smart cities as an application of internet of things

7/23/2019 Smart Cities as an Application of Internet of Things

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Smart cities as an application of Internet of Things:

Experiences and lessons learnt in Barcelona

Tomas GeaBarcelona City CouncilBarcelona, Spain

[email protected]

Mariano Lamarca

Institut Municipal d’Informàtica de Barcelona

Barcelona, [email protected]

Josep ParadellsUniversitat Politécnica de Catalunya UPC

Barcelona, Spain [email protected]

David Roldán

Ubiquitous Internet Technologies Uniti2CAT FoundationBarcelona, Spain

[email protected]

Abstract— Internet of things is a ubiquitous technology thatwill be present everywhere. One of the first applications will be

smart cities. Cities are growing in population and citizens demand

better services from the administration without increasing taxes.

The only way to attend this demand is to improve information and

how this is treated to take decisions. In other words, we should

make the city smart. Smart cities are a novel concept that defines

new technologies but also reuses some of the existing ones. All

novel solutions phase the same problem: the lack of standards and

widely accepted solutions. The City of Barcelona with the

collaboration from research centers and industrial partners has

been testing the smart city concept with the double purpose to

contribute to the creation of standards and providing in the interim

a solution to cope with the heterogeneity of providers, in particular

from the wireless sensor part. This work has been structured as a

“Barcelona Intelligent City” project or BCI. BCI project considers

all the steps of the data process from its capture by a sensor

network to the processing to make it relevant (pointing events that

requires attention) and rich (with context information).

Conclusions from the pilots has started to be applied. One example

is the sensoring in civil works control. This paper includes some

lines about Avinguda de l’Estatut Civil Works Project and its

conclusions.

Keywords—smart, wireless sensor network, standards,

heterogeneity.

I. I NTRODUCTION

In recent years, Wireless Sensor Networks has taken specialrelevance in the field of R&D&I, for example, in the area of

Smart City. Although several descriptions about Smart Citiesare possible, they can be described as those cities that applyICT (Information and Communication Technologies) with theaim of providing an infrastructure which, to some extent,ensures sustainable development, increases the citizens qualityof life as well as the efficiency in resource usage (both personaland equipment) and improves citizen participation.

Nowadays Smart Cities are not directly related to onespecific technology or set of technologies. In contrary, they arerather linked to those technologies that can generate data

referent to the city as well as allow interaction within itselements. The word “smart” is used as a synonym for

providing a set of rules and algorithms with differentcomplexity, which combines different types of information inorder to assist decision taking procedures. In sensor networks,Smart Cities require different types of technologies, both at ahardware level of the nodes themselves (transducers, signalconditioning, communication links, energy harvesting, and soon) and at the application level (for instance: data presentation,geolocation or web integration).

In turn, most of the technologies involved in Smart Citieshave either their own standards, are proprietary technologies orchosen by each company as their own solutions. In addition,according our experience the equipment used for sensoring is

very heterogeneous. This fact is due to the existence ofmultiple providers, technologies, management systems, and soon. This is a reality that needs to be considered since thesuccess and viability of Smart Cities future platforms coulddepend on it.

Therefore, a new approach is needed, in order to allow theintegration of the different systems than can be used to get datafrom the city. This approach, in addition, has to facilitate newdeployments and the inclusion of new providers. Thedevelopment of standards or the adoption of standards widelyaccepted will solve the problem, but as this might take severalyears, if it becomes a reality, in the meantime a temporalsolution will be needed.

There are several possible solutions being developed in thecontext of the Smart Cities. In this paper, we propose a solution

based on two elements: the adoption of open standards and theusage of flexible platforms to build a multivendor system. Thisapproach is the one proposed and developed in the BarcelonaSmart City project.

The rest of the paper is organized as follows: Section 2contains an overview on the aspects considered in thedefinition of the BCI project and other projects of BarcelonaCity council. In Section 3 some details about the solutions

2013 Seventh International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing

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DOI 10.1109/IMIS.2013.158

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adopted and implementation are given. Section 4 describes animplementation of the solution and finally section 5 describesthe work to be done and offers conclusions reached so far.

II. PROJECT DEFINITION

Barcelona has deployed its telecommunications network inthe period 2007-12 with a wireless extension to reach any pointof the public space. This network has the aim to provideservices to the citizens and corporate workers. This networkcan be used as a backbone of a sensor and actuator network.This allows a better control of the city and the possibility to

build applications that take profit from all the informationavailable. With this idea in mind the City starts its participationon several sensoring test projects in its streets withtechnological qualified partners (Abertis, AIA, Arelsa, DOXAAventia, Cisco, Endesa, Indra, Libellium, Urbiotica,Worldsensing, Zolertia,…) and Universities and ResearchCenters (UPC, i2cat, UPF, UOC, BDigital,…). In figure 1 isshown the principal test area at 22@ District.

