Lomme Devriendt Et Al Cyberplace and Cyberspace - Two Approaches to Analyzing Digital Intercity Linkages

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Cyberplace and Cyberspace: TwoApproaches to Analyzing DigitalIntercity LinkagesLomme Devriendt , Ben Derudder & Frank WitloxPublished online: 19 Jan 2009.

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Cyberplace and Cyberspace: TwoApproaches to Analyzing DigitalIntercity Linkages

Lomme Devriendt, Ben Derudder, and Frank Witlox

FROM the mid-1990s, there has been an enormous growthin the use and diversity of information and communi-cations technologies (ICT), such as global positioningsystems (GPS), virtual reality (VR), voice over Internet protocol

(VoIP), short message service (SMS), and others. The use of

webcam conversation, digital signature, real-time chat, e-mail,

and several other digital communication applications are almost

everyday practices and are indispensable in business transactions.

Traditional activities such as shopping, banking, entertaining, and

working are being progressively supplemented by numerous

e-applications such as e-working, e-shopping, e-banking, and

e-entertainment. Although the effect of this e-volution has to

be put into perspective, most e-applications complement but do

not substitute for traditional activities.

A number of e-products also generate completely new fields

of application. For instance, in order to secure or send information,

we all put information into a digital format. Castells has pointed

out that the world annual production of information in different

forms amounts to 1.5 billion gigabytes of which, in 1999, 93

percent was already produced in digital format. The availability

of this huge volume of digital information enables us to communi-

cate and derive information any time, any place.

Mokhtarian et al.

Weltevreden

Castells 2001

Journal of Urban Technology, Volume 15, Number 2, pages 532.

Copyright # 2008 by The Society of Urban Technology.All rights of reproduction in any form reserved.

ISSN: 1063-0732 paper/ISSN: 1466-1853 onlineDOI: 10.1080/10630730802401926

Cyberplace and Cyberspace 5

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The increasing use of the Internet and its applications is also

perceptible in the global interrelationships between cities. Trans-

actions of information, communication, and the facility of other

intercity linkages are altered by new ICT development. Cities

have an important long-term role in the process of globalization

as centers of information exchange. The new digital technology

strengthens this important central coordination and control func-

tion. The mix of central functions applied to societal networks

and material and human resources, when combined with the

ability to communicate or obtain information at high speed,

makes cities into major players in the global economy.

Many research workers studying the various ways in which

cities and their linkages can be understood have based their

approaches on digital intercity networks.1 The aim of this paper

is to gain a comprehensive view of the various methods available

for the analysis of virtual intercity linkages, that is, a linkage

based on ICT and not an undefined relationship. We identify

two methods, the cyberplace (CP) approach and the cyberspace

(CS) approach.

The CP concept investigates virtual intercity links as actual

connections between physical points such as those within the

network of Internet cables and their interconnections. This

approach assumes that the physical infrastructure represents the

digital relationship between places. Most research on digital inter-

city linkages is based on this approach. On the other hand, the CS

concept has to our knowledge not hitherto been employed in the

urban network context (empirical analyses such as those of Hei-

mericks and Van Besselaar draw on the cyberspace approach to

study the international connections of scientific research). This

approach observes intercity linkages starting from the invisible

structure of the virtual world such as Internet hyperlinks, the struc-

ture of search engines, and e-mail traffic. In the cyber world, one

communicates in a new kind of space where rules other than those

of geographical separation apply because of the anticipated con-

trast between physical and virtual distance. In this, we consider

both approaches in the context of our review.2

This paper is organized as follows. The first section presents a

general introduction to the literature on transnational urban net-

works. We then present the analytical framework in which we

deal with the CP and CS approaches. Thirdly, we discuss the ana-

lyses based on both concepts and discuss the outcome. The empiri-

cal analysis based on CP is an additional contribution to existing

studies. The CS analysis, on the other hand, is new in urban

Townsend 2001

Sassen 2002

1A good overview of the literature

on cybercities is compiled by

Graham (2004).

Choi et al. 2006

Gorman and Malecki 2002

Moss and Townsend

Rutherford et al.

2The neglect of the cyberspace

approach compared to the

cyberplace approach for the

empirical analyses of digital

urban linkages could in all

probability be attributed to the

fairly intangible character of the

CS medium in contrast to the

physical CP. Hillis even attributes

this invisibility as the key to

grasping geographys relative

disinterest in communications.

Communication flows are less

studied than other flows in

geography (Hillis, Kellerman).

The confidentiality cited by private

telecoms contributes to this lack of

data and information.

6 Journal of Urban Technology/August 2008

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network research. In the concluding section, we summarize our

main findings and propose avenues for further research.

The Position of the Internetwork and Its Applicationswithin Research on Transnational Urban Networks

The contemporary literature on transnational urban networks can

be traced back to two interrelated papers. J. Friedmann was the

sole author of one, and with G. Wolff, was the co-author of

another. Both texts framed the rise of a global urban system in

the context of a major geographical transformation of the capitalist

world economy. This restructuring, most commonly referred to as

the new international division of labor, was premised on the

internationalization of production and the ensuing complexity in

the organizational structures of multinational enterprises

(MNEs). This increased economic-geographical complexity,

Friedmann argues, requires a limited number of control points in

order to function, and a select group of highly interconnected

metropolitan areas were deemed to be such points. The publication

of Saskia Sassens The Global City in 1991 marked a shift of atten-

tion to transnational inter-city flows resulting from the critical ser-

vicing of worldwide production rather than to its formal command

through the corporate headquarters of MNEs. Sassens approach

focuses upon the attraction of advanced producer service firms

(providing professional, financial, and creative services for

businesses) to major cities with their knowledge-rich environ-

ments and specialist markets. In the 1980s and 1990s, many

such service firms followed their global clients to become import-

ant MNEs in their own right. These advanced producer service

firms thereupon created worldwide office networks covering

major cities in most or all world regions, and it is exactly the

myriad of interconnections between service complexes that,

according to Sassen, made way for the formation of transnational

urban networks.

Empirical research on transnational urban networks has long

remained somewhat underdeveloped because of the lack of appro-

priate data, a problem which Short et al. referred to as the dirty

little secret of world cities research. This empirical poverty

can, for instance, clearly be seen in Castells book, which is part

of a trilogy that is above all an attempt to reformulate social

studies for a global age in which networks constitute the new

social morphology of our societies. However, when it comes to

Sassen 1991

Sassen 2001

Castells 1996


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providing a basic cartography of this global network society,

Castells argument falls short of the conceptual shift he advances:

the only actual evidence he comes up with in the chapter on the

space of flows consists of some limited information on inter-

city flows gathered from Federal Express. One can, therefore,

only conclude, as Taylor has recently done, that the evidence

[Castells] marshals is mightily unimpressive. This gap between

theoretical sophistication and evidential poverty was, however,

not a lacuna specific to Castells book: it has been a structural

feature of research on transnational urban networks because data

for assessing such urban networks are in general insufficient or

even totally absent.

The basic reason for this problem of evidence is that standard

data sources are ill-suited for such analyses. To get an evidential

handle on big issues, researchers normally rely on the statistics

that are available, that is to say, already collected. But such collec-

tion is carried out usually by a state agency for the particular needs

of government policy rather than for social science research. The

result is that such data that are available have an attributional bias

(measurements of administrative areas rather than between admin-

istrative areas) and are limited to national territories. Where offi-

cial statistics extend beyond a states boundaries, they will still

use countries as the basic units (e.g., trade data). Thus, there is

no official agency collecting data on, say, the myriad flows

between London and New York. The major result has been that

few of the available data reveal anything about the flows and

interdependencies that are at the heart of this body of literature.

