Wireless LANs Systems: An Advanced Resource Assignement Algorithm

The paper describes the design and simulation of a radio modem architecture, which provides wireless access to Internet in a single-hop, ad hoc network.The main emphasis is on the Medium Access Control (MAC) and Dynamic Link Control (DLC) layer’s design, and in particular on the adopted innovative scheduling algorithm, which has been developed to satisfy the system requirements of the WIND-FLEX radio modem. The algorithm is presented and compared to the Earliest Deadline First (EDF) solution.Several software simulation tests have been executed on the network, to test the performance of the system, in order to verify the capability of the scheduler algorithm to satisfy the expected requirements and the efficiency of the implemented solutions. Giuseppe Razzano was born in Roma, Italy, in 1974. He has graduated in Electronic Engineering “summa cum laude” and has received PhD in Communication Systems and Computer Science, in 2004 from University of Rome “La Sapienza”. From 2000 to 2001 he worked as research assistant at VTT electronics, in Finland. From 2004 to 2005 he worked as senior researcher at Forschungzentrum Telekommunikation Wien (Telecommunication Research Centre Vienna) in Austria. Currently, he works as System Engineer for Vitrociset S.p.A., working in a project funded by European Space Agency (ESA), for the development of a new generation space launcher vehicle (VEGA). In the past years, he worked in several projects funded by EC within the IST (Information Societies Technology) program, being also involved in projects in collaboration with Italian companies. His research is focused on resource management algorithms for wireless LANs and cellular networks. He is also interested in object-oriented programming and development methodologies. In these fields, he is author of several papers published in international journals and conferences. Francesco Delli Priscoli was born in Rome in 1962. He graduated in Electronic Engineering “summa cum laude” from the University of Rome “La Sapienza” in 1986. He received the Ph.D. in system engineering from the University of Rome “La Sapienza” in 1991. From 1986 to 1991 he worked in the “Studies and Experimentation” Department of Telespazio (Rome). Since 1991 he is working for the University of Rome “La Sapienza” where, at present, he is “Full Professor” and holds the courses “Automatic Controls”, “System Theory” and “Network Control and Management I and II”. In the framework of his activity, he researches in the nonlinear control theory and in the area of control-based resource management procedures for the third and forth generation of mobile systems. He is the author of about 150 technical papers on the above topics appeared on major international reviews (about 50) and conferences (about 100). In 2000 he has been scientific consultant for the Italian Council of Ministers in the framework of the auction for the assignment of the Italian Universal Mobile Telecommunication System (UMTS) licensees. He is an associate editor of Control Engineering Practice and a member of the IFAC Technical Committee on “Networked Systems”. He is/has been scientific responsible, for the University of Rome “La Sapienza”, of 17 projects financed by the European Union (fourth, fifth and sixth framework programmes) or by the European Space Agency (ESA), dealing with resource management for UMTS and broadband terrestrial and satellite wireless systems. He is also a project evaluator for the European Commission. Roberto Cusani received the “laurea” degree in Electronic Engineering (cum laude) and the Ph.D. in Communication Systems and Computer Science from the University of Rome “La Sapienza”. From 1986 to 1990 he was research engineer at the University of Rome “Tor Vergata”, teaching Digital Signal Processing. In 1991 he joined the University of Rome “La Sapienza” as Associate Professor of Signal Theory. In 2000 he becomes Full Professor and teaches Information Theory and Coding, and Mobile Communications. His former research activities concern transmission and coding of signals and images, with emphasis on random processes, spectral estimation and image coding. Since 1992 he focused his activities in the field of the digital communication systems, with emphasis on channel equalisation and coding for HF and radio-mobile (GSM) links, on the design of CDMA receivers for UMTS and, in general, on the use of digital techniques within telecommunication equipments. More recently his interests also includes the study of MAC (Multiple Access Control) protocols with application to wireless area networks (WLANs), reconfigurable ad-hoc networks and satellite links. He is author of more than 100 publications in international journals and conferences, of the text-book “Teoria dei Segnali” and of five patents regarding telecommunication applications. He was involved in many research programs, both national and international, and in projects with the industrie.     

Programmable CNN Analogue Chip for RD-PDE Multi-Method Simulations

Cellular Non Linear Networks can be useful applied for the solution of several types of Partial Differential Equations (PDEs). This paper will describe an analogue circuit implementation for the simulation of one-dimensional Reaction-Diffusion PDE with the possibility to set different boundary conditions as well as to select different discretization methodologies. Fausto Sargeni was born in Riano (ROMA) in 1961. He received the Dipl. Eng. degree in Electronic Engineering at the University of Rome “La Sapienza" in 1987. In 1989 he jointed the Dept. of Electronic Engineering at the University of Rome “Tor Vergata" as Assistant Professor. In 1998 he became Associate Professor. His research interests include analog VLSI circuits for non linear circuits and high-speed interconnections. Vincenzo Bonaiuto was born in Rome, Italy, in 1962. He received the Dipl. Eng. degree in Electronic Engineering at the University of Rome “La Sapienza". In 1997 he received the the Ph.D. in Telecommunication and Microelectronics. In 1996 he jointed the Electronic Engineering Dept. as Assistant Professor at the University of Rome “Tor Vergata” and, in 2002, he became Associate Professor. His main research interests are in the area of non linear circuits, Artificial Neural Networks analogue/digital VLSI circuits implementation.     

Energy efficient node-to-node authentication and communication confidentiality in wireless sensor networks

A distributed Wireless Sensor Network (WSN) is a collection of low-end devices with wireless message exchange capabilities. Due to the scarcity of hardware resources, the lack of network infrastructures, and the threats to security, implementing secure pair-wise communications among any pair of sensors is a challenging problem in distributed WSNs. In particular, memory and energy consumption as well as resilience to sensor physical compromise are the most stringent requirements. In this paper, we introduce a new threat model to communications confidentiality in WSNs, the smart attacker model. Under this new, more realistic model, the security features of previously proposed schemes decrease drastically. We then describe a novel pseudo-random key pre-deployment strategy ESP that combines all the following properties: (a) it supports an energy-efficient key discovery phase requiring no communications; (b) it provides node to node authentication; (c) it is highly resistant to the smart attacker.We provide both asymptotic results and extensive simulations of the schemes that are beingproposed. This work was partially funded by the WEB-MINDS project supported by the Italian MIUR under the FIRB program, and by the PRIN 2003 “Web-based Management and Representation of Spatial and Geographic Data” program from the Italian MIUR. Roberto Di Pietro is partially funded by ISTI-CNR, WNLab, Pisa, with a Post-doc grant under the IS-MANET program. Roberto Di Pietro received the Ph.D. in Computer Science from the University of Roma “La Sapienza”, Italy, in 2004. He received the Bs. and Ms. degree in Computer Science from the University of Pisa, Italy, in 1994. Since 1995 he has been working for the technical branch of the Italian Army and the Internal Affairs Ministry. His main research interests include: security for mobile ad hoc and wireless networks, security for distributed systems, secure multicast, applied cryptography and computer forensics. Luigi V. Mancini received the PhD degre in Computer Science from the University of Newcastle upon Tyne, UK, in 1989, and the Laurea degree in Computer Science from the University of Pisa, Italy, in 1983. From 2000, he is a full professor of Computer Science at the Dipartimento di Informatica of the University of Rome “La Sapienza”. Since 1994, he is a visiting research professor of the Center for Secure Information Systems, GMU, Virginia, USA. Currently he is the advisor of six Ph.D students. His current research interests include: computer network and information security, wireless network security, fault-tolerant distributed systems, large-scale peer-to-peer systems, and hard-real-time distributed systems. He published more than 60 scientific papers in international conferences and journals such as: ACM TISSEC, IEEE TKDE, IEEE TPDS, and IEEE TSE. He served in the program committees of several international conferences which include: ACM Conference on Computer and Communication Security, ACM Conference on Conceptual Modeling, ACM Symposium on Access Control Models and Technology, ACM Workshop of Security of Ad-hoc and Sensor Networks, IEEE Securecomm, IEEE Conference on Cluster Computing. He is also the program chair of the first two editions of the IEEE Workshop on Hot Topics in Peer-to-Peer Systems held in 2004 (Volendam, Holand) and in 2005 (San Diego, California). Currently, he is a member of the Scientific Board of the Italian Communication Police force, and the director of the Master degree program in Computer and Network Security of the University of Rome “La Sapienza”, Italy. Alessandro Mei received the Laurea degree in computer science from the University of Pisa, Italy, in 1994, and the PhD degree in mathematics from the University of Trento, Italy, in 1999. In 1998, he was at the Department of EE-Systems of the University of Southern California, Los Angeles, as a visiting scholar for one year. After holding a postdoctoral position at the University of Trento, in 2001 he joined the Faculty of Science of the University of Rome "La Sapienza", Italy, as an assistant professor of computer science. His main research interests include security of distributed systems and networks, algorithms for parallel, distributed, and optical systems and reconfigurable computing. He was presented with the Best Paper Award of the 16th IEEE International Parallel and Distributed Processing Symposium in 2002, the EE-Systems Outstanding Research Paper Award of the University of Southern California for 2000, and the Outstanding Paper Award of the Fifth IEEE/ACM International Conference on High Performance Computing in 1998. He is a member of the ACM and the IEEE and, from 2005, he is an Associate Editor of IEEE Transactions on Computers.     

