Matteo Repetto - Academia.edu (original) (raw)

Papers by Matteo Repetto

IEEE Systems Journal, 2015

IEEE 5th International Symposium on Wireless Pervasive Computing 2010, 2010

Abstract The rapid diffusion of wireless technologies for network access has fostered the expecta... more Abstract The rapid diffusion of wireless technologies for network access has fostered the expectation for enhanced forms of communication in the current and future Internet. To this aim, there is a large consent about pursuing user-centric and pervasive paradigms; that ...

2009 6th International Symposium on Wireless Communication Systems, 2009

ABSTRACT Real-time multimedia traffic requires some minimum delivery guarantees to be effectively... more ABSTRACT Real-time multimedia traffic requires some minimum delivery guarantees to be effectively transmitted over packet-switched networks. This is even more necessary when interactive sessions (e.g., voice-over-IP applications) are involved. Effective and timely packet delivery is sometimes achieved by overdimensioning network capacity. However, this is not the most practical and economic solution. Instead, providing a specific service to different traffic types may achieve better results without wasting network resources. Quality of service (QoS) be implemented at different layers of the protocol stack, but tight control at the link layer is essential when the physical medium is shared among a number of devices. Wireless LANs are a typical example of that. The IEEE 802.11e amendment enhances the original version of the WiFi standard with new QoS functionalities. It maintains backward compatibility with legacy hardware, and this may cause the priority scheme to be ineffective in those deployments where non-QoS enabled hardware is present. In this paper, we analyze some widespread commercial 802.11 products to check the effectiveness of the QoS mechanisms. We show that all hardware under examination fails in providing effective QoS guarantees when legacy stations are present.

2014 Eighth International Conference on Next Generation Mobile Apps, Services and Technologies, 2014

2013 4th Annual International Conference on Energy Aware Computing Systems and Applications (ICEAC), 2013

ABSTRACT Smart Grids provide an effective and efficient management of production, transmission, d... more ABSTRACT Smart Grids provide an effective and efficient management of production, transmission, distribution and usage of electricity. One of the main issues in designing applications for Smart Grids is the need to cope with a plethora of different devices, communication protocols and data representations. This paper presents the design of a Home Energy Gateway (HEG) that abstracts heterogeneous devices and communication protocols and can be used to develop intelligent applications following a technology-agnostic approach. It is especially conceived to take over efficient energy management at home. Main design issues of our framework are the ability to automatically discover available devices and appliances, to track their operational status, to support different communication protocols and paradigms and to run concurrently multiple services. As an example of service, we address the implementation of a Network Connectivity Proxy (NCP), which save energy by letting unused ICT devices to remain into low-power states without losing their presence on the network. Further, some preliminary results based on the aforementioned service are also presented.

2013 24th Tyrrhenian International Workshop on Digital Communications - Green ICT (TIWDC), 2013

Multimedia Tools and Applications, 2011

Current mobility protocols and architectures are mainly targeted to devices or applications and t... more Current mobility protocols and architectures are mainly targeted to devices or applications and they usually lack the ability to support user-centric paradigms; moreover, they usually face a single aspect of the problem, i.e., terminal handover or session mobility. Full mobility support is only available to specific applications or protocols (e.g., SIP) but these approaches do not exploit all facilities for movement detection at the network/link layers and do not allow to use the same framework for different applications. This paper proposes a generic mobility framework for terminal handover and session migration. It pursues the user-centric paradigm and builds a cross-layer architecture, yielding to a high level of generality, applicability and flexibility. Unlike other approaches, it does not require any modification in correspondent peers and works with a minimal network infrastructure. Software implementations are described for two representative real-time multimedia applications, i.e., media streaming and interactive conference. The effectiveness of the framework was analyzed by means of both performance measurements in local and Internet testbeds and user evaluation during a live demo conducted at a national science exhibition.

Journal of Networks, 2012

ABSTRACT Mobility is a common issue in modern communications. Traditionally, terminal devices hav... more ABSTRACT Mobility is a common issue in modern communications. Traditionally, terminal devices have been playing a leading role and thus the main interest has been targeted to terminal mobility. However, nowadays people claim and expect pervasive communications, with continuous and seamless media access, regardless of the device they are using. That requires new communication paradigms and mobility solutions, in order to overcome the legacy network- and device-centric approaches. In this paper we discuss our mobility framework for multimedia communications which accounts for both terminal handover and session migration implementing the user-centric paradigm in networking. It basically works at the network layer and requires only minimal application-specific operations, yielding to a high level of generality, applicability and flexibility. To prove this, we apply the mobility framework to the interactive multimedia communication, implementing a Video and Voice over IP application. The mobility framework has been deployed in a real testbed and submitted to user judgment in a live demo at an Italian national science exhibition. We report the qualitative feedback got from users which clearly demonstrates both the feasibility of the proposed solution and the growing attractiveness of communicating in a user-centric fashion.

Computer Networks, 2008

A multiservice IP Virtual Private Network is considered, where Quality of Service is maintained b... more A multiservice IP Virtual Private Network is considered, where Quality of Service is maintained by a DiffServ paradigm, in a domain that is supervised by a Bandwidth Broker (BB). The traffic in the network belongs to three basic categories: Expedited Forwarding (EF), Assured Forwarding (AF) and Best Effort (BE). Consistently with the DiffServ environment, the Service Provider's Core Routers (CRs) only treat aggregate flows; on the other hand, the user's Edge Routers (ERs) keep per-flow information and convey it to the BB. The latter knows at each time instant the number (and the bandwidth requirements) of flows in progress within the domain for both EF and AF traffic categories. A global strategy for admission control, bandwidth allocation and routing within the domain is introduced and discussed in the paper. The aim is to minimize blocking of the ''guaranteed'' flows (EF and AF), while at the same time providing some resources also to BE traffic. In order to apply such control actions on-line, a computational structure is sought, which allows a relatively fast implementation of the overall strategy. In particular, a mix of analytical and simulation tools is applied jointly, by alternating ''local'' decisions, based on analytical models, with flow-level simulation that determine the effect of the decisions on the whole system and provide feedback information. The convergence of the scheme (under a fixed traffic pattern) is investigated and the results of its application under different traffic loads are studied by simulation on three test networks.

Proceedings of the 2007 ACM symposium on Virtual reality software and technology - VRST '07, 2007