Giancarlo Portomauro

Information Distribution Techniques in Sensor Networks via Satellite

The reference environment is composed of a sensor network that conveys information towards earth stations (called sinks) that give access to the satellite backbone and, through it, to the destination. The choice of the sink where to convey sensor information may affect the overall communication performance. After introducing the application environment, the paper introduces a method to select the sink that assures the improvement of network performance in terms of energy consumption, load, and total time spent by information packets in the network, considering the fading level measured by earth stations. After selecting the sink, the technique how to propagate information within the sensor network has a main role. The paper compares flooding-based techniques on the basis of the metrics mentioned above.

Simple Protocol Enhancements of Rapid Spanning Tree Protocol over Ring Topologies

The paper addresses resilience over Ethernet networks using the Rapid Spanning Tree Protocol (RSTP). The topic constitutes an open issue of debate as clear indications on the real RSTP performance can hardly be found from the literature. Actually, the complicated protocol structure makes the analysis intricate and unsuitable for generalization. Moreover, the presence of other resilience algorithms, whose mechanisms and rules are explicitly designed for resilience, solves the problem beyond the application of RSTP. Even though those solutions are actually more efficient than RSTP, they are more expensive. In this perspective, the purposes of this paper are to critically evaluate the intrinsic limitations of RSTP and propose some simple protocol modifications to speed up its performance. The analysis validates the achievable performance as a trade-off between fast reactions and bandwidth overhead.

SAT05-3: Performance Evaluation of Sink Selection Techniques in Satellite Sensor Networks

Recent environmental monitoring systems are based on Satellite-based Sensor Networks (SSN) where earth stations (Sinks) gather messages from sensors and use the satellite channel to send sensible information to remote monitoring sites. In these systems, the Sink selection process may play a crucial role and needs to be investigated. The work includes: an introduction of the SSN scenario considered; a brief description of the Sink selection method aimed at guaranteeing the optimization of the energy consumption and, simultaneously, of the message transfer delay; a deep performance investigation, which represents the main contribution of this paper, carried out by simulation, of the studied technique.

Design and Performance Evaluation of a Packet-Switching Satellite Emulator

The increasing interest for the satellite technology as suitable means for transporting multimedia applications has fostered several research investigations aimed at identifying proper algorithm tunings and exploring the performance of communication protocols in general. To this end, the support of analysis and research tools is of primary importance to assess performance of data communication and, hence, to provide the satellite system designers with proper indications suited to develop effective satellite networks. From this standpoint, a satellite emulation tool is presented, showing the features it provides and a large set of applications in which it might be employed to asses the performance of data communication.

Comparative Performance Evaluation for Information Distribution Methods in Satellite-based Sensor Networks

The advances in satellite networking and material science enabled the deployment of low cost and low power small sized sensors that can transmit information through satellite channel to remotely located host. Earth stations represent sink nodes of the sensor network and often, for safety reasons, they are rebounded. In this environment, controlled information distribution methods may play a crucial role and represent a sensible field of investigation. In particular, distribution methods proposed in the paper are aimed at guaranteeing the lower energy consumption and the lower level of congestion in the network. The paper includes: the presentation of the application environment composed of sensor networks and sink Earth stations; the introduction of the sinks management functions and the description of the flooding-based techniques used to propagate information through the network; an introductive comparison of the performance in terms of energy consumption and total time spent in the sensor network

An Ns-3 based simulative and emulative platform

This chapter contains the description of a simulative/emulative platform developed by the authors and called the “Hybrid Simulative-Emulative Platform (HySEP).” It has been designed and built to simulate long term evolution (LTE) networks by using Network Simulator 3 (ns-3) and to emulate a backhaul network that implements the Differentiated Service (DiffServ) solution to guarantee Quality of Service (QoS). The former composes the Simulated Network Segment (SNS), the latter the Emulated Network Segment (ENS). The use of ns-3 assures a detailed LTE simulative model and an effective mechanism to connect the simulated scenario with real network nodes and links. Moreover, this platform enables the creation of a heterogeneous network through the exploitation of personal computers and free software without using any ad-hoc hardware. HySEP makes possible testing different network configurations, limiting costs and using technologies such as LTE whose real implementation is hardly applicable inside a research laboratory. The tool can be completely configured and used remotely through Internet connections.

Hybrid Simulated-Emulated Platform for Heterogeneous Access Networks Performance Investigations

The availability of different access technologies enables the creation of heterogeneous networks supporting users mobility and assuring several different services. Meanwhile these networks require complex control techniques to assure Quality of Service (QoS) to users. Before implementing such networks, a deep performance analysis, through the use of network simulators or real models, is necessary. In particular the first ones (e.g. Network Simulator 3 - ns-3 among the others) are quite simple and easy to manage and configure, while the second ones assure the handling of real traffic flows. The main contribution of this paper is the description of an hybrid simulated and emulated network evaluation platform, developed by the authors. The platform purpose is to execute a performance analysis of different wireless networks such as Long Term Evolution (LTE) and Wi-Fi, connected to a core network implementing the Differentiated Service (DiffServ) protocol. The paper contains also the results of preliminary validation tests.

Multi Attribute Based Algorithm for Reliable Satellite-Based Sensor Networks

Modern environmental monitoring systems are based on satellite-based sensor networks (SSN) where earth stations (Sinks) gather information from sensors and use the satellite channel to send it to remote sites. For the sake of efficiency of a whole monitoring system, the SSN has to be managed by following two main aims: to guarantee the reliability, in particular in case of failure of the satellite portion of the network, and to limit both delay, which is representative of a very important Quality of Service (QoS) metric, and energy consumption. The dynamic sink selection process may allow reaching both aims of the system. In more detail, the paper proposes: the description of the SSN architecture taken as reference, the quality requirements of the system, a revision of the Sink selection method called LINMAP, and an introductive simulative study of its performance in case of failure of the satellite portion of the system.

Multi Attribute Sink Selection Techniques in Satellite Sensor Networks: Study and Performance Evaluation

In satellite-based sensor networks (SSN), earth stations represent the sink nodes of the sensor field and they may be simultaneously used to sent messages from the sensors to the remote monitoring hosts where data are stored and managed. In this environment, the choice of the sink may play a crucial role and represent a interesting field of investigation. The work includes: an introduction of the network scenario considered; a brief description of the sink selection methods aimed at guaranteeing the optimization of the energy consumption and, simultaneously, of the message transfer delay; a performance investigation of the proposals, which represents the main contribution of this paper, carried out by simulation