An Integrated Medium Access Control and Traffic Management Architecture for DVB-RCS SkyplexNet Satellite Systems

The growing development of standard Internet services and the emerging exploitation of several broadband multimedia contents disclosing in the last years, significantly promoted scenarios where Satellite Networks can play key roles. Several satellite networks are currently implemented according to the Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) standard, assuming to operate with a transparent satellite and an hub-centric (star) network topology. The present work addresses the SkyplexNet (SKN) system: an advanced Broadband Satellite Network for meshed connectivity developed by Alenia Spazio, within the framework of ESA Artes 3 – Line 1 Program, according to the DVB-RCS standard with duly extensions for the on-Board multiplexing capability of the Skyplex Units currently embarked on HotBird VI and W3A satellites. In this paper an architecture design study aiming at integrating the Medium Access Control (MAC) and Traffic Management (TM) functionality in a DVB-RCS like Network is presented. The envisaged Traffic Management schemes shall enable the SKN System to guarantee an adequate support of various Quality of Service (QoS) requirements and their application according to pre-defined Traffic Profiles established at connection set up phase with the support of physical medium access management functions. The functional architectures studied for the SKN Inter-Working Layer, from Internet protocols to SkyplexNet ones, and the SKN MAC layer have been also analysed on the interoperability level of these layers in order to deploy such functions as SKN connection mapping, packet scheduling and Bandwidth on Demand (BoD) policies. In this paper two different schemes of Traffic Management and MAC are presented reporting a detailed analysis of advantages and drawbacks of both approaches to be taken into account for future SkyplexNet system implementations. Fabrizio Di Cola is a Network and System Engineer of the Telecommunication Mission Unit of Alenia Spazio company (Italy). He received the M.S. degree in Telecommunication Engineering from University of Rome “La Sapienza” in 1998 and he is in Alenia Spazio since 2000. He is currently involved in the design and deployment of the Ground Segment of EuroSkyWay and SkyplexNet satellite systems as responsible for the Satellite User terminals Design and Development. He also contributes to System Engineering in the framework of several ESA and EC projects. From 1999 up to 2000, he worked as Researcher in the University of Bradford (Bradford, UK), Telecommunication Research Centre, within the “Satellite Mobile Group”. His activity focused on several aspects of the Mobility Management within telecommunications network integrating satellite and terrestrial networks. Emiliano Micaloni was born in Rome, Italy, in 1977. He is a Junior Telecommunication System Engineer involved since 2003 in a collaboration between University of Rome “La Sapienza” and the TLC Mission Unit of Alenia Spazio company (Italy). He received his Master Degree in Electronic Engineering from the University of Rome “La Sapienza”, Italy, in 2002, defending a thesis on Connection and Congestion Control for Geostationary Satellite Networks. Currently his area of interest concerns the Medium Access Control in the SkyplexNet Satellite Network, also contributing at the development activities for the SkyplexNet Satellite Terminals. In 2002–03 he collaborated with the “Computer Science and Systems” Department of “La Sapienza“ implementing solutions for Traffic Management and Quality of Service in Satellite Networks. All his activities are carried out in the framework of different ESA and EU IST projects. Luigi Secondiani received his M.S. degree in Telecommunication Engineering from University of Rome “La Sapienza” in 1997. From 1998 to 1999 he received a post-degree grant issued by the “Infocom” Department of the University of Rome “La Sapienza” in the frame of the ACTS 4th framework programme. Since December 1999 he works as a Network Engineer in Alenia Spazio-TLC Mission Unit, and he is currently involved in Alenia's activities on EC, ESA and NATO programmes. His main research interests mainly lie on interworking between Next Generation Satellite Systems (NGSS) and IP networks, with particular emphasis on network architectures, terminal's architectures and routing issues. Giuseppe Tomasicchio is a Senior Telecommunication System Engineer of the TLC Mission Unit of Alenia Spazio company (Italy). He received his degree in 1989 from University of Bari (Italy) in the Artificial Intelligence field. He received a Post-degree Diploma on Technologies of Educational Communication in 1991 and a Post-degree Engineering Specialisation Diploma in Signal Processing in 1994 from University of Bari. Currently he is responsible of the Ground System Design of EuroSkyWay/SkyplexNet satellite systems and of the Network Operations and Service Centres engineering in satellite networks devoted to multimedia applications in the framework of different ESA and EC projects. In 1997–98 he was responsible at CERN (Geneva, Switzerland) of the Data Acquisition System involving the readout, calibration, event display and the networking setup tasks of high energy physics experiments. From 1994 to 1998 he was at INFN (Italian Institute for Nuclear Physics) as researcher. In 1994 he was an IS-specialist in the Italian Government data processing centre and collaborated with the Government Seismic Service for GIS processing. He worked in 1991–92 as a fellow of DIGITAL Corporation for a join research activity at INFN in the field of Image processing and Pattern recognition applied to raw-data images produced from detectors in high energy physics experiments at CERN. He is author of several scientific and engineering papers.     

Tightening the upper bound for the minimum energy broadcasting

In this paper we present a new upper bound on the approximation ratio of the Minimum Spanning Tree heuristic for the basic problem on Ad-Hoc Networks given by the Minimum Energy Broadcast Routing (MEBR). We introduce a new analysis allowing to establish a 6.33-approximation ratio in the 2-dimensional case, thus decreasing the previously known 7.6 upper bound [4], almost closing the gap with the lower bound of 6 [12]. Preliminary results concerning this paper appeared in [9]. Michele Flammini received the degree in Computer Science at the University of L’Aquila in 1990 and the Ph.D. degree in Computer Science at the University of Rome “La Sapienza” in 1995. He is full professor at the Computer Science Department of the University of L’Aquila since March 2005. His research interests include algorithms and computational complexity, game theory, communication problems in interconnection networks and routing. He has authored and co-authored more than 70 papers in his fields of interest published in the most reputed international conferences and journals. Ralf Klasing received the PhD degree from the University of Paderborn in 1995. From 1995 to 1997, he was an Assistant Professor at the University of Kiel. From 1997 to 1998, he was a Research Fellow at the University of Warwick. From 1998 to 2000, he was an Assistant Professor at RWTH Aachen. From 2000 to 2002, he was a Lecturer at King’s College London. In 2002, he joined the CNRS as a permanent researcher. From 2002 to 2005, he was affiliated to the laboratory I3S in Sophia Antipolis. Currently, he is affiliated to the laboratory LaBRI in Bordeaux. He has co-authored a Springer Monograph, a book chapter, and has published more than 40 papers in refereed international periodicals. His research interests include Communication Algorithms in Networks, Approximation Algorithms for Combinatorially Hard Problems, Web Graphs and Web Algorithms, and Optimization Problems in Ad-Hoc Wireless Networks. Alfredo Navarra received the degree in Computer Science at the University of L’Aquila in 2000 and the Ph.D. degree in Computer Science at the University of Rome “La Sapienza” in 2004. From 2003 to 2004, he joined the MASCOTTE project team at the INRIA institute of Sophia Antipolis as PhD student and PostDoc for almost two years. In 2005, he was a temporary researcher at the University of L’Aquila. In 2006, he joined the laboratory LaBRI in Bordeaux as PostDoc. His research interests include, algorithms and computational complexity, communication, modelling as well as analysis and experimentation problems on protocols and routing algorithms for interconnaction networks such as Ad Hoc, Wireless, Mobile and Sensor Networks. He has authored and co-authored more than 25 papers in his fields of interest published in the most reputed international conferences and journals. Stéphane Pérennes is a permanent researcher of the French Centre National de la Recherche Scientifique (CNRS). He is affiliated to the MASCOTTE project team at the Institut National de Recherche en Informatique et Automatique (INRIA) of Sophia Antipolis. He has authored and co-authored more than 70 papers in his fields of interest that vary from pure theoretical to applied issues on algorithms and complexity, networking and routing.     

Introducing consciousness in UWB networks by hybrid modelling of admission control

We formalize a model for a self-organizing network of nodes that operate according to the UWB principle based on hybrid modelling formalism. We design the rules that lead to the formation of the network and in particular an admission control procedure that is capable to handle both continuous and discrete perturbations, while maintaining the network in a condition of stability. Cognition is introduced in the model by allowing nodes to adjust their rules of operation based on the perception of the environment by an elected node, serving as the observer, that is aware of context, evaluates, and selects one strategy of operation. Maria-Gabriella Di Benedetto obtained her Ph.D. in Telecommunications in 1987 from the University of Rome La Sapienza, Italy. In 1991, she joined the Faculty of Engineering of University of Rome La Sapienza, where currently she is a Full Professor of Telecommunications at the Infocom Department. She has held visiting positions at the Massachusetts Institute of Technology, the University of California, Berkeley, and the University of Paris XI, France. In 1994, she received the Mac Kay Professorship award from the University of California, Berkeley. Her research interests include wireless communication systems and speech science. From 1995 to 2000, she directed four European projects for the design of UMTS. Since 2000, she has been active in fostering the development of Ultra Wide Band (UWB) radio communications in Europe. Within the 5th framework, she directed for the Infocom Dept. two European projects (whyless.com and UCAN) aimed at the design and implementation of UWB ad-hoc networks. Currently, within the 6th EU Framework, her “Networking with UWB” research group participates in the PULSERS Integrated Project which will integrate UWB research and development in Europe for the next years, and in the LIAISON Integrated Project as regards the application of UWB to location-based services. She also participates in the HYCON network of excellence. Dr. Di Benedetto has co-edited several Special Issues on UWB communications and networks for several Journals including IEEE JSAC, Journal of Communications and Networks, Mobile Networks and Applications, Eurasip. In 2004, Dr. Di Benedetto co-authored with G. Giancola the first published book on UWB for communications titled “Understanding Ultra Wide Band Radio Fundamentals” and published by Prentice Hall. She recently completed the co-edition of two new books on UWB that will be published by 2005: UWB Communication Systems—A comprehensive overview, with T. Kaiser, D. Porcino, A. Molisch, and I. Oppermann, Hindawi Publishing Corporation, 2005, and Ultra Wideband Wireless Communications with H. Arslan and Z.N. Chen, John Wiley & Sons, Inc., 2005. Maria Domenica Di Benedetto obtained the “Dr. Ing.” degree (summa cum laude) of Electrical Engineering and Computer Science, University of Roma “La Sapienza” in 1976 (Mosè Ascoli Best Student Award). In 1981, she obtained the degree “Docteur-Ingénieur” and in 1987 the degree “Doctorat d’Etat ès Sciences”, Université de Paris-Sud, Orsay, France. From 1979 to 1983, she had been Research Engineer at the scientific centers of IBM in Paris and Rome. From 1983 to 1987, she had been Assistant Professor at the University of Roma “La Sapienza”. From 1987 to 1990, she had been Associate Professor at the Istituto Universitario Navale of Naples. From 1990 to 1993, had been Associate Professor at the University of Roma “La Sapienza”. Since 1994, she has been Professor of Control Theory at University of L’Aquila. From 1995 to 2002, she was Adjunct Professor, Department of EECS, University of California at Berkeley. In 1987, she was Visiting Scientist at MIT; in 1988, 1989 and 1992, Visiting Professor at the University of Michigan, Ann Arbor; in 1992, Chercheur Associé, C.N.R.S., Poste Rouge, Ecole Nationale Supérieure de Mécanique, Nantes, France; in 1990, 1992, 1994 and 1995, McKay Professor at the University of California at Berkeley. Her research interests revolve around nonlinear control and hybrid systems. She was Associate Editor of the IEEE Transactions of Automatic Control and has been Subject Editor of the International Journal of Robust and Nonlinear Control since 1995. Since 2005, she has been a member of the IFAC Technical Committee on Discrete Event and Hybrid Systems. Since 2000, she has been the Director of the Center of Excellence for Research DEWS on “Architectures and Design methodologies for Embedded controllers, Wireless interconnect and System-on-chip”, University of L’Aquila. She is IEEE Fellow and Chairperson of the Standing Committee on Fellow Nominations, IEEE Control Systems Society. Guerino Giancola received the “Laurea” degree (magna cum laude) in Telecommunications Engineering, and the Ph.D. degree in Information and Communication Engineering from University of Rome La Sapienza, in 2001 and 2005, respectively. He is currently a research affiliate at the INFOCOM Department at University of Rome La Sapienza, where is actually holding the course of “Electrical Communications” for the degree on Electronic Engineering. His research interests include the analysis and modelling of Multi User Interference in Impulse Radio systems, and the design of Medium Access Control functions and protocols for UWB ad-hoc networks. Guerino Giancola recently co-authored with Prof. Maria-Gabriella Di Benedetto a book on Ultra Wide Band from radio to the network, titled “Understanding Ultra Wide Band Radio Fundamentals” and published by Prentice Hall in June 2004. He is now involved in the European project “PULSERS—Pervasive Ultra wideband Low Spectral Energy Radio Systems” and in the European Network of Excellence “HYCON—Hybrid Control: Taming Heterogeneity and Complexity of Networked Embedded Systems”. Guerino Giancola is a member of the IEEE Communication Society.     

