The objective of this dissertation is to propose the cross-layer spectrum management architecture for white space applications that improves the performance the main functions of the spectrum management. In the proposed cross-layer architecture, white space network devices such as white space devices and the spectrum map server cooperate to support the extended spectrum map, the inter-cell transmit power adaptation (ITPA), and the frequency-domain coexistence beacon (FCB). Upon the cross-layer architecture, firstly, white space devices (WSDs) achieve a faster search and higher accuracy in spectrum sensing with the extended spectrum map, the extended DHCP (Dynamic Host Configuration Protocol), and the FCB. Secondly, WSDs achieve the precise selection of their operating channel in spectrum decision with the extended spectrum map and the ITPA. In spectrum sharing, thirdly, the collaboration- based spectrum sharing with the ITPA achieve more accommodation of WSDs by increasing the number of channels shared between WSDs. Finally, WSDs with the FCB and the extended spectrum achieve effective spectrum mobility by obtaining the occupancy-status of channels precisely.

The aesthetic aspect of a functional product is growing to be an important reason for the consumers choice to buy the product. Despite this importance, aesthetics has not generally been incorporated into engineering design which makes much sense of functional and ergonomic designs. The study presented in this thesis aims to remedy this observed gap. The study focuses on the integration of aesthetic attributes with functional attributes of a product and on the quantification of the aesthetic principle from fine arts into design variables of the product. In particular, two hypotheses underlie this study: (1) design variables can be classified in terms of their relevance to functional, ergonomic, and aesthetic attributes, and (2) a particular aesthetic principle, namely visual balance, helps to achieve an improved aesthetic product.<p>The cell phone is used to ground this study. A statistic experiment using the cell phone product positively tests the first hypothesis, resulting in two design variable which are only related to the aesthetic attribute of the cell phone product. The study of the visual balance principle results in a more general formula which relates design variables to visual balance with consideration of both geometry and color of the cell phone product. Finally, another statistic experiment is designed, which positively tests the second hypothesis.<p>This study concludes: (1) the effective integration of aesthetics with function and ergonomics requires an analysis and classification of design variables, and (2) there is a potential to quantify all aesthetic principles from fine arts into design variables.

M. Tech. Business Administration / The purpose of this study was to identify and understand customer perceptions about service quality (SQ) at a telecommunications retail outlet. The theory of Parasuraman, Zeithaml and Berry (PZB) known as SERVQUAL was used to give theoretical grounding to the study.

Mobile communications are becoming integrated into society at an explosive rate. While 2nd generation (2G) systems limit the user to basic services such as voice and low-bit rate data, 3G networks are characterized by their ability to accommodate wideband multi-media traffic with Quality of Service (QoS) guarantees. In the design of a system the Medium Access Control (MAC) layer is responsible for multiplexing heterogeneous traffic onto a common transmission link and its design is critical to the overall performance of a system. A number of MAC protocols for wireless networks have been proposed in the literature - the majority having time division multiple access (TDMA) at the MAC layer. However in 3G systems there is a trend towards the use of code division multiple access (CDMA) due to its proven advantages in a wireless environment. Although several papers on CDMA based MAC protocols have been published, virtually none of them tackle the analysis aspect of the protocols. Those papers that do perform analyses of CDMA protocols don't often consider heterogeneous traffic, and even fewer support QoS. The thesis addresses these shortcomings by proposing a MAC protocol that supports QoS in the form of Bit Error Rate (BER) and packet delay guarantees. The thesis begins by giving an overview of proposed wireless ATM and 3G CDMA protocols and then details how power control may be used to support BER guarantees. Various Markov based analyses are presented along with Monte-Carlo Simulations. An Equilibrium Point Analysis is then performed and the work discusses how such analyses are generally infeasible for systems supporting heterogeneous traffic. After an overview of conventional scheduling algorithms the thesis proceeds to outline a novel approach by which delay guarantees may be offered using packet dropping rates as the QoS metric. Using a stochastic source model as opposed to the conventional leaky bucket traffic regulator the thesis diverges significantly from conventional literature. The thesis also details how to calculate the probability of QoS violation and concludes with suggestions on further research avenues. As a whole the work is unique in its approach to analyse heterogeneous traffic and the methods it uses to construct session admission zones for QoS guarantees. / Thesis (Ph.D.)-University of Natal,Durban, 2002.

