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Cloud computing provides virtualized information technology (IT) resources to ensure the workflow desired by user at any time and location; it allows users to borrow computing resources such as software, storage, and servers, as per their needs without the requirements of complicated network and server configurations. With the generalization of small embedded sensor devices and the commercialization of the Internet of Things (IoT), short- and long-range wireless network technologies are being developed rapidly, and the demand for deployment of cloud computing for IoT is increasing significantly. Cloud computing, together with IoT technology, can be used to collect and analyse large amounts of data generated from sensor devices, and easily manage heterogeneous IoT devices such as software updates, network flow control, and user management. In cloud computing, attacks on users and servers can be a serious threat to user privacy. Thus, various user authentication schemes have been proposed to prevent different types of attacks. In this paper, we discuss the security and functional weakness of the related user authentication schemes used in cloud computing and propose a new elliptic curve cryptography- (ECC-) based three-factor authentication scheme to overcome the security shortcomings of existing authentication schemes. To confirm the security of the proposed scheme, we conducted both formal and informal analyses. Finally, we compared the performance of the proposed scheme with those of related schemes to verify that the proposed scheme can be deployed in the real world.

Siitperf is the world’s first free software RFC 8219 compliant SIIT (Stateless IP/ICMP Translation, also called as Stateless NAT64) tester, which implements throughput, frame loss rate, latency and packet delay variation tests. In this paper, we show that the reliability of its results mainly depends on the accuracy of the timing of its frame sender algorithm. We also investigate the effect of Ethernet flow control on the measurement results. Siitperf is calibrated by the comparison of its results with that of a commercial network performance tester, when both of them are used for determining the throughput of the IPv4 routing of the Linux kernel.

In current field application of the smart substation, the normal flow is affected by the extensive flow control method of the process layer network. In this paper, the characteristics of process-layer network traffic and the importance of flow control are analyzed. An accurate process layer network flow control strategy is proposed based on virtual link. Virtual link information is extracted based on the SCD file, and the theoretical flow information is derived for each port of the process layer switch. As a result, the virtual link flow control strategy can be designed for each port. The proposed accurate flow control method is implemented via the switch access list control by configuration. Experiments are designed to confirm that this method is simple and feasible.

This paper evaluates the real-time distribution of data over Ethernet for the upgraded LHCb data acquisition cluster at CERN. The system commissioning ends in 2021 and its total estimated input throughput is 32 Terabits per second. After the events are assembled, they must be distributed for further data selection to the filtering farm of the online trigger. High-throughput and very low overhead transmissions will be an essential feature of such a system. In this work RoCE (Remote Direct Memory Access over Converged Ethernet) high-throughput Ethernet protocol and Ethernet flow control algorithms have been used to implement lossless event distribution. To generate LHCb-like traffic, a custom benchmark has been implemented. It was used to stress-test the selected Ethernet networks and to check resilience to uneven workload distribution. Performance tests were made with selected evaluation clusters. 100 Gb/s and 25 Gb/s links were used. Performance results and overall evaluation of this Ethernet-based approach are discussed.

With the development of information technology, intermodal transport research pays more attention to dynamic optimization and multi-role cooperation. The core issue of this paper was to realize container routing with dynamic adjustment, real-time optimization, and multi-role cooperation characteristics in the intermodal transport network. This paper first introduces the Intermodal Transport Cooperation Protocol (ITCP) that describes the operation and analysis of intermodal transport systems with the concept of encapsulation and layering. Then, a new network flow control method was built based on Model Predictive Control (MPC) in the ITCP framework. The method takes real-time information from all ITCP layers as input and generates flow control decisions for containers. To evaluate the method’s effectiveness, a discrete event simulation experiment is applied. The results show that the proposed method outperforms the all-or-nothing method in scenarios with high freight volume, which means the method proposed in this paper can effectively balance the network transport load and reduce network operating costs. The research of this paper may throw some new light on intermodal transport research from the perspectives of digitization, multi-role cooperation, dynamic optimization, and system standardization.

In this paper, we study decentralized multitask recursive least squares, where each node in a network has an unknown weight vector to estimate. The weight vectors of neigh-boring nodes are related through local linear equality constraints, e.g., the flow conservation constraints in network flow control. We propose a modified dual gradient ascent algorithm, which is both decentralized and online. The mean square convergence of the algorithm is established under standard assumptions. It is shown that both the mean square deviation and the excess mean square error converge to zero at geometric rates.

With the rapid development of modern network technology, business traffic in the network is exploding, and network traffic control technology is facing greater challenges. Traditional network flow control methods often cannot calmly deal with complex and dynamic network states, and it is difficult to avoid network congestion. Therefore, we need an intelligent method that can update flow control decisions according to the current network state.

