INTERNET OF THINGS FOR SMART CITIES BY ZANELLA ET AL.

Transcription

1 INTERNET OF THINGS FOR SMART CITIES BY ZANELLA ET AL. From IEEE INTERNET OF THINGS JOURNAL, VOL. 1, NO. 1, FEBRUARY 2014 Presented by: Abid Contents Objective Introduction Smart City Concept & Services Smart City Challenges Urban IoT Architecture An Experimental Study Padova Smart City Conclusion 2 1

2 Objective of the paper This paper provides a comprehensive survey of the enabling technologies, protocols, and architecture for an urban IoT. Furthermore, the paper will present and discuss the technical solutions and bestpractice guidelines adopted in the Padova Smart City project, a proof-of-concept deployment of an IoT island in the city of Padova, Italy, performed in collaboration with the city municipality. 3 Introduction The Internet of Things (IoT) is a recent communication paradigm that envisions A near future The objectives of everyday life will be equipped with microcontrollers, transceivers for digital communication Suitable protocol stacks that will make them able to communicate with one another and with the users, becoming an integral part of the internet. 4 2

3 Continued.. By enabling easy access and interaction with ta wide variety of devices such as, for instance, home appliances, surveillance cameras, sensors, vehicles and so on, the IoT will foster the development of a number of applications that make use of the potentially enormous amount and variety of data generated by such objects to provide new services to citizens, companies and all revenant public administrations. In complex scenario, application of IoT paradigm to an Urban context is of particular interest As it responds to the strong push of many national governments to adopt ICT solutions Management of public affairs, thus realizing the so-called Smart City concept 5 SMART CITY CONCEPT AND SERVICES 6 3

4 Smart City Definition Working Definition A Smart City connects human capital, social capital and ICT infrastructure in order to address public issues, achieve a sustainable development and increase the quality of life of its citizens. ICT Factor Use of Information and Communication Technologies (ICT) as a mean to achieve its objectives. ICT as tool for the improvement of the city Smart City Goals Achieve a sustainable development. Increase the quality of life of its citizens. Improve the efficiency of the existing and new infrastructure. 7 Smart City Services Services offered by Smart city Structural health of building Urban IoT may provide a distributed database of building structural integrity measurements, collected by suitable sensors located in the buildings. Noise Monitoring An urban IoT can offer a noise monitoring service to measure the amount of noise produced at any given time in the places that adopt the service. Waste Management A deeper penetration of ICT solutions in this domain, may result in significant savings and economical and ecological advantages. City Energy Consumption Together with air quality monitoring service, an urban IoT may provide a service to monitor the energy consumption of the whole city. Air quality An Urban IoT can provide means to monitor the quality of air in crowded areas, parks or fitness trails. Traffic congestion On the same line of air quality and noise monitoring, a possible Smart City service that can be enabled by Urban IoT consists in monitoring the traffic congestion in the city. 8 4

5 Smart City Services Continued.. Smart Lighting This service in particular can optimize the street lamp intensity according to time of the day, the weather conditions and the presence of the people. Automation & Salubrity of Public buildings Another important application of IoT technologies is the monitoring of the energy consumption and the salubrity of the environment in public buildings by means of different types of sensors and actuators that control lights, temperature and humidity. Smart Parking Smart parking service is based on road sensors and intelligent displays that direct motorists along the best path for parking in the city 9 Services Specifications for Padova Smart City Project Source: Zanella et al.: Internet of Things for Smart Cities 10 5

6 Smart City Challenges Political Barrier Attribution of decision-making power to the different stake holders. Technical Barrier The most relevant issue consists in the no interoperability of the heterogeneous technologies currently used in the city and urban developments. Financial Dimension A clear business model for smart city is still lacking, although some initiative to fill this gap has been recently taken. 11 URBAN IOT ARCHITECTURE 12 6

7 Urban IoT Architecture From earlier discussion, it clearly emerges that most Smart City services are based on a centralized architecture, where a dense and heterogeneous set of peripheral devices deployed over the urban area generate different types of data that are then delivered through suitable communication technologies to a control Center where data storage and processing takes place as shown in fig 1. This article will discuss three different components of an urban IoT system Web Service Approach for IoT Service Architechture Link Layer Technologies Devices Fig 1. Conceptual Representation of an Urban IoT network based on 13 the Web service approach Urban IoT Architecture Web Service Approach The IETF standards for IoT embrace a web service architecture for IoT services, which has been widely documented in the literature as a very promising and flexible approach web services permit to realize a flexible and interoperable system that can be extended to IoT nodes, through the adoption of the web-based paradigm known as Representational State Transfer (ReST) Fig 2. shows reference protocol architecture for Urban IoT systems that entails both an unconstrained and constrained protocol stacks. Three distinct functional layers are identified a) Data Format b) Application and Transport Layers c) Network Layer Fig 2. Protocol stacks for unconstrained (left) and constrained (right) IoT nodes. 14 7

8 Urban IoT Architecture Web Service Approach a) Data Format XML is used as the semantic representation language in architectures based on web services The size of XML messages often too large for limited capacity of typical devices for IoT EXI format makes it possible for very constrained devices to natively support and generate message using an open data format compatible with XML Fig 2. Protocol stacks for unconstrained (left) and constrained (right) IoT nodes. 15 Urban IoT Architecture Web Service Approach b) Application and Transport Layer Most of the traffic that crosses internet nowadays is carried at the application layer by http over TCP. Verbosity and complexity of native HTTP make it unsuitable for a straight deployment on constraint IoT devices HTTP relies on TCP transport protocol doesn t scale well on constraint devices, yielding poor performance for small data flows in lossy environment Solution : CoAP protocol, proposing binary format transported over UDP cross proxy, straightforwardly translate requests/responses between HTTP and CoAP Fig 2. Protocol stacks for unconstrained (left) and constrained (right) IoT nodes. 16 8

