Gianni Pasolini

Remote source coding for signal estimation via random sampling is analyzed. We consider a stationary Gaussian source to be estimated from samples randomly scattered according to a homogeneous Poisson point process, under a constraint on the number of bits per space unit. Building on the fact that homogeneous Poisson sampling introduces a white noise in the estimated signal spectrum and on results for indirect source coding by Dobrushin and Tsybakov, we derive an expression for the overall distortion rate as a function of the average sample intensity and of the bit rate constraint. The results enable the understanding of separation principle, between the distortion component due to sampling and that due to source coding, for Poisson random sampling. Finally, closed-form expressions for band-limited and non band-limited signals are provided.

Consensus among different entities is a fundamental feature of distributed systems, as it is the prerequisite for complex tasks such as distributed coordination of autonomous agents, network synchronization and localization in wireless sensor networks (WSNs). This paper introduces a novel iterative algorithm which is capable of achieving the distributed average consensus in a finite amount of time. This algorithm exploits the possibility of storing information received from neighboring nodes at each iteration. Moreover, we propose an adaptation to the distributed average consensus problem of the Tagged and Aggregated Sums (TAS) algorithm, which we introduced in a previous paper for the distributed confidence region evaluation. The performance of both algorithms is investigated through simulation and compared with state-of-the-art approaches.

One of the most important application areas of signal processing (SP) is, without a doubt, the software-defined radio (SDR) field [1]-[3]. Although their introduction dates back to the 1980s, SDRs are now becoming the dominant technology in radio communications, thanks to the dramatic development of SP-optimized programmable hardware, such as field-programmable gate arrays (FPGAs) and digital signal processors (DSPs). Today, the computational throughput of these devices is such that sophisticated SP tasks can be efficiently handled, so that both the baseband and intermediate frequency (IF) sections of current communication systems are usually implemented, according to the SDR paradigm, by the FPGA's reconfigurable circuitry (e.g., [4]-[6]), or by the software running on DSPs.

In this letter, we address the issue of Bluetooth (BT) piconets coexistence by analytically deriving a lower bound on the aggregated throughput offered by BT piconets deployed in the same region and by evaluating the optimal number of piconets as a function of the region dimension.

In questo articolo viene effettuato un confronto delle prestazioni dei sistemi DVB-S e DVB-T all\u2019interno di una galleria ferroviaria, al fine di valutarne il possibile impiego come gap filler per l\u2019estensione della copertura satellitare. Nel caso della tecnologia DVB-S viene inoltre individuato un modello analitico in grado di esprimere la probabilit\ue0 di fuori servizio all\u2019interno della galleria

This paper presents a smart city pilot project that will be developed in the city of Bologna. Different sensor devices will be deployed in several buildings to measure environmental quantities, such as temperature, humidity, luminosity and CO2. The pilot will use the LoRa low-rate, long-range communication technology to transmit sensed data to the control center. Results of a measurement campaign to characterize the propagation in the Bologna scenario are reported. Such results are then used as input to a simulator that provides both coverage and networklevel performance of the LoRa technology in the considered scenario. The paper shows that a proper parameter setting is needed to cover large urban areas while maintaining the timeon- air sufficiently low to keep packet losses at satisfactory levels

Future connected and automated vehicles (CAVs) will rely not only on their own sensors, but also on neighboring vehicles’ sensors as well as on roadside sensors, whose measurements will be exchanged by means of suitable vehicle-to-vehicle and vehicle-to-infrastructure communication technologies, thus enabling the collective perception service (CPS). This will allow CAVs to improve their awareness of the surroundings by receiving from other vehicles information about objects that are beyond their sensing range. In this paper, we discuss the CPS from the point of view of the ongoing standardization activities and of the evolution of wireless technologies. The integration of smart-lighting infrastructures and advanced driver assistance systems (ADAS) is also discussed through the description of radar- and camera-based traffic monitoring devices we developed in our lab.

Consensus among different entities is a fundamental feature of distributed systems, as it is the prerequisite for complex tasks such as distributed coordination of autonomous agents, network synchronization and localization in wireless sensor networks (WSNs). This paper introduces a novel iterative algorithm which is capable of achieving the distributed average consensus in a finite amount of time. This algorithm exploits the possibility of storing information received from neighboring nodes at each iteration. Moreover, we propose an adaptation to the distributed average consensus problem of the Tagged and Aggregated Sums (TAS) algorithm, which we introduced in a previous paper for the distributed confidence region evaluation. The performance of both algorithms is investigated through simulation and compared with state-of-the-art approaches.