Guaranteeing data transmission between modules is the key for application development of modular robotic systems. In a multi-channel modular robotic system, intersection modules play an essential role of communication channel selection in controlling data flow toward desired destinations. The gradient-based routing algorithm is an ideal solution to create an one-way communication path from any robotic module to a designated destination. To create bi-directional communication for a communication path of robotic configuration, virtual pheromone-based routing algorithm is a promising mechanism for intersection modules due to its simplicity and distributivity. In this paper, we address a virtual pheromone based network flow control based on the integration of gradient and virtual pheromone-based routing algorithms. We validated this method through an education and entertainment application using our newly developed modular robotic system.

Network flow classification plays a very important role in various network applications and is a fundamental task in network flow control. However, the innovations in the multi-source network application and the elastic network architecture with the network flows of high volume, velocity, variety, and veracity pose unprecedented challenges on accurate network flow classification. In this article, an improved stacked auto-encoder is proposed to learn the complex relationships over the multi-source network flows by stacking several basic Bayesian auto-encoders. Specifically, to model the uncertainty contained in the network flows, the Bayesian auto-encoder is trained on the objects using the unsupervised learning strategy. Furthermore, the stacked auto-encoder is trained by the back-propagation algorithm using the supervised learning strategy to capture the complex relationships over the network flows. Finally, to assess the performance of the improved model, extensive experiments are conducted on two synthetic datasets based on the representative network flow datasets, that is, MAWI and DARPA 99. The results demonstrate that the improved stacked auto-encoder outperforms the traditional one in terms of classification accuracy.

The recently-proposed and studied Dual-Mode Energy Efficient Ethernet (EEE) amends the conventional EEE with an additional low-power mode called Fast Wake. Dual-Mode EEE has shown to be much more effective than EEE in reducing the power consumption of Ethernet links at 40 Gb/s and higher due to impractically-high transition times of using only one low-power mode at these capacities. However, even with two low-power modes, the still relatively-high transition times between the modes prevent Dual-Mode EEE from taking full advantage of the power reduction of the low-power modes and approach energy-proportional operation. We design and formulate Packet Coalescing for Dual-Mode EEE links at 40 Gb/s and higher. Packet Coalescing is to collect multiple packets before transmitting them on a link as a burst of back-to-back packets. By coalescing packets into bursts, the overhead of transition times can be reduced and nearly energy-proportional operation can be achieved, albeit at the expense of a bounded increase in the packet delay. We analytically model the power consumption of Dual-Mode EEE with Packet Coalescing and present closed-form formulae for the average percentage of time a link would spend in each low-power mode and transition. We also simulate a 40 Gb/s Dual-Mode EEE link with Packet Coalescing and present results suggesting that the compromise in the average per-packet delay is likely to be worthwhile under most circumstances considering the power reduction.

Marine researchers and operators during their daily work need consistent data from the underwater environment to constantly monitor the habitat’s probes and the robots condition. For underwater applications, wireless communication is of paramount importance. Today, the needs for high-speed communication has prompted the exploration of the Underwater Optical Wireless Communications (UOWCs) method. This paper presents the design and validation aspects of the optical layer of a bidirectional UOWC system developed in the framework of the European Project SUNRISE, able to provide wireless connectivity compliant to 10Base-T Ethernet protocol (Manchester-coded signal with 10 Mb/s data rate). The designed modems are made of two similar optical transceivers, each including a transmitter, a receiver unit, and an optical power monitor part. The transmitter is based on an array of blue Light Emitting Diodes; the receiver exploits a commercially available Avalanche Photodiode (APD) and the monitoring relies on a pin-photodiode. The modems, after a deep characterization in controlled environments, were proved to work with the required 10Base-T Ethernet, up to 7.5 m distance in shallow harbor waters. The complete optical system is intended to become a node of the SUNRISE infrastructure.

