Wi-Dia: Data-Driven Wireless Diagnostic Using Context Recognition

The recent densification of Wi-Fi networks is exacerbating the effects of well-known pathologies including hidden nodes and flow starvation. This paper provides an automatic diagnostic tool for detecting the source roots of performance impairments by recognizing the wireless operating context. Our tool for Wi-Fi diagnostic, named Wi-Dia, exploits machine learning methods and uses features related to network topology and channel utilization, without impact on regular network operations and working in real-time. Real-time per-link Wi-Fi diagnosis enables recovering actions for context-specific treatments. Wi-Dia classifier recognizes different classes of interference; it is jointly trained us…

MAC–Engine: a new architecture for executing MAC algorithms on commodity WiFi hardware

In this demo, we prove that the flexibility supported by off–the–shelf IEEE 802.11 hardware can be significantly ex- tended if we move the control of the MAC programming interface from the driver to the firmware, i.e. from the host CPU to the card CPU. To this purpose, we introduce the concept of MAC–Engine, that is an executor of Pro- grammable Finite State Machines (PFSM) implemented at the firmware level: we show how the card itself can support different protocol logics thanks to PFSM bytecode repre- sentations that can be dynamically injected inside the card memory at run-time without incurring in down time issues or network disconnect events. We provide different PFSM examples in order…

Integration of WiFi ToF Positioning System in the Open, Flexible and Adaptive WiSHFUL Architecture

We integrate a prototypeWiFi Time-of-Flight (ToF) ranging and positioning system in the WiSHFUL software platforms and hardware radios for experimental prototyping. Users have access to ToF measurements as well as computed positions through unified programming interfaces that make possible to investigate innovative positioning and networking solutions. TRUE pub

WiSHFUL : enabling coordination solutions for managing heterogeneous wireless networks

The paradigm shift toward the Internet of Things results in an increasing number of wireless applications being deployed. Since many of these applications contend for the same physical medium (i.e., the unlicensed ISM bands), there is a clear need for beyond-state-of-the-art solutions that coordinate medium access across heterogeneous wireless networks. Such solutions demand fine-grained control of each device and technology, which currently requires a substantial amount of effort given that the control APIs are different on each hardware platform, technology, and operating system. In this article an open architecture is proposed that overcomes this hurdle by providing unified programming i…

Challenges and directions for Blockchain technology applied to Demand Response and Vehicle-to-Grid scenarios

Abstract Nowadays, Blockchain is considered a consolidated technology supporting many different applications that integrate well with Artificial Intelligence and the Internet of Things, and supports the creation of Decentralized Autonomous Organizations. Within this wider framework, the energy blockchain applications are now deserving more and more attention, since blockchain architectures, on one hand, provide transparency and solve the information asymmetry problem, on the other, provide disintermediation. In this way, the dream of an energy market closer to end-users becomes a reality, although, still, the regulatory framework is not clear, especially for what concerns the tokenization o…

BlockSee: Blockchain for IoT video surveillance in smart cities

The growing demand for safety in urban environments is supported by monitoring using video surveillance. The need to analyze multiple video-flows from different cameras deployed around the city by heterogeneous owners introduces vulnerabilities and privacy issues. Video frames, timestamps, and camera settings can be digitally manipulated by malicious users; the positions of cameras, their orientation and their mechanical settings can be physically manipulated. Digital and physical manipulations may have several effects, including the change of the observed scene and the potential violation of neighbors' privacy. To face these risks, we introduce BlockSee, a blockchain-based video surveillan…

A Test Bench for a Blockchain-based Management of Smart Prosumers' Flexibility

To date, the European regulatory framework requires the development of new energy policies at the national level that can reduce overall consumption and support the implementation of customer-focused control and management systems. Therefore, it is necessary to study the feasibility of the various strategies available, especially for the involvement of residential users in services that can contribute to the management of the electricity grid. The advent of blockchain technology has enabled the development of new business models for the electricity market, opening this world to end users who previously did not have the opportunity to participate in energy trading and allowing the implementa…

Self-validating bundles for flexible data access control

Modern cloud-based services offer free or low-cost content sharing with significant advantages for the users but also new issues in privacy and security. To protect sensitive contents (i.e., copyrighted, top secret, and personal data) from the unauthorized access, sophisticated access management systems or/and decryption schemes have been proposed, generally based on trusted applications at client side. These applications work also as access controllers, verifying specific permissions and restrictions accessing user’s resources. We propose secure bundles (S-bundles), which encapsulate a behavioral model (provided as bytecode) to define versatile stand-alone access controllers and encoding/d…