Input-Matching and Offset-Cancelling Networks for Limiting Amplifiers in Optical Communication Systems

The diffusion of optical communication systems in the access network and for short-haul datacom applications requires the use of low-cost plastic packages: the functional block most affected is the limiting amplifier, that is often the first stage of the Clock and Data Recovery (CDR) IC. In this paper we illustrate the design issues of the input-matching and offset-cancelling network for a differential limiting amplifier for optical communication systems, with particular emphasis on the effect of bond wires. We discuss the limitations of passive feedback networks when used both for offset suppression and for input matching, and propose a topology that overcomes such limitations by using an active feedback loop. A 50 Ω-loaded differential pair is used to achieve input matching and high offset suppression, and its buffering action desensitizes the input matching from the effect of the bond wires connecting off-chip filtering capacitors. Very good performance even with low cost plastic packages can be achieved by solving the trade-off between power consumption, offset suppression and the value of the low-pass filtering capacitors. Design examples of CDR IC's for 2.5 Gb/s optical systems are presented to compare the proposed topology with solutions based on passive feedback networks. Marco Balsi received the laurea (M.Sc.) degree in 1991 and the dottorato di ricerca (Ph.D.) in 1995 in Electronic Engineering from University of Roma “La Sapienza”, Roma, Italy. Since 1996 he is with “La Sapienza” University as ricercatore (assistant professor). He is engaged in research in nonlinear and soft-computing-based signal processing (especially for biomedical imaging), artificial vision, mechatronics, and anti-personnel mine detection. He has published about 60 paper in international journals and refereed conferences. Francesco Centurelli received the laurea degree (cum laude) and the Ph.D. degree in electronic engineering from the University of Roma “La Sapienza”, Roma, Italy, in 1995 and 2000, respectively. He is currently doing postdoctoral work with the Electronic Engineering Department of the University of Roma “La Sapienza.” His research interests include system-level analysis and design of clock recovery circuits and high-speed analog integrated circuits, with particular emphasis on gigabit-rate optical communication systems. Andrea Pallotta received the M.S. degree in electronic engineering from the University of Ancona, Ancona, Italy. From 1991 to 1999, he was with Italtel, Italy, where he joined several European Community research projects in the field of SDH and WDM fiber-optic transmission systems for both transport and access networks. From 1999 to 2000, he was with Siemens Information and Communication Networks, where he was responsible for the SDH Cross-Connect advanced development group. In September 2000, he joined the STMicroelectronics Company, where he is currently responsible for the electrooptical interface design group. His research interests include GaAs and silicon high-speed ICs, active optical devices, high-speed TX and RX optical modules, and fiber-optic transmission system engineering. Alessandro Trifiletti was born in Roma, Italy, in 1959. In 1991, he joined the Electronic Engineering Department of the University of Roma “La Sapienza” as a Research Assistant and is currently an Assistant Professor. His research interests include high-speed circuit design techniques and III-V device modeling.     

The ultra-wide bandwidth outdoor channel: From measurement campaign to statistical modelling

This paper proposes an investigation of the propagation behaviour for Ultra-Wide Bandwidth (UWB) signals in outdoor environments. Specifically, we first report on the results of an extensive measurement campaign carried out in three selected scenarios, namely “forest”, “hilly” and “sub-urban” environments. Then, we present the statistical model derived through the post-processing of collected samples by the CLEAN algorithm. While an extensive collection of results is provided in the paper, the main achievements can be summarized as follows: (i) the path-loss exponent varies from 2 to 3.5 and depends on the reference scenario and on the height of transmission and reception equipments with respect to the ground floor, (ii) the local mean of the received power experiences a Log-Normal shadowing with a standard deviation that may depend on the azimuth position, (iii) the statistics of the first received echo in the small-scale analysis also well fit a Log-Normal distribution; (iv) the delay spread in the small-scale multipath scenario turns out to be quite small (i.e. roughly 10 ns in the forest scenario and less than 32 ns in the sub-urban scenario). Marco Di Renzo (S’05) received the laurea degree (cum laude) in Electronic Engineering from the University of L’Aquila, Italy, in 2003. In 2002 he was with the Center of Excellence in Research DEWS (Design Methodologies for Embedded Controllers, Wireless Interconnections and System–on-Chip) at the Department of Electrical Engineering, University of L’Aquila, doing research on the analysis and design of Ultra Wide Band digital receiver architectures. Since 2003 he has been with the Department of Electrical Engineering, University of L’Aquila, where he worked on channel sounding and modelling for Ultra Wide Band systems and where he is currently pursuing his Ph.D. degree in Electric and Information Engineering. His current research activity is focused on channel modelling, synchronization and detection theory with specific interest to the Ultra Wide Band technology. In 2004 he played a key role in the successful creation of WEST Aquila S.r.l. (Wireless Embedded Systems Technologies Aquila), a R&D Spin-Off of the University of L’Aquila and the Center of Excellence in Research DEWS, where he currently holds the position of research engineer. Fabio Graziosi (S’96–M’97) was born in L’Aquila, Italy, in 1968. He received the Laurea degree (cum laude) and Ph.D. degree in electronic engineering from the University of L’Aquila, L’Aquila, Italy, in 1993 and 1997, respectively. Since February 1997 he has been with the Department of Electrical Engineering, at the University of L’Aquila, where he currently holds the position of Associate Professor. His current research interests are mainly focused on wireless communication systems with emphasis on wireless sensor networks and ultra wide band communication techniques. He is involved in major national and European research projects in the field of wireless systems. He is member of the Executive Committee of the Center of Excellence DEWS and serves as Chairman of the Board of Directors of WEST Aquila S.r.l., a Spin-off R&D Company of the University of L’Aquila and Center of Excellence DEWS, founded in December 2004. Riccardo Minutolo works in Thales Italia in the R&D department. He graduated in Electronic Engineering in the University of L’Aquila, in 1999. He joined Thomson-csf in 1999 working as junior engineer in the Radio propagation, interference and software development. In that period he gained expertise in HF, VHF, UHF, SHF radio propagation. In 2002 he joined Thales Italy (ex-Thomson-csf) working in the ad hoc networking area. In 2002 he was the National coordinator of a 3 years European international project (Euclide UWB). The Euclide UWB project aimed to study and research the potentiality of the emerging UWB technology for civil security and military purposes. Since 2002 his major areas of interest are: radio propagation, UWB physical layer, MAC and networking. Mauro Montanari was born in 1950 in Rimini and graduated in Electronic Engineering at Bologna University in 1974. He joined in 1976 Telettra, a national telecommunication company, working since the beginning in Defence R&D activities. His first experience was in the field of advanced automatic antenna matching unit in HF band. Afterwards he mastered, staying for several time periods in TRW—Redondo Beach/California, the technical issue of protecting radio communications through Spread Spectrum communications systems, in view of an important application to a new generation of tactical radio systems in VHF frequency band. On this topic he is co-author, with Prof. S. Pupolin of Padua University, of the book “Spread Spectrum Communications Systems” Collana Scientifica Telettra). From 1991 to 1998 he was responsible of the R&D Department within the Defence Division of Alcatel Italia (formerly Telettra) and in this position he managed several R&D projects: (i) Triservice Digital Network for the Italian MOD, in cooperation with Selenia Communications; (ii) SCRA (Single Channel Radio Access) and network management system for the Italian Army tactical network (SOTRIN) as a partner of Catrin Consortium; (iii) A new generation of radio equipment in HF band for fixed applications; (iv) High speed HF modem, according to several NATO waveforms; (v) HF fixed network for Italia Ministry of Foreign Affairs; (vi) Wide band Interception and jamming systems in HF band. Since 1999, he is responsible, within Thales Italia SpA—Land and Joint Systems Division, of Advanced Studies area with the task of promoting in the company new emerging technologies, specifically in the field of Wireless LAN, Tactical Internet, sensor networks, Ultra Wide Band for military applications and plasma antennas. This role includes establishing relations with most Thales R&D centres located in Europe and promoting new cooperative activities in new advanced technological areas. He also manages scientific relation with several Italian Universities. Fortunato Santucci (S’93–M’95–SM’00) was born at L’Aquila, Italy, in 1964. He received the laurea degree and the Ph.D. degree in Electronic Engineering from the University of L’Aquila, Italy, in 1989 and 1994, respectively. In 1989 he was with Selenia Spazio S.p.a., Rome, working on VSAT networks design. In 1991–1992 he was at the Solid State Electronics Institute (I.E.S.S.) of the National Research Council (C.N.R.), Rome, doing research on superconductor receivers for millimeter wave satellite systems. Since 1994 he has been with the Department of Electrical Engineering, University of L’Aquila, where he currently holds the position of Associate Professor. In 1996 he was a visiting researcher at the Department of Electrical and Computer Engineering of the University of Victoria, BC, Canada, where he researched on CDMA networks. His current research activity is focused on communication theory, access control and radio resource management in wireless systems, with special emphasis on technologies for networked embedded systems. He has participated in major national and European research programs in wireless mobile communications and coordinates research programs funded by industrial partners. He has been a reviewer for major technical journal in telecommunications and a session chairman in various conferences. He currently serves as an Editor for the IEEE Transactions on Communications and Kluwer Telecommunications Systems. He has been/is in the TPC of several conferences in communications. He is a Senior Member of the IEEE and is a member of the Communications Theory Committee. He is in the Executive Committee of the Center of Excellence DEWS at the University of L’Aquila and in the Executive Committee of CNIT.     

