Fog at the Edge:experiences building an Edge computing platform

Technology advancement has pushed computation to the network edge, paving the way for a class of IoT applications that leverage CPU, storage and communications in edge devices. Building these new IoT applications is not an easy task however. Two key challenges include: supporting the dynamic nature of the edge network and the context-dependent characteristics of application logic. In this paper we report our experience in building an edge computing platform that uses a distributed data flow programming model based on the popular open source Node-RED tool. We describe some of the challenges we faced as well as some novel solutions that were implemented in our platform. A new approach in applying the concept of exogenous coordination is also presented and shown to be necessary in building large scale IoT applications across the edge, fog and cloud

Developing applications in large scale, dynamic fog computing:A case study

In recent years, fog computing has emerged as a new distributed system model for a large class of applications that are data-intensive or delay-sensitive. By exploiting widely distributed computing infrastructure that is located closer to the network edge, communication cost and service response time can be significantly reduced. However, developing this class of applications is not straightforward and requires addressing three key challenges, ie, supporting the dynamic nature of the edge network, managing the context-dependent characteristics of application logic, and dealing with the large scale of the system. In this paper, we present a case study in building fog computing applications using our open source platform Distributed Node-RED (DNR). In particular, we show how applications can be decomposed and deployed to a geographically distributed infrastructure using DNR, and how existing software components can be adapted and reused to participate in fog applications. We present a lab-based implementation of a fog application built using DNR that addresses the first two of the issues highlighted earlier. To validate that our approach also deals with large scale, we augment our live trial with a large scale simulation of the application model, conducted in Omnet++, which shows the scalability of the model and how it supports the dynamic nature of fog applications. © 2019 John Wiley & Sons, Ltd

CityFlow:Exploiting Edge Computing for Large Scale Smart City Applications

This paper presents an approach to supporting the development process for large-scale smart city applications that leverage edge computing resources. A smart city testbed called CitiFlow is developed, which uses Distributed Node-RED as the underlying middleware to facilitate the decomposition and communication among sub components of large scale smart city applications. For the evaluation, a lab-based setup and a real world deployment were executed and are presented

Managing Event-Driven Applications in Heterogeneous Fog Infrastructures

The steady increase in digitalization propelled by the Internet of Things (IoT) has led to a deluge of generated data at unprecedented pace. Thereby, the promise to realize data-driven decision-making is a major innovation driver in a myriad of industries. Based on the widely used event processing paradigm, event-driven applications allow to analyze data in the form of event streams in order to extract relevant information in a timely manner. Most recently, graphical flow-based approaches in no-code event processing systems have been introduced to significantly lower technological entry barriers. This empowers non-technical citizen technologists to create event-driven applications comprised of multiple interconnected event-driven processing services. Still, today’s event-driven applications are focused on centralized cloud deployments that come with inevitable drawbacks, especially in the context of IoT scenarios that require fast results, are limited by the available bandwidth, or are bound by the regulations in terms of privacy and security. Despite recent advances in the area of fog computing which mitigate these shortcomings by extending the cloud and moving certain processing closer to the event source, these approaches are hardly established in existing systems. Inherent fog computing characteristics, especially the heterogeneity of resources alongside novel application management demands, particularly the aspects of geo-distribution and dynamic adaptation, pose challenges that are currently insufficiently addressed and hinder the transition to a next generation of no-code event processing systems. The contributions of this thesis enable citizen technologists to manage event-driven applications in heterogeneous fog infrastructures along the application life cycle. Therefore, an approach for a holistic application management is proposed which abstracts citizen technologists from underlying technicalities. This allows to evolve present event processing systems and advances the democratization of event-driven application management in fog computing. Individual contributions of this thesis are summarized as follows: 1. A model, manifested in a geo-distributed system architecture, to semantically describe characteristics specific to node resources, event-driven applications and their management to blend application-centric and infrastructure-centric realms. 2. Concepts for geo-distributed deployment and operation of event-driven applications alongside strategies for flexible event stream management. 3. A methodology to support the evolution of event-driven applications including methods to dynamically reconfigure, migrate and offload individual event-driven processing services at run-time. The contributions are introduced, applied and evaluated along two scenarios from the manufacturing and logistics domain

Visually-defined Real-Time Orchestration of IoT Systems

In this work, we propose a method for extending Node-RED to allow the automatic decomposition and partitioning of the system towards higher decentralization. We provide a custom firmware for constrained devices to expose their resources, as well as new nodes and modifications in the Node-RED engine that allow automatic orchestration of tasks. The firmware is responsible for low-level management of health and capabilities, as well as executing MicroPython scripts on demand. Node-RED then takes advantage of this firmware by (1) providing a device registry allowing devices to announce themselves, (2) generating MicroPython code from dynamic analysis of flow and nodes, and (3) automatically (re-)assigning nodes to devices based on pre-specified properties and priorities. A mechanism to automatically detect abnormal run-time conditions and provide dynamic self-adaptation was also explored. Our solution was tested using synthetic home automation scenarios, where several experiments were conducted with both virtual and physical devices. We then exhaustively measured each scenario to allow further understanding of our proposal and how it impacts the system's resiliency, efficiency, and elasticity

Public Policy Targets in EU Broadband Markets: The Role of Technological Neutrality

The European Commission has recently sought to substantially revise how it regulates the telecommunication industry, with a key goal being to incentivise investment in high-speed broadband networks. Ambitious goals to incentivise investment in high-speed broadband networks have been set across the European Union, initially in the "Digital Agenda for Europe" and more recently in its "Gigabit strategy". These goals reflect the view of many that there are widespread and significant socio-economic benefits associated with broadband. Our analysis explores the consequence of target setting at a European level, in terms of encouraging investment and picking which technology should be adopted within the context of technological neutrality. We demonstrate that while public policy targets might implicitly favour specific technologies, especially when gigabit targets are defined, the technological choices that occur within individual Member States are shaped by the complex and dynamic interaction between a series of path dependencies that may vary significantly across as well as within Member States. Adopting an ecosystem perspective, we propose a conceptual framework that identifies the key factors associated with technological neutrality and informs a rational decision-making process.Series: Working Papers / Research Institute for Regulatory Economic