Ancillary Services in the Energy Blockchain for Microgrids

The energy blockchain is a distributed Internet protocol for energy transactions between nodes of a power system. Recent applications of the energy blockchain in microgrids only consider the energy transactions between peers without considering the technical issues that can arise, especially when the system is islanded. One contribution of the paper is, thus, to depict a comprehensive framework of the technical and economic management of microgrids in the blockchain era, considering, for the first time, the provision of ancillary services and, in particular, of the voltage regulation service. When more PV nodes are operating in the grid, large reactive power flows may appear in the branches…

MAC-Engine

In this demo, we prove that the flexibility supported by off-the-shelf IEEE 802.11 hardware can be significantly extended if we move the control of the MAC programming interface from the driver to the firmware, i.e. from the host CPU to the card CPU. To this purpose, we introduce the concept of MAC--Engine, that is an executor of Programmable Finite State Machines (PFSM) implemented at the firmware level: we show how the card itself can support different protocol logics thanks to PFSM bytecode representations that can be dynamically injected inside the card memory at run-time without incurring in down time issues or network disconnect events. We provide different PFSM examples in order to t…

Demand Response Service Certification and Customer Baseline Evaluation Using Blockchain Technology

The use of Distributed Ledger Technologies such as Blockchain for certifying Demand Response services allows for the creation of a distributed system in which customers can communicate with the system operator to provide their flexibility, in a secure, transparent and traceable way. Blockchain technology also supports incentive mechanisms for users taking part in the service through the generation of utility tokens to recognize the user's contribution. This paper presents the experimental test of a novel methodology for Demand Response programs implementation by using the Blockchain technology. The latter is employed for defining a distributed Demand Response service and a new system for it…

Challenges and Opportunities using MultiChain for Real Estate

The real estate market involves multiple untrusted actors with contrasting objectives. We propose REchain, a blockchain-based platform for real estate, which provides benefits to all actors in terms of transparency, trust, immutability, and traceability. REchain architecture handles real estate data through well-defined workflows that leverage the MultiChain platform. REchain changes the real estate market enabling direct transactions without intermediaries, and providing new mechanisms for negotiating the purchase conditions. This paper refutes the misleading idea of using blockchains for solving generic problems as blockchain platforms have peculiar features that make them suitable for sp…

Blockchain review for battery supply chain monitoring and battery trading

The use of technologies such as Internet of Things (IoT), data processing and blockchain have allowed companies to serve their customers with better quality, efficiency, reliability and in the shortest possible time. The growing adoption of electric vehicles on the market has increased the demand for batteries that may have numerous manufacturers. Life expectancy is affected on manufacture, but also on operational conditions. A large number of parameters have a role on battery's health and thousands of data need to be evaluated and combined. The present work investigates the scenario of the battery industry in order to implement a blockchain-based platform for the supply chain implementatio…

A Blockchain-based Platform for Positive Energy Districts

The reduction of climate change effects (mitigation) is now mainly driven by the limitation of CO2 emissions which is currently becoming increasingly necessary and urgent to achieve. In this context, within the past Horizon 2020 program, the Urban Europe Joint Programming Initiative aimed to promote the development and deployment of at least 100 Positive Energy Districts by 2025. The latter are flexible, energy-efficient urban areas or groups of buildings that produce zero net CO2 emissions and actively manage annual renewable energy surplus production at the local or regional level. As they are connected to the electric power system, Positive Energy Districts have the ability to offer flex…

INDOOR LOCALIZATION USING COGNITIVE RADIOS AND SOFTWARE-DEFINED WIRELESS NETWORKS

CADWAN – A Control Architecture for Dense Wi-Fi Access Networks

The growing demands of ubiquitous computing are leading towards the densification of wireless access networks. The challenges of high density deployments can be addressed by network- wide centralized control. To this end we propose CADWAN – a Control Architecture for efficient management of Dense Wi-Fi Access Networks. Its main advantages are: flexibility (it supports software- defined wireless networking), scalability (it uses a three-tier optimization framework), and extendibility (it exploits a unified control interface with support for heterogeneous devices). Furthermore, CADWAN is complementary to ongoing developments in IEEE 802.11, especially 802.11ax.