This leads Alderson and Beckfield to note that in the past, rela-

tively few of the empirical global-city network (GCN) studies uti-

lized the sorts of relational data necessary for firmly establishing

such rankings empirically.

These data problems have put researchers to work in recent

years, and we have, therefore, witnessed a proliferation of empirical

studies that explicitly seek to rectify this situation. Researchers have

relied on a wide variety of data, but some information sources have

come to dominate the empirical research, especially information on

corporate organization (e.g., data on ownership links between firms

across space) and information on infrastructure networks (e.g., data

on the volume of air passenger flows across space). The success of

both approaches can, of course, be traced to their commonsensical

appeal: the corporate-organization approach acknowledges that

well-connected cities derive their status in large part from the pre-

sence of key offices of important firms, while the infrastructure

Taylor 2004

Taylor 2004

Knox

Derudder


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approach recognizes that well-connected cities are typified by the

presence of vast enabling infrastructures. Put simply: the most

important cities harbor the most important airports, while the exten-

sive fiber backbone networks that support the Internet have equally

been deployed within and between major cities, hence creating a

vast planetary infrastructure network upon which the global

economy has come to depend almost as much as it depends on

physical transport networks.

Table 1 summarizes the approaches developed in the empiri-

cal literature on transnational urban networks through an overview

of some key studies in this research domain. The table acknowl-

edges that the basic bifurcation between corporate organization

and infrastructure needs to be deepened on the basis of the exact

types of firms and infrastructures, and equally shows that all this

is in practice somewhat more complicated because of the presence

of a limited number of studies that make use of other types of data

(e.g., Taylors analysis of non-governmental organizations) and/or that combine indicators from both approaches. In the next

section, we focus on studies that use data on digital connections

between cities for assessing transnational urban networks.

The Cyberplace (CP) and Cyberspace (CS) Approaches

The Cyberplace (CP) ApproachThe cyberplace approach (CP) is an amalgamation of the vital

linkages and essential connections within the virtual network

among the existing infrastructures of satellite, telephone, computer,

TABLE 1A Taxonomy of Empirical Approaches in Empirical

Global-City Network Research

Indicators

Corporate Organization InfrastructureOther and/or a

combinationof indicators

Global servicefirms

Multinationalenterprises

Tele-communications

Airtransportation

Examples Beaverstocket al. (2000)

Alderson andBeckfield (2004)

Malecki (2002) Smith andTimberlake (2001)

Taylor (2005)

Derudder et al.(2003)

Rozenblat andPumain (2007)

Rutherford et al.(2004)

Derudder andWitlox (2005)

Rimmer (1998)

Source: Derudder 2006

Rutherford et al.

Taylor 2005

Beaverstock et al.


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facsimile, credit card, fiber-optic cable, and other information and

telecommunications systems. In general, it can be defined as the

Internets physical fabric. The CP approach makes use of the tan-

gible infrastructure to analyze the virtual transnational linkage of

cities.

Contemporary economic globalization is constituted by

intensive transnational networks of exchange and transaction.

Cities contain the junctions in the exchange of communication

and information. It is, therefore, in a citys interest to have a

well-developed communications network. Several studies have

explored the fundamental connection between telecommunica-

tions growth and economic success. Sommers and Carlson, for

example, document several examples of United States cities in

which large companies demanded a developed telecommunica-

tions infrastructure before they chose an urban area as a site for

operations. The extent and quality of digital telecommunications

infrastructure, through which the virtual exchange and trans-

actions occur, is consequently an important measure of digital

intercity relationships. The access to new technology is of prime

importance in large cities where the largest markets are found

and is of secondary importance in smaller places. Most empirical

studies on digital intercity flows base their analyses on the CP

approach. Gorman and Malecki examine the virtual network of

major United States cities, observing, for example, the most exten-

sive fiber-optic cable networks. Grubesic and OKelly explore the

fiber-optic backbone points of presence (PoPs) and note that these

are generally located in major cities such as Atlanta, Boston,

Chicago, DallasFort Worth, Los Angeles, New York, Philadel-

phia, San Francisco and Washington, D.C.3

To implement the CP approach, the first step is to find appro-

priate data concerning the physical infrastructure that guarantees

the digital accessibility of a place. The majority of CP studies

start from observation of the cable network that supports intercity

digital information flow. CP studies are mostly based on maps and

data that are available on the World Wide Web. Global telecom-

munications companies such as the BT Group, AT&T, or

Verizon give ample treatment to promoting their networks of

cables and satellites in order to demonstrate to potential customers

how extensive and capable these are4 Malecki and Boush even

state that during the last 10 years, telecommunications firms

have spent more money on advertising than on new technology.

The Internet architecture is, however, far more complex. Cable

networks are not the only elements of the infrastructure. The

Gorman and Makecki 2002

Hanley

Graham and Marvin

Hackler

Moss

Walcott and Wheeler

Malecki 1999

Choi et al. 2001

Choi et al. 2006


Grubesic and OKelly

Malecki and Gorman

Malecki and Boush

Moss and Townsend

Rutherford

Rutherford et al.

Townsend 2000

Townsend 2001

Wheeler and OKelly

Gorman and Malecki 20023A Point of Presence (PoP) is an

access point to the Internetwork.

4These are also used by

Internetwork engineers to

monitor and control traffic flows

and network performance. (Dodge

and Kitchen 2002). Detailed

network monitoring maps and

tools are, however, generally not

made public for reasons of

security and commercial

confidentiality.


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goal of this analysis is to broaden the existing CP studies to show

the importance of including the entire Internet infrastructure in

such an analysis. Internet users experience this network of

networks as a seamless, global, and ubiquitous communication

medium directly connecting two points. However, behind the

scenes lie many individual networks, owned and controlled by

different corporate, institutional, and governmental entities, and

joined to each other by various, less-known interconnection

arrangements.

Internet users need interconnection arrangements to commu-

nicate with one another via computers both next door and on the

other side of the globe. The Internet is a network of networks,

owned and organized by different companies. Communication

takes place in a manner similar to air travel, where, as a conse-

quence of the airlines organization, intercity passenger flows

are restricted to specific locations for their connections. Airline

passengers fly from A to B passing through a hub switching

point C. In the telecommunications industry, information trans-

mission is also limited to specific locations that structure the

network. Interconnection is needed because no single network

operator could possibly provide Internet access in every part of

the world. Different Internet service providers (ISPs) regulate

the network around the block and around the world. In order to

provide end users with universal connectivity, ISPs have to inter-

connect with one another to exchange traffic destined for each

others end users.

The exchange of Internet traffic between networks is called

peering. Peering is an interconnection of separate Internet net-

works for exchanging traffic between the customers of each

network.5 A bit flowing from point A on the network of Internet

Service Provider (ISP) A to point B on the network of ISP B has

to change its ISP at an interconnection point C. The physical

points that allow various ISPs to peer are called Internet eXchange

Points (IXPs). ISPs that want to use the IXP to connect to other

ISPs run one or more links from their own routers to the exchange

point and connect them to the IXP routers. An impact of intercon-

nection arrangements (IXPs) can be seen in Figure 1 below.