Inthis papertheissue ofnetworks interworking is faced withreference toUMTScellular networks andIEEE802.11 wireless local areanetworks. A feasible architectural solution oftheintegrated network isgiven andthepossibility toserve bymeansoftheWLAN technology alsothose voice calls that wouldbeblocked byUMTS,incaseofresource saturation, is investigated. Theperformance level provided bytheintegrated network ina realistic scenario ishereassessed considering bothIEEE802.11a andtheforthcoming IEEE802.11e WLAN technologies forpossible integration withUMTS. I.INTRODUCTION Third generation cellular networks arealready areality: theprovision ofhighspeed communications supporting an increasing number ofdifferent services isthechallenge faced byUMTS,whosedeployment isexpected tofoster multimedia communications andwideband access totheInternet with cellular terminals. Atthesametimewireless local areanetworks (WLANs) are achieving agreat penetration inthemassmarket asareally effective solution toprov...

One of the most important application areas of signal processing (SP) is, without a doubt, the software-defined radio (SDR) field [1]-[3]. Although their introduction dates back to the 1980s, SDRs are now becoming the dominant technology in radio communications, thanks to the dramatic development of SP-optimized programmable hardware, such as field-programmable gate arrays (FPGAs) and digital signal processors (DSPs). Today, the computational throughput of these devices is such that sophisticated SP tasks can be efficiently handled, so that both the baseband and intermediate frequency (IF) sections of current communication systems are usually implemented, according to the SDR paradigm, by the FPGA's reconfigurable circuitry (e.g., [4]-[6]), or by the software running on DSPs.

Remote source coding for signal estimation via random sampling is analyzed. We consider a stationary Gaussian source to be estimated from samples randomly scattered according to a homogeneous Poisson point process, under a constraint on the number of bits per space unit. Building on the fact that homogeneous Poisson sampling introduces a white noise in the estimated signal spectrum and on results for indirect source coding by Dobrushin and Tsybakov, we derive an expression for the overall distortion rate as a function of the average sample intensity and of the bit rate constraint. The results enable the understanding of separation principle, between the distortion component due to sampling and that due to source coding, for Poisson random sampling. Finally, closed-form expressions for band-limited and non band-limited signals are provided.

The IEEE 802.16 standard family enables the convergence of \ufb01xed and mobile broadband networks through a common wide area broadband access technology and a \ufb02exible network architecture. In this paper we provide an overview of the recent IEEE 802.16e-2005 amendment, aimed at supporting user mobility, and we discuss several issues related to a proper choice of system parameters and strategies to be adopted to fully exploit the technology potential. Moreover, we propose a scheduling strategy aimed at providing a fair service to best effort users. The effectiveness of this proposal is shown via simulation

... Alessandro Bazzi, Andrea Giorgetti and Gianni Pasolini are with IEIIT-BO/CNR, DEIS-University of Bologna, V.le Risorgimento 2, 40136 Bologna ... gain terrestrial antennas have to be adopted both for the gap filler and the train transceiver; here we considered horn antennas with ...

This work considers a scenario where a wireless infrastructure is rapidly deployed to provide assistance to a rescue team. The wireless network should support audio-video communications between agents and a remote Control Center coordinating operations. Here we propose to realize an heterogeneous network, characterized by an easy deployment and a wide geographical coverage, consisting of an integrated satellite-WiFi network. The scenario and the network are modelled and investigated through extensive simulations in order to derive the performance in terms of maximum number of voice/video connections simultaneously allowed

This paper considers a delay tolerant network consisting of nodes equipped with sensors, some of them producing outliers. A distributed faulty node detection (DFD) algorithm, whose aim is to help each node in estimating the status of its sensors, has been proposed recently by the authors. The aim of this paper is to analyze the robustness of the DFD algorithm to the presence of misbehaving nodes performing Byzantine attacks. Two types of attacks are considered and analyzed, each trying to mislead the other nodes in the estimation of the status of their sensors. This provides insights on the way the parameters of the DFD algorithm should be adapted to minimize the impact of misbehaving nodes. Theoretical results are illustrated with simulations considering nodes with random displacements, as well as traces of node inter-contact times from real databases.

