Laszlo Toka

Dr. Laszlo Toka

BUDAPEST UNIVERSITY OF TECHNOLOGY AND ECONOMICS
orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 February 2020 in Sensors
Verified
Journal Article
Open access
PDF file
Pal VargaPal Varga
Pal Varga
JPJozsef Peto
Jozsef Peto
AFAttila Ernő Frankó
Attila Ernő Frankó
DBDavid Balla
David Balla
DHDavid Haja
David Haja
Laszlo TokaLaszlo Toka
Laszlo Toka
Industrial IoT has special communication requirements, including high reliability, low latency, flexibility, and security. These are instinctively provided by the 5G mobile technology, making it a successful candidate for supporting Industrial IoT (IIoT) scenarios. The aim of this paper is to identify current research challenges and solutions in relation to 5G-enabled Industrial IoT, based on the initial requirements and promises of both domains. The methodology of the paper follows the steps of surveying state-of-the art, comparing results to identify further challenges, and drawing conclusions as lessons learned for each research domain. These areas include IIoT applications and their requirements; mobile edge cloud; back-end performance tuning; network function virtualization; and security, blockchains for IIoT, Artificial Intelligence support for 5G, and private campus networks. Beside surveying the current challenges and solutions, the paper aims to provide meaningful comparisons for each of these areas (in relation to 5G-enabled IIoT) to draw conclusions on current research gaps.

19 January 2021 in IEEE Transactions on Network and Service Management
Verified
Journal Article
Closed access
Laszlo TokaLaszlo Toka
Laszlo Toka
GDGergely Dobreff
Gergely Dobreff
BFBalazs Fodor
Balazs Fodor
BSBalázs Sonkoly
Balázs Sonkoly
Kubernetes, the container orchestrator for cloud-deployed applications, offers automatic scaling for the application provider in order to meet the ever-changing intensity of processing demand. This auto-scaling feature can be customized with a parameter set, but those management parameters are static while incoming Web request dynamics often change, not to mention the fact that scaling decisions are inherently reactive, instead of being proactive. We set the ultimate goal of making cloud-based applications' management easier and more effective. We propose a Kubernetes scaling engine that makes the auto-scaling decisions apt for handling the actual variability of incoming requests. In this engine various machine learning forecast methods compete with each other via a short-term evaluation loop in order to always give the lead to the method that suits best the actual request dynamics. We also introduce a compact management parameter for the cloud-tenant application provider to easily set their sweet spot in the resource over-provisioning vs. SLA violation trade-off. We motivate our scaling solution with analytical modeling and evaluation of the current Kubernetes behavior. The multi-forecast scaling engine and the proposed management parameter are evaluated both in simulations and with measurements on our collected Web traces to show the improved quality of fitting provisioned resources to service demand. We find that with just a few, but fundamentally different, and competing forecast methods, our auto-scaler engine, implemented in Kubernetes, results in significantly fewer lost requests with just slightly more provisioned resources compared to the default baseline.

30 July 2021 in IEEE Communications Surveys & Tutorials
Verified
Journal Article
Open access
BSBalázs Sonkoly
Balázs Sonkoly
JCJános Czentye
János Czentye
MSMark Szalay
Mark Szalay
Balázs NémethBalázs Németh
Balázs Németh
Laszlo TokaLaszlo Toka
Laszlo Toka
Edge computing is a (r)evolutionary extension of traditional cloud computing. It expands central cloud infrastructure with execution environments close to the users in terms of latency in order to enable a new generation of cloud applications. This paradigm shift has opened the door for telecommunications operators, mobile and fixed network vendors: they have joined the cloud ecosystem as essential stakeholders considerably influencing the future success of the technology. A key problem in edge computing is the optimal placement of computational units (virtual machines, containers, tasks or functions) of novel distributed applications. These components are deployed to a geographically distributed virtualized infrastructure and heterogeneous networking technologies are invoked to connect them while respecting quality requirements. The optimal hosting environment should be selected based on multiple criteria by novel scheduler algorithms which can cope with the new challenges of distributed cloud architecture where networking aspects cannot be ignored. The research community has dedicated significant efforts to this topic during recent years and a vast number of theoretical results have been published addressing different variants of the related mathematical problems. However, a comprehensive survey focusing on the technical and analytical aspects of the placement problem in various edge architectures is still missing. This survey provides a comprehensive summary and a structured taxonomy of the vast research on placement of computational entities in emerging edge infrastructures. Following the given taxonomy, the research papers are analyzed and categorized according to several dimensions, such as the capabilities of the underlying platforms, the structure of the supported services, the problem formulation, the applied mathematical methods, the objectives and constraints incorporated in the optimization problems, and the complexity of the proposed methods. We summarize the gained insights and important lessons learned, and finally, we reveal some important research gaps in the current literature.

13 September 2016 in Transactions on Emerging Telecommunications Technologies
Verified
Journal Article
Open access
PDF file
RGRiccardo Guerzoni
Riccardo Guerzoni
IVIshan Vaishnavi
Ishan Vaishnavi
DCDavid Perez Caparros
David Perez Caparros
AGAlex Galis
Alex Galis
FTFrancesco Tusa
Francesco Tusa
RSRobert Szabo
Robert Szabo
Over the last couple of years, industry operators' associations issued requirements towards an end‐to‐end management and orchestration plane for 5G networks. Consequently, standard organisations started their activities in this domain. This article provides an analysis and an architectural survey of these initiatives and of the main requirements, proposes descriptions for the key concepts of domain, resource and service slicing, end‐to‐end orchestration and a reference architecture for the end‐to‐end orchestration plane. Then, a set of currently available or under development domain orchestration frameworks are mapped to this reference architecture. These frameworks, meant to provide coordination and automated management of cloud and networking resources, network functions and services, fulfil multi‐domain (i.e. multi‐technology and multi‐operator) orchestration requirements, thus enabling the realisation of an end‐to‐end orchestration plane. Finally, based on the analysis of existing single‐domain and multi‐domain orchestration components and requirements, this paper presents a functional architecture for the end‐to‐end management and orchestration plane, paving the way to its full realisation. Copyright © 2016 The Authors. Transactions on Emerging Telecommunications Technologies Published by John Wiley & Sons Ltd.

1 November 2020 in Journal of Network and Computer Applications
Verified
Journal Article
Open access
BSBalázs Sonkoly
Balázs Sonkoly
DHDávid Haja
Dávid Haja
Balázs NémethBalázs Németh
Balázs Németh
MSMárk Szalay
Márk Szalay
JCJános Czentye
János Czentye
Laszlo TokaLaszlo Toka
Laszlo Toka

17 July 2021 in Journal of Grid Computing
Verified
Journal Article
Open access
PDF file
Laszlo TokaLaszlo Toka
Laszlo Toka
Novel applications will require extending traditional cloud computing infrastructure with compute resources deployed close to the end user. Edge and fog computing tightly integrated with carrier networks can fulfill this demand. The emphasis is on integration: the rigorous delay constraints, ensuring reliability on the distributed, remote compute nodes, and the sheer scale of the system altogether call for a powerful resource provisioning platform that offers the applications the best of the underlying infrastructure. We therefore propose Kubernetes-edge-scheduler that provides high reliability for applications in the edge, while provisioning less than 10% of resources for this purpose, and at the same time, it guarantees compliance with the latency requirements that end users expect. We present a novel topology clustering method that considers application latency requirements, and enables scheduling applications even on a worldwide scale of edge clusters. We demonstrate that in a potential use case, a distributed stream analytics application, our orchestration system can reduce the job completion time to 40% of the baseline provided by the default Kubernetes scheduler.