The early development of the Internet and the deregulation of

the long-distance telecommunications market in North America

resulted in interconnection arrangements between North American

ISPs and other providers that were strongly biased in favor of the

former ISPs. Even now, for example, it is common practice for

Internet users in Spain to communicate with users in Sweden or


Derudder et al. 2007

5ARPAnet was, for instance, at the

outset in 1969, not an Internet

but a network of computers. At the

time, the U.S. Defense Department

contractors permitted the use of

the ARPAnet by other U.S.

Government agencies to develop

similar networks, and they had to

interconnect and thereby

developed the real Internetwork.

(Chapin and Owens)

Kellerman


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Finland over a path that is led through an IXP in the United States.

(See Figure 1.) Although there exists a direct link, the time cost of

connecting through an exchange point located on the other side of

the world is significantly lower than the cost of a direct connection.

These extreme examples are being slowly reduced by the growth

of interconnection points spurred by the deregulation of the tele-

communications industry.

Figure 2 highlights the establishment of new IXPs (i.e., inter-

connection points) per year in comparison with the total number of

existing European IXPs.

Although the interest for urban scholars is not the physical

pathway but the endpoints of the connectivity package being

delivered, the examples above stress the importance of consider-

ing the entire Internet architecture. A number of cities have, in a

manner similar to the hubs in the airline network, major advantages

in terms of digital accessibility through their function as intercon-

nection points. Direct interconnection through these points avoids

data travel to other cities, and potentially to other continents, to get

from one network to another, thus reducing latency. They present

the ability to switch from a regional to a continental or global

network without first travelling on different regional networks.

Table 2 presents a number of these interconnection points. The

CP approach discussed here is based on such IXPs (results are

FIGURE 1Interconnection Points in the Global Internetwork

Akamai Technologies

European Internet Exchange

Association (Euro-IX)

Townsend 2001


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described in the empirical section below). The first goal of the

analysis is to prove the importance of considering the entire Inter-

net infrastructure in a CP approach. The second goal is to introduce

IXPs as important CP components to gain an insight into digital

intercity linkages.

Studies of telecommunications hubs have been performed from

many different perspectives, including the technical architecture

FIGURE 2The Establishment of New IXPs in Comparison to the Total

Number of Existing European IXPs

TABLE 2A Number of Internet Exchange Points

Abbreviation Name Location

AMS-IX Amsterdam Internet Exchange Amsterdam, NetherlandsLINX London Internet Exchange London, United KingdomDE-CIX Deutscher Commercial Internet

ExchangeFrankfurt am Main, Germany

JPNAP Japan Network Access Point Tokyo, JapanNetnod Netnod Internet Exchange i Sverige Stockholm, SwedenESPANIX Spain Internet Exchange Madrid, SpainJPIX Japan Internet Exchange Tokyo, JapanHKIX Hong Kong Internet eXchange Hong Kong, ChinaBIX Budapest Internet Exchange Budapest, HungaryKINX Korea Internet Neutral eXchange Seoul, Korea


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of exchange points, the business and economic models that

underlie peering, transit agreements, and so on. Grubesic and

OKelly analyze the geographical position of PoPs in the

United States in order to examine the digital accessibility of

cities. PoPs give information about the location of the access/switching points per ISP. Thus, while the IXPs do serve for

many ISPs, the PoPs tell something about the switching location

of a single ISP.6 Examining IXPs gives centralized information

about the Internet traffic passing through an exchange point.7

Other researchers note IXPs as important digital points in city

networks but do not give more detail.

The IXP data used here are drawn from the Euro-IX report.

This was compiled by the European Internet Exchange Associ-

ation (Euro-IX) and gives information about the amount of

traffic being transferred in IXPs that are members of the European

Internet Exchange Association.8 A substantial proportion of IXPs

publish traffic statistics on their websites in order to promote their

interconnection point to potential new ISP members. Amsterdam,

ams-ix.net (AMS-IX) for instance, gives information as daily and

yearly traffic load graphs and monthly reports about their traffic

volume, total multicast, IPv6, and broadcast traffic, ISP

members, technical and statistical information, topology, and so

on. The Euro-IX report has accumulated these graphs for cities

in Europe. The results of the empirical analysis based on these

data are described below in the CP approach section of the empiri-

cal analysis.

The Cyberspace (CS) ApproachIn addition to the traditional geographical space wherein the CP is

embedded, we have witnessed the emergence of a new approach

for analyzing digital flows: the CS approach. CS is the virtual

world wherein people communicate with each other using compu-

ter systems. The CS concept makes use of this new space

to analyze digital intercity linkages. Because the functioning

of several communication and information technologies such as

e-mail, web consulting, and video conferencing, are based on

CS, such an approach can give a refined picture of existing

virtual linkages between cities. To introduce this idea, we

discuss the most important features of cyberspace.

Although it is often referred to, cyberspace is quite a difficult

entity to grasp and define. It has been variously described as

follows: a consensual hallucination experienced daily by billions

Kende

Norton

6PoPs are housed in an IXP or in

data centers that are used to house

the server, storage, and network

infrastructure of ISPs.

7For an overview of the

geographical position of switching

facilities in the United States

(2001), see Malecki and McIntee,

and in Europe (2001), see

Kellerman.

Drewe


Townsend 2001

8On October 2006, Euro-IX had

36 member IXPs from 21

European countries, 7 IXPs from

Japan and the United States, and

four patrons from the switch

vendor community. Although the

Euro-IX report attempts to list all

known IXPs in Europe, it is

expected that a small number of

IXPs may have been left out. The

IXP data do not take into account

the traffic exchanged by privately

interconnected participants whose

traffic does not pass over the IXP

switching fabric (European

Internet Exchange Association).


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of legitimate operators, in every nation, by children being taught

mathematical concepts; unthinkable complexity; a parallel

universe; a multi-media skein of digital networks which is infus-

ing rapidly into social, cultural and economic life; a space that is

difficult to comprehend and mentally visualize . . . in which it iseasy to get lost and confused.9

A more concise definition of CS is given by Leadbetter, who

describes this space as an immaterial world of computers and

communications, in which we can work at the touch of a

button. This definition highlights the three most important fea-

tures of cyberspace:

. It is all about computers and virtual communication. CS isthe virtual network wherein computers communicate with

each other.

. CS is an immaterial world in that the physical aspects of thematerial world involving distance do not apply in this new

space.

. In this immaterial world of computers and communication,we work at the touch of a button.

Distance has a diminished importance in the cyber world. A

place in CS is close by when it is just one click away or at the

touch of a button. The need to click a lot to get on to a website that

is actually physically nearby is perceived as its being more remote

and less accessible than a site that, just one click away, is phys-

ically more than thousands of miles away. The time cost is so

small that virtual access is practically invariant with physical

distance. Access in virtual space, therefore, follows logical links

rather than physical paths. The CS approach uses these features

to analyze the virtual linkages of cities.

We discern two types of analysis applicable to the CS

approach: a content-based analysis (CBA) and a structure-based

analysis (SBA). The SBA is based on the CS structure seen as

the hierarchy of websites, connections via hyperlinks, and so

forth. The CBA examines intercity linkages using the information

available on the pages of the World Wide Web.

The most examined SBA, hyperlink analysis, is based on the

logical links that connect websites.10 Park and Thelwall (61)

promote this type of SBA in the belief that with the increasing

importance of the Web for an ever-broader spectrum of human

activities, the structure will reflect more and more the existing

relationships between people, cities, institutions, and so forth.

