Antonino Raucea

Design and Implementation of an Educational Testbed for Experiencing With Industrial Communication Networks

This paper presents the design and implementation of an educational testbed developed for a course on industrial communication networks at the Engineering Faculty, University of Catania. The aim is to realize a platform capable of emulating various network configurations, thus enabling students to find out by themselves through practical experiments how different design choices, parameter settings, network configurations, and algorithms impact on the overall network performance. The testbed comprises a number of basic components (hosts, routers, and access points) implemented on nodes equipped with operating systems and open source software, which together make up a modular system. Each router can be loaded with data flows and monitored over preestablished time windows so as to evaluate its performance in a wide range of operating conditions. The wireless part makes it possible to configure environments with different levels of noise and bandwidth utilization so as to emulate a broad spectrum of real operating environments. The testbed can be used via remote access through a web interface that not only allows the operating conditions to be configured but also permits real-time monitoring. Students can configure the testbed on the basis of the network they are studying and can measure its performance for evaluation purposes.

Dynamic Continuous clock Synchronization for IEEE 802.15.4 based sensor networks

Clock synchronization is an important service in wireless sensor networks (WSN) since it can be used for data integration, for the implementation of TDMA based approaches or for synchronous data acquisition. One main issue in WSN concerns the power consumption since the batteries have a limited capacity an often they cannot be replaced. In this paper we present a dynamic continuous clock synchronization algorithm which provides a virtual common clock among a master and a group of slaves. The main feature of the approach proposed is the ability to allow nodes to sleep for long times and exchange only rare synchronization packets however providing a good quality common clock. The synchronization algorithm has been implemented inside embedded devices as a middleware over the MAC, without any modification to the original communication protocol.

A motion capture system for sport training and rehabilitation

This paper presents a motion capture system which provides both an accurate measurement of some motion parameters of a human arm and a graphical reconstruction of the movement on a synthetic model. The hardware uses several MEMS inertial sensors whose data are processed using mathematical tools based on quaternions. Measurements on a prototype have proven the system to be very accurate, since through the sensors placed on the joints of the arms it was possible to extract a video motion very faithful to the real.

L-PTP: A novel clock synchronization protocol for Powerline networks

This paper proposes a Lightweight version of the Precision Time Protocol, called L-PTP, for implementation on Powerline communication systems. The aim of this novel protocol is to reduce the number of messages exchanged to achieve synchronization, without penalizing its quality. L-PTP introduces several modifications to the original PTP and can be implemented on COTS devices. The paper focuses on the protocol and on the benefits of its combination with a virtual clock computation performed by a dynamic clock synchronization algorithm.

ENEL PILOT: From a Research Testbed to a Virtual Educational Laboratory

Education in the field of distributed process control and intelligent actuation and measurement (IAM) systems can be greatly enhanced through the use of tools that simulate the behavior of real systems, thus allowing students to test and compare different configurations. In this paper, we present an educational virtual laboratory, called the IAM-Pilot Virtual Laboratory (IPVL), which simulates a physical process consisting of a closed circuit of treated water implementing four regulation loops for pressure, level, flow, and temperature, respectively. This tool is the virtual implementation of a real research laboratory (IAM-Pilot), which was developed a few years ago in the framework of several projects funded by the European Commission, in order to test concepts regarding distributed systems, technologies, and components. The tool allows students to set several different system configurations, both in the control and communication parts, and then assess the resulting behavior. They can also install on the plant different virtual devices, with different features, and monitor their effect on the system. The tool produces graphs that allow students to evaluate the performance offered by the control system. This paper describes the architecture and implementation of the IPVL and reports on its usage in the context of the distributed process control network course at the Faculty of Engineering, University of Catania.

Tree based routing in power line communication networks

Power Line Communication Networks (PLCN) represent a very attractive communication system which can be used for many applications in the area of both home/building automation and street lighting control. The main problem is how to organize the many nodes, in order to implement a network where all nodes can exchange information with a master node. In this paper a tree-based clustering approach is introduced and discussed. The approach has been tested on a real power line system and some operational tests and evaluations have been performed.

Home control system over an MHP based architecture

The interactions between controls units and users in Domotics applications constitute a critical aspect which has greatly limited the diffusion of home automation systems. Usually, ordinary people have not familiarity with automation systems and find difficult to use their control interface. In this paper the authors exploit the interactive and representative potentialities provided in synergy by both the MHP decoder and TV, in order to develop an innovative way to simplify this interaction. As an example the control of a home alarm system is presented.

Improving routing in long-distance wireless mesh networks via a distributed embedded router

The paper addresses some issues concerning routers for long-distance wireless mesh networks (LDWMNs) which are becoming increasingly popular in the last few years, above all to provide Internet access for small extra-urban communities. The paper discusses some main features of LDWMNs, the design challenges and the reasons behind the implementation choices. A router is described, based on a modular architecture which provides fault tolerance and guarantees gracefully degrading performances in case a fault occurs. One important feature of the router is the full-duplex capability of its wireless links which provides high throughput. Finally, the paper describes the implementation of the router using low-cost embedded components and addresses some issues concerning the management of the wireless links in the wireless mesh backbone.

Evaluation of clock synchronization protocols for Wireless Sensor Networks

In this paper we compare three clock synchronization protocols for Wireless Sensor Networks and evaluate their performances under different operating conditions. The “Dynamic Continuous Clock Synchronization” (DCCS), here is compared with the “Reference Broadcast Synchronization” (RBS) and the “Continuous Clock Synchronization” (CCS). The performance evaluation of the three protocols has been carried out via simulation using the OMNeT++ discrete event simulation system. Synchronization is a key aspect in WSNs but some features such as the limited bandwidth, hardware and energy available, as well as the nature of the wireless medium, make a good synchronization a challenging objective. We performed a set of simulations to evaluate how the protocols behave by varying some influent factors, and compared the results obtained in order to achieve information useful to select the most suitable protocol for a specific application.

Performance evaluation by petri nets of a full duplex wireless link for an industrial backbone

This paper addresses the performance evaluation of a full duplex wireless protocol for an industrial backbone making a comparison with the traditional IEEE802.11 half duplex protocol. A Petri net model is used as the basis for the evaluation. The paper first examines the features of a wireless backbone and some issues they impose. Then, the paper describes the limits of the 802.11 and the solution here proposed which is based on the use of full duplex wireless links and discusses the PN models. At last the results of the performance evaluation are presented and the advantages offered by the full duplex solution are discussed.