A Comparative Evaluation of Designs for Reliable Memory Systems

This paper addresses the design of storage systems for operation under critical environmental conditions. For these applications, these systems should have low latency time in access, high performance in throughput and high storage capabilities; therefore, they must be assembled using highly reliable components, while allowing flexibility in design. Commercial Off The Shelf (COTS) components have often been used. A COTS-based architecture is analyzed in this paper; the proposed architecture uses design-level techniques (such as error detection/correction codes and scrubbing) to make commercially available Dynamic Random Access Memory (DRAM) chips tolerant to faults. This paper provides a complete and novel analysis of engineering alternatives which arise in the design of a highly reliable memory system based on Reed Solomon coding. A comparative analysis of methods for permanent fault detection is provided; moreover using a Markovian characterization, different functional arrangements (based on code and scrubbing frequency) are investigated and evaluated.Gian Carlo Cardarilli received the Laurea (summa cum laude) in 1981 from the University of Rome La Sapienza. He works for the University of Rome Tor Vergata since 1984. At present he is full professor of Digital Electronics and Electronics for Communication Systems at the University of Rome Tor Vergata. During the years 1992–1994 he worked for the University of L Aquila. During the years 1987/1988 he worked for the Circuits and Systems team at EPFL of Lausanne (Switzerland). Professor Cardarilli interests is in the area of VLSI architectures for Signal Processing and IC design. In this field he published over 140 papers in international journals and conferences. He also participated to the work group of JESSI-SMI for the support to the medium and small industries. For this structure he consulted different SMIs, designing a number ASICs, in order to introduce the microelectronics technology in the industry’s products. He has also regular cooperation with companies like Alenia Aerospazio, Rome, Italy, STM, Agrate Brianza, Italy, Micron, Avezzano, Italy, Ericsson Lab, Rome, Italy and with a lot of SMEs. Scientific interests of Professor Cardarilli concern the design of special architectures for signal processing. In particular, he works in the field of computer arithmetic and its application to the design of fast signal digital processor. He also developed mixed-signal neural network architectures implementing them in silicon technology. Recently, he also proposed different new solutions for the implementation of fault-tolerant architectures.Fabrizio Lombardi graduated in 1977 from the University of Essex (UK) with a B.Sc. (Hons.) in Electronic Engineering. In 1977 he joined the Microwave Research Unit at University College London, where he received the Master in Microwaves and Modern Optics (1978), the Diploma in Microwave Engineering (1978) and the Ph.D. from the University of London in 1982.He is currently the holder of the International Test Conference (ITC) Endowed Professorship at Northeastern University, Boston. At the same Institution during the period 1998–2004 he served as Chair of the Department of Electrical and Computer Engineering. Prior to Northeastern University he was a faculty member at Texas Tech University, the University of Colorado-Boulder and Texas A&M University.Dr. Lombardi has received many professional awards: the Visiting Fellowship at the British Columbia Advanced System Institute, University of Victoria, Canada (1988), twice the Texas Experimental Engineering Station Research Fellowship (1991–1992, 1997–1998) the Halliburton Professorship (1995), the Outstanding Engineering Research award at Northeastern University (2004) and an International Research award from the Ministry of Science and Education of Japan (1993–1999). Dr. Lombardi was the recipient of the 1985/86 Research Initiation award from the IEEE/Engineering Foundation and a Silver Quill award from Motorola-Austin (1996).Dr. Lombardi was an Associate Editor (1996–2000) of IEEE Transactions on Computers and a Distinguished Visitor of the IEEE-CS (1990–1993 and 2001–2004). Since 2000, he has been the Associate Editor-In-Chief of IEEE Transactions on Computers and an Associate Editor of the IEEE Design and Test Magazine. Since 2004 he serves as the Chair of the Committee on “Nanotechnology Devices and Systems” of the Test Technology Technical Council of the IEEE.Dr. Lombardi has been involved in organizing many international symposia, conferences and workshops sponsored by professional organizations as well as guest editor of Special Issues in archival journals and magazines such as the IEEE Transactions on Computers, IEEE Transactions on Instrumentation and Measurement, the IEEE Micro Magazine and the IEEE Design & Test Magazine. He is the Founding General Chair of the IEEE Symposium on Network Computing and Applications.His research interests are testing and design of digital systems, quantum and nano computing, ATE systems, configurable/network computing, defect tolerance and CAD VLSI. He has extensively published in these areas and edited six books.Marco Ottavi is currently postdoctoral research associate at the ECE Department of Northeastern University in Boston. He received the Laurea degree in Electronic Engineering from University of Rome “La Sapienza” in 1999 and the Ph.D. in Microelectronics and Telecommunications from University of Rome “Tor Vergata” in 2004. In 2000 he was with ULISSE Consortium, Rome as designer of digital systems for space applications. In 2003 he was visiting research assistant at ECE Department of Northeastern University. His research interests include yield and reliability modeling, fault-tolerant architectures, on-line testing and design of nano scale circuits and systems.Salvatore Pontarelli is currently postdoctoral research associate at the University of Rome, Tor Vergata. He received the Laurea degree in Electronic Engineering from the University of Bologna in 1999 and the Ph.D. in Microelectronics and Telecommunications Engineering from the University of Rome Tor Vergata in 2003. His research mainly focuses on fault tolerance, on-line testing and reconfigurable digital architectures.Adelio Salsano was born in Rome on December 26, 1941 and is currently full professor of Microelectronics at the University of Rome, Tor Vergata where he teaches the courses of Microelectronics and Electronic Programmable Systems. His present research work focuses on the techniques for the design of VLSI circuits, considering both the CAD problems and the architectures for ASIC design. In particular, of relevant interest are the research activities on fault tolerant/fail safe systems for critical environments as space, automotive etc.; on low power systems considering the circuit and architectural points of view; and on fuzzy and neural systems for pattern recognition. An international patent and more than 90 papers on international journals or presented in international meetings are the results of his research activity. At present he is the President of a national consortium named U.L.I.S.S.E., between ten universities, three polytechnics and several of the biggest national industries, as STMicroelectronics, ESAOTE, FINMECCANICA. He is responsible for contracts with the ASI, Italian Space Agency, for the evaluation and use in space environment of COTS circuits and for the definition of new suitable architectures for space applications. Professor Salsano is also involved in professional activities in the field of information technology and is also consultant of many public authorities for specific problems. In particular, he is consultant of the Departments of the Research and of the Industry, of IMI and of other authorities for the evaluation of industrial public and private research projects. Professor Salsano was a member of the consulting Committee for Engineering Sciences of the CNR (National Research Council) from 1981 to 1994 and participated in the design of public research programs in the fields of Telematics, Telemedicine, Office Automation, Telecommunication and, recently, Microelectronics and Bioelectronics.     

Audio Fingerprinting: Nearest Neighbor Search in High Dimensional Binary Spaces

Audio fingerprinting is an emerging research field in which a song must be recognized by matching an extracted “fingerprint” to a database of known fingerprints. Audio fingerprinting must solve the two key problems of representation and search. In this paper, we are given an 8192-bit binary representation of each five second interval of a song and therefore focus our attention on the problem of high-dimensional nearest neighbor search. High dimensional nearest neighbor search is known to suffer from the curse of dimensionality, i.e. as the dimension increases, the computational or memory costs increase exponentially. However, recently, there has been significant work on efficient, approximate, search algorithms. We build on this work and describe preliminary results of a probabilistic search algorithm. We describe the data structures and search algorithm used and then present experimental results for a database of 1,000 songs containing 12,217,111 fingerprints. Ingemar J. Cox is currently Professor and Chair of Telecommunications in the Departments of Electronic Engineering and Computer Science at University College London and Director of UCL's Adastral Park Postgraduate Campus. He is currently a holder of a Royal Society Wolfson Fellowship. He received his B.Sc. from University College London and Ph.D. from Oxford University. He was a member of the Technical Staff at AT&T Bell Labs at Murray Hill from 1984 until 1989 where his research interests were focused on mobile robots. In 1989 he joined NEC Research Institute in Princeton, NJ as a senior research scientist in the computer science division. At NEC, his research shifted to problems in computer vision and he was responsible for creating the computer vision group at NECI. He has worked on problems to do with stereo and motion correspondence and multimedia issues of image database retrieval and watermarking. In 1999, he was awarded the IEEE Signal Processing Society Best Paper Award (Image and Multidimensional Signal Processing Area) for a paper he co-authored on watermarking. From 1997–1999, he served as Chief Technical Officer of Signafy, Inc, a subsiduary of NEC responsible for the commercialization of watermarking. Between 1996 and 1999, he led the design of NEC's watermarking proposal for DVD video disks and later colloborated with IBM in developing the technology behind the joint “Galaxy” proposal supported by Hitachi, IBM, NEC, Pioneer and Sony. In 1999, he returned to NEC Research Institute as a Research Fellow. He is a senior member of the IEEE, a Fellow of the IEE and a Fellow of the Royal Society for Arts and Manufactures. He is co-editor in chief of the IEE Proc. on Information Security and an associate editor of the IEEE Trans. on Information Forensics and Security. He is co-author of a book entitled “Digital Watermarking” and the co-editor of two books, ‘Autonomous Robots Vehicles’ and ‘Partitioning Data Sets: With Applications to Psychology, Computer Vision and Target Tracking’. This work was performed while the author was at NEC Research Institute, Princeton. ? [2002] IEEE, Reprinted, with permission, from Miller, M.L.; Rodriguez, M.A.; Cox, I.J.; Multimedia Signal Processing, 2002 IEEE Workshop on, 2002 Page(s): 182–185.     