Aggregation and remuneration in Demand-Response with a blockchain-based framework

This paper describes the possibility to use the blockchain technology for load and generation aggregation in a new distributed Demand Response (DR) service and customers remuneration system. The blockchain technology and the use of smart contracts for DR allow the creation of a distributed system in which customers can communicate directly, in a transparent, secure and traceable way, with the grid operator to provide their flexibility. In this paper, the DR problem formulation takes into account several aspects, which are periodically executed. First, the blockchain records customers’ energy consumption or production, then, the smart contract starts calculating the baseline and the potentia…

Wireless MAC processors: programming MAC protocols on commodity hardware

Programmable wireless platforms aim at responding to the quest for wireless access flexibility and adaptability. This paper introduces the notion of wireless MAC processors. Instead of implementing a specific MAC protocol stack, Wireless MAC processors do support a set of Medium Access Control “commands” which can be run-time composed (programmed) through software-defined state machines, thus providing the desired MAC protocol operation. We clearly distinguish from related work in this area as, unlike other works which rely on dedicated DSPs or programmable hardware platforms, we experimentally prove the feasibility of the wireless MAC processor concept over ultra-cheap commodity WLAN hardw…

The Peer Obervation: "Mentore" Project at the University of Palermo

During the last six years, at the University of Palermo, a group of academics has been involved in a project called “MENTORE” (“Modifying and ENhancing Teaching through peer Observation and Reflections with Experts”). The objectives of the project are: to help teachers improve their teaching, through the help of two mentors; to experiment new approaches in pilot courses to extend, if useful, to other ones; and to change the traditional model of academic teaching based on one single teacher with the class to go towards a model where there is a group of teachers working together in search of improvements. All the participants of the MENTORE project attend to lectures/workshops on teaching and…

Joint Usage of Dynamic Sensitivity Control and Time Division Multiple Access in Dense 802.11ax Networks

It is well known that in case of high density deployments, Wi-Fi networks suffer from serious performance impairments due to hid- den and exposed nodes. The problem is explicitly considered by the IEEE 802.11ax developers in order to improve spectrum efficiency. In this pa- per, we propose and evaluate the joint usage of dynamic sensitivity con- trol (DSC) and time division multiple access (TDMA) for improving the spectrum allocation among overlapping 802.11ax BSSs. To validate the solution, apart from simulation, we used a testbed based on the Wireless MAC Processor (WMP), a prototype of a programmable wireless card.

RSS-eye: Human-assisted Indoor Localization without Radio Maps

The pervasive diffusion of smartphones is boosting indoor positioning solutions and location-based services. We propose a novel methodology to perform indoor positioning of mobile users by the estimation of angles of arrival from access points whose locations are known. Angles of arrival are estimated by correlating WiFi RSSI measurements with data coming from a digital compass, which is provided by most current handsets. Our system has minimal requirements in terms of infrastructure and mobile hardware. The system neither needs calibration, nor radio maps but requires the user to perform a gesture when an estimation is needed. The resulting on-demand localization has advantages in terms of…

WMPS: A Positioning System for Localizing Legacy 802.11 Devices

The huge success of location-aware applications calls for the quick development of a positioning system alternative to GPS for indoor localization based on existing technologies such as 802.11 wireless networks. In this paper we propose WMPS, the Wireless MAC Processor Positioning System, that is a localization system running on off-the-shelf 802.11 Access Points and based on time-of-flight ranging of users’ standard terminals. We prove through extensive experiments that propagation delays can be measured with the accuracy required by indoor applications despite the different noise components that can affect the result, like latencies of the hardware transreceivers, multi- path, ACK jitters…

Supporting a Pseudo-TDMA Access Scheme in Mesh Wireless Networks

Wireless mesh networks appear a promising solution for pro- viding ubiquitous low-cost wireless access, but cannot rely on simple CSMA access protocols because of the critical inefficiencies that arise in topologies with hidden nodes. To overcome these limitations, some important protocol extensions based on synchronization and reservation mechanisms have been ratified. In this paper we show that an alternative approach to the standardiza- tion of new features and signaling messages for mesh networks can be the utilization of programmable nodes able to execute different MAC protocols programmed on the fly. Signaling messages are used only for disseminating the new protocol among the nodes. …