In this paper, we present a design for implementing network-based virtual Ethernet switches (NVESs) on top of a physical substrate consisting of a software-defined networking (SDN) network. An NVES has the same capability as a real Ethernet switch. A user makes a request to provision an NVES by specifying the number of ports and the maximum bandwidth for each port. The substrate network considered in this study is an Open Flow network. The entire network is controlled by an Open Flow controller. The controller is responsible for performing admission control, resource allocation, routing, address learning, and spanning tree protocol. To enhance the resource utilization of the substrate network, multipath routing is applied. Although using multipath routing can significantly improve bandwidth utilization, this approach results in out-of-order packet delivery and introduces additional error-control problems. To resolve these problems, we design a multipath agent to enhance the edge switch capability. The multipath agent is responsible for bandwidth metering, flow splitting, sequence number management, and packet reordering. We evaluated our virtual switches on top of a testbed network that includes not only commercial Open Flow switches but also a GPON-based virtual Open Flow switch. Multiple NVESs share the testbed network. The experimental results show that the user experience when using an NVES is identical to using a real Ethernet switch. In addition to the provision of guaranteed bandwidth for each NVES, traffic isolation among the NVESs is achieved. All NVESs are free of interference from others in the same network.

Design optimization for reliable networking is necessary for Ethernet ring mesh networks with ITU-T G.8032 Ethernet ring protection recommendation or with the IEC 62439-3 high-availability seamless redundancy protocol. To achieve this goal, the precise analysis of reliability/availability in Ethernet ring mesh consisting of single or multiple rings is one of the basic needs. Calculation of network reliability in these networks is an NP-hard problem. Therefore, most of the reliability and availability analyses were based on approximation and inaccurate methods. In this paper, at first, using decomposition method, a careful reliability analysis of Ethernet single-ring mesh networks will be presented. In addition, an accurate analysis of the reliability of Ethernet multiple-ring mesh networks will be performed by a novel approach named the spanning tree set method. Then, the availability of the ring networks with imperfect coverage and online repair assumptions will be analyzed using a hierarchical model in which each subsystem is modeled as a series system of independent Markov components.

Modern in-vehicle networks are comprised of heterogeneous systems that use various communication protocols with different source clocks. Moreover, gateway systems are designed with additional features that ensure converted/forwarded data meet real-time constraints. In this paper, we propose a synchronization mechanism for FlexRay and Ethernet audio video bridging (AVB) network that guarantees a high quality-of-service. We also designed the corresponding embedded system based-gateway system. Moreover, we built an in-vehicle network environment that consists of FlexRay and Ethernet AVB networks using an embedded system, which is integrated and synchronized by the gateway. We evaluate the synchronization performance of the proposed method using the developed gateway by conducting experiments as well as a theoretical analysis. The results of the experiment show that the synchronization mechanism provides timing guarantees for the FlexRay network that are similar to those of the Ethernet AVB network.

Ten-gigabit Ethernet was first standardized in 2002. Over the years, the success standardization has led to wide acceptance and commercialization in the industry. Ethernet has offered an attractive solution for data center to consolidate heterogeneous traffic into a single fabric. A data center usually consists of three overlapped networks, Storage Area Network (SAN), Local Area Network (LAN) and High Performance Computing (HPC) Network. To satisfy their specialized requirements, each of them transmits traffic through dedicated fabrics. Replacing dedicated switches, transceivers and adapters with Ethernet components, the consolidation reduces both capi- tal expenditure (CAPEX) and operational expenditure (OPEX). Although Ethernet exhibits many advantages, one must admit that it remains inad- equate due to the lack of congestion management support. In this thesis, an Ethernet congestion management solution is proposed to satisfy require- ments of loss-free, high throughput, and preferably, minimal energy usage for data center networks. Conventional Ethernet only offers best effort delivery which tolerates frame drops, whereas SAN/HPC traffic is sensitive to loss. The consolidation solution should control congestion to ensure SAN/HPC traffic free from loss with higher priorities. Moreover, Ethernet uses Spanning Tree Proto- col (STP) to prevent loops which prunes a mesh topology to a single tree structure eliminating redundancies and reducing network throughput. To preserve high bisectional bandwidth, the solution should enhance Ether- net with multipath feature to ease congestions. In addition, utilization of multipath, though increases network throughput, exerts extra power con- sumption by distributing traffic amongst all the paths when there is limited volume of traffic. The tradeoff of load balance or aggregation becomesanother research topic for adapting congestion with economizing data cen- ter cost. Thus a comprehensive Ethernet congestion management solution should satisfy three requirements, namely prioritize congestion control, high throughput congestion easing and energy efficient congestion adaptation. However, no systematic study has been found of such an approach. This research is conducted to fill the gap of existing approaches and ex- plore the possibility of an enhanced Ethernet congestion management for data centers. Firstly, a prioritized end-to-end congestion control scheme is proposed to combat congestion and protect traffic with higher through- put requirements, by introducing Active Queue Management (AQM) and Addictive Increase and Multiplicative Decrease (AIMD) to detect and con- strain source rates towards congestions. Systematic analytical work is also presented to study suitability of the proposal and recommendation of sys- tem parameters. Secondly, an in-depth study is conducted to investigate on multipath routing, where a central controller overviews network status and controls generation and distribution of traffic. This two-tiered study not only effectively eases congestion by a fine grained load balance but also throttles excessive traffic from entering network core. Finally, being aware that load balance among multiple paths is at odds with efficient energy usage, the relationship between power consumption and number of active links is studied and found to be in a linear order. A proposal for energy optimization that dynamically balances load and adapts link rate with con- gestions is then presented to achieve minimal power consumption without compromising on throughput. All these three studies are validated by ex- tensive simulations using OMNET++ simulator, which demonstrates the favorable performance of these schemes proposed. In summary, we propose prioritized congestion control that achieves ratio differentiation and combats congestion, loss-free multipath routing that distributes load almost equally to ease congestion and maximize network throughput, and efficient energy optimization that adapts load distribution and aggregation with congestion state. The congestion management solution proposed has achieved the ob- jectives of the study with 3.5 SAN/LAN ratio, two-folded traffic volume support and up to 60% power savings. DOCTOR OF PHILOSOPHY (SCE)

