Prof. William Tucker

Permanent URI for this collection

https://hdl.handle.net/10566/1723

Position: Associate Professor Department: Computer Science Faculty: Faculty of Natural Science Qualifications: BA (Trinity University, USA), MS (Arizona State University, USA), PhD (UCT) Research publications in this repository ORICD iD 0000-0001-8636-7281 More about me: here, here and here Tel: 021 959 2516 Fax: 021 959 1274 Email: btucker@uwc.ac.za

Browse

Now showing 1 - 20 of 89

Video Relay Service for Deaf people using WebRTC
(University of the Western Cape, 2019-03) Henney, Andre J; Tucker, William D
This paper reports on an experimental open source video relay service prototype that helps Deaf people communicate with hearing people by accessing a third party sign language interpreter on a mobile device. Deaf people are disadvantaged in many ways when communicating with the hearing world in real world scenarios, such as hospital visits and in cases of emergency. When possible, Deaf people can enlist the assistance of a family member, community worker or sign language interpreter to assist with such scenarios, however this assistance is pre-arranged and Deaf people would prefer on-the-fly assistance. Our application will assist Deaf people to contact any available sign language interpreter to facilitate communication between the Deaf person and a hearing person using a split screen model, effectively creating a three-way conversation between the Deaf person, the hearing person and the sign language interpreter. The prototype was developed using the WebRTC platform, with JavaScript for browser operability and hardware platform independence. Our hope is that the research can be used to persuade mobile network operators of the need for free or heavily discounted data connection to relay services for Deaf mobile customers.
Mobile video comparison to help Deaf people make informed choices: a South African case study with provincial data
(IIMC International Information Management Corporation, 2018) Henney, Andre; Tucker, William David
Deaf people use sign language to communicate and use mobile video calling to communicate with one another. Mobile video utilises much more bandwidth than text and voice communication modes, resulting in higher expenditure for communication by Deaf signers. We surveyed multiple Deaf communities to explore their level of mobile phone usage as a mode of communication. The findings indicated that despite high data cost video telephony is frequently utilized resulting in revenue generation for mobile service providers at the expense of poor Deaf end users. In South Africa, unlike for text and voice calls, both users of a video communication pay for upstream and downstream data. This paper presents a test bed comparison of the data usage and cost of the three mobile video applications with the four South African mobile network operators used by the Deaf communities. The results indicate which applications perform best on which networks and at what cost. The results can help anyone working with Deaf end users to help them make informed decisions about the use, and cost, of mobile video in South Africa.
Battery and data drain of over-the-top applications on low-end smartphones
(IIMC International Information Management Corporation, 2018) Om, Shree; Tucker, William David
Low-end smartphones with sub $50 price tags provide affordable device ownership to low-income populations. However, their limited capacity, when combined with the need for multimodal connectivity, raises usage concerns in rural off-grid regions. Some off-grid regions in sub-Saharan Africa provide recharge facilities using solar power and charge money for the service. Adding data bundle costs to frequent recharge costs, affordability of low-end smartphones becomes questionable in such areas. Community-controlled solar-powered wireless mesh network models with Session Initiation Protocol capability could alleviate the network usage cost conundrum and consume less power in low-end smartphones with the usage of WiFi. This paper reports on investigations that reveal usage of WiFi consumes less battery than 3G, 2G and Bluetooth. In addition, we feel that lowering recharge costs also requires battery consumption knowledge of the over-the-top applications. Using automated voice calls, this paper reports on battery and data consumption by multiple popular social media applications using one type of low-end smartphone. Data consumption was calculated with the objective of learning how to lower data bundle costs by selecting the application with least data consumption. Battery consumption due to CPU usage by the applications was also measured. Results show that WhatsApp consumes the least battery amongst instant messengers and also the least data over all apps measured. SipDroid consumes the least battery overall. Additionally, the reported experiments provide a framework for future experiments aimed at evaluating battery and data consumption by other smartphone applications.
Amplifying positive deviance with ICT enabling community development and interdependence
(Springer, 2017) Tucker, William David
Positive deviance is a social mechanism whereby a beneficial practice that is not considered as normal gets taken up and spread within a community. This enables a community to solve its own problems aided by mentorship and facilitation. Through two long term case studies, we have identified positive deviants and are now learning how to leverage the ICT inherent in our interventions to cultivate and amplify positive change. We find both ourselves and beneficiary communities developing through various stages of dependence, independence and interdependence. We consider the latter a strong form of development. We now look at ICT4D projects as opportunities to identify positive deviants, and to amplify positive deviance with ICT. We posit that affordable, accessible and generic ICTs offer a way to do so, and that explicitly aiming to mentor and facilitate positive deviance with such ICT offers a path toward community development and interdependence.