The emergence of portable terminals in work and living environments is accelerating the progression of wireless networks. A wireless ad hoc network is a new network concept where users establish peer-to-peer communication among themselves independently, in their small area. Since the wireless medium is a shared resource, it becomes an important design issue to efficiently allocate bandwidth among users. MAC (Medium Access Control) layer arbitrates the channel access to the wireless medium and is also responsible for bandwidth allocation to different users, therefore a large amount of research has been conducted on various MAC protocols for ad hoc wireless networks. This dissertation begins with a survey of existing wireless MAC protocols. The survey includes protocols designed for different network generations and topologies, classifying them based on architecture and mode of operation. Next, we concentrate on the MAC protocols proposed for distributed wireless networks. We propose a new MAC protocol based on a token-passing strategy; which not only incorporates the advantages of the guaranteed access scheme into the distributed type of wireless networks, but also the data rate and delay level QoS guarantees. Data rate QoS provides fairness into sharing of the channel, while delay level QoS introduces a flexible prioritized access to channels by adjusting transmission permission to the current network traffic activities. A simulation model for the protocol is developed and delay and throughput performance results are presented. To examine the efficiency and performance of the proposed MAC scheme in an ad hoc wireless environment, it is incorporated into the Bluetooth structured network. The model is then simulated in the Bluetooth environment and performance results are presented. Furthermore, an analytical model is proposed and an approximate delay analysis conducted for the proposed MAC scheme. Analytical results are derived and compared with results obtained from computer simulations. The dissertation concludes with suggestions for improvements and future work. / Thesis (M.Sc.-Engineering)-University of Natal, 2003.

Abstract available in digital copy. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.

It is common practice for service providers, such as cell phone network providers, to utilise relationship marketing strategies in an effort to retain their customers and thereby to increase profitability. Customers with relationship intentions are willing to respond to such efforts while other customers will refrain. Service failures negatively impact relationship marketing efforts and thus complicate service providers’ relationship-building efforts. Therefore, service providers endeavour to restore customers’ post-recovery satisfaction and loyalty through service recovery efforts to retain their customers. However, the influence that customers’ relationship intentions have on this process has not been considered. Previous research on relationship intention in South Africa focussed only on developing a valid and reliable relationship intention measurement scale. For this reason, the primary objective of this study was to determine the influence of relationship intention on customer satisfaction, loyalty and retention following service recovery within the cellular industry. Supporting the primary objective, a model depicting the influence of respondents’ relationships intentions on satisfaction, loyalty and retention following service recovery was developed. Furthermore, a model depicting the interrelationships of the relationship constructive dimensions of the service recovery process uncovered during this study was also developed. Through non-probability convenience sampling of adults 18 years and older (residing in Johannesburg and the surrounding residential suburbs) who have used a cell phone network provider for three years or longer, 605 respondents completed interviewer-administered questionnaires. Demographic and patronage information, together with respondents’ relationship intentions, attitudes towards complaining, customers’ complaint behaviour, expectations of service recovery, perceived service recovery as well as satisfaction, loyalty and retention following service recovery, were obtained. Results indicated that no associations exist between respondents’ levels of relationship intention and their relationship lengths, as well as whether they had contractual agreements with their cell phone network providers. It is therefore recommended that instead of using relationship length or contractual agreements, cell phone network providers should use customers’ relationship intentions to identify customers for relationship marketing purposes. Findings from this study furthermore include that respondents’ relationship intentions influence their propensities to complain, as well as the likelihood that they will voice a complaint regarding dissatisfactory service delivery. It is therefore recommended that cell phone network providers use the opportunity to identify customers with relationship intentions through customers’ complaint behaviour. This study found that respondents’ relationship intentions influence both their expectations of cell phone network providers to take service recovery action, as well as their perceptions of service recovery. Respondents’ relationship intentions also positively influence their satisfaction, loyalty and retention following service recovery. Based on these findings, it is recommended that cell phone network providers should always take corrective action following service failures (such as billing errors in this study), preferably by including at least an acknowledgement, apology, explanation and rectification of the problem as part of the service recovery efforts. Such a combination of service recovery efforts will increase the satisfaction, loyalty and retention of customers with higher relationship intentions. From the results it can be concluded that customers’ relationship intentions influence their behaviour with regard to propensity to complain, voicing, expectations of service recovery action, perceptions of service recovery, as well as satisfaction, loyalty and retention following service recovery, when service failures occur. The proposed model developed from these findings results in the recommendation that cell phone network providers should view the service recovery process as an interrelated process influenced by customers’ relationship intentions. Cell phone network providers should note that customers with higher relationship intentions will attempt to salvage the relationship when service failures occur, which contributes to their satisfaction, loyalty and retention following service recovery. This study contributes to establishing relationship intention theory by confirming the positive influence of customers’ relationship intentions on constructive behaviour when service failures occur. Moreover, practical recommendations concerning cell phone network providers’ response to billing errors are proposed. Future research should address the methodological limitations of this study by using probability sampling, and data should be collected from all South African provinces. Real-time service failures should be considered as opposed to the scenario-based approach used in this study. Important influences on customer behaviour when service failures occur, such as the perceived severity of service failure, service failure type, perceived justice and attributions, should also be considered with regard to their influence on the constructs of this study. Lastly, the antecedents of or differences with regard to customers’ relationship intentions based on personality, generational cohort or population group deserve further attention to establish relationship intention as study field within the domain of relationship marketing. / PhD (Marketing Management), North-West University, Potchefstroom Campus, 2014.