This paper studies a new sampling and control on-site module based on mature SOC chip technology, which is installed near primary equipment; and proposes a new protection and control system scheme in smart substation using on-site module and HSR ring network technology. It analyzes the delay characteristics of the application of HSR technology to implement the data transmission scheme of the on-site module, which shows that the scheme can meet the fast tripping requirements of the protection; proposes network flow control solution to improve network reliability, and proposes data transmission delay measurement technology to improve the synchronization reliability of network sampling, which effectively ensures the reliable application of the multi-bay protection that using the sampling and tripping method by network. The new protection and control system scheme simplifies the secondary system architecture, meets the technical development direction of intelligent primary equipment, and is beneficial to ensure the reliability and fast tripping of the protection device.

Vehicular networks need to ensure their systems to perform efficient resource allocations to the customer’s need. Vehicular networks have issues like data dissemination, packet loss and delay. Vehicles in the transmission range of a few hundred meters receive the messages in a single-hop scenario. Multi-hop forwarding messages can disseminate from source node to destination node. Due to intense stochastic traffic flow modeling on highways, servers remain busy, leading to a tremendous increase in waiting time, service time, blocking probability, and system response time. The Markov model ( M ∕ G ∕ m ∕ m ) analyzes the mobility at intersections to provide a solution. The model reduces congestion control and maximizes the network performance in Vehicular Ad-hoc Networks (VANETs). With this optimized network flow control performance, we propose a Multi-hop Cooperative Data Dissemination (MHCDD) based on buffer control, which can be more efficient when applied with a Markov process. We formulate and analyze the delay in the multi-class queueing system, enhancing data traffic forwarding from V2V and RSU or BS. Performance analysis and simulation outcomes show the proposed MHCDD significantly improves the stochastic multi-hop broadcast model. The single-hop end-to-end delay, waiting time, response time, throughput, blocking probability, and packet loss probability are optimized. System modeling improves the queue length, delay, and packet loss of the broadcast scheme’s queue using the IEEE 802.11p system.

This article proposes approaches used to verify 10 Gigabit Ethernet controllers developed by MCST. We present principles of the device operation - they provide a set of memory-mapped registers and use direct memory access, and their characteristics. We describe a set of approaches used to verify such devices - prototype based verification, system and stand-alone verification. We provide the motivation for the chosen approach - combination of system verification with stand-alone verification of its single component. The structure of the test systems that we used to verify devices and their components are presented. Test system of the controller transmits Ethernet frames to the network and receives frames from it. Algorithms to transfer packet to representation used by the device were implemented. Stand-alone test system was developed for a connector module between internal device buses and its external interface. Test systems were developed using UVM. This methodology and structure of test systems allowed to reuse components in a different systems. A set of test scenarios used to verify the device is described. The examination of network characteristics of the controller is very important in the verification process. Some approaches and techniques for throughput measuring and modes of device operations for the measurement are described. We present measured throughput in different modes. In conclusion, we provide a list of found errors and their distribution by different types of functionality they affected.

Design of an Ethernet network compatible data acquisition system for the measurement of yaw rate and longitudinal velocity in automobiles is presented. The data acquisition system includes a base node and a remote node. The remote node consists of a micro electro mechanical system (MEMS) accelerometer, an MEMS gyroscope, an advanced RISC machines (ARM) CORTEX M3 microcontroller and an Ethernet PHY device. The remote node measures the yaw rate and the longitudinal velocity of an automobile and sends the measured values to the base node using Ethernet communication. The base node consists of an ARM CORTEX M3 microcontroller and an Ethernet PHY device. The base node receives the measured values and saves in a microSD card for further analysis. The characteristics of the network and the measurement system are studied and reported.

