The following papers, company studies, market analyses, or technology evaluations were chosen to strengthen the position that a POS system in Linux-HA with LTSP technology is a viable idea. More specific relationships of the documents to the thesis project are stated after each literature review.

The National Information Infrastructure Enterprise Promotion Association (NII) has a “Thin-Client POS” [NATI2000] document says that by the year 2005 the whole market for thin-client will double. The document gives the general idea of a thin-client solution as a network-dependent terminal that can display applications running on the attached server. It also states that all applications, processing, and user configurations reside on the server. This enables system administrators to fix, add, or upgrade software for the whole enterprise within hours.

The document reviews the technology and components which ar the network and standard PCs. It also enumerates competing technologies like Sun’s SunRays, and Network Computers like the JavaOS.

The relationship of this study to the project-thesis is that the project will fully use the thin-client approach to lower workstation cost and simplify software maintenance.

Vertical Systems Reseller has a study [RETA2000] that states that the thin-client approach to POS is becoming more common as networking has improved. The benefit of thin-clients is the fact that each POS unit does not have to be very powerful. Because the application processing runs on the backend. This means a software and hardware cost reduction on individual POS units. The survey showed that 36% of respondents said that their applications could be deployed in a thin-client POS arrangement. Another 28% are planning to be able to support the thin-client approach within the next 18 months. The study shows why there is a trend towards thin-client POS setups.

The relationship of this study to the project-thesis is that the project jumps into the trend of being a thin-client POS therefore lowering the hardware requirement of workstations.

Adam Newman, VP of Research of Eduventures, has a whitepaper [NEWM2003] discussing the benefits of thin-client solutions, specifically Citrix Metaframe XP Presentation Server, to grade schools. It says that the solution helps establish a more “simple, reliable, supportable, and affordable” computing environment. Furthermore Total Cost of Ownership (TCO) has been reduced and therefore empowering the organization to save 50% on maintenance costs while extending the lives of old hardware. Thin-clients have also helped them improve the scale and efficiency of its technology infrastructure without incurring the cost of hiring additional staff.

The relationship of this whitepaper to this project-thesis is the adoption of the principles of “simple, reliable, supportable, and affordable” computing environment in the design and implementation of the project.

Paula Rosenblum in an article [ROSE2003] says that the most critical infrastructure watchwords are “security” and “reliability”, followed closely by “openness” and “functionality”. It enumerates some common paths in POS applications, infrastructure, and hardware configurations. One finding is that the TCO is still the jury for most infrastructure elements. Another position is that the application choice should dictate the infrastructure decision and not the other way around.

The relationships of this article to the project-thesis are the same interests in reliability, security, openness, and functionality. The overall TCO is also the very reason this project-thesis is conducted.

S.D. Xenitellis [XENT2002] exposes security vulnerabilities of POSes, ATMs, Windows, X Windows, and the Java Virtual Machine. The vulnerabilities exist wherein a malicious program can be written to pretend to be the user by sending events to the victim application. Enumeration of resources is also possible and leads to exposition of sensitive hidden data, like passwords, within the application. The author also states the vulnerabilities as categorized into the following groups:

The author, Simon, says that the primary countermeasure is to simplify things specially in establishing the security domain layer. Disabling unused events also helps reduce security bugs. Finally a security code audit would really help analyze and remove the possible vulnerabilities.

The relationship of this article to the project-thesis is in the security concerns. The project’s user interface will be a trimmed down X Windows system with the shell changed to the POS application therefore removing the possibility of operators running any other program in the system. Measures will be done to disable user accounts from installing, running, or logging into the system other than the intended use. Unix-type operating systems like Linux has many ways of barring illegal use of resources. The administrative monitor, which will be web-based, should also be secure using SSL. More security is ensured by LTSP since the operating system is downloaded from the server every time the workstation is turned on, therefore removing the possibility that an attacker install a software-based keyboard logger.

Transactions between application server and database server, and application displays and keystrokes between workstations and terminal server will all be encrypted and compressed over the network using OpenSSH capabilities. This is to deter network monitors from sniffing or hijacking sessions.

In 2001, Cybersource Pty. Ltd. made a study [CYBE2001] that was focused on the comparison of the cost of deployment of a windows or linux computing infrastructure for a 250 computer staff organization over a simulated 3-year period. Costs that were considered are workstations, mail server, database server, internet connectivity, firewall, IT staff salaries, software costs, and network costs. Both an organization with existing hardware and one that needed to purchase everything were considered. The study concluded with a savings of $251,393 in favor of the Linux/Opensource solution over three years for both existing hardware and new hardware computations. The percentage saved for the existing hardware used organization is 34.26% while the new hardware infrastructure organization’s saving is 24.69%.

