352 research outputs found
A Knowledge-Based Service Composition Algorithm with Better QoS in Semantic Overlay
A semantic overlay network (SON) is a visual framework clustered under similar metaknowledge units such as ontologies, algorithms, and rule engines. Knowledge-based service composition (KC) has become a prominent aspect of building new and creative composed service through a combination of semantically similar information at the knowledge level. In this study, a promising approach to construct a standard knowledge model is developed to utilize the progress of KC. To evaluate and optimize the composition, we define the quantity of service (QoS) regarding user requirements in the KC instance, and a KC instance path with better QoS is found in the model using the KC algorithm. Simulation results prove that our approach has a tradeoff between efficiency and equality
Using Dedicated and Opportunistic Networks in Synergy for a Cost-effective Distributed Stream Processing Platform
This paper presents a case for exploiting the synergy of dedicated and
opportunistic network resources in a distributed hosting platform for data
stream processing applications. Our previous studies have demonstrated the
benefits of combining dedicated reliable resources with opportunistic resources
in case of high-throughput computing applications, where timely allocation of
the processing units is the primary concern. Since distributed stream
processing applications demand large volume of data transmission between the
processing sites at a consistent rate, adequate control over the network
resources is important here to assure a steady flow of processing. In this
paper, we propose a system model for the hybrid hosting platform where stream
processing servers installed at distributed sites are interconnected with a
combination of dedicated links and public Internet. Decentralized algorithms
have been developed for allocation of the two classes of network resources
among the competing tasks with an objective towards higher task throughput and
better utilization of expensive dedicated resources. Results from extensive
simulation study show that with proper management, systems exploiting the
synergy of dedicated and opportunistic resources yield considerably higher task
throughput and thus, higher return on investment over the systems solely using
expensive dedicated resources.Comment: 9 page
Service-Driven Networking
This thesis presents our research on service-driven networking, which is a general design framework for service quality assurance and integrated network and service management in
large scale multi-domain networks. The philosophy is to facilitate bi-party open participation among the users and the
providers of network services in order to bring about better service customization and quality assurance, without sacrificing the autonomy and objectives of the individual
entities. Three primary research topics are documented: service composition and adaptation, self-stabilization in uncoordinated environment, and service quality modeling. The work involves
theoretical analysis, algorithm design, and simulations as evaluation methodology
Supporting QoE/QoS-aware end-to-end network slicing in future 5G-enabled optical networks
Copyright 2019 Society of Photo‑Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this publication for a fee or for commercial purposes, and modification of the contents of the publication are prohibited.Network slicing with Quality of Experience/Quality of Service (QoE/QoS) guarantees is seen as one of the key enablers
of future 5G networks. Nevertheless, it poses several challenges in both resource provisioning and management that
need to be addressed for the efficient end-to-end service delivery. In particular, network slice deployments considering
operation across several domains and network segments, require of inter-domain configurations, continuous monitoring,
potential actuations, inter-slice isolation, among other, in order to be provisioned and maintained, looking forward to
guaranteeing their assured Key Performance Indicators (KPIs). In such scenario, optical networks are of prime
importance, enabling the inter-connectivity between multiple far away segments and Points of Presence (PoPs). In light
of this, in this paper we present an architecture design enabling network slice provisioning for 5G service chaining in
multi-segment/multi-domain optical network scenarios. The presented design is enriched with a policy-based monitoring
and actuation framework able to maintain the desired QoS for the provisioned end-to-end (E2E) network slice. We
experimentally validated the proposal against real slice deployments and traffic generation, providing a proof of concept
for the presented architecture, with special emphasis in the demonstration of the actuation framework as a key element
for quality guarantees.Peer ReviewedPostprint (published version
A2THOS: Availability Analysis and Optimisation in SLAs
IT service availability is at the core of customer satisfaction and business success for today’s organisations. Many medium-large size organisations outsource part of their IT services to external providers, with Service Level Agreements describing the agreed availability of outsourced service components. Availability management of partially outsourced IT services is a non trivial task since classic approaches for calculating availability are not applicable, and IT managers can only rely on their expertise to fulfil it. This often leads to the adoption of non optimal solutions. In this paper we present A2THOS, a framework to calculate the availability of partially outsourced IT services in the presence of SLAs and to achieve a cost-optimal choice of availability levels for outsourced IT components while guaranteeing a target availability level for the service
Ubiquitous web services
Ubiquitous coming from the Latin word ubique, means existing or being everywhere, especially at the same time. Web Services are loosely specified and coupled components distributed over the internet [23] with the purpose of being accessed and used ubiquitously by suppliers, customers, business and trading partners. This must be done independently of any tools or environment in use by any party involved. The basic service oriented architecture is based on the publishing of a service by a service provider, the location of a service by a service requestor and the interaction between the two based on the service description. The necessary functionality for the full adoption of such web services must include routing, reliable messaging, security, transactions, binary attachments, work- flow, negotiation and management, web services description languages, choreography, orchestration and non-repudiation. A large number of companies and organizations are promoting this adoption and shifting their strategy to include this useful technology. A multitude of proposed standards and products have emerged in an attempt to meet the needs of this worldwide community of web services adopters. The core established standards include the Web Services Description Language (WSDL), the Simple Object Access Protocol (SOAP) and the Universal Description, Discovery and Integration (UDDI). The Web services Inspection Language (WSIL) is a more lightweight yet complimentary specification for service discovery[1]. Other definitions produced to tackle the re- quired functions have not been fully standardized and many are still competing. For the needed functionality to be produced a number of related issues must be tackled. Here we look at some of the important ones, and how they are being tackled, we then shortly describe our proposed project and related works.peer-reviewe
Peer-to-Peer Networks and Computation: Current Trends and Future Perspectives
This research papers examines the state-of-the-art in the area of P2P networks/computation. It attempts to identify the challenges that confront the community of P2P researchers and developers, which need to be addressed before the potential of P2P-based systems, can be effectively realized beyond content distribution and file-sharing applications to build real-world, intelligent and commercial software systems. Future perspectives and some thoughts on the evolution of P2P-based systems are also provided
Network emulation focusing on QoS-Oriented satellite communication
This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication
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