Search results for "Computer network"
showing 10 items of 1634 documents
Towards a software-defined Network Operating System for the IoT
2015
The heterogeneity characterizing the Internet of Things (IoT) landscape can be addressed by leveraging network operating systems (NOS)s. Current NOS solutions have been developed for traditional infrastructured networks: they do not take the specific features of fundamental IoT components such as wireless sensor and actuator networks into account. Accordingly, in this paper an innovative integrated network operating system for the IoT which is obtained as the evolution of the Open Network Operating System (ONOS) is proposed. This has been appropriately extended to enhance the recently proposed SDN-WISE platform for supporting SDN in wireless sensor networks and let it interact with standard…
Toward Unified Control of Networks of Switches and Sensors Through a Network Operating System
2018
Wireless sensor networks (WSNs) are an integral part of an Internet of Things (IoT) ecosystem. In fact, a typical IoT service deployment considers an integrated network of switches and sensors (as well as actuators). In order to manage this heterogeneous network infrastructure, the use of software defined networking (SDN) technologies is anticipated. However, existing SDN-enabling technologies consider only isolated networks and there has been no concrete solution that treats the whole network in a unified way. In this paper, a network operating system is proposed as a way to address the above issue. Starting from the open network operating system, which currently supports only OpenFlow net…
Exploiting state information to support QoS in Software-Defined WSNs
2016
Software-Defined Networking (SDN) is a promising paradigm initially proposed for the wired networks which has the potential to change the way in which networks are designed and managed. Recently, its use has been extended to wireless infrastructure-less networks such as ad-hoc and wireless sensor networks. In this paper, we take inspiration from our previous work where a scheme that extends the SDN paradigm to WSNs - called SDN-WISE - was proposed. Differently from OpenFlow, SDN-WISE is stateful; accordingly in this paper we investigate how state can be used to support different levels of QoS in WSNs. In fact, state can be used to represent the level of congestion of a node and rules can be…
Wireless MAC Processor Networking: A Control Architecture for Expressing and Implementing High-Level Adaptation Policies in WLANs
2013
The current proliferation of unplanned wireless local area networks (WLANs) is creating the need for implementing different adaptation strategies to improve network performance under mutating and evolving interference scenarios. In this article, we envision a new solution for expressing and implementing high-level adaptation policies in WLANs, in contrast to the current approaches based on vendor-specific implementations. We exploit the hardware abstraction interface recently proposed by the wireless medium access control (MAC) processor (WMP) architecture and some flow-control concepts similar to the Openflow model for defining MAC adaptation policies. A simple control architecture for dis…
Improved primary regulation for minimum energy losses in islanded microgrids
2017
In this paper, an improved primary regulation is proposed for grid forming units supplying islanded microgrids. A minimum losses Optimal Power Flow is run off-line to devise the operating set points composing the primary regulation curve. In this way, after load perturbations, generators can reach an optimized operating point for a given and unique minimum losses energy flows distribution. The idea is to skip the hierarchical control architecture and provide a feasible and optimized operating point. A case study over 24 hours shows the effectiveness of this new approach as well as the improved operation quality of the system.
Enterprise architecture operationalization and institutional pluralism: The case of the Norwegian Hospital sector
2021
Enterprise architecture (EA) is a systematic way of designing, planning, and implementing process and technology changes to address the complexity of information system (IS) landscapes. EA is operationalized when architecture visions move towards realization through concrete projects. We report a case study on the dynamics of operationalizing EA in the Norwegian hospital sector by exploring different EA project trajectories. Our empirical context is an institutionally pluralistic setting where multiple logics coexist. We show that the distinct logic of EA is added to the institutional context and we find that tensions among existing medical, technical, and managerial logics and EA principle…
A Planning and Control System for Self-Driving Racing Vehicles
2018
Autonomous robots will soon enter our everyday life as self-driving cars. These vehicles are designed to behave according to certain sets of cooperative rules, such as traffic ones, and to respond to events that might be unpredictable in their occurrence but predictable in their nature, such as a pedestrian suddenly crossing a street, or another car losing control. As civilian autonomous cars will cross the road, racing autonomous cars are under development, which will require superior Artificial Intelligence Drivers to perform in structured but uncertain conditions. We describe some preliminary results obtained during the development of a planning and control system as key elements of an A…
On-chip quantum optical frequency comb sources
2018
Integrated optical frequency comb sources, based on nonlinear microring resonators, can be used to generate complex quantum states. In particular, we achieved multi-photon and high-dimensional entangled quantum states, as well as their coherent control.
Inverse design of photonic crystal devices
2005
This work deals with the inverse design in the field of photonic crystal based devices. Here an inverse method containing a fast and accurate simulation method integrated with a competent optimization method is presented. Two designs yielded from this conjunction of multiple scattering theory with a genetic algorithm is analyzed. The potential of this approach is illustrated by designing a lens that has a very low F-number (F=0.47) and a conversion ratio of 11:1. We have also designed a coupler device that introduces the light from an optical fiber into a PC based wave-guide with a predicted coupling efficiency that exceeds 87%.
Automatic EMI filter design for power electronic converters oriented to high power density
2018
In this paper, a complete computer aided procedure based on the power density concept and aimed at the automatic design of EMI filters for power electronic converters is presented. It is rule-based, and it uses suitable databases built-up by considering information on passive components available from commercial datasheets. The power density constraint is taken into consideration by imposing the minimization of the filter volume and/or weight; nevertheless, the system in which the automatically designed filter is included satisfies the electromagnetic compatibility standards limits. Experimental validations of the proposed procedure are presented for two real case studies, for which the per…