A DISCUSSION OF THIN CLIENT TECHNOLOGY FOR

COMPUTER LABS

Jes´us Mart´ınez-Mateo, Susana Munoz-Hernandez and David P´erez-Rey

Facultad de Inform´atica, Universidad Polit´ecnica de Madrid, Campus de Montegancedo, Madrid, Spain

Keywords:

Thin client, e-Learning, Computer lab.

Abstract:

Computer literacy is not negotiable for any professional in an increasingly computerised environment. Ed-

ucational institutions should be equipped to provide this new basic training for modern life. Accordingly,

computer labs are an essential medium for education in almost any ﬁeld. Computer labs are one of the most

popular IT infrastructures for technical training in primary and secondary schools, universities and other ed-

ucational institutions all over the world. Unfortunately, a computer lab is expensive, in terms of both initial

purchase and annual maintenance costs, and especially when we want to run the latest software. Hence,

research efforts addressing computer lab efﬁciency, performance or cost reduction would have a worldwide

repercussion. In response to this concern, this paper presents a survey on thin client technology for computer

labs in educational environments. Besides setting out the advantages and drawbacks of this technology, we

aim to refute false prejudices against thin clients, identifying a set of educational scenarios where thin clients

are a better choice and others requiring traditional solutions.

1 INTRODUCTION

Traditional education has been hampered by the dif-

ﬁculties inherent in information and communication

technologies (ICT). Nowadays, modern education

faces a new challenge: the use of technology in the

classroom. Concerning these new educational chal-

lenges, probably one of the most popular is related to

improving computer lab performance. Note that con-

sidering the number of institutions that have to deal

with these infrastructures, any advantageous proposal

will have a worldwide repercussion.

There are a set of well-known problems that ed-

ucational institutions must address when using com-

puter labs. The main obstacles are usually related to

economic issues. Some institutions do not even have

computer labs due to unaffordable costs. The equip-

ment and the installation of a new computer lab is

very expensive. Moreover, both software and hard-

ware maintenance is a sustained cost over time. Soft-

ware and hardware evolve daily at a speed that most

institutions are unable to keep pace with. Thus soft-

ware and hardware upgrades especially are an ex-

pense that many institutions are unwilling to pay.

Thin client technology can be used to overcome

some of these problems. For instance, this technology

is an especially interesting option when upgrading an

educational computer lab, but it is not widespread

in these scenarios probably due to historical preju-

dices. An excessive triumphalism by supporters of

thin client technology, claiming the many advantages

of this technology sometimes rightly or wrongly but

usually without proper justiﬁcation, may have led to

the early dismissal of thin client technology by many

professionals. It has often been relegated to an imma-

ture technology status. However, today there are so-

lutions based on thin client technology that are simple

to use, and after many years of development and evo-

lution are highly reliable, which could be a very in-

teresting option in some speciﬁc scenarios. Some of

these solutions are the Linux Terminal Server Project

(LTSP) project

, especially designed for Unix-based

systems, or Lan Core

, a project originally focused

on the use of thin clients on Windows systems.

In this paper we summarise the main characteris-

tics of thin clients (Section 2), explicitly stating their

strengths and weakness related to the educational en-

vironment(Section 3). From this information we have

identiﬁed a set of scenarios (Section 4) where the use

thin client technology is a good option, and some

counter examples.

http://www.ltsp.org

http://lancore.sourceforge.net

119

Martínez-Mateo J., Munoz-Hernandez S. and Pérez-Rey D. (2010).

A DISCUSSION OF THIN CLIENT TECHNOLOGY FOR COMPUTER LABS.

In Proceedings of the Multi-Conference on Innovative Developments in ICT, pages 119-124

DOI: 10.5220/0002962901190124

 SciTePress

Figure 1: In a thin client network, all clients are continu-

ously connected to a common server in a centralised archi-

tecture. For each connection the server sends the desktop to

the client computer (the thin client). The user works using

a remote desktop session.

2 THIN CLIENT TECHNOLOGY

From the very beginning of computing, around the

1950s, early computers had to be shared by multi-

ple users on economic grounds. Mainframes, mainly

known for their large size and priced according by,

evolved towards the interaction of a single computer

with multiple users. A few years later the ﬁrst termi-

nal appeared: This was an speciﬁc device connected

to the mainframe enabling multiple users to access

and share computing resources through batch proces-

sing. The early terminals, today known as consoles,

worked in text mode only, and were connected via

serial lines. Therefore, a primitive type of general-

purpose device working much like a thin client was

there way back when the main commercial computers

ﬁrst came on the scene.