Gibson

Benedikt

Graham 1998

Dodge and Kitchen 20029This elusiveness has resulted in a

particular wording. Virtually all

cyberterms (even the notion

cyberspace) are described by

standard spatial and territorial

metaphors: e.g., web site, chat

room, mail box, portal site,

teleport, and so on (Adams, Smith

and Timberlake). Kellerman

pointed out that the geographical

language has become a major tool

for the structuring, organization,

and use of cyberspace.

Dodge

Mitchell

10There are in fact two approaches

to hyperlink analysis:

webometrics (e.g., counting

hyperlinks to websites, see for

example Smith and Thelwall,

Thelwall and Vaughan) and

hyperlink network analyses (e.g.,

social network analysis applied on

hyperlink networks; see, for

example, Rogers and Marres,

Krebs, Park and Thelwall). Here

we consider both analyses in

common.


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A hyperlink analysis (i.e., an SBA) is an analytical method for

studying the networked (or connected) structures on the World

Wide Web. A hyperlink transmits the information or contents

of a web page at the touch of a button. It is a technological capa-

bility that enables one website to connect seamlessly with another

and, therefore, functionally brings the two sites closer together.

Putting a hyperlink on your website implies the possibility of a

jump from one location/actor to the other and indicates theimplicit presence of other locations/actors such as firms,people, or information in the immediate vicinity. The use of

hyperlinks in the creation of a web structure belongs to the

designer, who, therefore, controls the potential ways a user can

move through the Web.

Commercial firms are supposed to be cautious in placing

hyperlinks. Any link to an external site is an extra exit route

for visitors. A natural reaction may be to avoid hyperlinks, thus

creating an isolated self-contained structure. Thelwall shows,

however, that 72 out of 232 sites (or 31 percent) of commercial

firms were found to have hyperlinks based on affiliated business

relations. For service reasons, commercial sites offer links to

complementary sites. Their intent is to build a trust-based custo-

mer relationship. Thus, while website creators have complete

freedom, hyperlink structures are designed, sustained, or modi-

fied to reflect relationship choices. Park and Thelwall note that

from these communicative choices and agenda, we can discern

the fingerprints of social relationships between the system com-

ponents (i.e., people, private companies, public organizations,

cities, nation-states, and so on). An example of a hyperlink analy-

sis is given by Heimeriks and Van den Besselaar. They analyze

hyperlink networks on the scientific web in order to study the

development of research fields and the relationship between

research organizations and the relevant institutions in their

environments. Before the digital age, joint papers in journals

and academic contacts at conferences were important measure-

ment tools. Nowadays, the Web gives us additional academic

network information.

Hyperlinks between websites represent not only direct

relationships in the offline world but also other and desired

relationships. Hyperlink analyses can be drawn up for several

layers. The underlying belief for the CS approach is that collabor-

ation and information exchanges between cities are reflected in the

hyperlink networks and/or in the number of hyperlinks to urbancomponents. Whatever the importance of hyperlinks for cities or

Pirolli and Card

Jackson

Siegel

Grossman

Matheison


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urban components, we should nevertheless consider that there are

some types of areas of the web for which links are important and

others where they are not, both accounting for a significant pro-

portion of the web.11

To implement the cyberspace approach in this paper, we have

opted to base the empirical analysis on web information, i.e., a

content-based analysis.12 The World Wide Web (WWW) is the

most up-to-date and most global information source. The relation-

ships between cities must be traceable in this large database. To

trace these relationships, we make use of web search engines

that draw on robots or spiders to index the huge amount of infor-

mation. Spiders are computer systems that continuously download

web pages and go through the published information. Depending

on the search engine, all or a part of the published information,

such as key words, links, and so on, is saved in a large database.

The spiders continuously pursue the search drawing on the

saved links. The final search result matching the query (i.e.,

number of presented pages and rank order) depends on the index

decisions. More than 150 criteria exist to determine the relevancy

of pages. PageRank and link popularity are the most important

techniques applied by Google. PageRank is a technique that,

according to the web search engine Google.com, relies on the

uniquely democratic nature of the web by using its vast link

structure as an indicator of an individual pages value. In

essence, Google interprets a hyperlink on a webpage as a vote,

by this page, for the linked page. When the page that casts the

vote is itself important, it weighs more heavily. Using these

and other factors, Google provides its views on a pages relative

importance. So far, we may conclude that the most trafficked

parts of the Web are indexed by search engines. Querying

the number of joint appearances of two city names will give

us the relative proportions of actual intercity linkages according

to the web search engine. For this empirical analysis (results are

described in the second part of the next section), we base our

search on the currently most popular search engine, Google.13

Taken together, of the two possible methods, CP and CS,

that can be applied to analyze the virtual intercity linkages,

one might say that the CP approach analyzes the virtual intercity

linkages via the real world, whereas the CS approach observes

linkages in a parallel world. Although both approaches may

seen similar at first sight, they start from completely different

observations of virtual urban linkages and must, therefore, be

analyzed separately.

Thelwall11According to Park and Thelwall,

little is known about the validity or

correct interpretation of hyperlink

analyses results except from

academic domains; i.e.,

bibliometrics (Tang and

Thelwall).12The above-mentioned structure-

based analysis (SBA) is not

worked out in this paper. An

empirical analysis based on the

SBA-method calls for an extensive,

paper-length discussion, and

hence falls outside the scope of the

present paper.

Brin and Page

Mostafa

Google

Austin

Seopage.nl

Marketshare.hitslink.com13We used

www.googlebattle.com/

godin.php, which enabled us to

query several city pairs at a time.


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Empirical Analyses

The Cyberplace (CP) ApproachFigure 3a shows the upward trend in peak aggregated IXP traffic

(in Gigabits per second, Gbps) per European city (based on the

Euro-IX report). We compare this graph with Figure 3b, which

presents the estimated bandwidth (in Gbps) per city.14 The

digital bandwidth capacity data used in Figure 3b is based on

the European Terrestrial Networks map.15

FIGURE 3aThe Peak Aggregated IXP Traffic (in Gigabits per second)

per European CityFIGURE 3b

The Estimated Bandwidth (in Gigabits per second)per European City

14Information on the amount of

digital traffic through these

infrastructures is generally

unavailable (Kellerman).

Telegeography.com15The European Terrestrial

Networks map illustrates the total

lit bandwidth traversing through

145 European cities (above 0.5

Gbps). The 145 cities exist as the

top 60 European cities, as ranked

by access to lit bandwidth, and 85

other important localities (major

city, capital city, etc.).

(Telegeography.com)


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Comparing both graphs gives an idea about the importance of

European cities in the digital city network.16 One major feature is

the divergent trend of the graphs. Whereas the bandwidth

increases gradually per city, the exchange of Internet traffic is

far more skewed towards a limited number of metropolitan

areas, i.e., Amsterdam, London, Frankfurt, Madrid, and Stock-

holm. These cities are responsible for 72.26 percent of the Euro-

pean Internet exchange traffic. Amsterdam is the overall number

one with 28.41 percent of total European IXP traffic. These

cities function as key points in the digital intercity network.

They significantly expand the reach of the virtual network.

A large amount of exchange traffic in a city points to its

important switching function between regional, national, and

global information communication networks. One would therefore

expect a large amount of IXP traffic to correspond to abundant

bandwidth availability.17 An important switching point has to

transfer its traffic to other places such as Frankfurt, London, or

Amsterdam. A city such as Budapest exchanges much traffic but

is less important in terms of bandwidth availability. This probably

results from a high regional exchange of traffic and a lesser global

traffic requirement.18 The IX point located in Budapest boosts the

surrounding region in terms of Internet traffic possibilities. To con-

sider this phenomenon in more detail, we look at Figure 4. This

FIGURE 4The Relationships of Cities in Terms of Equal Service

Providers

16We have to bear in mind that we

compare capacity with real traffic

where the former represents long

haul links and the latter local/

national/international exchange

traffic.