Controlled sink mobility for prolonging wireless sensor networks lifetime

This paper demonstrates the advantages of using controlled mobility in wireless sensor networks (WSNs) for increasing their lifetime, i.e., the period of time the network is able to provide its intended functionalities. More specifically, for WSNs that comprise a large number of statically placed sensor nodes transmitting data to a collection point (the sink), we show that by controlling the sink movements we can obtain remarkable lifetime improvements. In order to determine sink movements, we first define a Mixed Integer Linear Programming (MILP) analytical model whose solution determines those sink routes that maximize network lifetime. Our contribution expands further by defining the first heuristics for controlled sink movements that are fully distributed and localized. Our Greedy Maximum Residual Energy (GMRE) heuristic moves the sink from its current location to a new site as if drawn toward the area where nodes have the highest residual energy. We also introduce a simple distributed mobility scheme (Random Movement or RM) according to which the sink moves uncontrolled and randomly throughout the network. The different mobility schemes are compared through extensive ns2-based simulations in networks with different nodes deployment, data routing protocols, and constraints on the sink movements. In all considered scenarios, we observe that moving the sink always increases network lifetime. In particular, our experiments show that controlling the mobility of the sink leads to remarkable improvements, which are as high as sixfold compared to having the sink statically (and optimally) placed, and as high as twofold compared to uncontrolled mobility. Stefano Basagni holds a Ph.D. in electrical engineering from the University of Texas at Dallas (December 2001) and a Ph.D. in computer science from the University of Milano, Italy (May 1998). He received his B.Sc. degree in computer science from the University of Pisa, Italy, in 1991. Since Winter 2002 he is on faculty at the Department of Electrical and Computer Engineering at Northeastern University, in Boston, MA. From August 2000 to January 2002 he was professor of computer science at the Department of Computer Science of the Erik Jonsson School of Engineering and Computer Science, The University of Texas at Dallas. Dr. Basagni’s current research interests concern research and implementation aspects of mobile networks and wireless communications systems, Bluetooth and sensor networking, definition and performance evaluation of network protocols and theoretical and practical aspects of distributed algorithms. Dr. Basagni has published over four dozens of referred technical papers and book chapters. He is also co-editor of two books. Dr. Basagni served as a guest editor of the special issue of the Journal on Special Topics in Mobile Networking and Applications (MONET) on Multipoint Communication in Wireless Mobile Networks, of the special issue on mobile ad hoc networks of the Wiley’s Interscience’s Wireless Communications & Mobile Networks journal, and of the Elsevier’s journal Algorithmica on algorithmic aspects of mobile computing and communications. Dr. Basagni serves as a member of the editorial board and of the technical program committee of ACM and IEEE journals and international conferences. He is a senior member of the ACM (including the ACM SIGMOBILE), senior member of the IEEE (Computer and Communication societies), and member of ASEE (American Society for Engineering Education). Alessio Carosi received the M.S. degree “summa cum laude” in Computer Science in 2004 from Rome University “La Sapienza.” He is currently a Ph.D. candidate in Computer Science at Rome University “La Sapienza.” His research interests include protocols for ad hoc and sensor networks, underwater systems and delay tolerant networking. Emanuel Melachrinoudis received the Ph.D. degree in industrial engineering and operations research from the University of Massachusetts, Amherst, MA. He is currently the Director of Industrial Engineering and Associate Chairman of the Department of Mechanical and Industrial Engineering at Northeastern University, Boston, MA. His research interests are in the areas of network optimization and multiple criteria optimization with applications to telecommunication networks, distribution networks, location and routing. He is a member of the Editorial Board of the International Journal of Operational Research. He has published in journals such as Management Science, Transportation Science, Networks, European Journal of Operational Research, Naval Research Logistics and IIE Transactions. Chiara Petrioli received the Laurea degree “summa cum laude” in computer science in 1993, and the Ph.D. degree in computer engineering in 1998, both from Rome University “La Sapienza,” Italy. She is currently Associate Professor with the Computer Science Department at Rome University “La Sapienza.” Her current work focuses on ad hoc and sensor networks, Delay Tolerant Networks, Personal Area Networks, Energy-conserving protocols, QoS in IP networks and Content Delivery Networks where she contributed around sixty papers published in prominent international journals and conferences. Prior to Rome University she was research associate at Politecnico di Milano and was working with the Italian Space agency (ASI) and Alenia Spazio. Dr. Petrioli was guest editor of the special issue on “Energy-conserving protocols in wireless Networks” of the ACM/Kluwer Journal on Special Topics in Mobile Networking and Applications (ACM MONET) and is associate editor of IEEE Transactions on Vehicular Technology, the ACM/Kluwer Wireless Networks journal, the Wiley InterScience Wireless Communications & Mobile Computing journal and the Elsevier Ad Hoc Networks journal. She has served in the organizing committee and technical program committee of several leading conferences in the area of networking and mobile computing including ACM Mobicom, ACM Mobihoc, IEEE ICC,IEEE Globecom. She is member of the steering committee of ACM Sensys and of the international conference on Mobile and Ubiquitous Systems: Networking and Services (Mobiquitous) and serves as member of the ACM SIGMOBILE executive committee. Dr. Petrioli was a Fulbright scholar. She is a senior member of IEEE and a member of ACM. Z. Maria Wang received her Bachelor degree in Electrical Engineering with the highest honor from Beijing Institute of Light Industry in China, her M.S. degree in Industrial Engineering/Operations Research from Dalhousie University, Canada and her Ph.D. in Industrial Engineering/Operations Research from Northeastern University, Boston. She served as a R&D Analyst for General Dynamics. Currently MS. Wang serves as an Optimization Analyst with Nomis Solutions, Inc.     

Training Sequence Aided Signature Waveform Estimation

In code division multiple access channels multiuser detection techniques are known to be effective strategies to counter the presence of multiuser interference towards improving spectral efficiency. Generally, multiuser detectors can provide excellent performance only when the signature waveforms of all users are precisely known. Hence, the estimation of signature waveforms is a challenging issue in mobile communication systems. In this paper, we compare the performance of two short training sequence aided signature waveform estimators. One is maximum likelihood type signature waveform estimator that requires the knowledge of spreading sequences and short training sequences. The other estimator is recently proposed based on subspace method and requires the knowledge of training sequences only. Through the simulations, we show the signature waveform estimation performance of both systems and the effect of the estimation error on the performance of a multiuser detector. The complexity comparisons of both systems are also given. We use the term “signature waveform” to refer to the convolution of the channel and the spreading code throughout the paper. Hasan AMCA was born in 1961 in Nicosia-Cyprus. He graduated from the Higher Technological Institute in Magosa – Cyprus (which is renamed later as Eastern Mediterranean University). He joined EMU in 1985 after receiving a M.Sc. (Digital Signal Processing) degree from the University of Essex in England (1985). He took his Ph.D. (Mobile Communications) from the University of Bradford where he was on a Commonwealth scholarship. He has been teaching in the Electrical and Electronic Engineering Department of Eastern Mediterranean University since 1993 where he also served as the Vice Chairman from Spring 1998 to Spring 2000. He has been appointed as the Director of the School of Computing and Technology of the EMU since Spring 2000. His research interests include Multi User Detection of CDMA signals, Adaptive Equalisation, Multi Carrier Systems, Mobile Radio Systems and Networks, Internet and Information Technology Applications in Education. Ahmet Rizaner was born in Larnaca, Cyprus, on January 31, 1974. He received the B.S. and M.S. degrees in Electrical and Electronics Engineering from the Eastern Mediterranean University, Famagusta, North Cyprus, in 1996 and 1998, respectively. He completed his PhD. degree in Electrical and Electronic Engineering in Eastern Mediterranean University and joined Eastern Mediterranean University as a lecturer in 2004. He is lecturing in the School of Computing and Technology. His main research interests include CDMA communications, adaptive channel estimation, and multiuser detection technique. Kadri Hacioğlu was born in Nicosia, Cyprus. He received the B.Sc., M.Sc., and Ph.D. degrees in electrical and electronic engineering from the Middle East Technical University, Ankara, Turkey, in 1980, 1984, and 1990, respectively. After his two-year military service, in 1992, he joined the faculty of Eastern Mediterranean University, Magosa, North Cyprus, as an Assistant Professor, and became an Associate Professor in 1997. While there, he taught several classes on electronics, digital communications, speech processing and neural networks. During this time, he conducted research on applying fuzzy logic, neural networks, and genetic algorithms to signal processing and communications problems. From 1998 to 2000, he was a Visiting Professor in the Department of Computer Science, University of Colorado, Boulder. Here, he taught classes on neural networks and continued his research. Since 2000, he has been a Research Associate at the Center for Spoken Language Research, University of Colorado. He has authored or coauthored numerous papers and supervised a dozen M.Sc./Ph.D. theses. His current research interests are concept-based language modeling, speech understanding, natural language generation, and search methods in speech recognition/understanding. He also does research on multiuser detection and equalization in CDMA systems. Ali Hakan Ulusoy was born in Eskişehir, Turkey, on June 3, 1974. He graduated from the double major program of the department of Electrical and Electronic Engineering and department of Physics in Eastern Mediterranean University as the first rank student of Faculty of Engineering in 1996. He received his M.S. degree in Electrical and Electronic Engineering in Eastern Mediterranean University in 1998. He completed his Ph.D. degree in Electrical and Electronic Engineering in Eastern Mediterranean University and joined Eastern Mediterranean University as a lecturer in 2004. He is lecturing in the School of Computing and Technology. His current research interests include receiver design, multi-user detection techniques, blind and trained channel estimation in Code Division Multiple Access (CDMA).     