The most relevant impairment experienced by on-channel repeaters (OCRs) in single frequency networks scenarios is the presence of a coupling-channel between the transmitting and receiving antennas, that generates unwanted echoes. This phenomenon causes a degradation of the repeated signal and, above all, could lead to the instability of OCRs, owing to the positive feedback that could result. For this reason, OCRs are usually equipped with echo canceller units, aimed at removing the coupling contributions. In this paper, we consider a realistic OCR setup and we analytically derive proper design criteria for echo-cancellers, showing the role of system parameters and implementation aspects on their performance. Here, in particular, we investigate the joint effect of the estimation noise and the finite precision arithmetic of digital systems, the system sensitivity to different design parameters and the relation between the echo-cancelling performance and the probability of instability.

ABSTRACT We consider the secret key generation (SKG) problem for short-range communication (SRC) systems. Specifically, we focus on the problem that secret key generation schemes relying on the entropy of the channel are not suitable for SRC systems, which are characterized by the absence of fading. To mitigate this problem, we introduce the concept of geometric secrecy and propose a new phase-based SKG which relies only on the reciprocity of the channel in order to securely generate mutual secret keys in the presence of an eavesdropper. The method is validated via a theoretical analysis which shows that for the signal-to-noise ratio (SNR) ranges typical of SRC systems, an efficient secret key generation can be achieved.

In June 2001, operators and equipment vendors in the communications ecosystem founded the nonprofit WiMAX Forum, an industry-led organization aimed at harmonizing broadband wireless access standards, and certifying interoperability among devices from different manufacturers. Nowadays, about 10 years later, the WiMAX technology is a mature and affordable solution for high-speed IP-based 4G mobile broadband, fully supporting bandwidth-intensive services, such as high-speed Internet access and television, as well as less bandwidth-demanding but more latency-sensitive services, such as voice-over-IP calls. The deployment of WiMAX networks, which are based on the IEEE 802.16-2004 Air Interface Standard, started in many countries in 2005, as soon as manufacturers released the first equipments. The early WiMAX networks were aimed at providing fixed broadband wireless services in a wide geographical scale and proved to be a really effective solution for the establishment of wireless metropolitan area networks. On February 2006, the IEEE802.16e-2005 amendment gave a further extension to the potentialities of this technology, introducing a number of features aimed at supporting also users mobility; in this way, the so-called Mobile-WIMAX profile was born.. The result was a complete standard family that specified the air interface for both fixed and mobile broadband wireless access, enabling thus the convergence of fixed and mobile networks through a common wide area radio access technology. Since then, the interest in WiMAX increased dramatically; nowadays this technology is at work in more than 100 countries, providing both residential and mobile connectivity in urban areas as well as remote locations, due to the relatively low costs associated with its deployment (in comparison with 3G, HSDPA). The parallel development of the 4G Long Term Evolution (LTE) wireless access technology, currently deployed in many countries, is not expected to displace WiMAX, which had a first-mover advantage. It is likely, in fact, that the two technologies will be complementary. As LTE networks begin to roll out, it is extremely likely, for instance, that WiMAX will be used as the wireless backhaul for those networks, leaving to LTE the access provision. Moreover, WiMAX seems preferable for DSL replacement, especially in developing countries and rural regions, where wireline broadband technologies are not available. For these reasons, both the industrial and the scientific communities keep on developing and investigating WiMAX, with the final aim to get the best from this technology. In this book, a collection of selected papers is presented, which covers several aspects of the WiMAX technology, investigated by specialists working in universities and research centres all over the world. In particular, the book is organized following a bottom up structure, starting from link aspects up to the whole system. Chapter 1 is focused on multiuser (MU) multiple input multiple output (MIMO) diversity techniques. It provides a comprehensive overview of various MIMO strategies and a critical discussion on the recent research in multiuser MIMO communications with emphasis on the design of precoders. State-of-the-art in research on MU-MIMO precoding and multi-cell processing is presented. A new precoder design and its application in WiMAX setting is also provided. In chapter 2 the issue of the high peak-to-average power ratio (PAPR) that affects WiMAX is investigated, with particular reference to the adoption of companding as a PAPR mitigation strategy. Impairments from nonlinear distortion at the transmitter, multipath and noise are considered. Chapter 3 deals with the adoption of mesh architectures within WiMAX, and provides an overview of the main challenges of the WiMAX mesh mode, with a focus on routing protocols and the effect of quality of service mechanisms on scenarios with mobile clients. Chapter 4 investigates the handover mechanism, with particular reference to the cell selection scheme. A multi-criteria selection scheme is proposed, based on the experienced carrier-to-interference plus noise ratio, the required bandwidth and the expected congestion delay. In chapter 5 the issue of coordinated authentication in a heterogeneous network environment is investigated. A Coordinated Robust Authentication (CRA) Mechanism is presented, with the ability to use a single set of credentials with any network. Finally, Chapter 6 reviews the Multicast and Broadcast re-keying Algorithm (MBRA) of IEEE 802.16e, that ensures the confidentiality of communications. The operational efficiency, scalability and 1-affects-n phenomenon are discussed

