This paper clarifies the scalability of the hitless wavelength-tuning (λ-tuning) sequence for dynamic wavelength allocation (DWA) on a λ-tunable ...wavelength-division-multiplexing/time-division-multiplexing passive optical network (WDM/TDM-PON). The λ-tuning that induces no data-frame loss, i.e., hitless λ-tuning, is essential in DWA. We derive requirements to prevent two types of upstream data-frame loss that the λ-tuning causes. To clarify the scalability of the hitless λ-tuning sequence against system parameters, we theoretically analyze the maximum input data rate to the optical network units (ONUs) to achieve λ-tuning without upstream data-frame loss while varying values for buffer size and λ-tuning time of the transceivers in ONUs and the DWA cycle. Then, using media access control boards that we developed for symmetric 40 Gbit/s λ-tunable WDM/TDM-PONs, we demonstrate hitless λ-tuning and confirm the validity of the theoretical analysis.
An important challenge of modern data centers is to reduce energy consumption, of which a substantial proportion is due to the network. Switches and NICs supporting the recent energy efficient ...Ethernet (EEE) standard are now available, but current practice is to disable EEE in production use, since its effect on real world application performance is poorly understood. This paper contributes to this discussion by analyzing the impact of EEE on MapReduce workloads, in terms of performance overheads and energy savings. MapReduce is the central programming model of Apache Hadoop, one of the most widely used application frameworks in modern data centers. We find that, while 1GbE links (edge links) achieve good energy savings using the standard EEE implementation, optimum energy savings in the 10 GbE links (aggregation and core links) are only possible, if these links employ packet coalescing. Packet coalescing must, however, be carefully configured in order to avoid excessive performance degradation. With our new analysis of how the static parameters of packet coalescing perform under different cluster loads, we were able to cover both idle and heavy load periods that can exist on this type of environment. Finally, we evaluate our recommendation for packet coalescing for 10 GbE links using the energy-delay metric. This paper is an extension of our previous work 1, which was published in the Proceedings of the 40th Annual IEEE Conference on Local Computer Networks (LCN 2015).
Field-level networks have been one of the keys to modern automation systems. Be it in factory, process, or building automation, networks allow for horizontal and vertical integration of distributed ...devices and functions. This paper reviews the evolution of field-level networks comprising fieldbus systems, industrial Ethernet, and recent industrial wireless networks. The main focus is on demonstrating the continuity in the development of the three generations that ensured backward compatibility at the expense of radical innovation. Given the wide set of modern communication technologies, this paper then discusses how architectures for future automation networks might look. Particular emphasis is put on hybrid architectures for combined wired/wireless networks. A generic concept for integration of multiple wireless segments will be presented that supports seamless roaming for mobile nodes in industrial environment.
Abstract
The stability of the entire base station depends on the synchronization of the base station’s clock. The clock synchronization management chip 8A34002 supports SyncE Ethernet and IEEE 1588. ...In this architecture, the GPS receiver, SSI, and master/slave switching device all emit PPS/TOD signals. PPS/TOD signals are input into the FPGA, which outputs one PPS/TOD signal. The PPS/TOD signal enters 8A34002 in this design scheme, and the DPLL of 8A34002 provides filtering and clock-following output. The 8A34002‘s signal output is used as the system’s clock after processing. The switching chip, X86 main control chip, and BBU base station board are all driven by the system clock, which serves as a reference clock. The 8A34002 uses four DPLLs, one each for the SyncE, PTP, GNSS, and test functions.
The industrial communication market is dominated by Ethernet-based fieldbus systems. Although they share similar requirements and market segments, their implementations and ecosystems differ ...considerably. As a result, end customers and device manufacturers are faced with a multitude of technologies that need to be produced, run, diagnosed, maintained, and kept in stock. Although the availability of products and services is largely satisfactory, dealing with multiple solutions generates high costs and limits IoT capability. This paper introduces Open Platform Communication Unified Architecture Time-Sensitive Networking (OPC UA TSN) as a new technology and presents the current view. This time, the industrial prospects of fulfilling industrial communication requirements while leveraging the cost benefits of standard Ethernet hardware in the midterm are in reach. We anticipate that OPC UA TSN will reveal itself as a game changer in the field of industrial automation, being a candidate for establishing a holistic communication infrastructure from the sensor to the cloud.
In this letter, we show an approach to 800G Ethernet based on dense channel allocation in the O-band and successfully demonstrate Formula Omitted GBaud PAM-4 with narrowest so far 240 GHz channel ...grid data transmission below HD-FEC over 1 km of standard single mode fiber (SSMF) without any optical amplification, resulting in a total net throughput of 800 Gbit/s. Additionally we study theoretical limits of FWM on 108 Gbit/s channel system in SSMF zero-dispersion region.