Walking and the social life of solar charging in rural Africa
(Association for Computing Machinery, 2013) Bidwell, Nicola J.; Siya, Masbulele Jay; Marsden, Gary; Tucker, William David; Tshemese, M.; Gaven, N.; Ntlangano, Senzo; Robinson, Simon; Eglinton, Kristen Ali
We consider practices that sustain social and physical environments beyond those dominating sustainable HCI discourse. We describe links between walking, sociality, and using resources in a case study of community-based, solar, cellphone charging in villages in South Africa’s Eastern Cape. Like 360 million rural Africans, inhabitants of these villages are poor and, like 25% and 92% of the world, respectively, do not have domestic electricity or own motor vehicles. We describe nine practices in using the charging stations we deployed. We recorded 700 people using the stations, over a year, some regularly. We suggest that the way we frame practices limits insights about them, and consider various routines in using and sharing local resources to discover relations that might also feature in charging. Specifically, walking interconnects routines in using, storing, sharing and sustaining resources, and contributes to knowing, feeling, wanting and avoiding as well as to different aspects of sociality, social order and perspectives on sustainability. Along the way, bodies acquire literacies that make certain relationalities legible. Our study shows we cannot assert what sustainable practice means a priori and, further, that detaching practices from bodies and their paths limits solutions, at least in rural Africa. Thus, we advocate a more “alongly” integrated approach to data about practices.
Development consortium: HCI across borders
(Association for Computing Machinery, 2016) Tucker, William David
Though every country and context is unique, and much of HCI research aims to design for situatedness, there are lessons to be learned across borders, across contexts. Questions we ask include: What are common themes that tie together different contexts? For instance, could a maternal health project in India benefit from lessons learned from a project in Kenya and vice versa? How can we, as a global HCI4D community, work within countries and across them as well? The short-term goal of this event is to link research and practice across disparate HCI4D contexts by creating a forum for conversations where 'HCI4Ders' from across the globe can speak and be heard, as they develop themes of common interests, and work on potential projects or proposals to concretely target an action plan they can pursue as collaborators. Our longterm goal is to advance HCI4D research so that, as a community, we can engage more productively in research conversations that focus on learning and collaborating across borders.
Making a community network legal within the South African regulatory framework
(ACM, 2015) Rey-Moreno, Carlos; Tucker, William David; Cull, Domonic; Blom, R.
Community networks often operate at the fringe of legality with respect to spectrum, network infrastructure and providing services. We have been involved with such a network in a rural community, and together with them, have devised a way to become legal within the South African regulatory framework. A not-for-profit co-operative was formed and successfully applied for license exemption to operate the network infrastructure and offer services. Revenue is used to sustain the network and can also be used for other community needs. The network has equipment that is not 100% type-approved, and operates at a higher output power than is allowed. However, we have a simple plan to comply with such regulations. This paper offers our experience as a precedent for how to go about making a community network completely legal in South Africa and other countries that have a similar regulatory environment.
Towards a scalability model for wireless mesh networks
(Telkom, 2015) Om, Shree; Rey-Moreno, Carlos; Tucker, William David
Zenzeleni mesh network is a wireless ad-hoc mesh network that provides voice services using public analogue telephones to the Mankosi community in the Eastern Cape Province. We would like to improve on the network infrastructure by upgrading the mesh routers and introducing low-end smartphones onto the network; and offer both data and voice over Internet protocol services. However, before deploying resources, it is imperative to identify the maximum number of mesh nodes, clients and simultaneous voice over internet protocol calls that can be supported by the mesh network while maintaining acceptable quality of service levels. Absence of such data might lead to financial risk and time depletion when setting up an optimal network. Bolstering the claim are investigations that report drop in quality levels as network density and hop count escalate. As current investigations mostly yield capacity models to predict per-node throughput with increasing hop count, we propose experiments to devise a scalability model to quantify scalability of mesh networks in this paper. We recommend experimental implementations at simulation level in Network Simulator-3 moving on to testbeds built using WiBed, and then finally take results to the field.
