Browsing Computer Science by Subject "Voice over IP"
Now showing items 1-7 of 7
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Zulu, Docas Dudu; Tucker, William D. (Telkom, 2010)[more][less]
Abstract: This paper describes work in progress on call capacity optimization for voice over Internet Protocol on wireless mesh networks. In a developing country such as South Africa, evidence has shown that rural inhabitants find it difficult to afford the voice services offered by cellular networks. Voice over Internet Protocol is known for its affordability relative to cellular voice services, therefore deploying such services for rural communities will not only benefit rural inhabitants but also offer economic advantages to service providers. We are interested in the provision of voice services with rural wireless mesh networks. Unfortunately voice on mesh networks can experience packet loss and delays that cause reduction in voice quality. Transmission of small voice packets over wireless mesh networks imposes high overhead that leads to a tremendous decrease in call capacity. Therefore, we aim to study the performance of voice over 802.11 wireless mesh networks and evaluate packet aggregation mechanisms that merge small voice packets into a single large packet, in order to preserve voice quality with more calls. We will implement and evaluate packet aggregations mechanisms on a 'mesh potato' network with iterative cycles of laboratory experiments using a network simulator to collect data for performance evaluation. URI: http://hdl.handle.net/10566/618 Files in this item: 1
ZuluTucker-SATNAC2010.pdf (138.4Kb) -
Yi, Long; Tucker, William D. (Telkom, 2008)[more][less]
Abstract: This paper describes Kiara, an open source SIPbased communication system that provides the building blocks to enable Deaf relay services. We have implemented a prototype that provides real-time text, voice and video to a variety of end user devices over a variety of networks. The work-in-progress concerns the addition of relay services for the Deaf. URI: http://hdl.handle.net/10566/523 Files in this item: 1
YiTuckerKiara2008.pdf (173.6Kb) -
Tucker, William D.; Blake, Edwin H.; Marsden, Gary; Pearson, Murray; Westerveld, Rudi (Telkom, 2007)[more][less]
Abstract: This paper reports on three years of research and fieldwork with a rural wireless Internet Protocol communication project. We built a long-range WiFi network and custom communication software to support a rural telehealth project in the remote Eastern Cape. We report on our work using cellular networks, devices and applications as reference technologies because our users and beneficiaries are very comfortable with them. Of most concern are the technological and contextual issues affecting take up of the systems we designed. The paper intends to provide a summary analysis of our experience so that others in the field can learn from our successes and mistakes with respect to rural Information and Communication Technology for Development (ICT4D) in a South African context. URI: http://hdl.handle.net/10566/487 Files in this item: 1
TuckerIP-Communication2007.pdf (1.427Mb) -
Daniels, Francois; Tucker, William D. (Telkom, 2008)[more][less]
Abstract: This paper presents a fully decentralised peer-topeer voice communication tool intended for use across mobile ad hoc networks (MANET) by distributed groups who desired collaboration. We examined the synergy between MANETs and peer-to-peer virtual overlay networks which allowed the creation of ad hoc applications. One style of communication considered suitable for task oriented distributed group collaboration was push-to-talk. This research was focused on providing a push-to-talk communication platform suitable for deployment across MANETs. The research methodology employed was a proof of concept approach within a classical experimental computer science paradigm. We developed a prototype which used JXTA, a peer-to-peer virtual overlay network, to provide push-to-talk functionality across MANETs. Guaranteed delivery of messages was provided via a peer-to-peer voicemail delivery system. While the system did what intended we show that JXTA had a problem with the efficient delivery of voice samples. URI: http://hdl.handle.net/10566/508 Files in this item: 1
DanielsTuckerMANET2008.pdf (216.0Kb) -
Roro, Zukile; Rey-Moreno, Carlos; Tucker, William D.; Siya, Masbulele Jay (Telkom, 2012)[more][less]
Abstract: This paper describes work in progress towards developing a business case and preliminary design for an 802.11-based mesh network in the remote rural community of Mankosi in the Eastern Cape province of South Africa. Aside from the technical challenges to building the network to be sustainable in the long term, this network needs to generate some revenue. Hence, there needs to be a business model that has revenue generation potential. This study will explore the economical and social aspects of voice over Internet- Protocol as a service for this community. After talking to the village leaders, we learned that there is a demand for telecommunication services and that most of them were interested only in telephony service. Very few villagers were interested in or had any knowledge about the Internet. We also learned that most of their cellular phone calls are local within the Mankosi community. This allows us to deploy an experimental local telephony service; a perfect opportunity for a low-cost and lowcosting inverse mesh infrastructure that can easily be connected to breakout and Internet services in the future. URI: http://hdl.handle.net/10566/594 Files in this item: 1
RoroRey-MorenoTuckerSiya-SATNAC2012.pdf (150.8Kb) -
Chetty, Marshini; Tucker, William D.; Blake, Edwin H. (Telkom, 2004)[more][less]
Abstract: Rural areas in South Africa have unique conditions such as remoteness and scarcity of reliable public facilities. Information and Communication Technologies (ICTs) introduced into these areas must be suitable for these conditions. Using a user-centred design approach based on Participatory Design and Action Research, we have developed a telemedicine application for a rural village in the Eastern Cape. This paper describes how we determined the requirements and design for the application and why we chose Voice over Internet Protocol (VoIP) combined with a store and forward approach to achieve our telemedicine goals. We present an overview of the methodology we are using, describe the software application we have developed and mention several challenges we have faced to date. Finally we conclude that VoIP and store and forward technologies are appropriate to the South African rural situation. URI: http://hdl.handle.net/10566/621 Files in this item: 1
ChettyTuckerBlake-SATNAC2004.pdf (287.0Kb) -
Chetty, Marshini; Tucker, William D.; Blake, Edwin H. (Telkom, 2003)[more][less]
Abstract: There is a great disparity between those who have access to Information and Communication Technologies (ICTs) and those that do not. This phenomenon forms part of the Digital Divide. Many ICTs may be used to help overcome this divide if they are applied in a useful way, providing locally applicable content and services. Critical Action Research (CAR) is an approach used to develop such applications. CAR aims to empower people by involving them in the development process. Using CAR, this project investigates how Voice over IP (VoIP) may be applied in a productive way in an underserviced community. VoIP is an ICT used for sending voice over packet switched networks using Internet Protocol. It can be used to integrate data and voice to produce multimedia applications. In South Africa (SA), VoIP may only be provided by Telkom, the Second National Operator and the Under-Serviced Area Licensees. Using CAR and VoIP, an application is being developed to service a specific need of a particular rural community. The application will either provide a service to a small rural business or aid the provision of healthcare in rural areas. The project evaluates how well CAR integrates with a normal Software Development Lifecycle and makes policy recommendations for the use of VoIP in rural SA. URI: http://hdl.handle.net/10566/479 Files in this item: 1
ChettyTuckerBlakeDigitalDivide2003.pdf (35.78Kb)
Now showing items 1-7 of 7