On Nash equilibria for multicast transmissions in ad-hoc wireless networks

We study a multicast game in ad-hoc wireless networks in which a source sends the same message or service to a set of receiving stations via multi-hop communications and the overall transmission cost is divided among the receivers according to given cost sharing methods. We assume that each receiver gets a certain utility from the transmission and enjoys a benefit equal to the difference between his utility and the shared cost he is asked to pay. Assuming a selfish and rational behavior, each user is willing to receive the transmission if and only if his shared cost does not exceed his utility. Moreover, given the strategies of the other users, he wants to select a strategy of minimum shared cost. A Nash equilibrium is a solution in which no user can increase his benefit by choosing to adopt a different strategy. We consider the following reasonable cost sharing methods: egalitarian, semi-egalitarian next-hop-proportional, path-proportional, egalitarian-path-proportional and Shapley value. We prove that, while the first five cost sharing methods in general do not admit a Nash equilibrium, the Shapley value yields games always converging to a Nash equilibrium. We then turn our attention to the special case in which the receivers’ set R is part of the input (that is only the stations belonging to R have a positive utility which is set equal to infinity) and show that in such a case also the egalitarian and the egalitarian-path-proportional methods yield convergent games. In such a framework, we show that the price of anarchy is unbounded for the game yielded by the egalitarian method and provide matching upper and lower bounds for the price of anarchy of the other two convergent games with respect to two different global cost functions, that is the overall cost of the power assignment, that coincides with the sum of all the shared costs, and the maximum shared cost paid by the receivers. Finally, in all cases we show that finding the best Nash equilibrium is computationally intractable, that is NP-hard. Vittorio Bilò received the degree in Computer Science and the Ph.D. degree in Computer Science at the University of L’Aquila in 2001 and 2005 respectively. He is currently an assistant professor at the Department of Mathematics “Ennio De Giorgi” of the University of Lecce. His research interests include algorithms and computational complexity, communication problems in interconnection networks and game theoretical issues in non-cooperative networks. Michele Flammini received the degree in Computer Science at the University of L’Aquila in 1990 and the Ph.D. degree in Computer Science at the University of Rome “La Sapienza” in 1995. He is full professor at the Computer Science Department of the University of L’Aquila since March 2005. His research interests include algorithms and computational complexity, game theory, communication problems in interconnection networks and routing. He has authored and co-authored more than 70 papers in his fields of interest published in the most reputed international conferences and journals. Giovanna Melideo received the Laurea degree in computer science in 1997 from the University of L’Aquila (Italy) and the Ph.D. degree in computer engineering in 2001 from the University of Rome “La Sapienza”. From November 1999 to February 2000 she was visitor at IRISA/INRIA, University of Rennes 1, Rennes (France) in the ADP group. She was research fellow from June to October 2001 at the University of L’Aquila, where she is currently an assistant professor in the Computer Science Department. Her research interests include algorithms and complexity, algorithmic game theory, wireless networks, models for information integration and cooperative information systems, certification and security in e-service, distributed protocols and dependability. She has been a member of the scientific and organizing committee of the IFIP international workshop on Certification and Security in E-Services (CSES 2002), Montreal, Canada. Luca Moscardelli received the degree in Computer Science at the University of L’Aquila in 2004. He is currently a Ph.D. student in Computer Science at the University of L’Aquila. His current research interests include optimization problems in social and communication networks, and the analysis of the interaction between selfish agents in non-cooperative networks.     

Enhancing Transport Layer Capability in HAPS–Satellite Integrated Architecture

The use of HAPS/UAV to enhance telecommunication capabilities has been proposed as an effective solution to support hot spot communications in limited areas. To ensure communication capabilities even in case of emergency (earthquake, power blackout, chemical/nuclear disaster, terrorist attack), when terrestrial fixed and mobile infrastructures are damaged or become unavailable, the access to satellites represents a reliable solution with worldwide coverage, even though it may suffer from shadowing impairment, especially in an urban environment. In this paper we approach an innovative and more challenging architecture foreseeing HAPS/UAV connected to the satellite in order to enlarge coverage and to allow interconnection with very remote locations. In this scenario, we have analysed TCP-based applications proposing some innovative techniques, both at protocol and at architectural level, to improve performance. In particular, we propose the use of a PEP technique, namely splitting, to speed up window growth in spite of high latency, combined with TCP Westwood as a very efficient algorithm particularly suitable and well performing over satellite links.Cesare Roseti graduated cum laude in 2003 in Electronic Engineering at University of Rome “Tor Vergata”. In 2003 and 2004, he was a visiting student at Computer Science Department of University of California, Los Angeles (UCLA). Since 2004 he is a PhD student at the Electronic Engineering Department and his research interests include satellites communications and transport protocols in heterogeneous (wired/wireless) systems.Claudio Enrico Palazzi studied computer science at University of Bologna, Campus of Cesena. He has been a student representative in several bodies of University of Bologna and, in particular, from 2000 to 2001 he was part of the Board of Governors. In 2001, he received the Sigillum Magnum of Alma Mater Studiorum University of Bologna. He graduated cum laude in 2002 with a thesis on transport protocols in wireless environments. In 2003, he was the first student enrolled in the Interlink joint PhD program in computer science by which he is currently a PhD student in Computer Science at both University of Bologna and University of California, Los Angeles (UCLA). His research interests include protocol design, implementation and performance analysis for wired/wireless networks.Michele Luglio received the Laurea degree in electronic engineering from the University of Rome “Tor Vergata”. He received the PhD degree in telecommunications in 1994. From August to December 1992 he worked as visiting staff engineering at Microwave Technology and Systems Division of Comsat Laboratories (Clarksburg, Maryland, USA). He received the Young Scientist Award from ISSSE’95. Since October 1995, he is research and teaching assistant at University of Rome “Tor Vergata” where he works on designing satellite systems for multimedia services both mobile and fixed, in the frame of projects funded by EC, ESA and ASI. He taught signal theory and collaborated in teaching digital signal processing and elements of telecommunications. In 2001 and 2002 he was visiting professor at the Computer Science Department of University of California Los Angeles (UCLA) to teach Satellite Networks class. Now he teaches satellite telecommunications and signals and transmission. He is a member of IEEE.Mario Gerla received a graduate degree in engineering from the Politecnico di Milano in 1966, and the MS and PhD degrees in engineering from UCLA in 1970 and 1973, respectively. After working for Network Analysis Corporation from 1973 to 1976, he joined the Faculty of the Computer Science Department at UCLA where he is now professor. His research interests cover the performance evaluation, design and control of distributed computer communication systems; high-speed computer networks; wireless LANs; and ad hoc wireless networks. He has worked on the design, implementation and testing of various wireless ad hoc network protocols (channel access, clustering, routing and transport) within the DARPA WAMIS, GloMo projects. Currently, he is leading the ONR MINUTEMAN project at UCLA, and is designing a robust, scalable wireless ad hoc network architecture for unmanned intelligent agents in defense and homeland security scenarios. He is also conducting research on QoS routing, multicasting protocols and TCP transport for the Next-Generation Internet (see www.cs.ucla.edu/NRL for recent publications). He became IEEE Fellow in 2002.M. Yahya “Medy” Sanadidi was born in Damanhour, Egypt. He received his high school diploma from College Saint Marc, and his BSc in electrical engineering (computer and automatic control section) from the University of Alexandria, Egypt. Dr. Sanadidi received his PhD in computer science from UCLA in 1982. He is currently a research professor at the UCLA Computer Science Department. As co-principal investigator on NSF-sponsored research, he is leading research in modeling and evaluation of high-performance Internet protocols. He teaches undergraduate and graduate courses at UCLA on queuing systems and computer networks. Dr. Sanadidi was a manager and senior consulting engineer at Teradata/AT&T/NCR from 1991 to 1999 and led several groups responsible for performance modeling and analysis, operating systems, and parallel query optimization. From 1984 to 1991, he held the position of computer scientist at Citicorp, where he pursued R&D projects in wireless metropolitan area data communications and other networking technologies. In particular, between 1984 and 1987, he lead the design and prototyping of a wireless MAN for home banking and credit card verification applications. From 1981 to 1983, Dr. Sanadidi was an assistant professor at the Computer Science Department, University of Maryland, College Park, Maryland. There, he taught performance modeling, computer architecture and operating systems, and was principal investigator for NSA-sponsored research on global data communications networks. Dr. Sanadidi has consulted for industrial concerns, has co-authored conference as well as journal papers, and holds two patents in performance modeling. He participated as reviewer and as program committee member of professional conferences. His current research interests are focused on congestion control and adaptive multimedia streaming protocols in heterogeneous (wired/wireless) networks.James Stepanek received his BS in computer science from Harvey Mudd College in 1994 and his MS in computer science from University of California, Los Angeles (UCLA) in 2001 where he is currently enrolled in the PhD program. He is also currently a member of the technical staff in the Computer Systems Research Department of The Aerospace Corporation. His research interests include wireless and satellite networks.     

Analysis, testing and optimisation of electrostatic comb-drive levitational actuators

This work presents an analysis of the levitation effect in electrostatic comb fingers and of its possible use for vertical or torsional actuation of micromachined structures. Two different levitational mechanical resonators were designed and fabricated in a thick-polysilicon technology. A study of the dependence of the force intensity on the geometric parameters of the actuators were performed using FEM simulations, and information about critical geometrical parameters in the design of operative levitational actuators were obtained. The devices were characterized and the obtained results were compared with FEM simulations. Antonio Molfese received the M.S. degree cum laude in Electronic Engineering from the University of Pisa, Italy on March 2003. In the summer 2003 he was at IMEC, Belgium for an internship. On November 2003 he received the diploma degree cum laude in Industrial and Information Engineering from Scuola Superiore Sant'Anna di Studi Universitari e Perfezionamento of Pisa, Italy. He is currently pursuing the Ph.D. degree in Information Engineering at University of Pisa and he is working at IEIIT-Sezione di Pisa of Italian National Research Council (CNR) as research assistant. His main research interests include design, modeling and characterization of micro-electro-mechanical systems and microfluidics. Giovanni Pennelli was born on October 23, 1967 in Lucca, Italy. He graduated in 1992, cum laude, in Electronic Engineering. He obtained his Ph.D. in 1997 for a thesis entitled "New Materials for a Silicon-Based Optoelectronics". He moved to the University of Glasgow in April 1997 to work as a Research Assistant in the MBE group concerned with optoelectronic device fabrication and process development. He developed some MBE grown structures for HEMT applications. In September 2000, Dr Pennelli has been appointed assistant professor in the Department of Information Engineering, University of Pisa, Italy, pursuing research in electron beam lithography and nanometer scale process development. Francesco Pieri received the laurea and the Ph.D. degree in Electrical Engineering, both from the University of Pisa, Italy, in 1996 and 2000 respectively. He joined the Department of Information Engineering of the same University as an assistant professor in 2001. His current research interests include applications of porous silicon to sensors and microtechnologies, and development of microelectromechanical systems. Andrea Nannini received his laurea degree in Electronic Engineering from the University of Pisa, Italy, in 1982; He received his Ph.D. degree in 1987 at the end of the first Italian Ph.D. course held by the University of Padova, Italy. From 1988 to 1992 he was a Researcher at the “Scuola Superiore di Studi Universitari e Perfezionamento S. Anna” – Pisa- Italy. Since 1992 he joined the Department of Information Engineering of the University of Pisa as an Associate Professor. Since November 2000 he is a full professor of “Sensor and Microsystem Design”. He is currently chairman of the postgraduate school of Electronic Engineering and vice-chairman of the PhD school of Information Engineering of the University of Pisa. His main research interests concern solid state sensors, microelectronic devices and technologies, MEMS.     