Effects of COVID19 pandemic on the Italian power system and possible countermeasures

Abstract The paper analyses the dramatic effects of the first wave of the COVID-19 pandemic on the Italian power system, considering the impacts on load and generation, market issues and ancillary services provision. During the period between March and May 2020, the Italian scenario was considered as exemplary due to the large reduction of loads and thermal generation caused by the hard lockdown across the Country. Italy has experienced the most severe effects of pandemic in terms of increase of death rates and of pressure on the health system as well as severity of the countermeasures. As a domino effect, the total lockdown of one of the most industrialized countries in the world has creat…

Statistical analysis of RaptorQ failure probability applied to a data recovery software

In this work, we have implemented a data recovery software integrating the most recent rateless codes, i.e., RaptorQ codes. Thanks to the above-mentioned software, it is possible to recover data loss occurring on several kinds of network conditions. We have performed a statistical analysis of failure probabilities at several configurations of RaptorQ parameters. We have found a good agreement with the theoretical values of a random linear fountain code over Galois Field GF(256). Moreover, we have shown that the probability of having a certain number of failed decoded source blocks - when sending a fixed size file - follows a Poisson distribution.

Enabling Cognitive-Radio Paradigm on Commercial Off-The-Shelf 802.11 Hardware

Cognitive Radio paradigm (CR) has been recognized as key enabler for next generation wireless networking: the pos- sibility to access the limited radio spectrum in an oppor- tunistic manner allows secondary users to boost their trans- mission performance without interfering with existing pri- mary networks. Full testing and experimenting with this paradigm, however, is still a tough task, given either the i) limited capabilities above the PHY layer of cheap SDR so- lutions, or the ii) heavy investment required for setting up multi-node testbeds powered by FPGAs. In this demo we show how we leveraged our Wireless MAC Processor archi- tecture to tackle the two issues at the same time, providi…

Breaking layer 2: A new architecture for programmable wireless interfaces

This paper introduces a new architecture for programmable wireless interfaces, aiming at responding to the emerging request of wireless access flexibility and adaptability. Instead of implementing a specific MAC protocol stack, the proposed architecture supports a set of programmable services, devised to customize the wireless access operations according to specific network and application scenarios. The services are composed by means of simpler functions, which in turns work on system primitives (i.e. elementary non-programmable functionalities, natively provided by the system) dealing with the physical transmission and reception of the frames. Our approach significantly differs from softw…

An Energy Blockchain, a Use Case on Tendermint

The recent advances in distributed energy systems require new models for exchanging energy among prosumers in microgrids. The blockchain technology promises to solve the digital issues related to distributed systems without a trusted authority and to allow quick and secure energy transactions, which are verified and cryptographically protected. Transactions are approved and subsequently recorded on all the machines participating in the blockchain. This work demonstrates how users, which are nodes of the energy and digital networks, exchange energy supported by a customized blockchain based on Tendermint. We focus on the procedures for generating blocks and defining data structures for stori…

Blockchain for Smart Cities: Applications for IoT and Video Surveillance Systems

The recent revolution of the Internet of Things introduces new engaging operat- ing scenarios. The IoT paradigm enables the intertwined use of physical and soft- ware components through the interconnection of devices that exchange data with each other without direct human interaction in several fields, especially in industrial and home environments. In the framework of the Italian-Vietnamese cooperation on the topics of smart cities and Blockchain, we present two applications of the blockchain technology, which can be applied, respectively in indoor, for monitoring and controlling smart homes, and in outdoor, for visual monitoring through video surveillance systems. In both cases, we propos…

Tracing battery usage for second life market with a blockchain-based framework

This work describes the design of a platform based on a permissioned blockchain for sharing relevant information among the actors involved in grid service provision programs. The information collected by a proprietary monitoring on-board system accessing the central unit of the Electric Vehicle, EV, is then sent to a dropbox folder owned by the car owner and then written on a blockchain platform. The platform could be supplied from similar data from the grid operator collected on the grid during the provision of services. In this way data can be validated and used for tracing the health status of the EV's battery. The design of customized smart contract allows to acquire the profiles of bat…

A Coexistence Analysis of Blockchain, SCADA Systems, and OpenADR for Energy Services Provision