The study presents the design of a 32-channel field-programmable gate arrays (FPGA) for ultrasound instruments working at high frame rates of the order of 1000 fps. The FPGA does multiline acquisition and Ethernet framing of the received data stream from the analog-to-digital converters (ADCs). The study also presents implementation of innovative methods of moving window algorithm, critical window capture, and envelope detection in the FPGA, for data rate reduction to aid video processing in laptops. The FPGA has serial peripheral interfacing bus interface towards microcontroller. FPGA also has data interface towards ADCs and Gigabit Ethernet MAC device. The microcontroller has in-line management interface with Gigabit Ethernet MAC through the FPGA. The FPGA dataflow consists of received signal processing of captured ultrasound data from ADCs, temporary storage in FPGA, and forwarding to external Ethernet devices after Ethernet framing. All the functional blocks are integrated and synchronized wit...

A non-blocking optical Ethernet switching architecture with liquid crystal on a silicon-based beam-steering switch and optical output buffer strategies are proposed. For preserving service packet sequencing and fairness of routing sequence, priority and round-robin algorithms are adopted at the optical output buffer in this research. Four methods were used to implement tunable fiber delay modules for the optical output buffers to handle Ethernet packets with variable bit-rates. The results reported are based on the simulations performed to evaluate the proposed switching architecture with traffic analysis under a traffic model captured from a real-core network.

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.

Worst-case end-to-end delay analysis is important for real-time applications of switched Ethernet network. The Trajectory approach is one of the mature tools for worst-case delay analysis to calculate the upper bound of delay. The delay analysis based on the Trajectory approach as well as the packet serialisation of such networks is presented. An optimisation of packet serialisation is proposed in order to improve the Trajectory approach. A case study is illustrated to compare the improved Trajectory approach with the classical one, and the result shows that the improved Trajectory approach can get tighter upper bound of end-to-end delay.

In this paper, we consider a network whose nodes are regions between which it is necessary to distribute electricity coming from its source. Any power plant is a complex economic system that always combines simple concepts - the need to supply the power plant with the main resource for the production of electricity and the need to sell the generated electricity. In this model, due to the need to sell electricity to two regions, the prices for the sale of electricity do not matter. Profit maximization is achieved by minimizing production costs. The optimal policy for generating electricity in the i-th time period is found.

To avoid the congestion in flow control, this paper proposes an optical network flow control algorithm based on benefit optimization and dynamic path coefficient (BO-DPC). This algorithm adjusts path coefficient in time according to the network information. When the flow of requests can be passed lightly, the metric coefficient should be reduced. Whereas path metric coefficient should be increased. The adjustment can make request flow to a less congestion path. And if there is a congestion coming, the bigger request must be automatically abandoned. It has significant advantage compared with traditional SPF algorithm in the same circumstances, which verifies the applicability and rationality of the algorithm.

We present the architecture and protocols of ROME, a layer-2 network designed to be backwards-compatible with Ethernet and scalable to tens of thousands of switches and millions of end-hosts. Such large-scale networks are needed for emerging applications including data center networks, wide area networks, and metro Ethernet. ROME is based upon a recently developed greedy routing protocol, greedy distance vector (GDV). Protocol design innovations in ROME include a stateless multicast protocol, a Delaunay distributed hash table (DHT), as well as routing and host discovery protocols for a hierarchical network. ROME protocols do not use broadcast and provide both control-plane and data-plane scalability. Extensive experimental results from a packet-level event-driven simulator, in which ROME protocols are implemented in detail, show that ROME protocols are efficient and scalable to metropolitan size. Furthermore, ROME protocols are highly resilient to network dynamics. The routing latency of ROME is only slightly higher than shortest-path latency. To demonstrate scalability, we provide simulation performance results for ROME networks with up to 25 000 switches and 1.25 million hosts.

Ethernet network, standardized by IEEE 802.3, is vastly installed in Local Area Network (LAN) for cheaper cost and reliability. With the emergence of cost effective and enhanced user experience needs, the Quality of Service (QoS) of the underlying Ethernet network has become a major issue. A network must provide predictable, reliable and guaranteed services. The required QoS on the network is achieved through managing the end-to-end delay, throughput, jitter, transmission rate and many other network performance parameters. The paper investigates QoS parameters based on packet size to analyze the network performance. Segmentation in packet size larger than 1500 bytes, Maximum Transmission Unit (MTU) of Ethernet, is used to divide the large data into small packets. A simulation process under Riverbed modeler 17.5 initiates several scenarios of the Ethernet network to depict the QoS metrics in the Ethernet topology. For analyzing the result from the simulation process, varying sized packets are considered. Hence, the network performance results in distinct throughput, end-to-end delay, packet loss ratio, bit error rate etc. for varying packet sizes.