The integration of layer-2 carrier-class packet technologies with optical transport network is termed as packet-optical integration and is being deployed by service providers for migration from ...legacy SONET/SDH systems. We present a state-of-the-art carrier-class switch router that facilitates packet-optical integration, thereby achieving best of both the optical and packet worlds. The premise of this switch router is the use of carrier ethernet technology as a packet enabler for achieving statistical multiplexing at fine granularities, while maintaining rich operations, administration, maintenance, and provisioning features. To this end, we proposed the omnipresent ethernet concept that uses binary routing and source routing to support: 1) layer 2 and layer 3 switching and routing, 2) low latency of the order of 1-5 μs even for layer 3 processing, and 3) low-energy consumption. The omnipresent ethernet framework leads to a software defined networking solution, whereby a centralized controller admits services and configures nodes based on homogenous networking parameters. In this paper, we report a commercial implementation of a packet-optical network demonstrated by our designed, fabricated, developed carrier ethernet switch router (CESR). We discuss the architectural considerations, design, and implementation of both the hardware and the control software. A switch architecture achieving 1-μs port-to-port delay across layers 1, 2, and 2.5 based on an opportunistic principle of virtual output queuing is showcased. The novelty is a scalable 96-Gbps cross connect fabric implemented in a field programmable gate array using a two-stage buffer system. A multistate software defined control plane is also reported. An exact analysis of the switch architecture using a combinatorial G/G/1 model is developed. An energy audit of the CESR is showcased. A test bed in the lab replicating a field deployment is presented. An exhaustive set of test cases are developed to test our designed CESR. Results are shown for latency, throughput, service support, frame-size stability, power, and bit error rate, thus validating our design. PUBLICATION ABSTRACT
5G NR is designed from the ground up to provide support for mission critical communication with ultra-reliability and low latency (URLLC) in addition to other use cases such as enhanced mobile ...broadband. URLLC allows 5G network performance to approach that of wired networks (e.g., Ethernet) and paves the way for new use cases. In this paper, we focus on the end-to-end design of 5G networks for industrial factory automation. Providing URLLC wireless communication in these environments is especially challenging due to highly dynamic RF variations with possible signal blockage or reflections from moving metal objects. Coordinated Multipoint (CoMP) communication, which leverages spatial diversity to improve reliability without relying on packet retransmission, is a promising approach in these environments. We present a design and performance trade-offs between different CoMP techniques and their implication to capacity, robustness, and architecture. Subsequently, we describe architecture and protocol design aspects that allow 5G to operate as part of a time sensitive network including Ethernet bridging, time synchronization, and QoS. A prototype system that validates certain aspects of the design is also presented.
The Internet of Things (IoT) is entering the daily operation of many industries; applications include but are not limited to smart cities, smart grids, smart homes, physical security, e-health, asset ...management, and logistics. For example, the concept of smart cities is emerging in multiple continents, where enhanced street lighting controls, infrastructure monitoring, public safety and surveillance, physical security, gunshot detection, meter reading, and transportation analysis and optimization systems are being deployed on a city-wide scale. A related and cost-effective user-level IoT application is the support of IoT-enabled smart buildings. Commercial space has substantial requirements in terms of comfort, usability, security, and energy management. IoT-based systems can support these requirements in an organic manner. In particular, power over Ethernet, as part of an IoT-based solution, offers disruptive opportunities in revolutionizing the in-building connectivity of a large swath of devices. However, a number of deployment-limiting issues currently impact the scope of IoT utilization, including lack of comprehensive end-to-end standards, fragmented cybersecurity solutions, and a relative dearth of fully-developed vertical applications. This paper reviews some of the technical opportunities offered and the technical challenges faced by the IoT in the smart building arena.
In this article, industrial control systems include networked control systems (NCS), which use real-time Ethernet (RTE) protocols since many years, well before the time sensitive networking ...initiative debut. Today, ethernet-based control systems are used all across Industry 4.0, including in critical applications, allowing for straight integration with information technology layers. Even if it is known that current RTE protocols do not have strong authentication or ciphering options, it is still very challenging to perform undetected cyber-attacks to these protocols while the NSC is in operation, in particular because such attacks must comply with very strict and small temporal constraints. In this article, a model-based attack is proposed for service degradation of NCS. The attack is carried out in real-time and it can remain undetected for the entire plant life. The attack can be applied to any RTE protocols and, without loss of generality, a detailed analysis of stealth techniques is provided for a specific real use case based on PROFINET. The experimental results demonstrate the feasibility of the proposed attack and its high effectiveness. The article also points out some possible future investigation directions in order to mitigate the attack.
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