17We expect that a large amount of

bandwidth availability is related

to a high amount of exchange

traffic. The long haul links are

market-based decisions and

probably correspond the need to

exchange a high amount of traffic

(and vice versa).

18As mentioned above, the IX point

exchanges also traffic on the city/

country level and prevent the use

of expensive long haul links to

other cities to switch from local

ISP


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presents the relationships that cities have in terms of equal service

providers.19 The relationship between cities is seen as the number

of ISPs that peer in both cities. This means that service providers

are active in both the cities shown and are consequently more

global in reach. The volume of the nodes is based on the

number of ISPs peered at the IXP.20 The most important exchange

cities also control the most jointly peered ISPs. The big three of

Amsterdam, London, and Frankfurt, with London first, hold

almost all the ISPs that peer in the European Internetwork.

These exchange cities function as global switching points. Cities

such as Lyon, Florence, Budapest, and Ljubljana on the other

hand are more regional exchange points. A small number of

global ISPs link these IXPs with a more global exchange point

such as LyonParis, LjubljanaVienna, and FlorenceMilan.

The difference between more global exchange points such as

Amsterdam, Paris, Zurich, and Stockholm and the regional IXPs

such as Ljubljana, Lisbon, and Florence can be observed by the

number of shared ISPs as compared with their individual ISPs.

The global exchange point of Amsterdam has 80 percent of

its ISPs peering at other ISPs (Stockholm, 83 percent; Zurich, 82

percent; Paris, 90 percent), whereas there are fewer ISPs peering

at other IXPs for Ljubljana (17 percent), Lisbon (16 percent), and

Florence (50 percent). Budapest, as mentioned above, is a more

regional exchange point. Eighty-four percent of the ISPs in Buda-

pest peer only at that city. This difference can also be observed

from the position of the IXPs in Figure 4. Two cities situated

on the edge of this figure are more regional exchange points

linked with one or two more global exchange cities. There are,

furthermore, internal differences between the regional IXPs.

Warsaw and Athens are, for example, less linked to the global

ISP network than Florence or Ljubljana. The three shared ISPs

for Athens are the global service networks of AT&T Global

Network Services, Viatel Global Communications B.V., and

Verizon Business, whereas the shared ISPs for Florence and

Ljubljana are more regional ISPs such as FlorenceMilan with

Telecom Italy. It is interesting to note that Brussels has less

IXP traffic but profits from its geographical position between

the global exchange points of London, Paris, Frankfurt, and

Amsterdam. Brussels is situated at the crossroads of European

and global service providers AT&T, Deutsche Telekom (T-

Online), France Telecom/Opentransit, United Global Com, andKPN Nederland. Building an IXP in such a city boosts its

virtual network reach.

19This figure is based on the peer-

matrix of the Euro-IX report. Only

the relationships of three or more

equal-peered ISPs are drawn.

20Figure 4 is constructed using the

lay-out technique spring-

embedding (UCINET (Borgatti

et al.)).This technique is based on

the concept of a system in which N

cities are connected. According to

the volume and the number of

flows of a city, the intercity links

have different strengths. From the

initial arrangement of the city

locations, the system oscillates

until it stabilizes at a minimum-

energy arrangement resulting in a

dynamically balanced system.

(Castillo and Sim)


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The geographical position of Brussels results also in a high

amount of bandwidth availability. (See Figure 3b.) The more

regional exchange cities such as Budapest have low intercity band-

width linkages. A further comparison between bandwidth capacity

and exchange power can be observed in Figure 5. In this figure, we

compare the logarithm of exchange traffic per city with the esti-

mated digital bandwidth capacity.21 Four groups of cities can be

discerned.22 The first group, with the most bandwidth and IXPs,

are Amsterdam, Frankfurt, London, Brussels, Dusseldorf, and

Paris. These centers receive a large amount of traffic from their

feeding cities and transfer it to the global network (and vice

versa). A second group, ranked slightly below, consists of

Zurich, Munich, Madrid, Stockholm, Vienna, and Nurenberg. A

third groupPrague, Malmo, Oslo, Torino, Bratislava, Dublin,

Manchester, Barcelona, and Bilbaois important in terms of

bandwidth but less important in terms of exchange traffic. A

fourth groupBudapest, Helsinki, Gothenburg, Warsaw, Rome,

Tallinn, Lisbon and Bucharestis more important in terms of

IXP traffic than the available bandwidth capacity. These cities

are regional IXP cities.

Increasing the number of clusters to 10 puts the relative

importance of IXP traffic versus bandwidth availability into the

picture. The first group is, for example, split up in three groups:

FIGURE 5The (Logarithm of) Exchange Traffic in Comparison with the

Estimated Digital Bandwidth Capacity per European City

21Note that there is a time

difference between the two

different CP datasets.

Telegeographys data are from

2002 while the IXPs data refer to

2006. However, since there is a

serious lack of data in the

cyberplace literature, we argue

that using (and comparing) these

data sources outweighs the deficits

due to the time difference.22The clusters are based on the

hierarchical Ward and K-means

method.


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(1) Paris and London, which are the leaders in terms of exchange

traffic and digital bandwidth availability; (2) Amsterdam and

Frankfurt, which are foremost in terms of exchange traffic but

less important in terms of bandwidth; and (3) Brussels and Dussel-

dorf, which are important in terms of bandwidth but less important

in terms of exchange traffic. The other groups can be split up simi-

larly.23

The empirical analyses indicate the importance of increasing

the number of structural elements for a CP approach. Combining

IXP data with information about the bandwidth capacity tells us

a lot more than just the cable network information: it gives a

more general picture of the network of intercity flows.

The Cyberspace (CS) ApproachThe content-based analysis was set up in January 2008. We

assembled the city-pair relationships between 40 European

cities.24 For example, searching for (Google) web pages that

jointly mention Amsterdam and Kiev resulted in 596,000

different web pages with data on, for example, the transport,

business, history, and governmental relationships between both

cities. Figure 6 presents the most important of these relationships,

with more than 1 million results in the 40 40 intercity matrix.25

FIGURE 6The Digital Intercity Linkages According to Google.com

(January 9, 2008)

23The variation in IXP-traffic

decreases at the tail of the

distribution (see Figure 3a). This

makes it difficult to make solid

conclusions for cities such as

Tallinn, Lisbon, and Bucharest.

The expansion of IXPs in the

future will probably lead to more

transparency.

24The 40 cities rely on the world

city list of the Globalization and

World Cities (GaWC) Study

Group and Network.

25Figure 6 is constructed using the

lay-out technique spring-

embedding. (Borgatti et al.)


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The search was made without any preferences or specific

language choice in Google (http://www.google.com/advanced_search). City names are spelled in English, which is an underesti-

mation of regional city linkages. English is, however, not only the

dominant language on the World Wide Web in and by itself, but

especially for linking. Most web pages have next to their national

language page an international page in English.