Console terminals evolved gradually and continu-

ously for years until the advent of the personal com-

puter (PC) in the 1980s. Physical terminals were then

immediately replaced by PCs equipped with terminal

emulation software. Not only were PCs a substitute

for the old terminal devices, but they also marked a

profound change in the computing architecture. For

the ﬁrst time, the client (i.e. the PC) had its own pro-

cessing capacity, leading to the client and server di-

vision. It was also a turning point for terminal com-

puting, where terminals became known as thin clients

and they were no longer connected to a central com-

puter directly, but via a network. New graphical op-

erating systems, including the new Unix-based sys-

tems (e.g. Linux), introduced the new desktop con-

cept. The client side in a thin client solution had to be

modiﬁed to be adapted to graphical devices (see Fig-

ure 1), new user interfaces, the mouse and other new

input and output devices.

Because of everything discussed above, today it is

not possible to ﬁnd a primary reference introducing

the new concept of thin client, terminal, or diskless

devices in computing. However,there can be no doubt

that thin client technology has been always present in

computing, sometimes going by a different name or

terminology, running on primitive or highly evolved

hardware, even supported by entirely different oper-

ating systems, using batch processing, multitasking,

and other hardware and software sharing strategies.

2.1 Thin Client Beneﬁts

Thin client technology can make a network admin-

istrator’s job easier for three main reasons: it is

easy to manage, easy to secure and easy on the bud-

get (Romm, 2006). An explanation of each one of

these beneﬁts follows:

1. A thin client network is easy to manage and main-

tain thanks to its centralised set-up and support. It

simpliﬁes troubleshooting, network management,

and monitoring among other things.

2. Security is provided intrinsically by the architec-

ture of a thin client solution. Input devices such

as local Universal Serial Bus (USB) ports are eas-

ily disabled, thus avoiding a common source of

viruses. The integration of ﬁrewall functional-

ity in every computer in the network (i.e. a dis-

tributed ﬁrewall) is possible by just conﬁguring a

ﬁrewall on the server (Ioannidis et al., 2000).

3. The use of thin client technology is low cost in

terms of hardware (see Figure 2), software (just

one licence for the server), set-up and mainte-

nance (see Figure 3).

Points one and two are related to the fact that there

is only one processor and point three is related to the

simplicity of the thin client technology. In the context

of this paper there is one property of thin client tech-

nology that should be emphasised: a thin client has no

need of high processing capacity. Note that it will not

run anything apart from the hardware and software

needed to properly visualise the graphical user in-

terface. Accordingly low-performance hardware (i.e.

out-of-date computers or “ancient hardware”) could

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400

500

600

700

800

Thin Client

Figure 2: Evolution of the price (vertical axis in euros) per

unit (PC or thin client) according to the number of installed

workstations (horizontal axis). This estimate has been cal-

culated assuming the following costs: PC 600 EUR, thin

client 400 EUR, and server 1000 EUR; with an incremen-

tal discount (n × 0.5%) depending on the number of units

purchased.

be used to build a thin client. Considering these bene-

ﬁts, thin clients are an attractive technology for insti-

tutions with old computers, budget concern and lim-

ited maintenance staff (i.e. more than 80% of the ed-

ucational institutions in the world, most of them in

developing countries).

2.2 Green Computing

Reducing energy consumption is an attractivegoal not

only due to increasing energy costs, but also from

the standpoint of natural resources and environmental

conservation. There are many reasons for implement-

ing green IT systems, and hardware that is speciﬁcally

designed for thin clients seems to ﬁt in perfectly here

(UMSICHT, 2008).

In a comparison with other alternatives that have

similar possibilities to thin clients on other counts,

thin client technology has an important point in favour

of its aptness for green computing.

3 STRENGTHS AND

WEAKNESSES

Probably the main feature of a thin client is that users

do not appreciate any difference from a desktop PC

when they ﬁrst come into contact with the device. The

desktop displayed by a thin client is exactly the same

as one shown by a PC. This property of thin client

technology is essential in educational labs and it is

one of the strengths of this technology. Using thin

clients students can acquire the same skills that they

could learn using PCs because they actually use the

Thin Client

Figure 3: Estimated hours of maintenance per week (ver-

tical axis) depending on the number of workstations (hori-

zontal axis), comparing PCs versus thin clients.

same tools and applications (running on the server in-

stead of on their own machines).