Publisher Summary This chapter reviews the mobile radio access network reference scenarios (MORANS)—used to study the performance of the radio cellular networks related to UMTS and the methodologies for the radio network performance evaluation, including the theoretical connectivity models,. It discusses the techniques for radio network optimization such as the packet scheduling for cellular systems or system capacity maximization through the use of multiple antennas. . In order to perform system simulations, reference values for the main parameters characterizing a WCDMA network, are required. MORANS is used for the identification of such parameters. The parameters are classified in two groups: the parameters whose value can be found in the specification documents, and the parameters with unspecified value requiring optimization. The estimated performance in the downlink of a WCDMA network can be evaluated by means of two dynamic system simulators. The chapter concludes by discussing important RRM procedures, simplified algorithms. Some of them are: call admission control, congestion control, and soft handover procedure.

Wireless communications are nowadays considered as enablers of innovation in the field of smart mobility in smart cities. In this work, we focus on the smart navigation service, which is aimed at providing drivers with the best route to destination taking into account real time traffic conditions. Smart navigation is increasingly used today and expected to reduce traffic congestions, but the real impact on travel time and the cost in terms of wireless network resources are still open issues. These aspects are here discussed starting from the objectives and the outputs of the Italian project PEGASUS. More specifically, to what extent this application can reduce the travel duration and how frequently traffic information must be updated will be firstly discussed; then, the impact on wireless networks of both the uplink collection of traffic information and the downlink transmission to vehicles is shown, focusing on the UMTS cellular technology; finally, the use of short range IEEE 802....

Digital maps will revolutionize our experience of perceiving and navigating indoor environments. While today we rely only on the representation of the outdoors, the mapping of indoors is mainly a part of the traditional SLAM problem where robots discover the surrounding and perform self-localization. Nonetheless, robot deployment prevents from a large diffusion and fast mapping of indoors and, further, they are usually equipped with laser and vision technology that fail in scarce visibility conditions. To this end, a possible solution is to turn future personal devices into personal radars as a milestone towards the automatic generation of indoor maps using massive array technology at millimeter-waves, already in place for communications. In this application-oriented paper, we will describe the main achievements attained so far to develop the personal radar concept, using ad-hoc collected experimental data, and by discussing possible future directions of investigation.

The deployment of sensing nodes is crucial for applications relying on the reconstruction of spatial fields. Theoretical analysis usually assumes that nodes are distributed according to a homogeneous Poisson point process (PPP), in which nodes positions are stochastically independent. However, realistic scenarios for crowd sourcing and Internet of Things call for clustered layouts of sensing nodes, for which homogeneous PPP is not appropriate. This paper analyzes sampling and reconstruction of finite-energy signals in Rd, with samples gathered in space according to a Gauss-Poisson point process (G-PPP), which has been recently proposed to model node spatial distribution with attraction (as in clustering). In particular, it is shown that attraction between nodes modeled by G-PPP reduces the reconstruction accuracy with respect the case of homogeneous PPP with the same intensity. This represents the opposite case of the repulsion effect, which was investigated in a previous work relyi...

This paper analyzes distributed molecular communications with multiple transmitters and multiple receivers randomly placed in a 3D space. Receivers, whose positions are modeled by a homogeneous Poisson point process, are assumed to be passive and spherical. Since they are not dimensionless, their presence affects the statistics of transmitter points, resulting in a Poisson hole process, instead of the Poisson process usually adopted in previous works on multiple transmitters. Moreover, molecules emissions from different transmitters are considered asynchronous, according to a recently proposed stochastic model. Here, the intensity function of the time point processes modeling molecules emissions is given a further meaning; in particular, it is considered as the propensity function of a chemical reaction. The average amount of received molecules per time unit (receiving rate) is evaluated accordingly for each receiver. When the swarm of receivers is considered as an equivalent, singl...