These projects start deploying different type of sensors andfinishes with the Barcelona Smart City project [1] that offers a

platform to collect information and building services. Whenthis project finishes, Barcelona has started using the lessonslearned to build real applications, such the one used to controlcivil works and presented in the paper.

Barcelona Smart City aims are defining, designing and

developing a reference model of a network management

platform and sensor data for a Smart City and finally

validation it in a major city such as Barcelona. The ultimate

goal is to allow this model to be adopted by any other citiesaround the world. Some secondary objectives are the

following:

• Design and validate a communications network thatcan be used as a backhaul for a variety of sensornetworks and from different manufacturers.

•

Define and validate a framework based on openstandards, avoiding proprietary solutions.

• Develop a platform that is fully applicable both to largeand small cities, including metropolitan areas

• Study, implement and validate the most suitableservice and business models for the optimization of

public management.

The BCI project covers the whole value chain rangingfrom the sensors in charge of capturing data to the exploitationof data from third parties passing by its transmission and

management. BCI summarizes all the experiences obtained in previous pilots, mainly the one called BarcelonaSens (2009).

The first phase of the BCI project has consisted in the

development of a technical and functional analysis in order todefine all the requirements for the smart city platform. Theserequirements will consolidate the specifications and thefoundations for the future implementations, both in Barcelona

and other cities. The final target is to define a value-addedsystem that allows using the technology forward the best

services to the citizen, the city council and even the local business with the intention of offering new and better cityservices, more efficient public management and improving the

quality of life.

Once the requirements has been developed the architectureof the system and the functional model has been obtained.

In Figure 2 the architecture model applied in the projects isshown, including the specified proposed protocols. There asystem of data bases that implements the conceptual City

Council Data Warehouse. The access to this data is made

available to third parties following an Open Data model withweb services or other tools controlled by an interoperability

platform. Lower layers include the corporate informationsystem, the management and control platforms, the transport

network, the concentration function and finally, at the bottom,sensors and actuators devices in the field.

Figure 1 - Map of the area in the 22@ business district usedas a pilot site for the different smart city projects. Some detail

is given about the type and location of the sensors)

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III. IMPLEMENTATION

The existence of a variety of sensors networks that providedata in different formats, and a network infrastructure that cantransport the data to a management element is assumed to beoperative in the place.

The main goal is to develop a system able to cope with thisvariety of solutions, and that at the same time offers one single

point of storage for the data, with a uniform representation ofinformation and supporting mechanisms for data analysis anddata exploitation for third parties.

In addition of the complexity of the problem itself, it isneeded to consider the city is not isolated and has some

previous deployed vertical solutions. The City has strongrelationship with other entities like municipalities, regionalgovernment agencies, army, international organizations,enterprises, etc… These entities could provide informationuseful for the city and/or could need information about the dataresults of the city sensors. To fulfill this requirement it isneeded to have functionalities to understand informationacquired from third parties and to offer an interface to provideinformation.

A.

Sensor Capabilities

The BCI proposed model has used as a sensor base for thedeployment already available in the city, in particular the onein the area of the 22@1, which was built in the context of 22@Urban Lab project [2] and promoted by the BarcelonaMunicipality. The objective of this deployment was validatingthe solution and analyzing the applicability of the data obtainedindependently of manufacturer and technology.

Nowadays, Barcelona City council is trying to integrate allthe different types of sensors installed in the different pilotsand in the areas with services following the experience of BCIProject. A large variety of sensors are available such forexample: acoustic sensors, temperature, humidity, gas, specificsmells, radiation, smart metering and level sensors used tomeasure garbage containers spare capacity.

B. Gateway

In order to integrate these different infrastructures (sensornetworks) available and to minimize the number of platformsdeployed in the city, the BCI project proposes to develop agateway that supports the connectivity of the multiple sensornetworks and multiple transport networks.

So far four types of wireless sensor networks are supported,a raw solution using 802.15.4 radio, a ZigBee 2007, a RIMEstack used with the Contiki operating system and6LoWPAN/IPv6/RPL/UDP/CoAP interface available withContiki and TinyOS operating system.

The gateway differentiates three types of information: datathat is translated to a common format, sensor networkmanagement information that should be kept proprietary for

each provider and gateway management info that should beeasy to integrate in the existing network management platforms.