For the problems of evacuation with several exits under the limiting condition of fire smoke and routes capacity, an evacuation model combining of heuristic algorithm and network flow control was established in this study. Taking into account of routes capacity constraints, the aim of emergency evacuation is to minimize the total evacuation time for all people. The optimal evacuation path group, evacuation time and the number of evacuation in the evacuation network can be acquired through updating the evacuation network constantly and finding optimal routes iteratively. An example was presented to show the effectiveness and feasibility of this model and algorithm, and it can be used to explore the method to determine the optimal evacuation plan, while the actual routes inequality was not established.

Optimal control problems on dynamical systems are concerned with finding a control policy, which minimizes a desired objective, where the objective value depends on the future evolution of the system (the state of the system), which, in turn, depends on the control policy. For systems which contain subsystems that are disjoint across the state variables, distributed optimization techniques exist, which iteratively update subsystems concurrently and then exchange information between subsystems with shared control variables. This article presents a method, based on the asynchronous alternating directions method of multiplier algorithm, which extends these techniques to subsystems with shared control and state variables, while maintaining similar communication structure. The method is used as the basis for splitting network flow control problems into many subnetwork control problems with shared boundary conditions. The decentralized and parallel nature of the method permits high scalability with respect to the size of the network. For highly nonconvex applications, an efficient method, based on adjoint gradient computations, is presented for solving subproblems with shared state. The method is applied to decentralized, coordinated ramp metering and variable speed limit control on a realistic freeway network model using distributed model predictive control.

International audience; Due to increased bandwidth and scalability demands, Ethernet technology is finding its way into recent in-vehicle networks. Tomorrow's heterogeneous networks will feature legacy buses [e.g. controller area network (CAN) or FlexRay] as well as high-speed Ethernet devices, connected by switches and gateways. As Ethernet offers significantly larger frame sizes than CAN, the efficient transmission of CAN data over an Ethernet backbone depends heavily on the way this data is multiplexed into Ethernet frames. This article focuses on the timing impact introduced by various CAN/Ethernet multiplexing strategies at the gateways. We present a formal analysis method to derive upper bounds on end-to-end latencies for complex multiplexing strategies, which is key for the design of safety-critical real-time systems. We capture complex inter-domain signal paths spanning multiple buses, gateways, and switches and show the applicability in a realistic automotive setup

This paper proposes a new method to analyze Ethernet performance. Currently, most studies on Ethernet performance assume that the channel is divided into time slots, or the network load is saturated with little attention to a non-slotted channel and the non-saturation status. However, this situation is more consistent with the practical application of Ethernet. This paper first calculates the original collision probability and the retransmission collision probability in the original load, then obtains the retransmission load of the network based on those two collision probabilities, and finally acquires the actual load of the network by an iterative method. In addition, the accuracy of the analysis is checked against simulation results.

Optical Ethernet gains great success in varied optical domains. Ethernet while providing the elastic allocation of bandwidth per flow is currently restricted to being transported over fixed-rate fixed-grid optical channels. However, as data transmission and switching in optical networks is becoming more flexible, the current Ethernet to optical interface with fixed functions and fixed design face great challenges for applications in an elastic optical network. In addition, the coexisted Ethernet standards in optical networks also need a converter to transform low-capacity Ethernet signals to high-capacity Ethernet signals. In this paper, we propose a real-time Ethernet to software-defined programmable sliceable transponder based on network function programmable Ethernet to elastic optical networks (ETH-EON) interface, multiformat supported transmitter and architecture-on-demand (AoD)-based superchannel signal processor. The transponder parses the Ethernet traffic and then transports it over a number of optical carriers with the appropriate baud-rate, modulation format and associated spectral bandwidth. Software-defined reconfigurability of both electronic (i.e., FPGA) and optics (AoD) allow for a flexible transponder to offer high Ethernet to optical transport efficiency. Ethernet capacities from 40 Gbit/s to 2.88 Tbit/s can be provided by reconfiguring the modulation formats and the used optical carrier number. The modulation format adaptability also provides a tradeoff between transmission capacity and transmission distance, to optimize network performance. The designed software-defined sliceable elastic transponder aggregate multiple Ethernet traffic flows and send spectral-efficient signals through the elastic optical network with simple Ethernet protocols, avoiding using complex and expensive OTN technologies. Finally, we demonstrate the converter in elastic optical networks for several application scenarios.