Beyond traditional ethics when developing assistive technology for and with deaf people in developing regions
(Springer, 2015) Tucker, William David
There are limitations to traditional ethical approaches and procedures when engaged in assistive technology (AT) research for Deaf people in a developing region. Non-traditional issues arise as a consequence of employing action research, including but not limited to how informed consent is construed and obtained; empowerment of participants to become involved in co-design; awareness of unfamiliar cultural issues of participants (as opposed to subjects); and accommodating community-centred, as opposed to person-centred, nuances. This chapter describes AT research with an entity called Deaf Community of Cape Town (DCCT), a disabled people’s organisation (DPO) that works on behalf of a marginalised community of under-educated, under-employed and semi-literate Deaf people across metropolitan Cape Town. We describe how non-traditional ethical concerns arose in our experience. We reflect on how these ethical issues affect AT design, based on long-term engagement; and summarise the themes, what we have learned and how we modified our practise, and finally, offer suggestions to others working on AT in developing regions.
Untitled
(John Wiley & Sons, 2015) Tucker, William David; Westerveld, Rudi
Local access in the context of regions in the global South continues to undergo transformation due to the growing ubiquity of mobile connectivity and the recent appearance of what have been termed “inverse” telecommunication infrastructures, that is, bottom-up, self-organized, user-driven, and decentralized networks (Egyedi, Vrancken, & Ubacht, 2007).The “last mile” traditionally is defined in countries and regions in the global North in a telecommunications context as the physical connection between a subscriber and the nearest telephone exchange.
Clustered Multi-layer Multi-protocol Wireless Mesh Networks
(Telkom, 2015) Abdalla, Taha; Rey-Moreno, Carlos; Tucker, William David; Bagula, Antoine
Wireless Mesh Networks (WMNs) have emerged as an alternative option to the wired networks in areas where wired deployment is unfeasible and/or costly. They have been widely adopted in community networks as these networks are mostly built within “not for profit” projects and do not require enterprise class investment which can lead to inefficient network architectures and routing protocol designs. B.A.T.M.A.N-ADV has been designed as a simple routing protocol that adheres to lightweight equipment requirements of wireless mesh deployment in the rural areas of the developing countries. However, it is built around a flat WMN topology which is challenged with scalability, security and implementation issues; which can limit WMN growth and services expansion. This paper proposes and evaluates the performance of a new multi-layer, multi-protocol WMN architecture that addresses B.A.T.M.A.N-ADV scalability issues by borrowing from wired networks their clustering model and building around the B.A.T.M.A.N Experimental (BMX6) protocol to introduce layer2 tunnelling through a cloud of layer3 routers.
Usability of an authoring tool for generalised scenario creation for signsupport
(Telkom, 2015) Duma, Lindokuhle; Chininthorn, Prangnat; Glaser, Meryl; Tucker, William David
This paper presents the usability testing results for an authoring tool that generalises scenario creation for a tool called SignSupport. SignSupport is a mobile communication tool for Deaf people that currently runs on an Android smartphone. The authoring tool is computer-based software that helps a domain expert, with little or no programming skills, design and populate a limited domain conversation scenario between a Deaf person and a hearing person, e.g., when a Deaf patient collects medication at a hospital pharmacy or when a Deaf learner is taking a computer literacy course. SignSupport provides instructions to the Deaf person in signed language videos on a mobile device. The authoring tool enables the creation and population of such scenarios on a computer for subsequent 'playback' on a mobile device. The output of this authoring tool is an XML script, alongside a repository of media files that can be used to render the SignSupport mobile app on any platform. Our concern now is to iteratively develop the user interface for the authoring tool, focusing on the domain experts who create the overall flow and content for a given scenario. The current authoring tool was evaluated for usability; for both pharmacy and ICDL course scenarios with purposive sampling. The findings suggest that the authoring tool can generalise SignSupport for multiple limited domain scenarios, mobile platforms and signed languages.
