Vasileios Karagiannis

Bio: Vasileios Karagiannis is an academic researcher from Vienna University of Technology. The author has contributed to research in topics: Cloud computing & Edge computing. The author has an hindex of 9, co-authored 17 publications receiving 487 citations.

A Survey on Application Layer Protocols for the Internet of Things

Abstract: It has been more than fifteen years since the term Internet of Things (IoT) was introduced. However, despite the efforts of research groups and innovative corporations, still today it is not possible to say that the IoT is upon us. This is mainly due to the fact that a unified IoT architecture has not yet been clearly defined and there is no common agreement in defining communication protocols and standards for all the IoT parts. The framework that current IoT platforms use consists mostly in technologies that partially fulfill the IoT requirements. While developers employ existing technologies to build the IoT, research groups are working on adapting protocols to the IoT in order to optimize communications. In this paper, we present and compare existing IoT application layer protocols as well as protocols that are utilized to connect the “things” but also end-user applications to the Internet. We highlight IETF’s CoAP, IBM’s MQTT, HTML 5’s Websocket among others, and we argue their suitability for the IoT by considering reliability, security, and energy consumption aspects. Finally, we provide our conclusions for the IoT application layer communications based on the study that we have conducted.

A Framework for Optimization, Service Placement, and Runtime Operation in the Fog

Abstract: Fog computing provides a paradigm for executing Internet of Things services. Enabling the coordinated cooperation among computational, storage, and networking resources in the fog can be challenging due to the volatility of resources. For this reason, we design an architecture and implement a representative framework called FogFrame that defines the necessary communication mechanisms for instantiating and maintaining service execution in the fog. To evaluate our approach, we conduct a series of experiments that show how service placement, deployment, and execution is performed by the framework, and how the framework operates at runtime, i.e., adapts to changes in the available resources, balances the workload and recovers from resource failures and overloads.

Comparison of Alternative Architectures in Fog Computing

Abstract: Since the proliferation of fog computing, various distributed architectures have been proposed to extend the cloud to the edge of the network. However, so far there exists no study that compares different fog computing architectures, and produces quantitative results in order to examine the efficiency of each architecture for different use cases. Such a study could provide guidelines for selecting an appropriate distributed architecture for fog computing while taking into account the requirements of the final applications.To bridge this gap in the literature, we create a unified system model which is able to represent the basic architectures commonly used for fog computing, i.e., hierarchical and flat. Furthermore, we design algorithms that can be used for creating fog computing systems that follow these architectures, and we perform various experiments that focus on communication latency and bandwidth utilization. Notably, our results show that for applications that do not have a dependency on the cloud, i.e., no resource-demanding tasks are involved, the hierarchical architecture reduces the communication latency by 13% compared to the flat. However, for applications that also include resource-demanding tasks, the flat architecture reduces the communication latency by 16% compared to the hierarchical.

Compute node communication in the fog: survey and research challenges

Abstract: Fog and edge computing have given rise to applications that utilize cloud services at the edge of the network. To enable services at the edge, compute nodes are provisioned at strategic positions throughout the network in order to avoid bottlenecks and reduce latency. A lot of research has been conducted in this context, resulting in multiple computing platforms which organize the compute nodes using different communication types, i.e., hierarchical, peer to peer or hybrid. To better understand the role communication plays in fog and edge computing, this paper reviews key literature on fog computing platforms and identifies research challenges that emerge. The outcomes of this review also suggest that the communication type of a computing platform affects the functionality of the final applications.

Network-integrated edge computing orchestrator for application placement

Abstract: In an effort to detach applications from centralized clouds with high latency responses, service providers turn their attention to edge computing solutions that offer low latency and improved user experience. Existing edge deployment strategies use network-related information as decision basis, but their design and their placement logic are biased by the assumption that the network cannot be controlled. In this paper, we design an orchestrator that operates within the telecom infrastructure and assumes cooperation with access and core network controllers. As a result, network adjustments can be requested, which leads to an orchestrator that participates in the provisioning of resources and solves an optimization problem that — contrary to the state of the art-performs sequential component placement and does not assume a known or fixed replication degree of the applications. Its function relies on heuristics, including one based on pre-computed shortest paths, which runs in polynomial time (i.e., much faster than an exhaustive search) and finds the optimal solution in approximately 99% of the tested scenarios.