This article proposes two average consensus algorithms exploiting the memory of agents. The performance of the proposed as well as of several state-of-the-art consensus algorithms is evaluated considering different communication ranges, and evaluating the impact of transmission errors. To compare asymptotic and finite-time average consensus schemes, the <inline-formula><tex-math notation="LaTeX">$\varepsilon$</tex-math></inline-formula>-convergence time is adopted for a fair comparison. A discussion about memory requirements, transmission overhead, <italic>a priori</italic> information on network topology, and robustness to errors is provided.

We consider a multi-user scenario where sources transmit their messages to the destinations by means of a two-hop mechanism. To minimize the interference generated in the scenario, a simple opportunistic relay selection mechanism is investigated. The performance of the scenario is evaluated using some results of the stochastic geometry under the assumption that relay nodes are distributed according to a Poisson point process. Results show that, when the relay density is sufficiently high, a suitable choice of the relay leads to a limited amount of interference generated during source-relay and relay-destination transmissions.

ABSTRACT Wireless channel reciprocity can be successfully exploited as a common source of randomness for the generation of a secret key by two legitimate users willing to achieve confidential communications over a public channel. This paper presents an analytical framework to investigate the theoretical limits of secret-key generation when wireless multi-dimensional Gaussian channels are used as source of randomness. The intrinsic secrecy content of wide-sense stationary wireless channels in frequency, time and spatial domains is derived through asymptotic analysis as the number of observations in a given domain tends to infinity. Some significant case studies are presented where single and multiple antenna eavesdroppers are considered. In the numerical results, the role of signal-to-noise ratio, spatial correlation, frequency and time selectivity is investigated.

Among the low power wide area network communication protocols for large scale Internet of Things, LoRaWAN is considered one of the most promising, owing to its flexibility and energy-saving capabilities. For these reasons, during recent years, the scientific community has invested efforts into assessing the fundamental performance limits and understanding the trade-offs between the parameters and performance of LoRaWAN communication for different application scenarios. However, this task cannot be effectively accomplished utilizing only analytical methods, and precise network simulators are needed. To that end, this paper presents LoRaWANSim, a LoRaWAN simulator implemented in MATLAB, developed to characterize the behavior of LoRaWAN networks, accounting for physical, medium access control and network aspects. In particular, since many simulators described in the literature are deployed for specific research purposes, they are usually oversimplified and hold a number of assumptions ...

This paper introduces a possible architecture and discusses the research directions for the realization of the Cognitive Perceptual Internet (CPI), which is enabled by the convergence of wired and wireless communications, traditional sensor networks, mobile crowd-sensing, and machine learning techniques. The CPI concept stems from the fact that mobile devices, such as smartphones and wearables, are becoming an outstanding mean for zero-effort world-sensing and digitalization thanks to their pervasive diffusion and the increasing number of embedded sensors. Data collected by such devices provide unprecedented insights into the physical world that can be inferred through cognitive processes, thus originating a digital sixth sense. In this paper, we describe how the Internet can behave like a sensing brain, thus evolving into the Internet of Senses, with network-based cognitive perception and action capabilities built upon mobile crowd-sensing mechanisms. The new concept of hyper-map i...

Street lighting characterizes many smart city initiatives around the world. In fact, significant savings can be achieved by not only replacing traditional luminaires with low-power LEDs, but also providing streetlights with smart light controllers and network connectivity, allowing the introduction of a sensible light intensity management and reduction of maintenance costs. Moreover, if designed with a far-looking view, smart lighting infrastructure could also support city-wide Internet of Things services, becoming key enablers of the smart city revolution, also in the 5G perspective. In this paper, we provide a thorough discussion on network architectures and communication technologies that could be adopted for smart public lighting applications, showing their benefits and downsides. Starting with significant activity on research, implementation and in-field testing, we also outline the steps required for the deployment of a smart public lighting infrastructure, each discussed in a...

Information and Communication Technologies (ICTs), through wireless communications and the Internet of Things (IoT) paradigm, are the enabling keys for transforming traditional cities into smart cities, since they provide the core infrastructure behind public utilities and services. However, to be effective, IoT-based services could require different technologies and network topologies, even when addressing the same urban scenario. In this paper, we highlight this aspect and present two smart city testbeds developed in Italy. The first one concerns a smart infrastructure for public lighting and relies on a heterogeneous network using the IEEE 802.15.4 short-range communication technology, whereas the second one addresses smart-building applications and is based on the LoRa low-rate, long-range communication technology. The smart lighting scenario is discussed providing the technical details and the economic benefits of a large-scale (around 3000 light poles) flexible and modular imp...