Local ownership, exercise of ownership and moving from passive to active entitlement: a practice-led inquiry on a rural community network
(CCIRDT, 2015) Rey-Moreno, Carlos; Sabiescu, Amalia; Siya, Masbulele Jay; Tucker, William David
In this paper, we aim to shed light on local ownership from a double practical and theoretical perspective, and examine its meaning as well as the factors that are bound to influence its development in community based interventions. The questions we intend to answer are: How can 'local ownership' be defined in a way that facilitates its investigation in CI practice, and enables at the same time its theoretical examination and relation with other CI key conceptual constructs? What key factors contribute to fostering local ownership in CI initiatives, taking the case of an externally initiated rural community network? To answer these questions, the paper reports on a study which assessed the development of local ownership in a rural community network in South Africa and singled out the factors found to delineate the development of a sense of ownership in local people, as well as driving the exercise of ownership towards autonomous local action. Based on a detailed analysis of the development of community ownership in this project, and in constant dialogue with the community informatics and social science literature, the paper makes three key contributions to CI theory and practice, as well as more specifically to future practice in community networks: An operational definition of local ownership and a conceptual model which highlights relations to other constructs such as responsibility, power and control and emphasises the role of local ownership in moving from passive to active entitlement towards community assets or CI interventions An empirical analysis of the development of local ownership in a community network in rural South Africa, highlighting the critical factors that led to fostering ownership An examination and critical discussion of factors that are positively related with the development of ownership, carried out in dialogue with CI scholarship and highlighting the bearing of and relations with other critical constructs in CI research, such as participation, empowerment, and capacity building These contributions come at a critical stage in community informatics development as a discipline, in which, we argue, a more solid and critical engagement with theory is required to firmly establish its place and the premises for dialogue with other sociotechnical disciplines.
A participatory design for a billing system: A South African case study of a community based telephony system
(ACM, 2014) Ufitamahoro, Marie Josee; Venter, Isabella; Rey-Moreno, Carlos; Tucker, William David
This paper describes the role participatory design can play in developing and implementing an information and communication technology for development project in a rural area. It shows how the process of co-designing an artifact can reflect and shape social development. A case study was conducted in the Mankosi Community in the Eastern Cape with the aim of designing and implementing a billing system for an existing community-owned telephony system, by accommodating the community’s requirements. Relevant criteria had to be considered for this telephony system based on voice over Internet Protocol with the possibility of ‘break-out’ calls to external networks. Different payment modalities were explored that would allow for a transparent method of both collecting money and applying the collected funds to achieve the project’s sustainability. A participative methodology with future users and operators of the network—using scenarios and prototypes to illustrate the implementation—informed the design of the billing system. Data was collected by means of unstructured interviews and focus group discussions. Qualitative data was analyzed using a qualitative content analysis tool. The community indicated that a billing system, based on both vouchers and prepaid service, would satisfy their needs.
Rural Wireless Mesh Network Analysis on Mobile Devices
(Telkom SA, 2014) Tiemeni, Ghislaine Livie Ngangom; Venter, Isabella; Tucker, William David
The aim of this research effort is to build an efficient and accurate mobile traffic generator based on open source computer-based traffic generator software. A high performance mobile traffic generator would make the evaluation of the quality of networks, deployed in remote areas, simpler. The motivation for this software is to ease feasibility testing and monitoring in the field particularly in rural areas by using affordable and lightweight technology such as a mobile device. Furthermore, a mobile system is more suitable than a personal computer (PC) or laptop in a rural area where the deployment of computers is difficult and impractical. To conduct the research, both an experimental and a simulation research methodology will be applied and the method of investigation will combine methods such as laboratory experiments, document analysis and a literature survey.
An analysis of voice over Internet Protocol in wireless mesh networks
(IEEE, 2014) Meeran, Mohammed Tariq; Tucker, William David
The paper focuses on analyzing the affects of wireless mesh networks with some mobile nodes on Voice over Internet Protocol service quality. Our interest is to examine this in simulation to learn how to better deploy voice services on such a network in a rural community. Wireless mesh networks' unique characteristics like multi-hop, node mobility, coverage, and medium usage cause quality of service issues for Voice over Internet Protocol implementations. This research considers three wireless mesh scenarios on 26 mesh nodes. In the first scenario all nodes are stationary. In the second, 10 nodes are mobile and 16 nodes are stationary. In a third scenario, all nodes are mobile. Nodes move at a walking speed of 1.3m per second. The analysis and results show that while node mobility can increase packet loss, delay, jitter, Voice over Internet Protocol implementations in wireless mesh networks can be successful if there is no background traffic. We recommend that Voice over Internet Protocol implementations in wireless mesh networks with some mobile nodes and background traffic be supported by quality of service standards; else it can lead to service level delivery failures.