The relationship of this paper to the project-thesis is the interest in Total Cost of Ownership. The project avoids expensive software and will purely rely on GNU-style licenses which are mostly free and opensource. This will keep the TCO significantly lower.

Yang Weihong wrote a thesis [WEIH2002] titled “HYPOS: A POS Terminal Using Embedded Linux OS”. He stated problems in existing POS software which were:

He also mentioned that there were 5 steps in developing the software which were:

The survey in his study focused on usability, capability, user friendliness, and effectiveness of the HYPOS POS Terminal. His findings were that the HYPOS POS Terminal satisfied both the IT experts and supermarket assistants on the criteria: usability, capability, user friendliness, and effectiveness.

He recommends that 1)supermarkets use HYPOS instead of other POS software to reduce the cost of the whole system, 2) software companies are encouraged to adopt the software development procedure used in this study in developing the POS software to speedup the software development process, 3) GNU Glade which was used as the GUI design tool in the research was found to be effective although some other software that has the same functionality may also be used in the GUI design for POS software development.

The relationship of Yan Weihong’s study is that he also used Linux as the client POS terminal, Glade as the UI Design tool, GCC as the compiler, and gtk 1.2 as the user interface library.

Frederick Vincent Villar Tan [TAN2001] made a study entitled “I-text: Internet Text Messaging Portal To Mobile Phone” in April 2001. His conclusions were:

The relationship of Tan’s study to this paper is that both studies used text messaging to interface with the system.

Edward P. Anday wrote a thesis entitled “Finger Mark Scanning and Bar Code I.D. for Time Recording and Monitoring”. His thesis focused on the security of the Time Monitoring system. Functionalities such as the printing of monthly reports, logging in and out, accurate computation salary, and authentication of employees to record their daily attendance were included in his system. He says that the use of Finger Mark Scanning technology help the system to be fraud-free which means it avoid the singing in and out of employees for someone else. He also says that using bar codes, the application that accepts the bar code is 95% in control of the success or failure of the whole system.

Biometrics [http://en.wikipedia.org/wiki/Biometrics] refers to the use of technology for measuring and analyzing human physiological characteristics such as fingerprints, eye retinas and irises, voice patterns, facial patterns, and hand measurements, specially for authentication purposes.

Anday further points out that reducing errors translates to reducing cost. He said that typical human error rate is 1/300 characters while bar code error rate is 1/36 trillion depending on the type of bar code used.

The study makes interesting definition of terms that are of interest to this paper which are:

Usability - the attribute of software which tells iff the users can benefit from the software

Objectivity - if the software meets the end user’;s requirements. If it allows users to achieve high degree of productivity.

Reliability - software performance. If the software pperforms its intended function with required precision and outputs desired results.

Maintainability - when software can be enhanced or upgradeed for further improvement.

Security - ability to prevent unauthorized access wwhether accidental or deliberate to program and data.

The relationship of Edward’s thesis to this study is that he used barcodes to identify people using the system. He has also established the reliability of using barcodes for their accuracy and speed which is very important to this study.

Paul Krill wrote an article [KRILL2002] in InfoWorld about Google’s President and co-founder Sergey Brin who gave testimony to Linux’ scalability. Brin says “I think Linux has really enabled Google to grow to create a cost-effective computing platform”. Krill also mentions that Google has some 15,000 computers that handle 150 million searches per day from a 3 billion index of documents. Back in 2000 Google had about 5,000 linux computers only [SCHU2000]. This article gives the idea that for heavier loads Linux can be used in clusters to balance load among servers.

The thesis project to be built will be in parallel with the ideas and principles gathered by the mentioned authors above. The Thin-Client setup [NATI2000] will be used to lower per-terminal cost of the system and to simplify software maintenance of terminals. Thin-Client setups also will lower the POS terminal’s hardware requirements [RETA2000] and will improve infrastructure efficiency [NEWM2003].

Since the system will be transactional and will be dealing with credit with money value security will be very important [ROSE2003] and will get significant attention in the design and implementation of the system. The system must be fool-proof which means it has to be simple so it will be easy to analyze, debug, and do a security code audit. The system will also make it possible to do a transaction audit [XENT2002].

The Linux OS will be used to make the system more cost-effective [CYBE2001]. This means that the client gets more for less because it saves primarily from the free license of Linux. In the case of unprecedented application load, the scalability [KRIL2002] of Linux will help solve the problem.

The tools for building the application will be the same tools used by Yang Weihong which are Glade for the user interface design, GCC for the compiler, and GTK 1.2 for the graphical user interface library.

SMS capability [TAN2001] will be included to enable checking of credits using conventional cellphones.

Finally barcodes will be used to identify students with speed and accuracy [ANDA2004].

These with other newer technologies will be used to implement the thesis project.

________________________________________________________________________

Linux-Based Thin-Client Point Of Sale System with Mobile Application

3-10