Vision based technology such as motion detection has long been limited to the domain of powerful processor intensive systems such as desktop PCs and specialist hardware solutions. With the advent of much faster mobile phone processors and memory, a plethora of feature rich software and hardware is being deployed onto the mobile platform, most notably onto high powered devices called smart phones. Interaction interfaces such as touchscreens allow for improved usability but obscure the phone’s screen. Since the majority of smart phones are equipped with cameras, it has become feasible to combine their powerful processors, large memory capacity and the camera to support new ways of interacting with the phone which do not obscure the screen. However, it is not clear whether or not these processor intensive visual interactions can in fact be run at an acceptable speed on current mobile handsets or whether they will offer the user a better experience than the current number pad and direction keys present on the majority of mobile phones. A vision based finger interaction technique is proposed which uses the back of device camera to track the user’s finger. This allows the user to interact with the mobile phone with mouse based movements, gestures and steering based interactions. A simple colour thresholding algorithm was implemented in Java, Python and C++. Various benchmarks and tests conducted on a Nokia N95 smart phone revealed that on current hardware and with current programming environments only native C++ yields results plausible for real time interactions (a key requirement for vision based interactions). It is also shown that different lighting levels and background environments affects the accuracy of the system with background and finger contrast playing a large role. Finally a user study was conducted to ascertain the overall user’s satisfaction between keypad interactions and the finger interaction techniques concluding that the new finger interaction technique is well suited to steering based interactions and in time, mouse style movements. Simple navigation is better suited to the directional keypad.

Energy consumption and its management have been clearly identified as a challenge in computing and communication system design, where energy economy is obviously of paramount importance for battery powered devices. This thesis addresses the energy efficiency of mobile communication at the user end in the context of cellular networks. We argue that energy efficiency starts by energy awareness and propose EnergyBox, a parametrised tool that enables accurate and repeatable energy quantification at the user end using real data traffic traces as input. EnergyBox offers an abstraction of the underlying states for operation of the wireless interfaces and allows to estimate the energy consumption for different operator settings and device characteristics. The tool is used throughout the thesis to quantify and reveal inefficient data communication patterns of widely used mobile applications. We consider two different perspectives in the search of energy-efficient solutions. From the application perspective, we show that systematically quantifying the energy consumption of design choices (e.g., communication patterns, protocols, and data formats) contributes to a significantly smaller energy footprint. From the system perspective, we devise a cross-layer solution that schedules packet transmissions based on the knowledge of the network parameters that impact the energy consumption of the handset. These attempts show that application level decisions require a better understanding of possible energy apportionment policies at system level. Finally, we study the generic problem of determining the contribution of an entity (e.g., application) to the total energy consumption of a given system (e.g., mobile device). We compare the state-of-the-art policies in terms of fairness leveraging cooperative game theory and analyse their required information and computational complexity. We show that providing incentives to reduce the total energy consumption of the system (as part of fairness) is tightly coupled to the policy selection. Our study provides guidelines to select an appropriate policy depending on the characteristics of the system.

This thesis discusses the creation of a novel platform that incorporates multiple communication methods, including SMS, email and web-based technologies, for interacting with users of mobile communication devices. The platform utilises people in a mobile environment to solve a range of different application problems, where each problem is a separate and distinct scenario type with unique objectives. There are existing applications available that interact with users of mobile communication devices to provide a service, such as regular weather updates to the users. Other applications have been designed to manage and coordinate the users to perform tasks within a mobile environment, such as performing field studies for scientific purposes. However, the existing applications are designed for only one specific scenario, with the design and implementation solely focused on solving the objectives of that scenario. Each component of these applications needs to be developed from scratch in order to cater for the application s requirements. There is currently no integrated communications platform that offers a framework for supporting a range of different scenario types. The new platform, entitled the Connected-Mobile Platform, aims to support the rapid development and implementation of new scenarios. This platform is composed of a framework of generic components that enable the active running of multiple scenarios concurrently, with the ability to tailor to the requirements of new scenarios as they arise via a structured process. The platform facilitates a means to coordinate its users in order to tackle the objectives of a scenario. The thesis investigates several system architectures to determine an appropriate architectural design for constructing the proposed platform. The platform has a generic framework, based on a client-server architecture, to facilitate the inclusion of a multitude of scenarios. A scenario represents a problem or an event, whereby the platform can utilise and interact with users of mobile communication devices to attempt to solve the objectives of the scenario. Three mobile communication methods are supported; the Short Message Service, electronic mail and web-forms via the mobile internet. Users are able to select and switch between the different methods. The thesis describes the platform s tailored communication structure for scenarios and autonomous analysis of messages. The thesis discusses case studies of two different scenarios to evaluate the platform s facilities for rapid scenario development. The Diet Diary scenario, which is for individual users, aims to manage a user s daily calorie intake to help them reach their desired weight goal. The focus is on the platform s functionality for analysing and responding to messages autonomously. The Missing Persons scenario, which utilises multiple users, involves tracking and locating people who have been reported missing. The focus is on the platform s functionality for coordinating the multiple users, through the creation of assignments, in order to distribute the scenario objectives. The thesis concludes by highlighting the novel features of the platform and identifying opportunities for future work.