Co-designing a billing system for voice services in rural South Africa: Lessons learned
(ACM, 2014) Rey-Moreno, Carlos; Ufitamahoro, Marie Josee; Venter, Isabella; Tucker, William David
Access to information and communication technologies re- mains una ordable for many in rural areas despite recent progress in providing voice services to remote communities. The sustainability of alternative technical solutions is a chal- lenge, which can be addressed when local knowledge is taken into account during the design process. This research re- ects on the process of co-designing a billing system for voice services provided by a Community Network in rural South Africa. Several payment methods were explored with users and operators of the Community Network, focusing on the legal, nancial, technical and social feasibility - as well as constraints - of each method. Those methods that suited the community's needs were implemented and tested with stakeholders. The process revealed factors embedded in the provision of voice services by traditional voice operators in South Africa that prevent economically poor and illiterate users from fully bene ting from voice services. Solutions to these factors were explored with users and were implemented as a billing system. The system is currently being deployed in a rural South African community. Both the problems experienced and solutions proposed may inform similar ini- tiatives.
Towards communication and information access for deaf people
(SAICSIT, 2014) Blake, Edwin H.; Tucker, William David; Glaser, Meryl
In tightly circumscribed communication situations, an interactive system resident on a mobile device can assist Deaf people with their communication and information needs. The Deaf users considered here use South African Sign Language and information is conveyed by a collection of pre-recorded video clips and images. The system was designed and implemented according to our method of community-based co-design. We present several stages of the development as a series of case studies and highlight our experience and the implications for design. The first stage involved ethnographically inspired methods such as cultural probes. In the next stage we co-designed a medical consultation system that was ultimately dropped for technical reasons. A smaller system was developed for pharmaceutical dispensing and successfully implemented and tested. It now awaits deployment in an actual pharmacy. We also developed a preliminary authoring tool to tackle the problem of content generation for interactive computer literacy training. We are also working on another medical health information tool. We intend that a generic authoring tool be able to generate mobile applications for all of these scenarios. These mobile applications bridge communication gaps for Deaf people via accessible and affordable assistive technology
Optimisation of SlotTime for a single-radio Mid-Range Multi-hop Wireless Mesh Network
(Telkom SA, 2014) Rey-Moreno, Carlos; Tucker, William David; Simo-Reigadas, Javier
This paper presents the business context and results of an optimisation exercise for a single-radio mid-range multi-hop wireless mesh network for the provision of VoIP services. This WiFi mesh network physically covers 30 square kilometres in rural South Africa with a dozen solar-powered nodes. The firmware multiplexes the single radios in adhoc and infrastructure modes, essentially providing a distributed hotspot that can be used for WiFi-based Asterisk attachment in addition to POTS handsets via an ATA adapter in a node. We argue that this architecture is comparable yet cheaper and easier to install and maintain than multi-radio systems with directive antennas. Measurement of a range of values revealed a SlotTime setting that maximises throughput by 115%. We leverage this finding to argue a business case for a ground up community-based mesh network like this one; to provide a win-win situation for local residents and operators with free internal calls backed up by revenues from low cost voice breakout, Internet services and solar-based mobile phone charging. Our novel approach offers an accessible and affordable business model based on increased traffic volume from residents in a rural area that have mobile connectivity yet cannot afford to use it. The optimised architecture described herein offers an attractive and complementary alternative.
Abstractions for designing and evaluating communication bridges for people in developing regions
(ACM, 2010) Tucker, William David; Blake, Edwin H.
This paper describes two novel abstractions that help soft- ware engineers work in developing regions to align social and technical factors when building communication systems. The abstractions extend two concepts familiar to engineers of computer networks and applications: the Open Systems Interconnect stack for design, and Quality of Service for eval- uation. The novel nature of the abstractions lies in how they help cultivate awareness of socio-cultural and technical is- sues when designing and evaluating communication bridges in the eld. Advantages of the abstractions are that they can be understood easily by software engineers, they aid communication with bene ciaries, and can therefore facili- tate collaboration. The paper makes an argument for these socially aware abstractions, describes the abstractions in de- tail, provides examples of how we used the new abstractions in the eld and then gives practical guidelines for how to use them. The simple nature of the new abstractions can help software engineers and end-users to work together to produce useful information technology based communication systems for people in developing regions.

Browse

collection.page.browse.recent.head