Search results for "Telecomunicazioni"

Resource allocations in heterogeneous 4G wireless networks

2012

Performance Analysis in Spatially Correlated IEEE 802.11 Networks

2012

Wireless mesh networks are difficult to be characterized, especially under multi-hop traffic streams. The problem is that the local view of the channel and the correlation between the buffers of consecutive nodes in a stream path make complicated the identification of the contention level perceived by each station along the time. Such a figure is used in the models based on the so called decoupling assumption for evaluating the final scheduling of simultaneous channel access grants. In this paper we propose a simplified mesh network model focused on capturing the correlation due to the network topology and traffic routes rather than the access protocol state at each node. To this purpose, w…

Multi-cloud privacy preserving schemes for linear data mining

2015

This paper presents an approach to privacy-preserving data mining that relies upon a relatively simple secret sharing scheme. Its main feature is that users, sensitive data owners, are engaged in the secret sharing operations that protect their privacy. They are grouped in independent clouds connected to a central unit, the data miner, that only manages the aggregated data of each cloud, therefore avoiding the disclosure of information belonging to single nodes. We propose two privacy preserving schemes, with different privacy levels and communication costs. When designing them, we assume that some users' data might become inaccessible during the operation of the privacy preserving protocol…

An interest-aware video streaming platform: Shaping its architecture to better suit users' demands

2014

This paper investigates how a p2p television platform can take advantage of the presence of frequent channel viewers to grant them a more satisfying service than to less regular spectators. The idea we explore is to learn beforehand about the users’ interests, in order to cluster them in groups that display different behaviors; then, the video chunk scheduling algorithm of the p2p overlay is altered, with the aim of serving frequent spectators in a privileged manner, providing them with a faster access to the selected channel. An analytical model is developed, to capture the difference in startup delay that the proposed changes introduce; several additional performance metrics are numerical…

Kata Containers: An Emerging Architecture for Enabling MEC Services in Fast and Secure Way

2019

New coming applications will be only possible through Mobile Edge Servers deployed in proximity of the mobile users. Due to the user's mobility and server's workload, service migration will be an integral part of the services. For this reason, a standardized architecture should be designed to accomplish a workload migration in a secure and timely manner. Most research done to date has focused on the use of either virtual machine (VM) or container or a mix of both recently. A final solution might be an architecture only having the advantages of both technologies as the security of the VM and the speed of the containers. Custom solutions, actually, by using both technologies, need continuous …

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…

Streams as Seams: Carving trajectories out of the time-frequency matrix

2020

A time-frequency representation of sound is commonly obtained through the Short-Time Fourier Transform. Identifying and extracting the prominent frequency components of the spectrogram is important for sinusoidal modeling and sound processing. Borrowing a known image processing technique, known as seam carving, we propose an algorithm to track and extract the sinusoidal components from the sound spectrogram. Experiments show how this technique is well suited for sound whose prominent frequency components vary both in amplitude and in frequency. Moreover, seam carving naturally produces some auditory continuity effects. We compare this algorithm with two other sine extraction techniques, bas…

Data fusion analysis applied to different climate change models: an application to the energy consumptions of a building office

2018

The paper aims to achieve the modelling of climate change effects on heating and cooling in the building sector, through the use of the available Intergovernmental Panel on Climate Change forecasted data. Data from several different climate models will be fused with regards to mean air temperature, wind speed and horizontal solar radiation. Several climatic models data were analyzed ranging from January 2006 to December 2100. Rather than considering each model in isolation, we propose a data fusion approach for providing a robust combined model for morphing an existing weather data file. The final aim is simulating future energy use for heating and cooling of a reference building as a conse…

A new approach to model the effect of climate change on the building sector: A climate models data fusion

2020

Several climate models have been developed and used to forecast the effects of the climate changes, however the variability of results due to different models lead to a significant uncertainty on the estimation of the building energy use for the next century. In this context, the paper analyses this uncertainty and combines different climate models in order to improve the robustness of energy consumption predictions. The data of the climate models were then used to generate hourly weather files for the future period 2020-2099 and energy simulations for a case study located in Palermo (Italy) were performed. Results show a wide variability among all models (either alone or combined with our …

A blockchain platform for Demand Response in Mediterranean islands: a smart contract for remuneration

2022

The Blorin project started at the end of 2019 to support the implementation of a blockchain platform to support the energy services provision from end users by means of Demand Response and Vehicle to Grid programs. The experimental part of the project is being carried out on two Mediterranean islands and inside the University campus in Palermo. Customized smart contracts have been designed to support the active participation of end users to regulation services for the two weak electrical grids of the islands in the view of a deep penetration of renewable energy in the two energy systems. In particular, the smart contract for remuneration accounts for the very special energy situation of isl…