This paper summarizes all research advancements obtained by the Polytechnic of Bari through the RES NOVAE Project activities in the field of the smart district. In this context it is important to investigate and apply new efficient technologies solutions for the building management in order to optimize the energy usage and to improve the inhabitants’ comfort. The integration of the ICT technologies and the building automation systems together with innovative renewables energy solutions is studied. Moreover, suitable control algorithms, communication protocols and measurement devices are proposed and tested to improve the efficiency of the building energy management systems.

This document describes two methods of congestion control when using real-time communications on the World Wide Web (RTCWEB); one sender- based and one receiver-based. It is published as an input document to the RMCAT working group on congestion control for media streams.

Adaptive video streaming is a relevant advancement with respect to classic progressive download streaming a la YouTube. Among the different approaches, the video stream-switching technique is getting wide acceptance, being adopted by Microsoft, Apple, and popular video streaming services such as Akamai, Netflix, Hulu, Vudu, and Livestream. In this paper, we present a model of the automatic video stream-switching employed by one of these leading video streaming services along with a description of the client-side communication and control protocol. From the control architecture point of view, the automatic adaptation is achieved by means of two interacting control loops having the controllers at the client and the actuators at the server: One loop is the buffer controller, which aims at steering the client playout buffer to a target length by regulating the server sending rate; the other one implements the stream-switching controller and aims at selecting the video level. A detailed validation of the proposed model has been carried out through experimental measurements in an emulated scenario.

Congestion control is a fundamental building block in packet switching networks such as the Internet due to the fact that communication resources are shared. It has been shown that the plant dynamics is essentially made up of an integrator plus time delay and that a proportional controller plus a Smith predictor defines a simple and effective controller. It has also been shown that the TCP congestion control can be modelled using a Smith predictor plus a proportional controller. Due to the importance of this control structure in the field of data network congestion control, we analyse the robust stability of the closed-loop system in the face of delay uncertainties that are present in data networks due to queuing. In particular, by applying a geometric approach, we derive a bound on the proportional controller gain which is necessary and sufficient to guarantee the closed-loop stability for a given bound on the delay uncertainty.

tcp, congestion control

La società ha per oggetto le attività di ricerca, sviluppo, progettazione e commercializzazione di software, hardware e servizi nei settori della telematica, dell'automazione, delle telecomunicazioni, dei sistemi di elaborazione dati, informativi, dei web services, di Voice su internet Protocol, di video su IP, e di videoconferenze; realizzazione e gestione di centri elettronici per l'elaborazione dei dati, la gestione di servizi inerenti al calcolo e l'archiviazione di dati; ideazione, realizzazione, installazione e assistenza di servizi telematici; ideazione, realizzazione, installazione e assistenza di servizi con tecnologie di cloud computing e di virtualizzazione; erogazione di servizi e applicazioni tramite l'utilizzo di infrastrutture di cloud computing.