The size of the nodes varies according to the total number of

results. Paris, London, and Berlin are the most important cities on

the Web. They have a high number of joint appearances on the

Web and maintain thereupon their important relationships with

almost all European cities. London represents the most dominant

place on the Web. We can also observe some prominent national

connections between cities; for example, HamburgBerlin,

BirminghamManchester, MadridBarcelona. Furthermore, it is

interesting to note the linkages of cities such as Bucharest, Dussel-

dorf, and Bratislava. These places are highly linked with second-

ary centers such as Copenhagen, Dublin, and Lyon. A strong

link between these cities and London does not exist. They are

located outside the strong central network of London, Paris, and

Berlin and can be seen to be less digitally accessible.

In order to compare the differences between two time

periods/search engines, we did two other Google search queriesin April and November 2007, and a Google and AltaVista

search query in November 2007. The continuous update of

search engine databases results in a higher number of related docu-

ments for all city linkages queried in November 2007 with 8.4

percent more linkages found. There existed also a minimal rank

difference with correlation between both searches being 86

percent. To compare the difference between web search engines,

we performed the same analysis based on the AltaVista web

search engine. Here, we also observed a minimal difference.

The CS analysis is the first investigation using the content-

based analysis method. Using a so-called meta-search engine

such as MetaCrawler, MetaFind, or SurfWax or a topic-based

search engine such as, for example, business.com, news.google.

com, or newslink.org, it may be possible to map more detailed

digital intercity linkages. A meta-search engine transmits the

search query simultaneously to several individual search engines

such as Google, AltaVista, or Yahoo and their databases of

web pages. Within a few seconds, the results from all the

search engines queried are presented. A CBA based on this kind

of search engine may, therefore, give more general results.

Internetworldstatistics.com


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Topic-based search engines, in contrast to the meta-search engines,

may give us more accurate and relevant information.26

Discussion and Main Conclusions

This article has provided an overview of the dominant approaches

for understanding intercity links through digital flows. Most ana-

lyses to date on digital intercity relationships are based on what

we have dubbed the CP or cyberplace approach. The World

Wide Web that we have called the CS or cyberspace approach,

however, equally transcribes digital relationships. With the

growing importance of the Web for an ever-broadening spectrum

of human activity, the World Wide Web increasingly contains

digital linkages between people, cities, institutions, and other

entities. Examination of the CP and the CS approaches together

points out the dissimilarity between these methods. Although

both approaches deal with digital intercity relationships, the CP

and CS worlds or layers are derived from completely indepen-

dent observations and must, therefore, be discussed separately.

The CP approach is based on physical layer observations of

cables, servers, interconnection points, and related apparatus.

Although this approach is discussed in the literature at great

length, a comprehensive analysis of the physical digital intercity

flows is indispensable. The analysis presented here points out

the lack of investigation into structural CP elements. The flows

of bits are structured by different corporations and follow routes

other than the direct, predictable connections between end users.

In order to comprehend the cyberplace, it is important to study

the entire Internet architecture. Airline hubs or gateways influence

the way airline companies build up their networks, yet digital

flows are structured by gateways or interconnection points. For

instance, maps showing the network of undersea cables tell us

something about the speed at which digital information is trans-

mitted overseas. Being located at an appropriate place in this

network means that you have the ability to download and upload

information rapidly and to maintain strong digital communications

across oceans. The existence of exchange points forces the import-

ance of these linkages. Digital gateway cities are able to transfer

regional traffic to other interconnection points overseas and to dis-

tribute global traffic in their own region.

A comparison of digital bandwidth capacity with IXP traffic

has led so far to a more refined picture of intercity linkages. We

observed that in the European context, Amsterdam, Frankfurt,

26Additional difficulties of meta-

search engines are the use of

complex search terms based on

Boolean logic (U.C. Berkeley

library) and the information

required (i.e., number of related

documents). These are challenges

for further research.

Park and Thelwall


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London, Brussels, Dusseldorf, and Paris share the highest digital

bandwidth capacity. The digital weight of cities such as Paris,

Brussels, Zurich, Munich, and Dusseldorf is, however, overesti-

mated when only bandwidth capacity is observed. Amsterdam,

London, and Frankfurt are far more important in their gateway

functions than Paris, Brussels, and Dusseldorf. A combination of

both CP data sources shows at a glance that Amsterdam,

London, and Frankfurt are the top digital cities in Europe. It is

likely that this hierarchy in digital importance will continue to

shift, categorically and geographically, in the future. Continued

infrastructure investment in cities such as Budapest will increase

the digital possibilities of those regions and create significant

regional gateways. Global gateways such as Amsterdam, Frank-

furt, and London will increasingly serve at the global level.

It is important to note that CP analyses rely on recent data.

The market for interconnection is changing rapidly. In less than

five years, the number of European interconnection points has

more than doubled. The Euro-IX (23) report is the first account

available online concerning European IXPs, and more research

about these data is required. The Internet infrastructure is con-

stantly growing, and although the boom in cable infrastructure is

already past, some regions are just beginning to develop cable

networks based on modern technology. Examination of the

entire Internet architecture will broaden our knowledge of digital

intercity linkages.

The CS approach provides insights into intangible digital

flows, which must be observed in the cyberlayer. Measurement

of hyperlinks, e-mail contacts, or search results gives a notion

of the existing relationships via the digital web. The CS exercise

herein is a first investigation of a content-based analysis on

intercity linkages. The measured relationships engage airline

connections, governmental agreements, family ties, firm

locations, and so on, in several different formats, for example

PDF, TXT, and URL. It is one of the most up-to-date existing

data queries. Although the World Wide Web is constantly chan-

ging, search engines provide daily updates. At the end of

January 2005, the indexed web contained more than 11.5

billion pages.27 Querying this huge amount of information by

web search engines is the most general search on digital

linkages that can be made. It provides information that is not

accessible by a traditional metrical approach.

The content-based analysis (CBA) here shows that Paris,

London, and Berlin collectively have the most important digital

27Indexed means the part of the

Web that is searchable through

search engines. Estimating the

size of the whole Web is quite

difficult, because of its dynamic

nature. Three sources for tracking

the growth of the Internet are

Search Engine Showdown,

Search Engine Watch, and

World Wide Web size.

Gulli and Signorini


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linkages on the Web. The dominance of North-west Europe on the

Web is obvious. Amsterdam, Rome, and Frankfurt are secondary

cities. Looking at the intercity relationships, we observe a number

of strong regional linkages such as LyonParis, Rotterdam

Amsterdam, and MadridBarcelona. However, we have to bear

in mind that the CBA presented also has some shortcomings:

First, in addition to the surface World Wide Web there is also

an immeasurable private web accessible only to banks, firms, and

confidential organizations and a deep web, publicly accessible but

not reachable by search engines.28 Search engines index only a

proportion of current web pages.

Second, the applied search engine in a CBA has a great influ-

ence on the results. Using meta-search engines or topic-based

search engines, for instance, would give more detailed information.

Third, we have to be aware that the CBA herein actually

measures non-digital relationships saved in digital format. Under-

taking a structure-based analysis is a next step in this context.

Hyperlinks represent desired, existing, or obligatory relationships

between website owners that are institutions, organizations, or

firms. The SBA has already been widely examined in bibliometric

studies. The investigation of structural intercity relationships on

the Web is an avenue for further research.

This paper shows that two approaches can be used to measure

digital intercity linkages. Both methods analyze different relation-

ships digitally. The broader exploration of both empirical analyses

will probably cause us to arrive at more refined methods for the

study of digital intercity linkages. In our future research, we

intend to explore new techniques of applying the CS approach,

and we will gather other CP components for this approach.

Acknowledgements

We would like to thank the editor and the anonymous referees for

their useful comments on an earlier version of this paper. The

usual disclaimers apply. This research work is funded by the

Research FoundationFlanders.

