PROPOSAL OF AN ARCHITECTURE FOR DIGITAL CITIES

CREATION

Proposal of an Architecture P2P for Digital Cities Creation

André M. Panhan, Denys G. Santos and Leonardo S. Mendes

Communication Networks Laboratory, Communications Department, Eletrical and Computer Engineering Faculty

University of Campinas – UNICAMP - Cidade Universitária "Zeferino Vaz"- Barão Geraldo, Campinas, SP - Brazil

Keywords: Digital Cities, Middleware, Open Access Metropolitan Networks.

Abstract: The term digital cities do not have a precise definition. The number of digital cities, whose development

started from the 90s, is constantly growing. Motivated by the increase of these cities, this paper describes

architecture for digital cities environment as a proposal to create a middleware for the interconnection of the

various segments of society. This middleware is structured in a Platform for P2P networks, also known as

DHT, with emphasis in the JXTA modified protocol.

1 INTRODUCTION

Also known as Virtual City, Digital City, Intelligent

City and other names, digital cities represent a kind

of projection of a city in the digital world and

emerge as one of the forces that may contribute to

space organization (Silvia, 2002).

The digital cities can have many definitions. In

(Silvia, 2002), it is defined that digital cities are

people, systems and institutions that remain

connected through a digital communication

infrastructure. In digital cities, one uses real cities as

reference for their digital counterpart, aiming at

developing social relations of different purposes.

These include one or more of the items cited below.

- Creation of political and cultural spaces for

people and groups manifestation;

- Creation of communication channels between

individuals and groups;

- Creation of communication and negotiation

channels between municipal government and

citizens;

- Favoring a greater identification from the

visitors with the reference city;

- Creation of a collection of information from

many different species and easily accessible

on the reference city.

Digital Cities, as defined by Graham (Graham,

2007), can serve as a tool to improve communication

between citizens and local government, stimulating

many activities that promote new opportunities to

the citizens, as we identify below.

"... virtual cities are electronic spaces, generally

based on the World Wide Web, which were

developed to connect, in an explicit way, the

development schedules of each city. These virtual

cities are working as political tool for a variety of

urban plans and objectives: global urban marketing,

stimulus to business and consumption, improving

communications between citizens and local

governments, increase the local enterprise

competitiveness, greater local economies integration

and the rebirth of civic and local culture." (Graham,

2007)

Motivated by the increased number of digital

cities developed during the 90s, this article presents

an architecture for digital cities environments and a

proposal to create a middleware based on a DHT

structure to people, groups and services (public and

private) interconnections for this proposed

environment.

M. Panhan A., G. Santos D. and S. Mendes L. (2008).

PROPOSAL OF AN ARCHITECTURE FOR DIGITAL CITIES CREATION - Proposal of an Architecture P2P for Digital Cities Creation.

In Proceedings of the International Conference on e-Business, pages 89-92

DOI: 10.5220/0001910900890092

 SciTePress

2 DIGITAL CITIES

ARCHITECTURE

In (Yamaoka, 2006) it is defined a minimal set of

assumptions, policies and technical specifications

that rules the use of Information and Communication

Technologies (ICT) by the government, establishing

the conditions for interaction. This middleware

emphasizes the JXTA modified protocol, extending

the interoperability traditional models in government

for other society segments as citizens, companies

and the third sector. Our proposition is developed

based on these minimal premises.

Figure 1: Interaction with digital cities and segments

society.

The proposed architecture establishes rules on

the following areas responsible for the

interoperability of various society segments,

Interconnection, Security, Access Media and

organization and Information exchange.

For each of these areas we specify components,

for which standards are established.

2.1 Interconnection

The segment "Interconnection" establishes the rules

for enterprises (such as service or commercial

companies) and governments to interconnect

themselves upon the local network, which can be a

metropolitan network, a community network, or

even the Internet. This segment also treats the

interoperation rules of enterprises and governments

with the citizen. In this segment are defined

Electronics Message Transport, Electronics Message

Safely Content, Intercommunication LAN/ WAN

and Transportation.

2.2 Security

This segment deals with the proposed architecture

ICT security aspects that should be considered for

Digital Cities creation. We treat in this segment

security IP patterns, encryption, System

Development and Network Services.

2.3 Access Media

In the segment Access Media one explains issues

relating to devices standards, which are used to

access the services offered by Digital Cities. We also

define how devices must be treated. Some of these

devices are computers, mobile phones, hand-helds

and digital television, for example.

2.4 Organization and Information

Exchange

This segment deals with aspects related to the

processing and transfer of information among

services offered by Digital Cities. It includes

components for data exchange, data processing, data

definition and Standards Database Catalogue (SDC).

Information distribution for these situations requires

the construction of suitable metadata structures for

each of the cases above.

Clearly defined policies and specifications for

interoperability and information management are

key issues for providing the enterprise connection

among citizen, enterprise, government and service

providers. The Digital City is designed as a basic

structure for the government strategy and business in

the several business scenarios (B2B, B2C, B2G,

G2G, G2C and C2C). This approach allows the

rationalization of investments in ICT, through the

sharing, reuse and exchange of technology

resources.

Enterprises, government and services providers

information resources are valuable economic assets.

By ensuring that information or service can be

quickly located and exchanged between the public

and private sectors, keeping the privacy obligations

and security, one encourages and stimulates local

economy.