Energy Efficiency of Error Control for High Data Rate WPAN

This paper addresses the issue of energy efficiency for error control mechanisms over WPAN systems. An analytical formulation has been developed to study the trade-off between link layer performance and energy consumption for two types of error control schemes: pure ARQ and type II hybrid ARQ protocol. An MC-CDMA-based system is considered. First of all, the analysis has been used to compare different error recovery schemes from the energy efficiency point of view. Moreover, it has been found that, for any channel conditions, there exists an optimal value of the transmit power that maximizes the energy efficiency. The paper also shows how this result can be used to design the power control of an energy efficient CDMA-based communication system. Mauro De Sanctis received the “Laurea' degree in Telecommunications Engineering from the University of Roma “Tor Vergata' in 2002. He is currently a Ph.D. Student and Assistant Professor in the Department of Electronics Engineering of the same University. He is involved in the DAVID (DAta and Video Interactive Distribution) satellite mission of the ASI (Italian Space Agency); his research is funded by the ASI. He is also involved in the MAGNET (My personal Adaptive Global NET) European FP6 integrated project and in the SatNEx European network of excellence. He worked on Italian national research projects on satellite-terrestrial systems integration such as SHINES (Satellite and HAP Integrated NEtworks and Services) and CABIS (CDMA for Broadband mobile terrestrial-satellite Integrated Systems). On autumn 2004 he joined the CTIF (Center for TeleInFrastructure), a research center focusing on modern telecommunications technologies located at the University of Aalborg (Denmark). His main areas of interest are: integration of different satellite networks, stratospheric platforms and terrestrial networks in a multi-layered fashion, internetworking and resource management in satellite systems and energy efficiency of WPAN systems. Simone Quaglieri received the “Laurea' degree cum laude in Telecommunications Engineering from the University of Roma “Tor Vergata', Italy, in 2004. His thesis, concerning the study of an analytic model for the Raman amplifier in optical systems with high bit rate, has been developed in the same University. During 2002 he worked as stagiaire on the design and development of optical submarine systems at the Elettra company (Telecom Italia group, Italy). He is joining the IRIS (Innovative Radio Integrated Systems) group at the University of Roma “Tor Vergata' as Research Engineer, where he is working on MC-CDMA based technology in the frame of the MAGNET (My Adaptive Global NETwork) European project. He is also working on error recovery mechanisms over satellite systems, and his research is funded by the EC in the frame of the SatNEx (Satellite Network of Excellence) European project. Ernestina Cianca graduated cum laude in Electronics Engineering in 1997 at the University of L'Aquila. She was with Italtel/Siemens (L'Aquila) from 1997 to 1998. She got her Ph.D. degree from the University of Rome Tor Vergata (URTV). The thesis work was on power management in CDMA-based satellite systems. She has been employed by the University of Aalborg, Denmark, in the Wireless Networking Groups (WING), as Research engineer (2000–2001) and as Assistant Professor (2001–2003). In particular, from Sept. 2002 she has been Technical Manager of Aalborg University for the IST-STRIKE project. She is currently Assistant Professor in Telecommunications at the URTV (Dpt. of Electronics Engineering), teaching DSP, Information and Coding. Her research mainly concerns wireless access technologies (CDMA and MIMO-OFDM-based systems), in particular, Radio Resource Management at PHY/MAC layer, ARQ/HARQ, TCP-IP issues over wireless links, integration of terrestrial and satellite systems. She has been the vice-coordinator of the following national research programs: CABIS, on CDMA integrated mobile systems (2000-2002) and SHINES, on satellite-HAP integrated networks for multimedia applications co-financed by MIUR (2002–2004). She is currently working on various European Projects: EU FP6 IP MAGNET (My personal Adaptive Global NET); EU ASIA LINK EAGER-NetWIC (Euro-Asian Network for Strengthening Graduate Education and Research in Wireless Communications); EU Network of excellence NEXWAY. She is author of about 40 papers, on international journals/transactions and proceedings of international conferences. Marina Ruggieri graduated in Electronics Engineering in 1984 at the University of Roma. She was: with FACE-ITT and GTC-ITT (Roanoke, VA) in the High Frequency Division (1985–1986); Research and Teaching Assistant at the University of Roma Tor Vergata (URTV) (1986–1991); Associate Professor in Telecommunications at the University of L'Aquila (1991–1994). Since November 2000 she is Full Professor in Telecommunications at the URTV (Dpt. of Electronics Engineering), teaching DSP, Information and Coding. In 1999 she has been appointed member of the Board of Governors of the IEEE AES Society (2000–2002) and re-elected for the period 2003–2005. Her research mainly concerns space communications and navigation systems (in particular satellites) as well as mobile and multimedia networks. She is the Principal Investigator of: satellite scientific communications missions (DAVID, WAVE) of ASI; national research programs (CABIS) on CDMA integrated mobile systems (2000–2002) and on satellite-HAP integrated networks for multimedia applications (SHINES), co-financed by MIUR (2002–2004). She co-ordinates the URTV Unit in various European Projects: EU FP6 IP MAGNET (My personal Adaptive Global NET); EU ASIA LINK EAGER-NetWIC (Euro-Asian Network for Strengthening Graduate Education and Research in Wireless Communications); EU Network of excellence NEXWAY; GALILEO JU 1st Call – July 2003: VERT (VEhicular Remote Tolling); and in the ASI program on V-band payloads (TRANSPONDERS). She is member of the Editorial Board of Wireless Personal Communications – an International Journal (Kluwer). She was awarded the 1990 Piero Fanti International Prize and she had a nomination for the Harry M. Mimmo Award in 1996 and the Cristoforo Colombo Award in 2002. She is author of about 170 papers, on international journals/transactions and proceedings of international conferences, book chapters and books.     

Pre-equalization Techniques for Downlink and Uplink TDD MC-CDMA Systems

Time division duplex (TDD) multi carrier-code division multiple access (MC-CDMA) systems have recently been proposed as potential candidates for next generation (4G) technology. In order to mitigate multiple access interference, in this paper we investigate pre-equalization schemes for both downlink and uplink transmissions, the former also in a multiple transmit antenna scenario. In particular, new pre-equalizer techniques are introduced and complexity issues addressed. Numerical results are given to highlight the effectiveness of the proposed schemes with respect to other existing pre-equalizer solutions. Paola Bisaglia was born in Padova, Italy, on August 8, 1971. She received the Laurea (cum laude) and Ph.D. degrees in electronic engineering from the University of Padova, Padova, Italy in 1996 and 2000 respectively. In 2000 she joined Hewlett-Packard Research Laboratories, Bristol, England, working on Home Phoneline Networking and wireless LANs. From 2002 she is a research fellow at the Department of Information Engineering of the University of Padova, Italy. Her research interests include wireless local area networks; modulation, coding techniques and detection strategies for next generation (4G) broadband cellular systems, based on the combination of multi-carrier and spread-spectrum modulations. Luca Sanguinetti is a Ph.D. Student of the University of Pisa. He was born in Empoli, Italy, on February 19, 1977, and he received the Doctor Engineer degree (cum laude) in information engineering from the University of Pisa, Italy, in 2002. Since 2002 he was with the Department of Information Engineering of the University of Pisa, where he is working toward the Ph.D. degree in information engineering under the supervision of Prof. Umberto Mengali and Prof. Michele Morelli. In 2004, he was a visiting Ph.D. student at the German Aerospace Center (DLR), Oberpfaffenhofen, Germany. Currently he is involved in a research project dealing with the design and the development of base stations and user terminals for wideband wireless communications systems able to cope with those reconfigurability and interoperability characteristics required by the next generation mobile communication systems. His research interests are in wireless communication theory, with emphasis on synchronization and detection algorithms and channel estimation in multiple-access communication systems. Michele Morelli received the Laurea (cum laude) in electrical engineering and the “Premio di Laurea SIP” from the University of Pisa, Italy, in 1991 and 1992 respectively. From 1992 to 1995 he was with the Department of Information Engineering of the University of Pisa, where he received the Ph.D. degree in electrical engineering. In September 1996 he joined the Centro Studi Metodi e Dispositivi per Radiotrasmissioni (CSMDR) of the Italian National Research Council (CNR) in Pisa where he held the position of Research Assistant. Since 2001 he has been with the Department of Information Engineering of the University of Pisa where he is currently an Associate Professor of Telecommunications. His research interests are in wireless communication theory, with emphasis on synchronization algorithms and channel estimation in multiple-access communication systems. Nevio Benvenuto received the Laurea degree from the University of Padova, Padova, Italy, and the Ph.D. degree from the University of Massachusetts, Amherst, in 1976 and 1983, respectively, both in electrical engineering. From 1983 to 1985 he was with AT&T Bell Laboratories, Holmdel, NJ, working on signal analysis problems. He spent the next three years alternating between the University of Padova, where he worked on communication systems research, and Bell Laboratories, as a Visiting Professor. From 1987 to 1990, he was a member of the faculty at the University of Ancona. He was a member of the faculty at the University of L'Aquila from 1994 to 1995. Currently, he is a Professor in the Electrical Engineering Department, University of Padova. His research interests include voice and data communications, digital radio, and signal processing. Silvano Pupolin received the Laurea degree in Electronic Engineering from the University of Padova, Italy, in 1970. Since then he joined the Department of Information Engineering, University of Padova, where currently is Full Professor of Electrical Communications. He was Chairman of the Faculty of Electronic Engineering from 1990 to 1994, Chairman of the PhD Course in Electronics and Telecommunications Engineering from 1991 to 1997 and Director of the PhD School in Information Engineering from 2004. Also, he was member of the programming and development committee from 1997 to 2002 and member of Scientific Committee from 1996 to 2001 of the University of Padova; member of the budget Committee of the Faculty of Engineering from 2003. He has been actively engaged in research on: Digital communication systems over copper wires and fiber optics; Spread spectrum communication systems; Design of large reliable communications networks; Effects of phase noise and HPA nonlinearities in OFDM systems; 3G mobile radio communications systems (UTRA-FDD and TDD) and beyond 3G (OFDM modulation and MC CDMA); Packet radio, Ad-hoc networks with the use of Bluetooth and WLAN. He was Chairman of the 9-th and 10-th Tyrrhenian International Workshop on Digital Communications devoted to “Broadband Wireless Communications” and to “Multimedia Communications”, respectively, and he was General Chair of the 7th International Symposium on Wireless Personal Multimedia Communications (WPMC'04). He spent the summer 1985 at AT&T Bell Laboratories on leave from Padova, doing research on digital radio systems. He was Principal investigator for research projects entitled “Variable bit rate mobile radio communication systems for multimedia applications”, “OFDM Systems with Applications to WLAN Networks”, and “MC-CDMA: an air interface for the 4th generation of wireless systems”.     