Ethernet based on TCP/IP is a standard open network, which promotes the development of data acquisition in the direction of network. Data acquisition and processing systems connected by Ethernet make the data acquisition terminals (lower computer) and processing control center (upper computer) from integrated to discrete. Separate data acquisition terminals can realize miniaturization and modularization and increase the flexibility of the application. A new type, low cost, high precision data acquisition terminal based on ARM processor was designed for solving the problem of complicated structure, big volume and high cost of traditional data acquisition system. Combined with the technologies of network communication, a data acquisition PC system based on virtual instrument technology was designed by LabVIEW.

This paper discusses the implementation of an Ethernet communications network in a ring that connects substations in a closed communications loop at a large industrial facility. Data are transmitted at protection speeds and must be dependable for industrial power system operation and maintenance applications. The redundant electric power system Ethernet communications network is used for a supervisory control and data acquisition (SCADA) system that automates industrial electric power system operations. Within individual substations as well as between substations, communications based on IEC 61850 protocols eliminate copper control wiring, which results in reduced cost, construction time, commissioning time, and wiring errors and makes future upgrades simpler. A fast load-shedding system uses the same communications network to stabilize system frequency in response to a loss of generation by detecting the events that lead to a power deficit and automatically responding by shedding load to balance generation and load in less than 40 milliseconds. This paper focuses on integrating three major electrical control systems at a refinery onto one Ethernet network: a SCADA system for controlling and monitoring operations, a peer-to-peer high-speed communications-assisted protection scheme, and a fast load-shedding system.

This technical note describes a redesign framework for fluid-flow models of network congestion control algorithms. Motivated by the augmented Lagrangian method, we introduce extra dynamics to algorithms resulting from traditional primal-dual methods to improve their performance while guaranteeing stability. We use our method to redesign the primal-dual, primal and dual algorithms for network flow control. In particular, we investigate the influence of the gains resulting from the extra dynamics on system stability and robustness to time delays. We provide a method to improve the transient performance and delay robustness of the overall system by tuning these gains.

In the literature, congestion control schemes have been broadly studied. Nevertheless, this subject needs to be reviewed in the context of Carrier Ethernet. Congestion happens when the capacity cannot cover the resource demands. Nowadays, users are witnessing the networks saturation because of the expanding demands for bandwidth. The addressed issue is not only how to avoid congestion but also how to use all available capacity without overuse it or underuse it. To deal with congestion, link level algorithms drop or mark packets with increasing probability as buffer congestion increases. The most common solution is based on the transport layer algorithms to adjust the resources transmission rate by using these dropped or marked packets. Carrier Ethernet defined by layer two uses new proposals specified by the 802.1Qau standards committee in order to handle congestion problems. This paper surveys and studies different properties of Carrier Ethernet congestion control schemes. This paper also draws a parallel between the different schemes and point out the advantage and disadvantage of each one. Then, this paper presents a taxonomy of the Carrier Ethernet congestion control mechanism and correlate it with existing taxonomies.

To increase the energy efficiency of Ethernet networks, in 2010, the IEEE published the IEEE 802.3az amendment, known as Energy Efficient Ethernet (EEE). The amendment introduces a new operational mode, defined as Low Power Idle (LPI), that allows to considerably reduce the power consumption of inactive Ethernet links. In this paper, we address the application of EEE to Real-Time Ethernet (RTE) networks, the popular communication systems typically employed in factory automation, characterized by tight timing requirements. We start with a description of the EEE basics and, subsequently, focus on the introduction of EEE in the industrial communication scenario. Then, we specifically address the implementation of effective EEE strategies for some popular RTE networks. The analysis is carried out on configurations commonly deployed at low levels of factory automation systems. The obtained results show that considerable power savings can be achieved with very limited impact on network performance.