The advent of blockchain technology allows the raise of new business models for the electricity market, opening the way also to end-users and letting them offer regulation services to the power grid. Thanks to the characteristic of being distributed, the blockchain technology could be a solution to balancing problems caused by the penetration of renewable sources, implementing a platform for Demand-Response programs delivery. Demand-Response allows consumers to respond to market signals by increasing or reducing their energy consumption, contributing to greater flexibility and stability of the grid and to a more efficient use of infrastructures and energy resources. Currently, Demand-Respon…

Correlated channel model for terrestrial Free Space Optics: performance analysis of rateless codes

We describe a novel correlated channel model able to predict random temporal fluctuations of optical signal irradiance caused by scintillation. With regards to the same channel, we also report simulation results on the error mitigation performance of Luby-Transform and Raptor codes.

SDN@home: A Method for Controlling Future Wireless Home Networks

Recent advances in wireless networking technologies are leading toward the proliferation of novel home network applications. However, the landscape of emerging scenarios is fragmented due to their varying technological requirements and the heterogeneity of current wireless technologies. We argue that the development of flexible software-defined wireless architectures, including such efforts as the wireless MAC processor, coupled with SDN concepts, will enable the support of both emerging and future home applications. In this article, we first identify problems with managing current home networks composed of separate network segments governed by different technologies. Second, we point out t…

DeCyMo: Decentralized Cyber-physical System for Monitoring and Controlling Industries and Homes

The recent revolution of the Internet of Things has given the birth of a series of new technologies and cyber-physical systems to be used in industrial and home scenarios. Cyber- physical systems include physical and software components for providing smart monitoring and control with flexibility and adaptability to the operating context. The IoT paradigm enables the intertwined use of physical and software components through the interconnection of devices that exchange data with each other without direct human interaction in several fields, especially in industrial and home environments. We propose DeCyMo, a decentralized architecture that aims at solving common IoT issues and vulnerabiliti…

A unified radio control architecture for prototyping adaptive wireless protocols

Experimental optimization of wireless protocols and validation of novel solutions is often problematic, due to limited configuration space present in commercial wireless interfaces as well as complexity of monolithic driver implementation on SDR-based experimentation platforms. To overcome these limitations a novel software architecture is proposed, called WiSHFUL, devised to allow: i) maximal exploitation of radio functionalities available in current radio chips, and ii) clean separation between the logic for optimizing the radio protocols (i.e. radio control) and the definition of these protocols.

Demand Response for Integrating Photovoltaic Plants in Lampedusa Island

This paper presents the results of a simulation study concerning different Demand Response logics applied to Electric Storage Water Heaters on the island of Lampedusa. Electric Storage Water Heaters are the devices that are primarily used on the island to produce domestic hot water. Starting from measured load profiles collected in Lampedusa, a domestic hot water consumption profile was derived, to simulate the energy usage of the Storage Water Electric Heaters during the day. This work was carried out as a preliminary feasibility study for the BloRin project, financed by cohesion funds in the Sicilian region. According to the project, which also includes the installation of domestic photov…

Charging Electric Vehicles Using Opportunistic Stopovers

The diffusion of electric vehicles asks for efficient energy replenishment, which requires geographical and temporal coordination of shared charging resources. We introduce a novel charging methodology that exploits users’ opportunistic mobility. This paper focuses on vehicle stopovers detecting potential charg- ing opportunities. Our mobility-assisted methodology protects users privacy and permits a hybrid centralized/distributed ap- proach avoiding clashes with other potential users. A preliminary analysis on our charging system, obtained with mobility data from the field, shows that among the available charging stations, some are more relevant and have a key role in serving electric vehi…

Impact of LTE’s Periodic Interference on Heterogeneous Wi-Fi Transmissions

The problem of Wi-Fi and LTE coexistence has been significantly debated in the last years, with the emergence of LTE extensions enabling the utilization of unlicensed spectrum for carrier aggregation. Rather than focusing on the problem of resource sharing between the two technologies, in this paper, we study the effects of LTE's structured transmissions on the Wi-Fi random access protocol. We show how the scheduling of periodic LTE transmissions modifies the behavior of 802.11's distributed coordination function (DCF), leading to a degradation of Wi-Fi performance, both in terms of channel utilization efficiency and in terms of channel access fairness. We also discuss the applicability and…

