethernet network and the transducers involved in the acquisition process were studied. Tests were performed with Ethernet cable lengths of 2, 10, 50, and 75 m. The results were validated with 24-bit Sigma-Delta converters and high-precision resistor networks specialised in high-voltage monitoring. It was observed that with an appropriate choice of sensors and TSN synchronism, phase errors of less than ±1 µs can be guaranteed by performing distributed captures up to 50 kS/s. Statistical analysis showed that uncertainties of less than ±100 ns were achieved with 16-bit Successive Approximation Register (SAR) converters at a moderate cost. Finally, the requirements of the IEEE C37.118.1-2011 standard for phasor measurement units (PMU) were also satisfied. This standard establishes an uncertainty of ±3.1 μs for 50 Hz systems. These results demonstrate the feasibility of implementing a simultaneous sampling system for distributed acquisition systems coordinated by a µPMU.

A digital twin network solution for end-to-end network service level agreement (SLA) assurance

With the gradual development of the 5G industry network and applications, each industry application has various network performance requirements, while customers hope to upgrade their industrial structures by leveraging 5G technologies. The guarantee of service level agreement (SLA) requirements is becoming more and more important, especially SLA performance indicators, such as delay, jitter, bandwidth, etc. For network operators to fulfill customer’s requirements, emerging network technologies such as time-sensitive networking (TSN), edge computing (EC) and network slicing are introduced into the mobile network to improve network performance, which increase the complexity of the network operation and maintenance (O&M), as well as the network cost. As a result, operators urgently need new solutions to achieve low-cost and high-efficiency network SLA management. In this paper, a digital twin network (DTN) solution is innovatively proposed to achieve the mapping and full lifecycle management of the end-to-end physical network. All the network operation policies such as configuration and modification can be generated and verified inside the digital twin network first to make sure that the SLA requirements can be fulfilled without affecting the related network environment and the performance of the other network services, making network operation and maintenance more effective and accurate.

Security Analysis of the TSN Backbone Architecture and Anomaly Detection System Design Based on IEEE 802.1Qci

With the development of intelligent and connected vehicles, onboard Ethernet will play an important role in the next generation of vehicle network architectures. It is well established that accurate timing and guaranteed data delivery are critical in the automotive environment. The time-sensitive network (TSN) protocol can precisely guarantee the time certainty of the key signals of automotive Ethernet. With the time-sensitive network based on automotive Ethernet being standardized by the TSN working group, the TSN has already entered the vision of the automotive network. However, the security mechanism of the TSN protocol is rarely discussed. First, the security of the TSN automotive Ethernet as a backbone E/E (electrical/electronic) architecture is analyzed in this paper through the Microsoft STRIDE threat model, and possible countermeasures for the security of automotive TSNs are listed, including the security protocol defined in the TSN, so that the TSN security protocol and the traditional protection technology can form a complete automotive Ethernet protection system. Then, the security mechanism per-stream filtering and policing (PSFP) defined in IEEE 802.1Qci is analyzed in detail, and an anomaly detection system based on PSFP is proposed in this paper. Finally, OMNeT++ is used to simulate a real TSN topology to evaluate the performance of the proposed anomaly detection system (ADS). As a result, the protection strategy based on 802.1Qci not only ensures the real-time performance of the TSN but can also isolate individuals with abnormal behavior and block DoS (denial of service) attacks, thus attaining the security protection of the TSN vehicle-based network.

Bringing Time-Sensitive Networking to Wireless Professional Private Networks

Private professional environments such as manufacturing industry, warehouses, hospitals, airports, among others, increasingly rely on end-to-end connected solutions to support and to improve their daily operational performance. This comes with a demand for real-time and deterministic communication, without evading the flexibility offered by wireless communication. Currently, wireless networks are lacking time-sensitive networking (TSN) features, making them only suitable for non-time-critical communication. To support end-to-end wireless-wired deterministic communication in these private professional environments, it is necessary to introduce TSN features to the wireless network segments. In this paper, we list a number of considerations that have to be addressed before such communication may become a reality, including accurate time synchronization and fine-grained scheduling. Based on these considerations, we present a proof-of-concept realization of a TSN-capable Wi-Fi system, which enables end-to-end wireless-wired deterministic communication.

A perspective on industrial quantum networks

The vision is a software-defined quantum network that enables a flexible experimental platform for developing quantum applications for industry. While components of the quantum Internet are under development, the control plane remains undefined. The quantum Internet, like the classical Internet, will be a network of networks. Operation of an industrial quantum network is viewed as a networked control problem, and a time-sensitive network control plane is proposed to enable a quantum software-defined network. Measurement-device-independent quantum key distribution is used as an example implementation since it provides a foundation for a quantum repeater and, by extension, the quantum Internet. Results indicate that a time-sensitive network control plane design is feasible, and its pros and cons are discussed.