28Private networks account for

around 14 percent of Internet

traffic (McClelland). Besides the

inaccessible private networks,

there are also web pages that are

publicly accessible but not

reachable by search engines (i.e.,

the deep or invisible web). This

part of the web consists of web

pages with no hypertext links to

their content, pages you need to be

registered for and logged-on to

access, documents with a content

that is dynamically generated

(based on constantly changing

databases) and other pages

difficult to index by search

engines.


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Bibliography

P. Adams, Cyberspace and Virtual Places, Geographical Review 87 (1997) 155171.

Akamai Technologies. Akamais Technologies: Visualizing the Internet, 2008 Accessed January 21, 2008.

A. Alderson and J. Beckfield, Power and Position in the World City System,American Journal of Sociology 109 (2004) 811851. Quotation from page 814.

D. Austin, How Google Finds Your Needle in the Webs Haystack: As Well See,the Trick Is to Ask the Web Itself to Rank the Importance of Pages. . . 2006 Access April 25, 2007.

J. Beaverstock, R. Smith, P. Taylor, D. Walker, and H. Lorimer, Globalization andWorld Cities: Some Measurement Methodologies, Applied Geography 20 (2000)4363.

M. Benedikt, Introduction, in M. Benedikt, ed., Cyberspace: First Steps (Cam-bridge, MA: MIT Press, 1991). Quotation from page 15.

S. Borgatti, M. Everett, and L. Freeman, Ucinet 6 for Windows: Software for SocialNetwork Analysis (Harvard: Analytic Technologies, 2002).

S. Brin and L. Page, The Anatomy of a Large-Scale Hypertextual Web SearchEngine, paper presented at the Seventh International World Wide Web Conference(Brisbane, Australia, 1998).

M. Castells, The Rise of the Network Society (Oxford: Blackwell, 1996). Quotationfrom page 469.

M. Castells, Internet Galaxy (Oxford: Blackwell, 2001).

I. Castillo and T. Sim, A Spring-Embedding Approach for the Facility LayoutProblem, Journal of the Operational Research Society 55 (2003) 7381.

L. Chapin and C. Owens, Interconnection and Peering among Internet ServiceProviders: A Historical Perspective (2005) ,ww.interisle.net. AccessedApril 23, 2007.

J. Choi, B. Chon, G. Barnett, and Y. Choi, World Cities and Internet BackboneNetworks: A Network Approach, paper presented at the Digital Cities Conference(Chicago, 2001).

J. Choi, G. Barnett, and G. Chon, Comparing World City Networks: A NetworkAnalysis of Internet Backbone and Air Transport Intercity Linkages, GlobalNetworks 6 (2006) 8199.

B. Derudder, On Conceptual Confusion in Empirical Analyses of a TransnationalUrban Network, Urban Studies 43 (2006) 20272046.


Dow

nloa

ded

by [

b-on

: Bib

liote

ca d

o co

nhec

imen

to o

nlin

e IS

CT

E]

at 1

2:36

10

Mar

ch 2

015

B. Derudder and F. Witlox, An Appraisal of the Use of Airline Data in Assessmentsof the World City Network, Urban Studies 42 (2005) 23712388.

B. Derudder, P. Taylor, F. Witlox, and G. Catalano, Hierarchical Tendencies andRegional Patterns in the World City Network: A Global Urban Analysis of 234Cities, Regional Studies 37 (2003) 875886.

B. Derudder, L. Devriendt, and F. Witlox, Flying Where You Dont Want to Go: AnEmpirical Analysis of Hubs in the Global Airline Network, Tijdschrift voor Econ-omische en Sociale Geografie 98 (2007) 307324.

M. Dodge, Accessibility to Information Within the Internet: How Can It BeMeasured and Mapped? paper prepared for the Varenius Meeting (1998) Accessed November 27, 2007

M. Dodge and R. Kitchin, Atlas of Cyberspace (London: Pearson Education, 2001).

M. Dodge and R. Kitchen, New Cartographies to Chart Cyberspace, Geoinfor-matics April/May 2002 (2002) 14. Quotation from page 1.

P. Drewe, The Internet Infrastructure as a Location Factor for the Internet Industry,paper presented at TIC et Reorganisation Spatiale des Activites Economiques (ENS-Bretagne, Brest 2002).

European Internet Exchange Association (Euro-IX), Euro-IX Report (2006) Accessed December 11, 2007.

J. Friedmann, The World City Hypothesis, Development and Change 17 (1986)6383.

J. Friedmann and G. Wolff, World City Formation: An Agenda for Research andAction, International Journal of Urban and Regional Research 3 (1982) 309344.

W. Gibson, Neuromancer (London: Harper and Collins, 1984). Quotation frompage 69.

Google, Web Search Engine Google (2007) AccessedNovember 27, 2007.

S. Gorman and E. Malecki, The Networks of the Internet: An Analysis of ProviderNetworks in the USA, Telecommunications Policy 24 (2000) 113134.

S. Gorman and E. Malecki, Fixed and Fluid: Stability and Change in the Geographyof the Internet, Telecommunications Policy 26 (2002) 389413.

S. Graham, The End of Geography or the Explosion of Place? ConceptualizingSpace, Place, and Information Technology, Progress in Human Geography 22(1998) 165185. Quotation from page 165.

S. Graham, ed., The Cybercities Reader (London: Routledge, 2004).


Dow

nloa

ded

by [

b-on

: Bib

liote

ca d

o co

nhec

imen

to o

nlin

e IS

CT

E]

at 1

2:36

10

Mar

ch 2

015

S. Graham and S. Marvin, Splintering Urbanism (London and New York: Routledge,2001).

W. Grossman, Get Linked, Information Age 1 (1997) 2122.

T. Grubesic and M. OKelly, Using Points of Presence to Measure Accessibility tothe Commercial Internet, Professional Geographer 54 (2002) 259278.

A. Gulli and A. Signorini, The Indexable Web is More than 11.5 Billion Pages,WWW 2005 (2005). Accessed January 15, 2008.

D. Hackler, Invisible Infrastructure and the City: The Role of Telecommunicationsin Economic Development, American Behavioral Scientist 46 (2003) 10341055.

R. Hanley, Moving People, Goods and Information in the 21st Century: The Cutting-Edge Infrastructures of Networked Cities (London-New York: Routledge, 2004).

G. Heimeriks and P. Van den Besselaar, Analyzing Hyperlinks Networks: TheMeaning of Hyperlink Based Indicators of Knowledge Production, InternationalJournal of Scientometrics, Informetrics, and Bibliometrics 10 (2006) 117.

K. Hillis, On the Margins: The Invisibility of Communications in Geography,Progress in Human Geography 22 (1998) 543566. Quotation from page 545.

Internet World Statistics (2007) Accessed January11, 2008.

M. Jackson, Assessing the Structure of Communication on the World Wide Web,Journal of Computer-Mediated Communication 3 (1997) Accessed February 11, 2008.

A. Kellerman, The Internet on Earth: A Geography of Information (West Sussex,England: John Wiley & Sons Ltd, 2002). Quotation from page 31.

M. Kende, The Digital Handshake: Connecting Internet Backbones, FCC Office ofPlans and Policy Working Paper 32 (2000).

V. Krebs, Working in the Connected World Book Network, International Associ-ation for Human Resource Information Management Journal 4 (2000) 8790.

P. Knox, Globalization and World City Formation, in S. Gravesteijn, ed., TimingGlobal Cities (Netherlands Geographical Studies, 1998).