Blockchain for power systems:Current trends and future applications

Abstract Today, the blockchain is synonymous of technological innovation, being recognized among the 10 top strategy technologies in 2018 by the consulting company Gartner, it is more and more adopted in different sectors. However, the initial enthusiasm around this technology is going beyond the peak of inflated expectations, towards more stable applications in money transactions, cryptocurrencies and Digital Commodity Exchanges. Essentially, misguided efforts, the overuse of blockchain, and the Bitcoin's price drop have been the main reasons for this decay in expectations. Nevertheless, the exploitation of the blockchain technology in the power systems area appears largely underexplored, …

Certifying battery usage for V2G and second life with a blockchain-based framework

This paper describes a blockchain-based approach for sharing data among all the actors involved in Vehicle-to-Grid programs. The shared information is used both for monitoring the health status of the vehicle’s battery and for remuneration in Vehicle-to-Grid programs. A blockchain platform and a set of appropriate smart contracts have been developed for supporting the interactions among the different actors and for creating battery usage profiles. To protect sensitive data, we limit the visibility scope of such data only to subsets of actors using blockchain channels. This approach preserves the privacy of the car owner on one hand and guarantees the compliance to correct charging and disch…

Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks

The Blockchain in Microgrids for Transacting Energy and Attributing Losses

In recent years novel models for energy distribu- tion appeared and islanded microgrids quest for new ways to exchange energy between consumers and producers without the need of central authorities. The blockchain mechanism has emerged as a distributed solution for recording energy transactions in power systems. The blockchain has been used to permit users bartering and selling energy and to keep track of such exchanges without exposing them to tampering. In this work, we consider a novel application of the blockchain in islanded microgrids that includes also annotating energy losses caused by energy transactions, in order to have a more realistic matching between the physical status of the…

Wireless MAC Processor Networking: A Control Architecture for Expressing and Implementing High-Level Adaptation Policies in WLANs

The current proliferation of unplanned wireless local area networks (WLANs) is creating the need for implementing different adaptation strategies to improve network performance under mutating and evolving interference scenarios. In this article, we envision a new solution for expressing and implementing high-level adaptation policies in WLANs, in contrast to the current approaches based on vendor-specific implementations. We exploit the hardware abstraction interface recently proposed by the wireless medium access control (MAC) processor (WMP) architecture and some flow-control concepts similar to the Openflow model for defining MAC adaptation policies. A simple control architecture for dis…

DLT, BLOCKCHAIN E SMART CONTRACT

La tecnologia blockchain nasce nel 2008 con l’annuncio di BitCoin [1], una delle più diffuse criptovalute. Il ruolo fondamentale della blockchain nell’ambito delle criptovalute è quello di garantire l’impossibilità di spendere due volte lo stesso valore in transazioni successive, fattispecie che viene indicata nel mondo anglosassone come double spending. Il problema del double spending è di difficile soluzione quando l’informazione di un valore è espressa in formato digitale, il quale ben si presta alla riproduzione di copie identiche consentendo quindi di spendere quel valore più volte. Il problema è superabile in presenza di una entità centralizzata fidata, quale ad esempio una banca, ma …

MAClets: Active MAC Protocols over hard-coded devices

We introduce MAClets, software programs uploaded and executed on-demand over wireless cards, and devised to change the card's real-time medium access control operation. MAClets permit seamless reconfiguration of the MAC stack, so as to adapt it to mutated context and spectrum conditions and perform tailored performance optimizations hardly accountable by an once-for-all protocol stack design. Following traditional active networking principles, MAClets can be directly conveyed within data packets and executed on hard-coded devices acting as virtual MAC machines. Indeed, rather than executing a pre-defined protocol, we envision a new architecture for wireless cards based on a protocol interpr…

Deploying Virtual MAC Protocols Over a Shared Access Infrastructure Using MAClets

Network virtualization has been extensively researched in the last years as a key enabler for improving the network performance. However, virtualization in wireless networks pose some unique challenges: first, the usual over-provisioning approach for providing isolation between multiple virtual entities is not viable; second, the partitioning criteria are often ambiguous, since the actual resources perceived by each entity depend on many external (and time-varying) factors. In this demo, we show an effective virtualization solution for wireless local area networks, solving the problem of isolation and flexible resource paritioning, based on the concept of MAClets. MAClets are software progr…

Fading mitigation coding techniques for space to ground free space optical communications (Euro Med Telco 2014)

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links.

