Giovanni Schembra

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Promoting the evolution of the Internet from a simple data network to a true multiservice network today constitutes a challenging task. To this end, the Internet Engineering Task Force (IETF) has set up the Integrated Services (Intserv) and Differentiated Services (DiffServ) Working Groups, with the goal of defining a next-generation Internet, in which(More)
In the last few years an increasing amount of attention has been paid to technologies for the transmission of voice over IP (VoIP). At present, the UDP transport protocol is used to provide this service. However, when the same bottleneck link is shared with TCP flows, and in the presence of a high network load and congestion, UDP sources capture most of the(More)
In this paper an analytical model is presented in order to evaluate both multimedia traffic characteristics, in terms of IDC, and loss performance of an ATM multiplexer loaded by multimedia traffic generated during a multimedia conference session. For this purpose each multimedia source is modeled by a Switched Batch Bernoulli Process (SBBP), and the(More)
The recent advancements in synthetic biology, and specifically in genetic engineering of bacteria, have enabled the use of bacterial populations to define and design a communication system for nanomachines in biological applications. The need for providing communication strategies in these challenging environments where electromagnetic waves cannot be used,(More)
In this paper an accurate and treatable Markov-based model for MPEG video traffic is proposed. Before reaching a definition of the model, a large number of MPEG video sequences are analyzed and their statistical characteristics are highlighted. Besides the well-known autocorrelation function, testifying the pseudo-periodicity of the sequence in the short(More)
Power consumption of the Information and Communication Technology sector (ICT) has recently become a key challenge. In particular, actions to improve energy-efficiency of Internet Service Providers (ISPs) are becoming imperative. To this purpose, in this paper we focus on reducing the power consumption of access nodes in an ISP network, by controlling the(More)
In this paper a multimedia source is modeled as an arrival process defined as the superposition of heterogeneous correlated arrival processes, each of which models one monomedia source. To this purpose each monomedia source is modeled as an ON-OFF process where the transition rates are functions of the states of the other monomedia sources. Auto-and(More)
—Guarantees of quality-of-service (QoS) in the real-time transmission of stored video on the Internet is a challenging task for the success of many video on demand (VoD) applications. Two QoS classes have been specified by the IETF Integrated Services (intserv) Working Group: Guaranteed Services and Controlled-Load Services. For both of them, it is(More)