Real-time information that informs transit riders about transit schedules, next bus or train arrivals, and service alerts, is becoming increasingly available, particularly through internet-enabled smartphone applications. However, the extent of communication technology usage amongst transit riders, specifically their access to mobile applications and alternative technologies that can provide real-time information, is largely unknown. Without this information, transit agencies are risking investing in an alternative technology that may not sufficiently supply real-time information to as many as possible riders. The purpose of this study is to identify the differences in individual technology accessibility and prioritize investing in real-time information application development that mirrors the unique characteristics of transit riders. This recognition and development will allow a wider availability of real-time information amongst transit riders. Paired with an investigation of cellular phone usage among transit riders and the general American population, an analysis of Saint Louis Metro’s Onboard Survey was performed. Cross tabulations and chi-squared tests were conducted to examine riders’ communication technology usage. Binary logit models were used to understand how, and whether, the ownership of smartphone applications is dependent on various demographic factors. These analyses identified specific demographic groups that would benefit from supplemental technology methods more conducive to their particular information accessibility. Results showed that communication technology usage has risen substantially in recent years but a portion of riders are still without access to smartphone applications. Specific demographic groups (e.g., riders over 40 years of age) were less likely to own smartphones, and these results indicate that computer-based websites and IVR are the best supplementary alternatives for those groups.

The licence is a regulatory tool that regulatory use to assist in their regulatory functions. Licences restricts operator’s’ functions, but also serve as a guideline of acceptable conduct because a licence is a legally binding document containing prescribed conditions that the licencee must meet. If the licencee does not comply with these prescribed obligations and requirements, the licence may be revoked or the licencee may be penalized (Bladwin & Cave 1999). However, in order fro the mechanism of issuing a licence to be an effective mechanism of regulation, the regulator needs to regulate effectively in order to ensure that the licencee’s performance is of acceptable standard. The purpose of this study is to investigate the relationship between issuing a licence and the licencee’s performance; to investigate whether the performance indicators, as defined by ICASA, are adequate, and to develop appropriate performance indicators in order to evaluate Cell C’s performance. Issuing a licence to licencee does not guarantee that the performance of the licencee, such as Cell C, will be effective. Thus, the licencee needs to be evaluated. The case study design has been used for this project. The methodology includes in-dept interviews, documentary analysis, and implementation evaluation research. The report concludes that Cell C has met its licence obligations, that licencing is coupled with effective mechanisms to ensure that the licencee complies with performance requirements, but that, in order for the licencee to improve its performance, effective regulatory intervention is needed. / Communication Science / MA (International Communication)

Historically, progress in technology development has continually created new opportunities for criminal activities which, in turn, have triggered the need for the development of new security-sensitive systems. Organisations are now adopting mobile technologies for numerous applications to capitalise on the mobile revolution. They are now able to increase their operational efficiency as well as responsiveness and competitiveness and, most importantly, can now meet new, growing customers’ demands. However, although mobile technologies and applications present many new opportunities, they also present challenges. Threats to mobile phone applications are always on the rise and, therefore, compel organisations to invest money and time, among other technical controls, in an attempt to protect them from incurring losses. The computerisation of core activities (such as mobile banking in the banking industry, for example) has effectively exposed organisations to a host of complex fraud challenges that they have to deal with in addition to their core business of providing services to their end consumers. Fraudsters are able to use mobile devices to remotely access enterprise applications and subsequently perform fraudulent transactions. When this occurs, it is important to effectively investigate and manage the cause and findings, as well as to prevent any future similar attacks. Unfortunately, clients and consumers of these organisations are often ignorant of the risks to their assets and the consequences of the compromises that might occur. Organisations are therefore obliged, at least, to put in place measures that will not only minimise fraud but also be capable of detecting and preventing further similar incidents. The goal of this research was to develop a unified fraud management and digital forensic framework to improve the security of Information Technology (IT) processes and operations in organisations that make available mobile phone applications to their clients for business purposes. The research was motivated not only by the increasing reliance of organisations on mobile applications to service their customers but also by the fact that digital forensics and fraud management are often considered to be separate entities at an organisational level. This study proposes a unified approach to fraud management and digital forensic analysis to simultaneously manage and investigate fraud that occurs through the use of mobile phone applications. The unified Fraud Management and Digital Forensic (FMDF) framework is designed to (a) determine the suspicious degree of fraudulent transactions and (b) at the same time, to feed into a process that facilitates the investigation of incidents. A survey was conducted with subject matter experts in the banking environment. Data was generated through a participatory self-administered online questionnaire. Collected data was then presented, analysed and interpreted quantitatively and qualitatively. The study found that there was a general understanding of the common fraud management methodologies and approaches throughout the banking industry and the use thereof. However, while many of the respondents indicated that fraud detection was an integral part of their processes, they take a rather reactive approach when it comes to fraud management and digital forensics. Part of the reason for the reactive approach is that many investigations are conducted in silos, with no central knowledge repository where previous cases can be retrieved for comparative purposes. Therefore, confidentiality, integrity and availability of data are critical for continued business operations. To mitigate the pending risks, the study proposed a new way of thinking that combines both components of fraud management and digital forensics for an optimised approach to managing security in mobile applications. The research concluded that the unified FMDF approach was considered to be helpful and valuable to professionals who participated in the survey. Although the case study focused on the banking industry, the study appears to be instrumental in informing other types of organisations that make available the use of mobile applications for their clients in fraud risk awareness and risk management in general. / Computing / M. Sc. (Computing)