Due to its high bandwidth, good maintainability and flexibility, Gigabit Ethernet is confoundedly suitable for high-performance server applications. As an interface between network and host, Ethernet controller has been continually evolving to meet the ever increasing communication demands being placed on it by enterprise applications. For the Ethernet, network links and physical devices, such as controller and switch, are likely to be out of order, which may result in system paralysis, service interruption and even intolerable consequence, especially when there are critical programs running on servers. In this scenario, Ethernet controller needs to not only achieve data reception and transmission, but also provide supports to the latest associate technology and standards. The objective of this paper therefore to design and implement an enhanced Gigabit Ethernet controller, called LCE5718, that provides fault tolerant transmission and prevention mechanism based on IEEE 802.3ad link aggregation and Network Controller Sideband Interface (NC-SI) respectively. Equipped with dual-port, LCE5718 is able to support link aggregation technology that can prevent connectivity loss even if one of the channels is out-of-order. In addition, we achieve a fault prevention mechanism in LCE5718 based on NC-SI. When prevention mechanism is adopted, potential device faults can be prevented by instantly reporting device's abnormal status to administrator and the corrective actions could be taken immediately. We also implemented LCE5718 in FPGA and performed experiments to evaluate its performance. The experiment results indicate that LCE5718 not only can guarantee fault tolerance transmission, but also can provide an effective prevention of network paralysis caused by device fault.

Congestion control is an indispensable mechanism in the new trend of enhanced Ethernet as a unified fabric for traditional LAN, SAN, and high-performance computing networks. A congestion management framework for Converged Ethernet (CE) networks has been standardized by IEEE 802.1 Qau work group, and QCN is recommended as the congestion control scheme in the standard draft. QCN is heuristically designed for 1/10Gbps Ethernet without considering the impact of delays. Recent work find that QCN will encounter stability issues with feedback delays, and these issues will be more serious as Ethernet extends to 40/100Gbps and the delays become heterogeneous and time-varying. This work aims to mitigate the negative impact of delays on congestion control scheme in CE. Specially, considering the delays are heterogeneous and time-varying, we build a model for Converged Ethernet with the standard congestion management framework. The model provides a new congestion detector to estimate the real congestion status under the impact of delays and regards the heterogeneous and time-varying feature as disturbances. Leveraging the new congestion detector and tolerating the disturbance through the sliding mode control method, we design the Delay-tolerant Sliding Mode (DSM) congestion control scheme. Extensive simulations show that DSM outperforms other congestion control schemes when the Ethernet ranges from 1Gbps to 100Gbps and the delays are heterogeneous and time-varying.

The article presents a simulation model of a Time-Triggered Ethernet real-time system. There are two types of traffic (real time traffic and standard traffic) that are used during frame processing in the Time-Triggered Ethernet. The authors considered a static configurable table of unique indexes and a static table of destination addresses when determining the destination address depending on the traffic type. The model consists of the following parts: the client, the guardian, the switch. The model is constructed using the apparatus of the hierarchical time colored Petri nets using the CPN Tools package. This article describes the algorithm of the guardian's work, calculation of time parameters of the acceptance window frame. Thus, the simulation model allows studying the mechanism of the Time-Triggered Ethernet.

Ethernet is the prevalent link layer mechanism in data communication networks. Today, it is used in enterprise and home networks, data center networks, telecommunication networks, and in various industrial deployments. In addition, more and more hosts are becoming mobile, connecting to Ethernet networks via Wi-Fi, or through virtualization solutions in data centers. Unfortunately, the Ethernet protocol suite itself has no generic support for host mobility. In this paper, we evaluate the effects of host mobility in Ethernet networks using real-time emulation. We compare routing bridges, an IETF-driven Ethernet frame forwarding protocol, with our DBridges design. DBridges is an evolution of the routing bridges standard, integrating a one-hop Distributed Hash Tables (DHT) scheme into the protocol. Our solution offers improved scalability characteristics in Ethernet networks, as well as enhanced support for host mobility. Our evaluation shows that while host mobility without any explicit signaling will remain a best-effort service in Ethernet networks, we can significantly improve its efficiency and reliability in certain use cases, while providing improved scalability and safety properties. We also show that while the host mobility support in DBridges suffers from transient forwarding loops, the problem is exceedingly rare in real networks and is mitigated by the base functionality in routing bridges.

Along with the development of industrial systems, real-time Ethernet (RTE) is widely utilized for control systems. S-TDMA is one of the RTE protocols, and it is a concept realizing a coexistence of real-time and best-effort communication over the Ethernet by time-division multiplexing. In previous work, a special switching hub capable of S-TDMA was implemented, and the capability of real-time communication on multi-hop topology was shown. It is expected to apply S-TDMA for the Internet; it is not practical that all nodes in the network support S-TDMA. Therefore, this paper proposes the integration method of existing Ethernet devices into S-TDMA network by using a pause frame. The performance of best-effort traffic between these devices over S-TDMA network was evaluated. The results verify the superiority of the proposed method. The proposed design greatly suppressed the performance deterioration of best-effort traffic. The throughput of the proposed method was 670 Mbps higher than that of the previous implementation at the effective bandwidth of 950 Mbps. The results also show the comparable performance, even if the number of hops has increased.