Choice of effective messaging protocols for IoT systems: MQTT, CoAP, AMQP and HTTP

Abstract: The standard and real-time communication technology is an unalloyed inevitability for the development of Internet of Things (IoT) applications. However, the selection of a standard and effective messaging protocol is a challenging and daunting task for any organisation because it depends on the nature of the IoT system and its messaging requirements. Copious messaging protocols have been developed and employed by various organisations based on their requirements in the last two decades. Though, none of them is able to support all messaging requirements of all types of IoT systems. Messaging protocol is an ongoing dilemma for the IoT industry; consequently, it is important to understand the pros and cons of the widely accepted and emerging messaging protocols for IoT systems to determine their best-fit scenarios. Therefore, this paper presents an evaluation of the four established messaging protocols MQTT, CoAP, AMQP and HTTP for IoT systems. Firstly, it presents the broad comparison among these messaging protocols to introduce their characteristics comparatively. Afterwards, it performs a further in-depth and relative analysis based on some interrelated criteria to gain insight into their strengths and limitations. Thus, based on this detailed evaluation, the user can decide their appropriate usage in various IoT systems according to their requirements and suitability.

Structural Health Monitoring Framework Based on Internet of Things: A Survey

Abstract: Internet of Things (IoT) has recently received a great attention due to its potential and capacity to be integrated into any complex system. As a result of rapid development of sensing technologies such as radio-frequency identification, sensors and the convergence of information technologies such as wireless communication and Internet, IoT is emerging as an important technology for monitoring systems. This paper reviews and introduces a framework for structural health monitoring (SHM) using IoT technologies on intelligent and reliable monitoring. Specifically, technologies involved in IoT and SHM system implementation as well as data routing strategy in IoT environment are presented. As the amount of data generated by sensing devices are voluminous and faster than ever, big data solutions are introduced to deal with the complex and large amount of data collected from sensors installed on structures.

A Survey of Communication Protocols for Internet of Things and Related Challenges of Fog and Cloud Computing Integration

Abstract: The fast increment in the number of IoT (Internet of Things) devices is accelerating the research on new solutions to make cloud services scalable. In this context, the novel concept of fog computing as well as the combined fog-to-cloud computing paradigm is becoming essential to decentralize the cloud, while bringing the services closer to the end-system. This article surveys e application layer communication protocols to fulfill the IoT communication requirements, and their potential for implementation in fog- and cloud-based IoT systems. To this end, the article first briefly presents potential protocol candidates, including request-reply and publish-subscribe protocols. After that, the article surveys these protocols based on their main characteristics, as well as the main performance issues, including latency, energy consumption, and network throughput. These findings are thereafter used to place the protocols in each segment of the system (IoT, fog, cloud), and thus opens up the discussion on their choice, interoperability, and wider system integration. The survey is expected to be useful to system architects and protocol designers when choosing the communication protocols in an integrated IoT-to-fog-to-cloud system architecture.

Resource Management in Fog/Edge Computing: A Survey on Architectures, Infrastructure, and Algorithms

Abstract: Contrary to using distant and centralized cloud data center resources, employing decentralized resources at the edge of a network for processing data closer to user devices, such as smartphones and tablets, is an upcoming computing paradigm, referred to as fog/edge computing. Fog/edge resources are typically resource-constrained, heterogeneous, and dynamic compared to the cloud, thereby making resource management an important challenge that needs to be addressed. This article reviews publications as early as 1991, with 85% of the publications between 2013 and 2018, to identify and classify the architectures, infrastructure, and underlying algorithms for managing resources in fog/edge computing.

Fog/Edge Computing-Based IoT (FECIoT): Architecture, Applications, and Research Issues

Abstract: The Internet-of-Things (IoT) is the future of the Internet, where everything will be connected. Studies have revealed that fog/edge computing-based services will play a major role in extending the cloud by carrying out intermediary services at the edge of the network. Fog/edge computing-based IoT’s (FECIoT) distributed architecture enhances service provisioning along the Cloud-to-Things continuum, thereby making it suitable for mission-critical applications. Furthermore, the proximity of fog/edge devices to where the data is produced makes it stand-out in terms of resource allocation, service delivery, and privacy. From the business perspective, FECIoT will lead to a boom and spring up of small-to-medium-sized enterprises, thereby encouraging inclusion for all. To this end, we present a comprehensive survey on state-of-the-art IoT literature over the period 2008–2018 and propose the FECIoT framework which covers the enabling technologies, services, and open research issues. A tutorial approach is employed, progressing from basic to more advanced concepts within the IoT domain. Lastly, we show how FECIoT can be deployed in real-life cyber-physical systems, such as the intelligent transportation system, smart grid, smart health-care, smart homes, and smart environment.