Ethernet AVB Research Articles

Bandwidth Allocation of Stream-Reservation Traffic in TSN

Time-Sensitive Networking (TSN) evolves from Ethernet AVB in which the Credit-Based Shaping (CBS) is employed to guarantee the deterministic transmission of traffic. In CBS, the real-time performance of traffic associated with the credits can practicably settle the uncertainty of queueing and forwarding for stream-reservation traffic. Hence, the optimization of bandwidth allocation under the CBS becomes a key point to ensure guaranteed performance in the network. In this paper, a bandwidth allocation method is proposed for stream-reservation traffic while the real-time requirements are satisfied. We first illustrate the significance of appropriate bandwidth allocation for traffic under the CBS and construct a general schema for its bandwidth allocation. Also, the influences of the protected window for Control Data Traffic (CDT) on stream-reservation traffic are considered in our method. Further, mathematical models are constructed to analyze the delay bounds and backlogs of traffic to form the feedback for the optimal bandwidth allocation process. Finally, two node-level cases with different bandwidth utilization and a synthetic industrial networking scenario are carried out to demonstrate our method. The results confirm that the excessive reserved bandwidth does not necessarily decrease the delay bound, especially under the high traffic loads scenario. A more desirable bandwidth allocation strategy under the CBS mechanism is that the reserved bandwidth should be just enough according to the traffic loads to ensure the deterministic transmission of traffic.

Real-time Camera and Video Streaming Through Optimized Settings of Ethernet AVB in Vehicle Network System

Real-time Camera and Video Streaming Through Optimized Settings of Ethernet AVB in Vehicle Network System

Design and Optimization of Ethernet AVB Network for Intelligent Vehicle

Design and Optimization of Ethernet AVB Network for Intelligent Vehicle

Independent WCRT analysis for individual priority classes in Ethernet AVB

In the high-tech and automotive industry, bandwidth considerations and widely accepted standardization are two important reasons why Ethernet is currently being considered as an alternative solution for real-time communication (compared to traditional fieldbusses). Although Ethernet was originally not intended for this purpose, the development of the Ethernet AVB standard enables its use for transporting high-volume data (e.g. from cameras and entertainment applications) with low-latency guarantees. In complex industrial systems, the network is shared by many applications, developed by different parties. To face this complexity, the development of these applications must be kept as independent as possible. In particular, from a network point of view, progress of all communication streams must be guaranteed, and the performance for individual streams should be predictable using only information regarding the stream under study and the general parameters of the communication standard used by the network. Initial methods to guarantee latency for Ethernet AVB networks rely on the traditional busy-period analysis. Typically, these methods are based on knowledge of the inter-arrival patterns of both the stream under study and the interfering streams that also traverse the network. The desired independence is therefore not achieved. In this paper, we present an independent real-time analysis based on so-called eligible intervals, which does not rely on any assumptions on interfering priority classes other than those enforced in the Ethernet AVB standard. We prove this analysis is tight in case there is only a single higher-priority stream, and no additional information on interference is known. In case there are multiple higher-priority streams, we give conditions under which the analysis is still tight. Furthermore, we compare the results of our approach to the two most recent busy-period analyses, point out sources of pessimism in these earlier works, and argue that assuming more information on the sources of interference (e.g. a minimal inter-arrival time between interfering frames) has only limited advantages.

SEtSim: A modular simulation tool for switched Ethernet networks

Abstract Using high bandwidth network technologies in real-time applications, for example in automotive systems, is rapidly increasing. In this context, switched Ethernet-based protocols are becoming more popular due to their features such as providing a collision-free domain for transmission of messages. Moreover, switched Ethernet is a mature technology. Several protocols based on switched Ethernet have been proposed over the years, tuned for time critical applications. However, research for improving the features and performance of these protocols is still on-going. In order to evaluate the performance of early stage proposed protocols, the mathematical analysis and/or experiments are required. However, performing an experiment for complex network topologies with a large set of messages is not effortless. Therefore, using a simulation based approach for evaluating a protocol’s performance and/or properties is highly useful. As a response to this we have developed a simulator, called SEtSim, for switched Ethernet networks. SEtSim is developed based on Simulink, and it currently supports different network topologies of the FTT-SE protocol as well as Ethernet AVB protocol. However, the kernel of SEtSim is designed such that it is possible to add and integrate other switched Ethernet-based protocols. In this paper, we describe the design of SEtSim and we show its scalability.

Security Aspects of Utilizing Ethernet AVB as the Converged Vehicle Backbone

With increasing demand for and sophistication of automotive applications such as infotainment and driver's assistance, the need for tighter integration between the many networks found in modern vehicles is likewise increasing. To enable this integrated vehicle architecture, there is a growing trend to use the Ethernet AVB as a converged backbone to enable cross-domain data exchange. This paper examines requirements for security and integrity posed by these inter- and intra-ECU and inter-vehicle communications. Solutions are proposed - and gaps are identified - with emphasis given to mapping the broad spectrum of Ethernet security mechanisms to vehicle networking solutions. We begin by examining the security aspects of bridging Body, Chassis/Safety, Powertrain, and Infotainment data, alongside sensor and actuator data across an Ethernet AVB backbone. Specifically discussed is partitioning and application of various Ethernet security solutions including protocols, algorithms, and encryption mechanisms appropriate for vehicular requirements. This includes a discussion of the strengths and vulnerabilities afforded by Ethernet for authenticated ECU/LAN access, data/message integrity, and intrusion protection. Language: en

Modeling of Ethernet AVB Networks for Worst-Case Timing Analysis

AbstractEthernet is currently explored as the upcoming network standard for distributed control applications in many different industries such as automotive, avionics and industrial automation. It offers higher performance and flexibility over traditional control bus systems such as CAN and ProfiBus. For distributed control applications, predictable communication timing is highly important which can be problematic using standard Ethernet. The new Ethernet AVB standard aims to improve this by a new scheduling algorithm based on traffic shaping. However, the current AVB standard lacks a formal timing guarantee which is important for safety-critical control applications. As a solution to this, we present a model for Ethernet AVB networks and a transformation into a timing analysis model. Based on the timing model, we apply a compositional performance analysis approach known from the analysis of distributed real-time systems to derive worst-case timing properties and hence timing guarantees of the original Ethernet AVB network. For this, we provide the required formalism for the analysis of the scheduling of Ethernet AVB.