Blockchain-based DR logic: a trade-off between system operator's and customer's needs

This paper describes a way to include the end users of the electrical network in the Demand Response mechanism using the Blockchain technology and the Smart Contract concepts, thus developing a distributed system where customers can communicate directly with the system operator to provide their flexibility in a transparent, secure and traceable way.The historical data on energy consumption and production of the customers is recorded on the Blockchain, with the Smart Contract evaluating the baseline and the potential support that each customer can provide to fulfill the requested load adaptation communicated by the grid operator. The baseline and the optimal power reduction for a customer (e…

Fading mitigation coding techniques for space to ground free space optical communications

A Technical Approach to the Energy Blockchain in Microgrids

The present paper considers some technical issues related to the “energy blockchain” paradigm applied to microgrids. In particular, what appears from the study is that the superposition of energy transactions in a microgrid creates a variation of the power losses in all the branches of the microgrid. Traditional power losses allocation in distribution systems takes into account only generators while, in this paper, a real-time attribution of power losses to each transaction involving one generator and one load node is done by defining some suitable indices. Besides, the presence of P–V nodes increases the level of reactive flows and provides a more complex technical perspective. For this re…

Cross-technology wireless experimentation: Improving 802.11 and 802.15.4e coexistence

In this demo we demonstrate the functionalities of a novel experimentation framework, called WiSHFUL, that facilitates the prototyping and experimental validation of innovative solutions for heterogeneous wireless networks, including cross-technology coordination mechanisms. The framework supports a clean separation between the definition of the logic for optimizing the behaviors of wireless devices and the underlying device capabilities, by means of a unifying platform-independent control interface and programming model. The use of the framework is demonstrated through two representative use cases, where medium access is coordinated between IEEE-802.11 and IEEE-802.15.4 networks.

Method of changing the operation of wireless network nodes

The Peer Observation: “Mentore” Project at University of Palermo

During the last 6 years at the University of Palermo, a group of academics has been involved in a project called “MENTORE” (“Modifying and ENhancing Teaching through peer Observation and Reflections with Experts.”) The objectives of the project are to help teachers improve their teaching, through the help of two mentors; to experiment new approaches in pilot courses to extend, if useful, to other ones; and to change the traditional model of academic teaching based on one single teacher with the class to go toward a model where there is a group of teachers working together in search of improvements. All the participants of the MENTORE project attend to lectures/workshops on teaching and lear…

A Remuneration Model of Energy Community Members in Italy

The Directive (EU) 2018/2001 (RED II) requires Member States to authorize the constitution of consumers as self-consumers of renewable electricity by ensuring them non-discriminatory and disproportionate treatment. Member States must establish a favorable framework for promoting and facilitating the development of self-consumption, including in collective form (art. 21). According to the Directive, the granting of rights to renewable energy self-consumers who act collectively allows to increase the energy efficiency of households and helps to combat energy poverty by reducing consumption and supply tariffs. In Italy, the decree n. 162/2019 and then amended with Decree 199/2021 has partially…

A new architecture for Smart Contracts definition in Demand Response Programs

The present paper shows the possibility to use a smart contract for defining a distributed Demand Response mechanism. The use of the blockchain and smart contracts for the Demand Response mechanism allows the creation of an automatic system, where network users can communicate with the DSO to provide their flexibility. The blockchain ensures that the same information is shared among the users of the grid, while preserving user privacy. The DSO notifies the request to increase or reduce the load in a given period of the day using channels, a native abstraction of Hyperledger Fabric. The smart contract computes the support provided by each user to fulfill the requested load adaptation and aut…

E-Fairs: a Cyber-Physical System for Aggregation and Economy of Scale in e-Commerce

In recent years, the e-commerce arena has deeply changed because of the advent of new business models and the growing weight of huge global actors like Amazon. Some business models create competition between users, and the product price tends to rise (e.g., online auctions); other models, including group-buying, make users cooperate, and the price tends to go down. The present study extends the group-buying model and proposes a cyber-physical system called e-fair, in which both sellers and buyers are grouped to negotiate on a specific product or service. E-fairs minimize the global purchase price and the shipping resources respectively with the aggregation of demand and supply as well as or…