Another important strength of thin clients is that

most of the applications used on a PC, such as those

included in an ofﬁce suite (e.g. Microsoft Ofﬁce

in Windows operating systems or Open Ofﬁce for

Linux) will probably run on a network with thin

clients. Similarly, Wikipedia (probably the most vis-

ited website on the Internet in academic environ-

ments) also has these advantages.

On the other hand, the thin client technology’s

main weakness materialises in what are technically

referred to as high-motion scenarios (Deboosere et al.,

2007). High-motion scenarios include:

• Streaming multimedia: video and audio are al-

most prohibitive using thin clients.

• Motion graphics: animations, slide effects, etc.,

are processes that are often affected by a desktop

virtualisation.

• Applications requiring a powerful graphics card:

everything related to games and 3D rendering.

• Latency-sensitive applications, where the time it

takes an event to reach the client through a net-

work is critical.

Hence, thin client technology is not an alternative

for scenarios with these requirements, but it could be

an optimal solution in the near future due to several

technical developments attempting to overcome the

above weaknesses (Simoens et al., 2008).

4 COMMON ACADEMIC

SCENARIOS

Each computer-based environment has particular re-

quirements that need to be considered to ﬁnd the opti-

mal hardware and software solution. Looking at thin

A DISCUSSION OF THIN CLIENT TECHNOLOGY FOR COMPUTER LABS

121

clients, some advantages and limitations of this tech-

nology will act as detriment or incentive for a thin

client solution. Below we analyse the main academic

scenarios regarding thin client suitability.

Note that we havehighlighted overlaps among dif-

ferent scenarios.

4.1 Computer Labs

As discussed above (Figures 2 and 3) thin clients have

an edge in terms of budget and maintenance concerns

over PCs in installations from ﬁve and eight com-

puters respectively. This covers almost all computer

labs in education. Thus a computer lab intended for

traditional computer-based learning may also beneﬁt

from thin clients if they support the required tools. A

previous study suggests that most tools used in the

academic environment can be used with thin clients

(Brinkley, 2006). The results of this research are con-

clusive: of the 45 tools used in this case, only three

could not be used, and there were some minor prob-

lems with another three. The rest of tools run cor-

rectly using thin client technology.

Technology facilitates student participation and

computer labs are beginning to be used with this aim

(Peiper et al., 2004). Although there are interactiv-

ity increments in collaborative environments they are

supported by thin client technology.

4.2 Distance Learning

Distance learning is a relatively modern academic sit-

uation in computer-based learning, where ICTs are

used to circumvent the boundaries of a physical class-

room. This is a wider scenario than the one consid-

ered in a computer lab. A range of situations depend-

ing on student and professor location are listed below:

• Local students and professors. Traditional

computer-enhanced learning to meet today’s ICT

literacy need. This situation is spreading fast and

is being combined with novel trends, such as dig-

ital ink (Section 4.4), which are suitable to work

on thin clients.

• Local students with a remote professor. Students

gathered in a computerlab (see Section 4.1) attend

a lecture by a remote professor. Not a common

situation at traditional universities, it is an optimal

solution in most cooperation for developmentsce-

narios. It is also suitable for thin client implemen-

tations due to the number of computers required

and the limited budget and staff available.

• Remote students with a local professor. Students

using off-campuscomputersto access teaching re-

sources. This is the new model being adopted by

universities worldwide and not suitable for thin

clients (Casella et al., 2007).

• Remote students and professors. Pure e-learning

scenario also not suitable for thin clients.

Although the last two situations rule out a thin

client solution given that the academic organization

is not providing computers to access the resources,

thin client implementations have been proven to be a

feasible solution for use in most “local student” situ-

ations.

4.3 Web-based Learning

Web-based solutions are in widespread use for e-

learning. These solutions could be part of distance

learning or e-learning generally, but we have pre-

ferred to examine them separately due to their wide

dissemination.

Special-purpose hardware for thin clients or com-

mon PCs operate here as thin clients for remote learn-

ing, since its limitations do not affect most web ap-

plications. Some educational solutions that use web-

based services have already proposed the use of thin

client technology in the classroom (Andria et al.,

2007). Even web-based scenarios including complex

requirements are good scenarios for the use of thin

clients (Callaghan et al., 2007), provide they do not

use multimedia or high-motion services.