Modeling and characterization of three kinds of MEMS resonators fabricated with a thick polysilicon technology

Three different kinds of two-port flexural resonators, with both clamped and free ends, and with nominal resonance frequencies between 5 MHz and 50 MHz, were designed and fabricated. Among them, a novel free-free third-mode resonator, as well as a tunable free-free resonator, designed to maintain a high quality factor despite its tunability, are presented. Because of reduced energy loss in the clamps, higher quality factors are expected from free-free devices. To estimate the resonators performance, the effect of temperature and axial stresses on the resonators is investigated: for the clamped-clamped resonator, a theoretical model is also presented. FEM simulations are performed for the three geometries and the results are discussed. Dario Paci studied electronic engineering at University of Pisa and at “Scuola Superiore Sant’Anna”. He received his Master Degree in 2003, with a dissertation on MEMS resonators for RF applications. In 2003 he worked at PEL-ETHZ for three months, modelling chemical sensors. In 2005 he was visiting scholar at the Katholieke Universiteit Leuven (Belgium), working at IMEC on MEMS resonators anchor losses modeling. His research interests include MEMS modelling and design and development of circuits for MEMS conditioning. Now he is pursuing the Ph.D. in Information Engineering at University of Pisa, and he is working as a research assistant for the IEIIT of the Italian National Council for the Research (CNR). Massimo Mastrangeli got the MS degree in Electronic Engineering at the University of Pisa (Italy) on July, 2005; his thesis concerned project and measurements of MEMS flexural resonators. During summer 2005 he was visiting scholar at the Katholieke Universiteit Leuven (Belgium), working at IMEC on the mechanical characterization of PolySiGe layers for MEMS applications. He is currently a PhD student at KULeuven, developing a techniques for self-assembly of IC/MEMS for highly integrated microsystems. Andrea Nannini received his laurea degree in Electronic Engineering from the University of Pisa, Italy, in 1982; He received his Ph.D degree in 1987 at the end of the first Italian Ph.D course held by the University of Padova, Italy. From 1988 to 1992 he was a Researcher at the "Scuola Superiore di Studi Universitari e Perfezionamento S. Anna" – Pisa- Italy. Since 1992 he joined the Department of Information Engineering of the University of Pisa as an Associate Professor. Since November 2000 he is a full professor of “Sensor and Microsystem Design”. He is currently chairman of the postgraduate school of Electronic Engineering and vice-chairman of the PhD school of Information Engineering of the University of Pisa. His main research interests concern solid state sensors, microelectronic devices and technologies, MEMS. Francesco Pieri received the laurea and the Ph.D. degree in Electrical Engineering, both from the University of Pisa, Italy, in 1996 and 2000 respectively. He joined the Department of Information Engineering of the same University as an assistant professor in 2001. His current research interests include applications of porous silicon to sensors and microtechnologies, and development of microelectromechanical systems.     

Dynamic utility and price based radio resource management for rate adaptive traffic

This paper explores analytical Radio Resource Management models where the relationship between users and services is mapped through utility functions. Compared to other applications of these models to networking, we focus in particular on specific aspects of multimedia systems with adaptive traffic, and propose a novel framework for describing and investigating dynamic allocation of resources in wireless networks. In doing so, we also consider economic aspects, such as the financial needs of the provider and the users’ reaction to prices. As an example of how our analytical tool can be used, in this paper we compare different classes of RRM strategies, e.g., Best Effort vs. Guaranteed Performance, for which we explore the relationships between Radio Resource Allocation, pricing, provider’s revenue, network capacity and users’ satisfaction. Finally, we present a discussion about Economic Admission Control, which can be applied in Best Effort scenarios to further improve the performance. Part of this work has been presented at the conference ACM/IEEE MSWiM 2004, Venice (Italy). Leonardo Badia received a Laurea degree (with honors) in electrical engineering and a Ph.D. in information engineering from the University of Ferrara, Italy, in 2000 and 2004, respectively. He was a Research Fellow at the University of Ferrara from 2001 to 2006. During these years, he also had collaborations with the University of Padova, Italy, and Wireless@KTH, Royal Institute of Technology, Stockholm, Sweden. In 2006, he joined the “Institutions Markets Technologies” (IMT) Institute for Advanced Studies, Lucca, Italy, where he is currently a Research Fellow. His research interests include wireless ad hoc and mesh networks, analysis of transmission protocols, optimization tools and economic models applied to radio resource management. Michele Zorzi received a Laurea degree and a Ph.D. in electrical engineering from the University of Padova in 1990 and 1994, respectively. During academic year 1992–1993, he was on leave at UCSD, attending graduate courses and doing research on multiple access in mobile radio networks. In 1993 he joined the faculty of the Dipartimento di Elettronica e Informazione, Politecnico di Milano, Italy. After spending three years with the Center for Wireless Communications at UCSD, in 1998 he joined the School of Engineering of the University of Ferrara, Italy, where he became a professor in 2000. Since November 2003 he has been on the faculty at the Information Engineering Department of the University of Padova. His present research interests include performance evaluation in mobile communications systems, random access in mobile radio networks, ad hoc and sensor networks, energy constrained communications protocols, and broadband wireless access. He was Editor-In-Chief of IEEE Wireless Communications, 2003–2005, and currently serves on the Editorial Boards of IEEE Transactions on Communications, IEEE Transactions on Wireless Communications, Wiley’s Journal of Wireless Communications and Mobile Computing, and ACM/URSI/Kluwer Journal of Wireless Networks, and on the Steering Committee of the IEEE Transactions on Mobile Computing. He has also been a Guest Editor of special issues in IEEE Personal Communications (Energy Management in Personal Communications Systems) and IEEE Journal on Selected Areas in Communications (Multimedia Network Radios).     

Fluid coding and coexistence in ultra wide band networks

Time Hopping Ultra Wide Band (TH–UWB) commonly encodes the data symbols by shifting the position of the transmitted pulses by a quantity that is quantized over the inter-pulse interval range. In this paper, we relax the hypothesis of a discrete value for the time shift introduced by the TH code, by considering the possibility of generating real-valued codes that introduce time hopping in a “fluid” way. The effect on the power spectral density of generated signals is analyzed, and application of fluid coding to multiple access and to network coexistence is investigated by simulation. Portions of this work were presented at the 2005 2nd International Workshop Networking with Ultra Wide Band, Workshop on Ultra Wide Band for Sensor Networks [M.G. Di Benedetto, G. Giancola, D. Domenicali and P. Ingargiola “Fluid Coding in Time Hopping Ultra Wide Band Networks,” Proceedings of the IEEE 2nd International Workshop Networking with Ultra Wide Band—Ultra Wide Band for Sensor Networks, July 2005, Rome, Italy]. Daniele Domenicali took his Laurea degree in Telecommunications Engineering at the University of Rome La Sapienza in 2004. In November 2004 Domenicali wins the open competition for PhD scholarship in Information and Communication Engineering. He is teaching assistant for the course of “UWB Communication Systems” conducted by Professor Maria Gabriella Di Benedetto at the University of Rome La Sapienza. His research activity includes Pulse Shaping and the related modulation and coding techniques (Time Hopping Coding, PAM and PPM Modulation). Particular attention is paid to the effects produced in the Power Spectral Density, in order to find solutions capable of optimizing spectrum occupation while meeting the constraints imposed by emission masks. Daniele Domenicali is involved in the European Network of Excellence HYCON (Hybrid Control: Taming Heterogeneity and Complexity of Networked Embedded Systems). Guerino Giancola received the “Laurea” degree (magna cum laude) in Telecommunications Engineering, and the Ph.D. degree in Information and Communication Engineering from University of Rome La Sapienza, in 2001 and 2005, respectively. He is currently a research affiliate at the INFOCOM Department at University of Rome La Sapienza, where is actually holding the course of “Electrical Communications” for the degree on Electronic Engineering. His research interests include the analysis and modelling of Multi User Interference in Impulse Radio systems, and the design of Medium Access Control functions and protocols for UWB ad-hoc networks. Guerino Giancola recently co-authored with Prof. Maria-Gabriella Di Benedetto a book on Ultra Wide Band from radio to the network, titled “Understanding Ultra Wide Band Radio Fundamentals” and published by Prentice Hall in June 2004. He is now involved in the European project “PULSERS – Pervasive Ultra wideband Low Spectral Energy Radio Systems” and in the European Network of Excellence “HYCON- Hybrid Control: Taming Heterogeneity and Complexity of Networked Embedded Systems”. Guerino Giancola is a member of the IEEE Communication Society. Maria-Gabriella Di Benedetto obtained her Ph.D. in Telecommunications in 1987 from the University of Rome La Sapienza, Italy. In 1991, she joined the Faculty of Engineering of University of Rome La Sapienza, where currently she is a Full Professor of Telecommunications at the Infocom Department. She has held visiting positions at the Massachusetts Institute of Technology, the University of California, Berkeley, and the University of Paris XI, France. In 1994, she received the Mac Kay Professorship award from the University of California, Berkeley. Her research interests include wireless communication systems and speech science. From 1995 to 2000, she directed four European projects for the design of UMTS. Since 2000, she has been active in fostering the development of Ultra Wide Band (UWB) radio communications in Europe. Within the 5th framework, she directed for the Infocom Dept. two European projects (whyless.com and UCAN) aimed at the design and implementation of UWB ad-hoc networks. Currently, within the 6th EU Framework, her “Networking with UWB” research group participates in the PULSERS Integrated Project which will integrate UWB research and development in Europe for the next years, and in the LIAISON Integrated Project as regards the application of UWB to location-based services. She also participates in the HYCON network of excellence. Dr. Di Benedetto is co-edited several Special Issues on UWB communications and networks for several Journals including IEEE JSAC, Journal of Communications and Networks, Mobile Networks and Applications, Eurasip. In 2004, Dr. Di Benedetto co-authored with G. Giancola the first published book on UWB for communications titled “Understanding Ultra Wide Band Radio Fundamentals” and published by Prentice Hall. She recently completed the co-edition of two new books on UWB that will be published by 2005: UWB Communication Systems - A comprehensive overview, with T. Kaiser, D. Porcino, A. Molisch, and I. Oppermann, Hindawi Publishing Corporation, 2005, andUltra Wideband Wireless Communications with H. Arslan and Z.N. Chen, John Wiley & Sons, Inc., 2005.