C. Leadbetter, Living on Thin Air: The New Economy (London: Sphere, 2000).

E. Malecki, The Associational Economy: Firms, Regions, and Innovation, Growthand Change 30 (1999) 308310.


Dow

nloa

ded

by [

b-on

: Bib

liote

ca d

o co

nhec

imen

to o

nlin

e IS

CT

E]

at 1

2:36

10

Mar

ch 2

015

E. Malecki, The Economic Geography of the Internets Infrastructure, EconomicGeography 78 (2002) 399424.

E. Malecki and C. Boush, Telecommunciations Infrastructure in the SoutheasternUnited States: Urban and Rural Variation, Growth and Change 34 (2003) 109129.

E. Malecki and S. Gorman, Maybe the Death of Distance, but not the End ofGeography: The Internet as a Network, in T. Leinbach and S. Brunn, eds.,Worlds of E-Commerce: Economic, Geographical, and Social Dimensions(Chichester: John Wiley & Sons, 2001).

E. Malecki and A. McIntee, Making the Connections: Interconnecting the Networksof the Internet, paper presented at the Digital Cities Conference (Chicago, 2001).

Marketshare Hitslink (2007) Accessed January11, 2008.

K. Matheison, Building Effective Marketing Web Sites, EDI Forum: The Journalof Electronic Commerce 11 (1998) 1421.

S. McClelland, PTC 08: International Backbone Traffic Growth NighUnstoppable, Telecommunications Online (2008) Accessed July 15, 2008.

Meta-Search Engines, U.C. Berkeley Library (1999) Accessed April 19, 2007.

W. Mitchell, City of Bits: Space, Place, and the Infobahn (Cambridge, MA: MITPress, 1995).

P. Mokhtarian, I. Salomon, and S. Handy, The Impacts of ICT on Leisure Activitiesand Travel: A Conceptual Exploration, Transportation 33 (2006) 263289.

M. Moss, Technology and Cities, Cityscape: A Journal of Policy Development andResearch 3 (1998) 107127.

M. Moss and A. Townsend, The Internet Backbone and the American Metropolis,Information Society 16 (2000) 3547.

J. Mostafa, Seeking Better Web Searches, Scientific American Magazine (February2005) 6674.

W. Norton, A Business Case for Peering in 2004, paper presented at the GigabitPeering Forum IX (New York City, 2004).

H. Park and M. Thelwall, Hyperlink Analysis of the World Wide Web: A Review,Journal of Computer-Mediated Communication 8 (2003) Accessed February 20, 2008.


Dow

nloa

ded

by [

b-on

: Bib

liote

ca d

o co

nhec

imen

to o

nlin

e IS

CT

E]

at 1

2:36

10

Mar

ch 2

015

P. Pirolli and S. Card, Information Foraging, Psychological Review 106 (1999)643675.

P. Rimmer, Transport and Telecommunications among World Cities, in F.-C. Loand Y.-M. Yeung, eds., Globalization and the World of Large Cities (Tokyo:United Nations University Press, 1998).

R. Rogers and N. Marres, Landscaping Climate Change: A Mapping Technique forUnderstanding Science and Technology Debates on the World Wide Web, PublicUnderstanding of Science 9 (2000) 141163.

C. Rozenblat and D. Pumain, Firm Linkages, Innovation and the Evolution of UrbanSystems, in P.J. Taylor, B. Derudder, P. Saey and F. Witlox, eds., Cities in Globa-lization: Practices, Policies, and Theories (London-New York: Routledge, 2007).

J. Rutherford, Networks in Cities, Cities in Networks: Territory and GlobalisationIntertwined in Telecommunications Infrastructure Development in Europe, UrbanStudies 42 (2005) 23892406.

J. Rutherford, A. Gillespie, and R. Richardson, The Territoriality of Pan-EuropeanTelecommunications Backbone Networks, Journal of Urban Technology 11 (2004)134.

S. Sassen, The Global City: New York, London, Tokyo (Princeton, NJ: PrincetonUniversity Press, 1991).

S. Sassen, The Global City: New York, London, Tokyo, second edition (Princeton, NJ:Princeton University Press, 2001).

S. Sassen, Towards a Sociology of Information Technology, Current Sociology 50(2002) 365388.

Search Engine Showdown (2007) AccessedJanuary 11, 2008.

Search Engine Watch (2007) Accessed January11, 2008.

Seo Pagerank Search (2007) Accessed January 11, 2008.

J. Short, Y. Kim, M. Kuss, and H. Wells, The Dirty Little Secret of World CityResearch, International Journal of Regional and Urban Research 20 (1996) 697717. Quotation from page 697.

D. Siegel, Creating Killer Web Sites (Indianapolis: Hayden Books, 1997).

A. Smith and M. Thelwall, Web Impact Factors for Australasian Universities,Scientometrics 54 (2002) 363380.


Dow

nloa

ded

by [

b-on

: Bib

liote

ca d

o co

nhec

imen

to o

nlin

e IS

CT

E]

at 1

2:36

10

Mar

ch 2

015

D. Smith and M. Timberlake, World City Networks and Hierarchies, 19771997:An Empirical Analysis of Global Air Travel Links, American Behavioral Scientist44 (2001) 16561678.

P. Sommers and D. Carlson, What the IT Revolution Means for Regional EconomicDevelopment (Washington, D.C.: Brookings Institution Center on Urban and Metro-politan Policy 2003).

M. Stefik, Internet Dreams: Archetypes, Myths, and Metaphors (Cambridge, MA:MIT Press, 1996).

R. Tang and M. Thelwall, U.S. Academic Departmental Web-Site Interlinking in theUnited States: Disciplinary Differences, Library & Information Science Research25 (2003) 437458.

P. Taylor, World City Network: A Global Urban Analysis (London: Routledge,2004).

P. Taylor, New Political Geographies: Global Civil Society and Global Governancethrough World City Networks, Political Geography 24 (2005) 703730.

Telegeography (2007) Accessed January 11, 2007.

M. Thelwall, Commercial Web Site Links, Internet Research-Electronic Network-ing Applications and Policy 11 (2001) 114124.

M. Thelwall and L. Vaughan, Scholarly Use of the Web: What Are the Key Inducersof Links to Journal Web Sites? Journal of the American Society for InformationScience and Technology 54 (2003) 2938.

A. Townsend, The Internet Backbone and the American Metropolis, AcademicSearch Elite 16 (2000) 113.

A. Townsend, Network Cities and the Global Structure of the Internet, AmericanBehavioral Scientist 44 (2001) 16971716. Quotation from page 1704.

S. Walcott and J. Wheeler, Atlanta in the Telecommunications Age: The Fiber-Optic Information Network, Urban Geography 22 (2001) 316339.

J. Weltevreden, Winkelen in het Internettijdperk (Shopping in the Internet Age)(Rotterdam: Nai Uitgevers & Ruimtelijk Planbureau, 2007).

D. Wheeler and M. OKelly, Network Topology and City Accessibility of theCommercial Internet, Professional Geographer 51 (1999) 327339.

World Wide Web Size (2007) Accessed January11, 2008.


Dow

nloa

ded

by [

b-on

: Bib

liote

ca d

o co

nhec

imen

to o

nlin

e IS

CT

E]

at 1

2:36

10

Mar

ch 2

015

Documents

Lomme Devriendt Et Al Cyberplace and Cyberspace - Two Approaches to Analyzing Digital Intercity Linkages