Search results for "Computer network"
showing 10 items of 1634 documents
A Multi-channel Communication Framework
2013
We present a modular framework for a business-to-customer communication service integrating several communication channels. Using such a service it is possible to find hidden relationships between messages and thus collect more customer-related data. The framework core is a message-conversion engine capable of converting channel-independent abstract messages into concrete messages and vice-versa. The conversion process is context-dependent. The context consists of formally described communication channel characteristics and user preferences. The framework is based on semantic technologies due to a balance between their expressive power, reasoning properties, and existence of production-qual…
An Integrated Multi-service Software Simulation Platform: SIMPSONS Architecture
2005
This paper describes SIMPSONS (SIp and MPls Simulations On NS-2), which is a software platform for simulating multiple network scenarios, such as Telephony Over IP (TOIP), and multi-services networks extending the functionalities of Network Simulator NS-2. The innovative aspects of SIMPSONS is the complete integration of control protocols and traffic engineering mechanisms inside the same simulation tool. In fact, next generation networks must meet basically two fundamental requirements: support of Quality of Service (QoS) and Traffic Engineering (TE) functionalities. SIMPSONS is able to simulate DiffServ, MPLS, OSPF and SIP and their interaction in everything TOIP scenario. So with this po…
Breaking layer 2: A new architecture for programmable wireless interfaces
2012
This paper introduces a new architecture for programmable wireless interfaces, aiming at responding to the emerging request of wireless access flexibility and adaptability. Instead of implementing a specific MAC protocol stack, the proposed architecture supports a set of programmable services, devised to customize the wireless access operations according to specific network and application scenarios. The services are composed by means of simpler functions, which in turns work on system primitives (i.e. elementary non-programmable functionalities, natively provided by the system) dealing with the physical transmission and reception of the frames. Our approach significantly differs from softw…
Context-aware vehicular cyber-physical systems with cloud support: architecture, challenges, and solutions
2014
[EN] The advances in wireless communication techniques, mobile cloud computing, and context-aware technologies boost a growing interest in the design, development, and deployment of vehicular networks for emerging applications. This leads to an increasing evolutionary tendency to change from vehicular networks toward cloud-assisted context-aware vehicular cyber-physical systems. In this article, we first propose a multi-layered context-aware architecture and introduce two crucial service components, vehicular social networks and context-aware vehicular security. Then we propose an application scenario regarding the context-aware dynamic parking services by illuminating the cloud-assisted ar…
Integrating Variability Management in Data Center Networks
2017
International audience; Data centers have an important role in supporting cloud computing services (i.e. checking social media, sending emails, video conferencing,..). Hence, data centers topologies design became more important and must be able to respond to ever changing service requirements and application demands. An ultimate challenge in this research is the design of data center network that interconnects the massive number of servers, and provides efficient and fault-tolerant routing algorithm. Several topologies such as DCell, FlatNet and ScalNet have been proposed. However, these topologies generally seek to improve the scalability without taking into consideration the energy usage …
A Simulation Analysis for Assessing the Reliability of AC/DC Hybrid Microgrids - Part I: Underground Station and Car Parking
2021
This paper reports the results of a simulation study with the aim of evaluating the capability of two portions of a hybrid AC/DC MV/LV network of maintaining their operation in off-grid mode during the loss of the main AC grid due to a failure. In particular, the study aims to verify, in the case of islanded operation of the two microgrids, the continuity of the electricity service by exploiting the local generation plants, Energy Storage Systems (ESSs), and other flexible resources managed by suitable algorithms in different energy scenarios. The analysis was carried out considering two microgrids: an underground station and a car parking with Electric Vehicles (EVs). For assessing the per…
Improvement of a Service Level Negotiation Protocol using Formal Verification
2013
International audience; The goal of the pervasive connectivity is to enable mobile users to be permanently connected to the Internet. Mobile users are often connected to wireless networks and consuming services that require quality of service guarantees. Accessing services using wireless technologies may make the service delivery vulnerable to security attacks because of the open medium of these technologies. In this context, we need to guarantee both quality of service and security for mobile users communications. In this paper, we present a protocol for service level negotiation which covers both quality of service and security and assigns a profile to each user in order to optimize and a…
Network channel allocation and revenue maximization
2002
This paper introduces a model that can be used to share link capacity among customers under different kind of traffic conditions. This model is suitable for different kind of networks like the 4G networks (fast wireless access to wired network) to support connections of given duration that requires a certain quality of service. We study different types of network traffic mixed in a same communication link. A single link is considered as a bottleneck and the goal is to find customer traffic profiles that maximizes the revenue of the link. Presented allocation system accepts every calls and there is not absolute blocking, but the offered data rate/user depends on the network load. Data arriva…
A genetic approach for adding QoS to distributed virtual environments
2007
Distributed virtual environment (DVE) systems have been designed last years as a set of distributed servers. These systems allow a large number of remote users to share a single 3D virtual scene. In order to provide quality of service in a DVE system, clients should be properly assigned to servers taking into account system throughput and system latency. The latter one is composed of both network and computational delays. This highly complex problem is known as the quality of service (QoS) problem. In this paper, we study the implementation of a genetic algorithm (GA) for solving the QoS problem in DVE systems. Performance evaluation results show that, due to its ability of both finding goo…
Antecedents of online banking satisfaction and loyalty: empirical evidence from Finland
2009
This study endeavours to contribute to a better understanding of Service Quality (SQ) in online banking by examining the various dimensions related to creating a satisfactory online banking experience. The authors develop a conceptual model and test it with a convenience sample of 183 online banking users. The empirical test of the model finds strong support for the links between perceived security and Perceived Usefulness (PU) and Perceived Ease Of Use (PEOU), reliability and PU and PEOU, between PEOU and satisfaction and finally between satisfaction and loyalty. The study finally provides both theoretical and practical contributions, outlines the main limitations of the study and gives id…