Multilevel Parallel Communications

The research reported in this thesis investigates the use of parallelism at multiple levels to realize high-speed networks that offer advantages in throughput, cost, reliability, and flexibility over alternative approaches. This research specifically considers use of parallelism at two levels: the upper level and the lower level. At the upper level, N protocol processors perform functions included in the transport and network layers. At the lower level, M channels provide data and physical layer functions. The resulting system provides very high bandwidth to an application. A key concept of this research is the use of replicated channels to provide a single, high bandwidth channel to a single application. The parallelism provided by the network is transparent to communicating applications, thus differentiating this strategy from schemes that provide a collection of disjoint channels between applications on different nodes. Another innovative aspect of this research is that parallelism is exploited at multiple layers of the network to provide high throughput not only at the physical layer, but also at upper protocol layers. Schedulers are used to distribute data from a single stream to multiple channels and to merge data from multiple channels to reconstruct a single coherent stream. High throughput is possible by providing the combined bandwidth of multiple channels to a single source and destination through use of parallelism at multiple protocol layers. This strategy is cost effective since systems can be built using standard technologies that benefit from the economies of a broad applications base. The exotic and revolutionary components needed in non-parallel approaches to build high speed networks are not required. The replicated channels can be used to achieve high reliability as well. Multilevel parallelism is flexible since the degree of parallelism provided at any level can be matched to protocol processing demands and application requirements

Infant Industry Protection and Industrial Dynamics

A perennial case for industrial policy is based on the protection of young or emerging industries. Despite a natural association with concepts of life cycles, industrial policy has not been analyzed in the context of an industry life-cycle model. In particular, an important life-cycle characteristic, the potential for very large changes in the rate of net entry, is ignored. In this paper, we demonstrate how the impact of industrial policy depends critically on the entry and exit dynamics within an industry. In particular, we construct a model of technology adoption in which the number of firms is endogenous, and derive a set of novel predictions about the effects of protection on firm technology decisions. Specifically, we show that permanent protection can induce earlier adoption, but also decreases the probability that a given firm adopts the new technology. Likewise, we demonstrate that reducing the duration of protection results in faster adoption than permanent protection, but also reduces a given firms probability of adoption. Finally, we show that, for industries characterized by flexibility in firm numbers, protection does not change the rate of technology adoption but does increase the size and probability of a shakeout (large scale net exit)

Time-Sensitive Networking for Industrial Automation: Challenges, Opportunities, and Directions

With the introduction of Cyber-Physical Systems (CPS) and Internet of Things (IoT) into industrial applications, industrial automation is undergoing tremendous change, especially with regard to improving efficiency and reducing the cost of products. Industrial automation applications are often required to transmit time- and safety-critical data to monitor and control industrial processes, especially for critical control systems. There are a number of solutions to meet these requirements (e.g., priority-based real-time schedules and closed-loop feedback control systems). However, due to their different processing capabilities (e.g., in the end devices and network switches), different vendors may come out with distinct solutions, and this makes the large-scale integration of devices from different vendors difficult or impossible. IEEE 802.1 Time-Sensitive Networking (TSN) is a standardization group formed to enhance and optimize the IEEE 802.1 network standards, especially for Ethernet-based networks. These solutions can be evolved and adapted into a cross-industry scenario, such as a large-scale distributed industrial plant, which requires multiple industrial entities working collaboratively. This paper provides a comprehensive review on the current advances in TSN standards for industrial automation. We present the state-of-the-art IEEE TSN standards and discuss the opportunities and challenges when integrating each protocol into the industry domains. Finally, we discuss some promising research about applying the TSN technology to industrial automation applications