The connection of the gateway to the Internet can be doneusing the most common interfaces: Ethernet, Wi-Fi andCellular (GPRS, 3G and HSPA). Other interfaces, not socommon, can also be added (such for example WiMAX). The

board offers two Gigabit Ethernet interfaces with RJ-45connector. Any of the two supports Passive Power OverEthernet. Also serial interfaces such USB, RS232 or RS485 are

Figure 2 - Architecture model of the Smart City

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available. In the specific case of Barcelona the connection ofthe gateway is over the municipality network and using

powering facilities deployed on purpose.

The Wi-Fi interface is very flexible since the gateway can be configured as an access point, as a client to be connected toan access point and also as peer to peer to support meshnetworking. With the present hardware based on an Atheroschipset the Wi-Fi interfaces supported are IEEE802.11b/a/gwith WEP, WPA and WPA2 security. The Barcelonamunicipality uses IEEE802.1x protocol to authenticate andauthorize devices connected to the network to supportindividual access control of each node connected to thenetwork.

C. Transport Network

The Barcelona Municipality has a corporate network usingstate of the art technologies and a wide coverage: 380 km ofoptical fiber and more than 2000 Access Points define thecorporate network. At the lowest level of the access networkthere is a capillarity that offers Ethernet, Wi-Fi, WIMAX, andcellular access. Depending on the location one of the listed

access options can be the most suitable but others should bekept as backup.

For this reason the BCI gateway offer these types ofconnectivity in one single hardware and software version.

D. Data Management

There is a part of the system that hosts and manages thedata base and supports intelligence modules intended to

identify patterns and events that result relevant for themanagement of the city infrastructure. The data management

also offers web services to make available the raw and processed data to third parties in charge of exploiting the data.The main difficulty of this element is to support the variety ofsensor nodes and large volume of information that a city can

generate.

To facilitate the data transfer and data availability to third

parties the BCI project uses two ways to code informationfrom sensors. The one used for transport inside the corporatenetwork uses JSON coding and a HTTP REST model forgateway polling and notification, following the work done at

the CoRE working group of the IETF [3]. This solution has been adopted in front of XML to reduce the bandwidth needed

in case of using a cellular interface. To minimize theinteraction with sensors the gateways performs functions of

proxy web. In this way if a sensor has been interrogated once,

later requests can be replied with the data stored in the cacheof the proxy. The gateway also supports the usage of CoAP,

even it is not used at this phase of the project. From the data bases to third parties the format used is XML following theSensorML encoding [4] defined by OGC. This solution allowsa detailed description of the data and its interoperability since

it is widely accepted by the community.

E. Intelligence

The large volume of information that can be collected it isnot only difficult to handle, it is difficult to analyze and toderive indications about alarms or trends that can result in

problems in the long term. To cope with the difficulty the BCI project has incorporated an intelligent module that is able tocorrelate data in time and space to identify potential problems.The indications generated should be validated by humanoperators to verify the indication and to feed the learningcapability of the intelligent module.

Barcelona City council considers the possibility of performintelligent and security tools at three levels: application level,datawarehouse level and gateway level. The services with lowlatency require Gateway intelligence. The common intelligencemodules will be placed at datawarehouse level and maybe eachservice needs specific intelligence modules.

F. Front-End Applications

In BCI project, an intelligent front-end application that provides Smart Services to the citizens and to the municipalityworkers, helping them to access and understand theinformation, has been developed.

The front-end application has access both to the raw andrich data (the ones available once processed), offers them to thefinal user in a friendly manner and collects all the requests andactions to perform in the city from them.

The proposed model has been validated in a real scenariosuch as the city of Barcelona. This validation phase showedthat the system developed was able to integrate the alreadydeployed sensors networks with the new ones. An intelligentfront-end application that provides Smart Services to thecitizens, helping them to consult and understand theinformation, has been developed. It is based on the latest webtechnologies, data processing and presentation.

IV. APPLICATION

Once the model proposed has been validated in pilots it

arrives to a mature status to be implemented in realdeployments. The first one was the usage it to control theenvironmental impact in a civil work.

In order to make an effective work of control the

Environment Department of Barcelona City Council haslaunched the monitoring of air pollution and noise parametersof the works of urbanization of the area of “Estatut” avenue.This work aims to make the rehabilitation of an Avenue, in a

degrade area of the city that needed improvements on mobility(vehicle and pedestrians) and with services for residents.

These works started in 2011 and they are about to finish inJuly of 2013.

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The Department of Environment, responsible of thecontract of the urbanization collaborates with the technicalareas and IT Department of the Municipality (IMI) in order to

control the effect of their works in the surrounding areas. Theydefine the measurement ranges, the user interface, the list of

potential users and maximum allowed values of the parameters that produce impact on the life of citizens. They

decided to use sensors of sound, amount of particles on the air(PM10), gases (NO, CO

2), movement (cameras) and level of

the water table.