Large-scale periodic scheduling in time-sensitive networks

The real-time and safety-critical demands posed in a variety of industrial systems can now be handled on the Ethernet architecture by virtue of the IEEE Time-Sensitive Networking task group. In particular, deterministic nature and timeliness guarantees can be achieved by time-triggered communication schedules that are enabled by the IEEE 802.1Qbv standard. However, generating such a schedule is a computationally challenging task due to several harsh constraints that must be satisfied. This problem is usually transformed into some existing formalism, e.g., Satisfiability Modulo Theories, and solved using a general third-party solver, which has the drawback of limited scalability. Except for some one-pass heuristics, such as the earliest deadline first or as-soon-as-possible scheduling, the current literature does not provide any algorithm tailored to this specific problem of scheduling time-triggered traffic in time-sensitive networks. In this paper, we develop an efficient algorithm that does not use any third-party solver and is based on the search in the space of partial schedules while being guided by the discovered conflicts. Our algorithm calculates schedules for problem instances consisting of 2000 network nodes and more than 10000 flows.

Time Sensitive Networking for 5G NR Fronthauls and Massive Iot Traffic

Integration of public fifth generation mobile network (5G) backhaul and non-public networks is key for the private/local 5G network ecosystem. However, such shared networks, namely, x-haul, must satisfy the extremely diverse traffic demands including low latency and massive number of internet of things (IoT) devices. We propose an x-haul platform with autonomous time aware shaper and adaptive mobile fronthaul compression, which simultaneously accommodates two 5G NR-class fronthauls (2*29.5 Gbps CPRI-equivalent rate) and backhaul traffic with 1,000 IoT devices. From an experiment we conducted to evaluate the proposed platform, mobile fronthaul traffic was transferred with 76-μs deterministic latency via 4 switches and 10-km optical fiber by autonomous time aware shaper while improving the achievable transmission rate of IoT traffic owing to the integration of adaptive compression.

A Survey on Vulnerabilities and Countermeasures in the Communications of the Smart Grid

Since the 1990s, the digitalization process has transformed the communication infrastructure within the electrical grid: proprietary infrastructures and protocols have been replaced by the IEC 61850 approach, which realizes interoperability among vendors. Furthermore, the latest networking solutions merge operational technologies (OTs) and informational technology (IT) traffics in the same media, such as time-sensitive networking (TSN)—standard, interoperable, deterministic, and Ethernet-based. It merges OT and IT worlds by defining three basic traffic types: scheduled, best-effort, and reserved traffic. However, TSN demands security against potential new cyberattacks, primarily, to protect real-time critical messages. Consequently, security in the smart grid has turned into a hot topic under regulation, standardization, and business. This survey collects vulnerabilities of the communication in the smart grid and reveals security mechanisms introduced by international electrotechnical commission (IEC) 62351-6 and how to apply them to time-sensitive networking.

Simulation of Time Delay Characteristics of Time Sensitive Networking Based on MATLAB/Simulink

In order to realize the optimal design of time sensitive networking flow scheduling strategy and meet the communication requirements of time sensitive applications to the greatest extent, it is necessary to conduct a comprehensive study on the delay characteristics by using effective simulation methods. Firstly, the working principle of time sensitive networking flow control mechanism and the influencing factors of time delay are analyzed, and the basic goal of simulation research on time delay characteristics is defined. Then, the technical characteristics of different network simulation methods are compared, and MATLAB/Simulink is selected as the simulation tool to design the time sensitive networking delay model and simulation algorithm. Finally, aiming at the main flow control mechanism application scenarios, the feasibility and correctness of the time sensitive networking delay simulation method based on MATLAB/Simulink are verified. The research results have reference value for the study of time delay characteristics and the optimization design of flow control strategy of time sensitive networking.

Time-Sensitive Networking Technologies for Industrial Automation in Wireless Communication Systems

The fourth industrial revolution is accelerating industrial automation. In industrial networks, manufacturing processes require hard real-time communication where the latency is less than 1ms. Time-sensitive networking (TSN) technology over Ethernet already supports deterministic delivery for real-time communication. However, TSN technologies over wireless networks are currently in their initial development stage. Therefore, this study presents an overview of TSN research trends in wireless communications. This paper focuses on 5G networks and IEEE 802.11. We summarize standardization trends for TSN in 5G networks and introduce the TSN technologies for 802.11-based WLAN. Then, we introduce the integration scenario of 5GS with WLAN. This study provides insights into wireless communication technologies for wireless TSN.

Time-Sensitive Networking in IEEE 802.11be: On the Way to Low-Latency WiFi 7.

A short time after the official launch of WiFi 6, IEEE 802.11 working groups along with the WiFi Alliance are already designing its successor in the wireless local area network (WLAN) ecosystem: WiFi 7. With the IEEE 802.11be amendment as one of its main constituent parts, future WiFi 7 aims to include time-sensitive networking (TSN) capabilities to support low latency and ultra-reliability in license-exempt spectrum bands, enabling many new Internet of Things scenarios. This article first introduces the key features of IEEE 802.11be, which are then used as the basis to discuss how TSN functionalities could be implemented in WiFi 7. Finally, the benefits and requirements of the most representative Internet of Things low-latency use cases for WiFi 7 are reviewed: multimedia, healthcare, industrial, and transport.