9 Urban IoT Architecture Web Service Approach c) Network Layer IoT networks are expected to include billions of nodes, each shall be uniquely addressable IPv4 exhaustion, solution: IPv6 Problem : overheads of IPv6 are not compatible with scarce capabilities and constrained nodes Solution : 6LowPAN, which is an established compression format for IPv6 Border router, a device directly attached to 6LowPAN network, performs the conversion between IPv6 and 6LowPAN Fig 2. Protocol stacks for unconstrained (left) and constrained (right) IoT nodes. 17 Urban IoT Architecture Link Layer Technologies Link Layer technologies for IoT are classified into Unconstrained and Constrained technologies Unconstrained Technologies This kind of technologies includes all traditional LAN, MAN, WAN communication technologies, such as Ethernet, WiFi, fiber optics, broadband Power Line communication and cellular technologies such as UMTS and LTE. Characteristics include high reliability, low latency and high transfer rate. Due to inherent complexity and energy consumption, these kind of technologies are not suitable for peripheral IoT nodes. Constrained Technologies It includes IEEE , Bluetooth, Bluetooth low energy, IEEE low power, PLC NFC and RFID. Characteristics include low energy consumption, low transfer rate as compared to Unconstrained Technologies (typically less than 1 Mbit/s ) 18 9

10 Urban IoT Architecture Devices Below are the devices that are essential to realize an urban Io, classified based on the position they Backend Servers At the root of the system, backend servers are being found, located in the control centre, where data are collected, stored and processed to produce added-value services. Backend systems commonly considered for interfacing with the IoT data feeders include the following Data base Management Systems Websites Enterprise Resource planning systems (ERP) Gateways At the edge of IoT, gateways role is to interconnect the end devices to the main communication infrastructure of the system. IoT Peripheral Nodes At the periphery of the IoT systems, IoT peripheral nodes or simply IoT nodes are in charge of producing the data to be delivered to the control centre. 19 Urban IoT Architecture Devices Below are the devices that are essential to realize an urban Io, classified based on the position they Backend Servers At the root of the system, backend servers are being found, located in the control centre, where data are collected, stored and processed to produce added-value services. Backend systems commonly considered for interfacing with the IoT data feeders include the following Data base Management Systems Websites Enterprise Resource planning systems (ERP) Gateways At the edge of IoT, gateways role is to interconnect the end devices to the main communication infrastructure of the system. IoT Peripheral Nodes At the periphery of the IoT systems, IoT peripheral nodes or simply IoT nodes are in charge of producing the data to be delivered to the control centre. May be classified based on wide number of characteristics, such as empowering mode and supported link layer technologies 20 10

11 Urban IoT Architecture Devices Below are the devices that are essential to realize an urban Io, classified based on the position they Backend Servers At the root of the system, backend servers are being found, located in the control centre, where data are collected, stored and processed to produce added-value services. Backend systems commonly considered for interfacing with the IoT data feeders include the following Data base Management Systems Websites Enterprise Resource planning systems (ERP) Gateways At the edge of IoT, gateways role is to interconnect the end devices to the main communication infrastructure of the system. IoT Peripheral Nodes At the periphery of the IoT systems, IoT peripheral nodes or simply IoT nodes are in charge of producing the data to be delivered to the control centre. May be classified based on wide number of characteristics, such as empowering mode and supported link layer technologies 21 AN EXPERIMENTAL STUDY: PADOVA SMART CITY 22 11

12 Padova Smart City Practical implementation of an urban IoT named Padova Smart City that has been realized in the city of Padova. Primary goal of Padova Smart City The primary goal of Padova Smart City is to promote early adoption of open data and ICT solutions in the public administration. Fig 3:System Architecture of Padova Smart City 23 Padova Smart City Components Street Light WSN Gateway Constrained link layer Technologies Database Server Proxy Operator Mobile Device HTTP-CoAP All above components work together to create Padova Smart City urban IoT 24 12

13 Padova Smart City Components Street light: It is the leaf part of the system where IoT nodes are placed. Each street light is geographically localized on the city map and uniquely associated to the IoT node attached to it, so that IoT data can be enhanced with context information. Constrained link layer technologies The IoT nodes mounted on the street light poles form a 6LoWpan multihop cloud, using IEEE constrained link layer technology. WSN Gateway The gateway has the role of interfacing the constrained link layer technology used in the sensors cloud with traditional WAN technologies used to provide connectivity to the central backend servers. HTTP-CoAP proxy The HTTP-CoAP proxy enables transparent communication with CoAP devices. The proxy logic can be extended to better support monitoring applications and limit the amount of traffic injected into the IoT peripheral network. This service is located on the switchboard gateway in the Padova Smart City system, though it could also be placed in the backend servers, thus making it possible to control multiple gateways by using a single proxy instance. 25 Padova Smart City Components Cont.. Database Server The database server collects the state of the resources that need to be monitored in time by communicating with the HTTP-CoAP proxy server, which in turn takes care of retrieving the required data from the proper source. The data stored in the database are accessible through traditional web programming technologies. Operator Mobile Device Public lighting operators will be equipped with mobile devices that can locate the streetlight that requires intervention, issue actuation commands directly to the IoT node connected to the lamp, and signal the result of the intervention to the central system that can track every single lamppost and, hence, optimize the maintenance plan

14 CONCLUSION 27 Conclusion IoT is definetly a technology enabler for Smart City Smart City concept aims to improve the quality of existing services and creating new valuable services IoT urban architecture includes web services, approach, link layer technology and IoT nodes. A concrete proof-of-concept implementation, deployed in collaboration with the City of Padova, Italy, has been a living example of application of the IoT paradigm to smart cities