ARIANNA: a smartphone-based navigation system with human in the loop

In this paper we present a low cost navigation system, called ARIANNA, primarily designed for visually impaired people. ARIANNA (pAth Recognition for Indoor Assisted NavigatioN with Augmented perception) permits to find some points of interests in an indoor environment by following a path painted or sticked on the floor. The path is detected by the camera of the smartphone which also generates a vibration signal providing a feedback to the user for correcting his/her direction. Some special landmarks can be deployed along the path for coding additional information detectable by the camera. In order to study the practical feasibility of the ARIANNA system for human users that want to follow …

ErrorSense: Characterizing WiFi Error Patterns for Detecting ZigBee Interference

Recent years have witnessed the increasing adoption of heterogeneous wireless networks working in unlicensed ISM bands, thus creating serious problems of spectrum overcrowding. Although ZigBee, Bluetooth and WiFi networks have been natively designed for working in presence of interference, it has been observed that several performance impairments may occur because of heterogeneous sensitivity to detect or react to the presence of other technologies. In this paper we focus on the WiFi capability to detect interfering ZigBee links. Despite of the narrowband transmissions performed by ZigBee, in emerging scenarios ZigBee interference can have a significant impact on WiFi performance. Therefore…

Downlink channel access performance of NR-U: Impact of numerology and mini-slots on coexistence with Wi-Fi in the 5 GHz band

Coexistence between cellular systems and Wi-Fi gained the attention of the research community when LTE License Assisted Access (LAA) entered the unlicensed band. The recent introduction of NR-U as part of 5G introduces new coexistence opportunities because it implements scalable numerology (flexible subcarrier spacing and OFDM symbol lengths), and non-slot based scheduling (mini-slots), which considerably impact channel access. This paper analyzes the impact of NR-U settings on its coexistence with Wi-Fi networks and compares it with LAA operation using simulations and experiments. First, we propose a downlink channel access simulation model, which addresses the problem of the dependency an…

WIDAR: Bistatic WI-fi Detection And Ranging for off-the-shelf devices

The huge spread of wireless networks and the success of location-aware applications require novel indoor po- sitioning mechanisms based on existing technologies such as IEEE 802.11. Taking inspiration from the RADAR, we propose WIDAR: a bistatic WI-fi Detection And Ranging system for off- the-shelf devices. WIDAR implementation is based on the USRP2 platform and is able to locate 802.11 stations while they operate in existing legacy networks. No substitution or repositioning of the Access Points is necessary. WIDAR works passively and does not expect any dedicated action from the target WiFi node. No airtime is wasted and the target cannot even detect that it is being ranged. Such features …

Fading mitigation coding techniques for space to ground free space optical communications

In this manuscript, a Geostationary satellite-toground Free Space Optics (FSO) downlink channel model has been implemented, which is able to predict temporal irradiance fluctuations caused by scintillation at a wide range of turbulence conditions and for different values of the zenith angle. In order to mitigate fading events that occur in FSO communications, we have also tested the performance of three different families of Rateless Codes (Luby Transform, Raptor and RaptorQ) into our model and found that RaptorQ is the best candidate to mitigate errors in FSO links. Keywords— Optical Wireless Communications; Space-toGround FSO links, time-series, rateless codes; fading mitigation

Control Architecture for Wireless MAC Processor Networking

Abstract: In these years, the proliferation of unplanned WLANs is creating the need of implementing different adaptation strategies for improving the network per- formance under mutating and evolving interference scenarios. Many vendors pro- pose undisclosed MAC/PHY optimization solutions, such as ambient noise immunity schemes, dynamic tuning of operating channels and contention parameters, etc., rely- ing on low-level implementations in the card hardware/firmware. In this paper we envision a new solution for expressing and implementing high-level adaptation policies in WLANs, in contrast to the current approaches based on vendor- specific implementations. We exploit the hardware abstracti…

e-Fair: Aggregation in e-Commerce for Exploiting Economies of Scale

In recent years, many new and interesting models of successful online business have been developed, including competitive models such as auctions, where the product price tends to rise, and group-buying, where users cooperate obtaining a dynamic price that tends to go down. We propose the e-fair as a business model for social commerce, where both sellers and buyers are grouped to maximize benefits. e-Fairs extend the group-buying model aggregating demand and supply for price optimization as well as consolidating shipments and optimize withdrawals for guaranteeing additional savings. e-Fairs work upon multiple dimensions: time to aggregate buyers, their geographical distribution, price/quant…