The water table level measurement was installed in theground and the rest of the sensors were grouped in eight sitesbuild over light poles with solar energy and lithium batteries.

Two radio interfaces were used (IEEE802.15.4 andIEEE802.11) for communication between the sensors andtransport network that cover the area were the urbanizationworks were done. The transport network has been build with aWI-FI/WiMAX mesh network with five active nodes. Thenetwork is self configuring so the location of sensors can bechanged as the works are done without any furtherconfiguration. The information is delivered to the centraltransform using a redundant connection based on a fiber opticand a GPRS connection.

This deployment offers a solution to the monitoring ofdifferent parameters, it uses one single point of storage for the

data, with a uniform representation and supportingmechanisms for data analysis and data exploitation for third

parties.

The data obtained was used to control de impact of the

municipality works on the citizens and to define a set ofenvironmental requirements to the construction companies to

be fulfilled during the works.

V. CONCLUSIONS AND FUTURE WORKS

The project of building a smart city suffered at its initial

phases the lack of standards. This problem becomes evenworse if the aim is to build a non proprietary solution. A smart

city has to satisfy requirements from the public administration,companies providing services to the citizen on behalf of the

administration, the citizens and third parties that want to get profit from the information obtained by the smart city

infrastructure. The results obtained so far are a networkarchitecture that overlays on an existing infrastructure and

with minimal modifications fulfils the pointed objectives. Thekey components of this architecture are a gateway able toconcentrate equipments from different sensor networks,

providing uniform interfaces for data gathering andmanagement. The second key element is the selection of data

encoding standards and protocols for handling them, widelyaccepted facto standards, when possible.

Knowing that the best solution would be the existence of

open standards to support a plug-in play approach the project

offers an interim solution that uses open and well acceptedsolutions.

Following the conclusions of the pilots, mainly BCI andAv. Estatut Project, Barcelona City council have taken somestrategic decisions towards building smart cities based on the

IoT principles. In the following lines main conclusions aresummarized:

• City council workers (policemen, fire-fighters,

inspectors,..) define the physical parameters that will bemeasured, what kind of sensors will be used for a specificservice, how install these sensors in the street and how

deliver the information to municipality workers, trustedthird parties and citizens.

•

A set of requirements has been identified to facilitate the

deployment of a wireless sensor network:

o Transport network is based in TCP/IP protocols (IP

version 4 with tunneling for the IP version 6) over WI-FI, WiMAX, Ethernet.

o Access network should allow easy internetworking

with the transport networks so they should be able totransport IP packets. In particular intended technologies

are: WI-FI, Bluetooth, ZigBee IP corresponding toSmart Energy Profile Version 2.0 and 6LoWPAN on

top of IEEE802.15.4e when possible.

o When used, batteries should be Lithium to achieve long

duration and minimum impact to the environment.

o All the elements deployed should provide informationabout its location and should be remotely managed.

• The interaction between gateways and the data warehouse

and from it to the application will follow a REST(Representational State Transfer) model using HTTP.

• An extension of the language used to exchangeinformation on existing elements is being done to

Figure 3 - Drawing of the affected area and it final

aspect.

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anticipate the introduction of new information sources

and actuation elements.

As the technology evolves rapidly the list of potentialtransport and access technologies can change, but there is aclear compromise with the usage of IP, and as a consequence

with the Internet of Things.

The list of recommendations is the result of several pilotsapplied to the Barcelona Municipality. Other cities with other

interests and background may reach other recommendations.

ACKNOWLEDGMENTS

BCI is carried out by a consortium of companies, academic partners and research centers. The components of the

consortium are: Abertis Telecom (leader of the project), Doxa,Aventia, AIA, Institut Municipal d’Informàtica (IMI),Universitat Politècnica de Catalunya (UPC) and i2CAT, which

make a well balanced consortium.

This work is partially funded by Departament d’Empresa i

Ocupació (Generalitat de Catalunya) with the support of theEuropean Union.

The authors also thank the funding from project TIN2010-

20136-C03-03.

R EFERENCES

[1] Barcelona Smart City project web site;http://smartbarcelona.cat/en/.

[2] 22@ Urban Lab project:

http://www.22barcelona.com/content/view/698/897/lang,en/.

[3] IETF CoRE Working Group ,https://datatracker.ietf.org/wg/core/charter/

[4] Web site of the SensorML initiative.

http://www.opengeospatial.org/standards/sensorml

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smart cities as an application of internet of things

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