Nowadays, most of the countries of world

recognize the needs for high investments in

developing universal access to multiservice

networks for all citizens. Economic analyses show

that universal services cause a direct and almost

immediate increase in GNP. Its also understood that

universal access to services, particularly when we

talk about e-Gov services, can only be achieved

through the creation of virtual (and, sometimes, real)

local networks (or Digital Cities). In creating the

Digital Cities one is primarily concerned with

establishing policies development, procedures and

standards for ICT, mounting dedicated structures to

reach local interoperability and seeking better

quality provision services at reduced costs. The

existence of a middleware as a foundation for

ICE-B 2008 - International Conference on e-Business

electronic services creation is a pre-requisite for

better services provision at a reduced cost for all the

actors of the Digital City.

Figure 2: Proposal of Architecture for Digital Cities.

A modern knowledge society requires the

development of integrated and interoperable

intelligent systems, which must work in a safe and

consistent environment. These requirements cannot

be attained unless a common interoperable

standardized environment is established. The

middleware, whose architecture is shown in Figure

3, is also the solution for this exigency. This

architecture covers the information exchange

between the services offered by all society segments.

3 MIDDLEWARE

To create the Middleware, we propose to add an

abstract slice on JXTA architecture. This slice will

be acting as an access control to digital cities

network.

3.1 Structure

The basic structure to the proposed middleware is

based on the JXTA overlay network topology as can

be seen in Théodoloz (2004), or in Traversat (2003).

This model creates a network of Randezvous servers

to establish interconnection links among these, and

forming a complete graph, where each server is a

vertex and the connections are the edges.

In a JXTA network each server has a complete

and updated list of connected peers. Therefore, it is

possible that the search for a service in the network

be performed in a linear order when the network

servers are consistent. Otherwise, when an

inconsistency is found in the server’s network,

another mechanism must be activated to return the

identifier of a peer in time n.

Figure 3 represent the proposed architecture for

middleware model described in this paper. In this

architecture the Rx peers provide routing, the Ex

peers services and the Px peers access to the

interaction portal of Digital City.

Figure 3: Proposal of Architecture for Middleware.

Another relevant element to build a Digital City

is the creation of a protocol of multiple connections

to the peers connected to the network. In order to use

the multi-connection resources already available in

the JXTA architecture and seeking to make an

efficient use of the network and maintain its

workload low, it is proposed the creation of an

abstraction layer that keeps the peer connected to

only one Digital City. However, the protocol allows

the peer to make connections to other peers and

other Digital Cities without loosing the main

connection. This resource allows that the peer uses

services from other digital cities and, at the same

time, allows other digital cities to access its services.

To provide this resource, the abstraction layer

cannot treat the peer identifier like it is treated in the

JXTA architecture. In the proposed abstraction

layer, the peer identification must be done using a

pair of identifiers (GPID, PRID), where GPID is the

group identifier and PRID is the peer identifier.

3.2 Security

In a corporative or government communication

environment, data security is an extremely important

issue both in storage and transport of information.

To provide security in the operations of data

applications and transactions, one can use resources

offered by the JXTA API. This resource has a set of

algorithms that provide a base to security control in

the applications developed using this API.

PROPOSAL OF AN ARCHITECTURE FOR DIGITAL CITIES CREATION - Proposal of an Architecture P2P for Digital

Cities Creation

3.3 Digital City Directory

To maintain a consistent identifier services list in the

digital cities network, one can create agents

associated to the digital city portals and systems

interfaces. These agents can perform periodic

searches in the network to look for active services

and to map these services with an appropriate

description. With this map, the creation, ordering

and availability of data are responsibility of the

respective digital city through their portals and

access interfaces.

4 USE CASE

The concept of Digital City can be easily explained

how a user makes use of the digital city environment

to plan and contract a travel to a congress in another

city.

The citizen enters in the portal a make

authentication. Authentication done, the citizen

makes them registration and makes a payment with a

credit card. As the bank system also was developed

within digital city architecture, the congress page

makes a request to the bank system with totally

transparent to the user.

After registration, the citizen chooses a hotel in

the city of the congress, buy the airplanes tickets and

rent a car, paying all of this in the same bank

systems

Although these actions performed by the citizen

are familiar to the common user of the Internet, the

Internet users are not able to follow, and even

interfere in the process. In the Digital City, the user

is able to perform all these activities by accessing

only one page and yet follows all the process that

happening behind the scenes.

5 CONCLUSIONS

The creation of digital cities provides

communication channels to facilitate and improve

the relations between citizens and government,

citizen and enterprises, and enterprises and

government. This communication environment is

suitable to head these relationships because the

sophisticated identification, authentication and

security offered by the digital city middleware. For

the authenticated user, the digital city can provide an

environment rich in information and services.

The DHTs proposed in this work has as one of its

main characteristics the separation between

identifier and locator. This feature provides superior

mobility and improves security. Another important

feature of this DHT is the service doesn’t have

mapped in a physical address. The service can be

mapped in a simple name, allowing an improved

transparency with respect to migration.

To provide interoperability among different

digital cities without creating inconsistency or

service address replication, the creation of the

abstraction layer proposed in this paper is

indispensable.

ACKNOWLEDGEMENTS

The work presented here has been developed under

the umbrella of the projects “Municipal Infovia – An

Open Access Network for Cities” and “SIGM – An

Integrated e-Gov Environment for Cities”. These

projects have been supported in part by the

governments of the cities of São José do Rio Preto,

Pedreira, Penápolis, and Campinas, São Paulo State,

Brazil.

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