4.4 Digital Ink

New technologies are making a claim for a place in

education in the classroom. Most of these technolo-

gies are publicised as new e-learning strategies, but

some, such as digital ink, should be studied sepa-

rately. It is not possible to decide whether a sce-

nario is suitable for the use of thin client technology,

based only on the above strengths and weaknesses. In

this case, digital ink should be singled out from other

e-learning strategies because it proposes the use of

special-purpose hardware devices instead of common

computersused in conventional e-learning. For exam-

ple, a proposal for the use of the Classroom Presen-

ter

application (a software platform for digital ink)

recommends the use of tablet PCs by students. Table

PCs are really modern devices for which a thin client

is no suitable (Anderson et al., 2007).

4.5 Education in Developing Countries

Health and education are fundamental aspects for a

country’s development. Education, especially in tech-

http://classroompresenter.cs.washington.edu

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nical ﬁelds, is an important goal if developing coun-

tries are to emulate the information access opportuni-

ties of developed nations (Krikke, 2004). However, an

educational institution in a developing country can-

not afford the cost of setting up and maintaining a

computer lab. Cooperation for development guide-

lines call for the use of sustainable technologies and

solutions, meaning the purely ﬁnancial contribution

of purchasing a computer lab is not acceptable. Thin

client technology could further the use of computer

labs in developing countries in a sustainable way. In

this regard the following is an example of a success

story in terms of the technology proposed in this pa-

per.

In 2006 the Technology for Development and Co-

operation (TEDECO) Group

led by professors of the

School of Computing at Universidad Polit´ecnica de

Madrid, Spain, launched a new distance education

project at University of Ngozi (UNG), in Burundi.

A committee formed by members of the TEDECO

group and expert engineers explored several options

for setting up two computer labs at UNG. The limited

budget and the availability of very old computer re-

sources were key points to consider when making a

ﬁnal decision (Mart´ınez-Mateo et al., 2009).

The use of thin client technology in computer

labs proved to be a success, especially taking into

account that it was tested in a really tough environ-

ment, where there were no qualiﬁed staff, apart from a

technical support staff working exclusively on main-

tenance. The project was considered a success due

to (Mart´ınez-Mateo et al., 2010): (i) the increase in

the number of subjects that were offered over an e-

learning platform like Moodle using the new com-

puter labs, (ii) the increase in the number of students

choosing to study at UNG, and (iii) the offer of a new

course (fourth year) as result of student demand and

the new subjects offered.

4.6 Unsuitable Scenarios

Although tt is important to ascertain the main scenar-

ios where the use of thin client technology is suitable,

it is even more necessary to identify scenarios where

this technology should be avoided. To identify scenar-

ios that are unsuitable for the use of client technology,

always keep in mind the key weakness highlighted in

Section 3: high-motion. A list of scenarios that are

not suitable for thin clients follows:

• Distance learning, unless it requires the physical

presence of students in a classroom.

http://tedeco.ﬁ.upm.es

• Multimedia learning, which is a discipline that

has been especially developed in certain sectors

of education, such as medicine (Ruiz et al., 2006).

• Mobile learning. As stated in Section 4.4, e-

learning strategies calling for student mobility can

not be implemented with thin clients. These sce-

narios require the use of special devices that are

not covered by the current thin client technology.

Although there are unsuitable scenarios related to

multimedia, video, and other high-motion resources,

the majority of computer-based scenarios do not re-

quire these features. Therefore, thin client technology

is an alternative that is worthwhile considering.

5 CONCLUSIONS

Computer-based learning methodologies and related

infrastructures are essential nowadays at any level of

the academic world. Computer labs and required ICT

are becoming an economic and staff resource barrier

for all educational institutions. Thus efforts to provide

more effective solutions will have a practical impact

on education.

Thin client technologies have proven to be a good

option for reducing budget and maintenance require-

ments in scenarios with more than ﬁve to eight com-

puters. However, it would be a mistake to defend this

solution without examining what use is going to be

made of the lab equipment. There are many educa-

tional scenarios where thin clients are cheaper to use,

easier to maintain and easier to upgrade. In this pa-

per, we have identiﬁed the main advantages and limi-

tations of thin clients regarding the most common sce-

narios. A widespread of this technology in some cases

would improve global computer literacy.

ACKNOWLEDGEMENTS

We would like to thank the UniversidadPolit´ecnica de

Madrid’s Ofﬁce of Cooperation for the Development

for its ﬁnancial an logistic support

, and the mem-

bers of TEDECO group for their interest, constructive

comments and active participation in the development

of this paper.

This work is partially supported by the project MES-

TUN (Monitoring, evaluation and technological sustain-

ability of the University of Ngozi) funded by the call 2009

of the Direction of Cooperation for the Development of the

Technical University of Madrid.

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123

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