Temporal sensitive heterogeneous graph neural network for news recommendation

News recommendation plays an important role in alleviating information overload and helping users find their interesting news. Most of the existing news recommendation methods make a recommendation based on static data. They ignore the time dynamic characteristics of the interaction between users and news, that is, the order in which users click on news implicitly indicates the user’s interest in news. In this paper, we propose a time sensitive heterogeneous graph neural network for news recommendation. The network consists of two subnetworks. One subnet utilizes convolutional neural network and improved LSTM to learn a user’s stay period on the page and click sequence characteristics as the temporal dimension feature. The other subnet constructs an attention-based heterogeneous graph to model the user-news-topic associations, and apply graph neural network to learn the structural features of the heterogeneous graph as spatial dimensional features. Experiments conducted show that our model outperforms the state-of-the-art models in accuracy and has better interpretability.

5G URLLC: Evolution of High-Performance Wireless Networking for Industrial Automation

At the core of digital transformation of the manufacturing industry is the objective to unlock data at multiple points of the production system and produce insights to improve and optimize all aspects of the business operations. Tremendous advances in artificial intelligence and machine learning make it possible to analyze a vast volume of the field and production data and translate them into optimization decisions. Real-time access to the data complements efficient machine learning inference for timely and actionable insights. Flexible and re-configurable manufacturing also demands high-performance, pervasive, and low-la-tency communication links supporting mobility of workers, devices, and robots. Fifth Generation (5G) New Radio (NR) introduced basic support for Ultra Reliable and Low Latency Communication (urLLC) in Release-15 through intrinsic design features. Release-16 extends real-time capabilities of 5G NR to different verticals, addressing use cases in factory automation, the transport industry, and electrical power distribution. Wireless technologies such as 5G urLLC should co-exist with incumbent and emerging industrial Ethernet systems such as Time Sensitive Networking (TSN) in a heterogenous networking architecture. Hence, specification of interworking with TSN is also part of 3GPP Release-16. In this article, we discuss low-latency and high-reliability features supporting industrial automation, focusing on Release-16 design specifications. The interworking aspects with TSN and time synchronization accuracy limits are also highlighted, followed by performance evaluation of control and data traffic channels of 5G NR with respect to urLLC requirements.

HX-DS09: A Customized Low Power Time Sensitive Networking Chip for High-End Equipment

HX-DS09: A Customized Low Power Time Sensitive Networking Chip for High-End Equipment

Reliability-aware Scheduling and Routing for Messages in Time-sensitive Networking

Time-sensitive Networking (TSN) on Ethernet is a promising communication technology in the automotive and industrial automation industries due to its real-time and high-bandwidth communication capabilities. Time-triggered scheduling and static routing are often adopted in these areas due to high requirements on predictability for safety-critical applications. Deadline-constrained routing and scheduling in TSN have been studied extensively in past research. However, scheduling and routing with reliability requirements in the context of transient faults are not yet studied. In this work, we propose an Satisfiability Modulo Theory-based technique to perform scheduling and routing that takes both reliability constraints and end-to-end deadline constraints into consideration. Heuristics have been applied to improve the scalability of the solution. Extensive experiments have been conducted to demonstrate the efficiency of our proposed technique.

An Architecture for In-Vehicle Networks

As vehicles get equipped with increasingly complex sensors and processors, the communication requirements become more demanding. Traditionally, vehicles have used specialized networking technologies designed to guarantee bounded latencies, such as the controller area network (CAN) bus. Recently, some have used dedicated technologies to transport signals from cameras, lidars, radars, and ultrasonic sensors. In parallel, IEEE working groups are defining Ethernet standards for time-sensitive networks (TSN). This paper describes an Ethernet-based architecture with provable guaranteed performance and simple configuration that is suitable for supporting the communication requirements of in-vehicle networks.

Delay optimization strategy based on aperiodic traffic in time-sensitive networking

Time-Sensitive Networking (TSN) is a cluster of protocols working in the data link layer of the OSI reference model, which has been introduced into the industrial Internet due to its ability to ensure the deterministic transmission of data. Through IEEE 802.1AS clock synchronization and IEEE 802.1 Qbv gating mechanism, TSN networks allocate separate transmission time slots for periodic signals to ensure low delay and jitter, but this increases the delay of aperiodic stream to some extent. In this paper, a scheduling scheme of Grouping transmission is proposed. By changing the sending time of periodic data stream, the periodic data stream which is originally continuously transmitted is divided into several groups to be transmitted in different time periods in a cycle, so as to reduce the real-time aperiodic data stream delay. Experimental results show that the proposed scheduling scheme can reduce the transmission delay of the non-periodic traffic without affecting the quality of service (QoS) of the periodic traffic.