published_or_final_version / Business Administration / Master / Master of Business Administration

published_or_final_version / Business Administration / Master / Master of Business Administration

published_or_final_version / Management Studies / Master / Master of Business Administration

published_or_final_version / abstract / Electrical and Electronic Engineering / Doctoral / Doctor of Philosophy

<p>SIP is receiving much attention these days and it seems to be the most promising candidate as a signaling protocol for the current and future IP telephony services. Realizing this, there is the obvious need to provide a certain level of quality comparable to the traditional telephone service signalling system. Thus, we identified the major costs of SIP, which were found to be delay and security. This thesis discusses the costs of SIP, the solutions for the major costs, and the development of a low cost SIP application. The literature review of the components used to develop such a service is discussed, the networks in which the SIP is used are outlined, and some SIP applications and services previously designed are discussed. A simulation environment is then designed and implemented for the instant messaging service for wireless devices. This environment simulates the average delay in LAN and WLAN in different scenarios, to analyze in which scenario the system has the lowest costs and delay constraints.</p>

M.Ing. / The increase of interest in the development of radio communications, both terrestrial and satellite is reaching far and beyond the most optimistic expectations. There has been an accelerated emergence of newer technologies, all claiming highly coveted radio frequency spectrum resources. With the push for the development of location based services, utilizing satellite com- communications for military purposes and later for civilian use; there has been a parallel development in terrestrial communications technology making it possible to implement cost efficient reliable user systems for voice and data services ...

Research report submitted to the Faculty of Commerce, Law and Management, Graduate School of Public and Development Management, in partial fulfilment of the requirements for the Master of Management in the field of ICT Policy and Regulation, University of the Witwatersrand, 2012. / Universal Service Obligations (USOs) have been used, for over a decade, as a regulatory mechanism to bridge the digital divide in South Africa. For USOs to be effective and efficient in bridging the digital divide, it requires close coordination between various impacted and interested stakeholders, such as mobile network operators (MNOs), the ICT regulatory authority (the Independent Communications Authority of South Africa), and the Universal Service and Access Agency of South Africa in order to extend the number of beneficiaries of the USOs. Furthermore, this requires stakeholders to understand the full impact, as well as the costs and benefits (financial and non financial) before imposing the USOs. The evidence from this research confirms that there was no monitoring and evaluation of USOs for MNOs during their implementation. More importantly, the Regulatory Impact Assessment (as a regulatory tool) was never used by ICASA in respect of the USOs initiative. This led to the failure of the initiative in achieving most of its objectives. Such failure can be attributed to lack of understanding by ICASA of the general impact of imposing the USOs upon MNOs, given that no impact assessment was done before such imposition. Recommendations arising from the research include the need for a shared vision on the USOs initiative, the need for clearly identified and defined roles for all stakeholders with an interest in the initiative, the need for a properly analysed and know ICT access gap, the need to balance the use of market and non market mechanisms in respect of USOs, the to ensure a proper funding mechanisms for USOs, and the need to identify effective regulatory governance in respect of USOs.