26 research outputs found
A MARK-UP APPROACH TO SERVICE CREATION
The paper presents a new mark-up approach to service creation in Next Generation Networks. The approach allows access to network functions exposed by open application programming interfaces. Based on ontology analysis of the application domain, language constructions are synthesized and formally defined. Language supporting tools are developed. The approach functionality is tested by simulation
Parlay X Web Services for Policy and Charging Control in Multimedia Networks
The paper investigates the capabilities of Parlay X Web Services for Policy and Charging Control (PCC) in managing all Internet-protocol-based multimedia networks (IMSs). PCC is one of the core features of evolved packet networks. It comprises flow-based charging including charging control and online credit control, gating control, and Quality of Service (QoS) control. Based on the analysis of requirements for PCC, the functionality for open access to QoS management and advanced charging is identified. Parlay X Web Services are evaluated for the support of PCC, and some enhancements are suggested. Implementation aspects are discussed, and Parlay X interfaces are mapped onto IMS control protocols. Use cases of Parlay X Web Services for PCC are presented
Open Access to Resource Management in Multimedia Networks
The paper is dedicated to mechanisms for open
access to resource management in the Internet Protocol (IP)
multimedia networks. First we present the concept of IP
Multimedia Subsystem (IMS) and explain the IMS functional
architecture, principles of quality of service management and
service control in IMS. Then we describe the idea behind the
opening of network interfaces for third parties so that others
besides the network operator can create and deploy services.
Open Service Access (OSA) and Parlay appear to be the
technologies for value-added service delivery in multimedia
networks. In the paper we take a closer look to the
Parlay/OSA interfaces that allow third party applications to
access the resource management functions in IMS. OSA
"Connectivity Manager" interfaces and OSA "Policy
Management" interfaces are considered. Parlay X Web
Services interfaces provide a higher level of abstraction than
Parlay/OSA interfaces and gain an amazing amount of
support among service developers. We address "Applicationdriven Quality of Service" Parlay X Web Service and
"Policy" Parlay X Web Service also
Mobile edge computing applications for connectivity management
Connectivity management is the ability to connect and manage mobile devices in Machine-to-Machine (M2M) communications. Resilient and scalable connectivity management, which is fundamental to M2M solutions, may be achieved by using Mobile Edge Computing (MEC) technology. MEC enables applications to timely response to dynamic changes in radio conditions and thus to improve effectiveness of connectivity management. In this paper, we present models of device connectivity management that may be supported by MEC applications. We suggest a method for automatic detection of undesired interaction between applications using standard reasoning over description logic
Usage Monitoring Control in Radio Access Network
Multi-access Edge Computing is a promising re- search domain in 5G networks, as it is aimed at improving network efficiency by distributing cloud computing capabilities at the network edge. In this paper, we present a new mobile edge service for usage monitoring control. Usage monitoring control is defined as a part of Policy and Charging Control functionality in the core network. Moving the usage monitoring function close to the end user enables efficient control on data traffic. The proposed mobile edge service is described by typical use cases, data model and interface definition. As proof of concept, we propose resource state models as seen by mobile edge applications and platform, which are formally described and verified
Mobile Edge Service for Charging Control
5G systems will provide a flexible charging capabilities including policy control based on spending limits for a subscription. Edge computing possesses the potential for exposing policy control and charging capabilities to third party applications close to the end users. In this paper, we propose a new mobile edge service that provides open access to functions related to monitoring the usage limits regardless the way of measurement i.e. monetary, volume, duration, etc. Currently, this function is a part of the core network functionality. Using the proposed service interfaces, an intended application may track the usage of network resource by a subscriber and to request applying of enforcement action to user traffic such as quality of service downgrade, traffic redirection or blocking close to the end user. The description of the proposed mobile edge service is provided in form of typical use cases, data model, interface definition, and formally verified state models
Immune response – genesis, duration, and strength in patients with moderate and severe coronavirus infection of different age groups
Acquired (adaptive) immunity is a major factor determining effective immune response against a few infectious diseases. The immune response during recovery from COVID-19 is complex, involving both cellular and humoral adaptive immunity. The purpose of the study is to determine the intensity and effectiveness of the immune response at the end of the second year after discharge from the hospital in patients who have suffered from moderate and severe forms of coronavirus infection. A study among 2683 patients who suffered from moderately severe and severe coronavirus SARS-CoV2 infection with recorded complications which have not received a vaccine against SARS-nCoV-2 was performed. In the studied group of patients there were no deaths. In the whole cohort, the share of underlying prehospital comorbidity was also analyzed. The immune response induced because of moderate and severe infection with COVID-19 could serve as source of protection from recurrent severe infection for patents of different ages with various comorbidities
Equilibrium ordering properties of Au-Pd alloys and nanoalloys
Equilibrium configurations of bulk and surface Au-Pd alloys as well as of nanoalloy clusters are studied using Metropolis Monte Carlo importance sampling and the embedded atom method. The clusters contain about 1000 atoms. Three ordered bulk phases are predicted at low temperature, centred on compositions around 25%, 50%, and 75% Pd. The predicted order-disorder transition temperatures partially disagree with the available experimental results, but they are in good agreement with ab initio calculations. Surface enrichment in Au is systematically predicted, accompanied by partial subsurface enrichment in Pd, best enhanced around the equiatomic overall composition. The subsurface enrichment in Pd is suggested to play a decoupling role between surface and bulk conditions and, subsequently, ordered surface structures not induced by the order in the bulk are predicted at low temperatures. Clusters display similar segregation and ordering properties as flat infinite surfaces. However, the stability of the ordering at cluster surfaces is not globally characterized. The order-disorder transitions in the clusters occur at temperatures between 50 and 100 K lower than in the bulk. The disorder appears at the surface and proceeds to the core as the temperature is increased. © 2009 Elsevier B.V. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Model Aspects of Open Access to Multimedia Broadcast Services in the Evolved Packet System
Multimedia broadcast is the most efficient method to distribute identical content to multiple users in the Evolved Packet System (EPS). EPS enables efficient usage of network resources and provisioning of quality of service for every user. Third-party control allows applications in an enterprise domain to invoke network functions like multimedia broadcast. In this paper, an approach to modeling the behavior of Service Capability Server (SCS) for multimedia broadcast in EPS is presented. Third-party applications can access multimedia broadcasting capabilities by using Parlay X Web Service interfaces. The SCS for multimedia broadcast exposes Parlay X interfaces toward 3rd-party applications and control protocols toward the network. The SCS functional behavior has to be synchronized with the application view on message broadcast and the state of the network resources intended for the broadcast session. Models of multicast session, IP connectivity session, and bearers’ and charging session are proposed and formally described using the notation of Label Transition Systems. The concept of weak bisimilarity is used to prove that models expose equivalent behavior; that is, they are synchronized
Thermodynamic properties of Au-Pd nanostructured surfaces studied by atomic scale modelling
We address the question of the sensitivity of the segregation and ordering properties to the surface energy of Au-Pd alloys and nanoalloys. To this purpose, the parameterization of an EAM potential fitted to the vacancy formation energy was modified in order to predict surface energies closer to the experimentally measured ones. Metropolis Monte Carlo sampling was used to predict segregation and ordering. We show in the detail that modifying the surface energies of Au and Pd by up to 50 percent and, their surface energy difference by about 35 percent is of no major importance for the ordering and segregation properties of nanostructured Au-Pd alloy surfaces. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe