Modular wireless networks for infrastructure-challenged environments

While access to Internet and cellular connectivity is easily achieved in densely-populated areas, provisioning of communication services is much more challenging in remote rural areas. At the same time Internet access is of critical importance to residents of such rural communities. People's curiosity and realization of the opportunities provided by Internet and cellular access is the key ingredient to adoption. However, poor network performance can easily impede the process of adoption by discouraging people to access and use connectivity. With this in mind, we evaluate performance and adoption of various connectivity technologies in rural developing regions and identify avenues that need immediate attention to guarantee smoother technology adoption. In light of this analysis we propose novel system designs that meet these needs. In this thesis we focus on cellular and broadband Internet connectivity. Commercial cellular networks are highly centralized, which requires costly backhaul. This, coupled with high price for equipment, maintenance and licensing renders cellular network access commercially-infeasible in rural areas. At the same time rural cellular communications are highly local: 70% of the rural-residential calls have an originator-destination pair within the same antenna. In line with this observation we design a low-cost cellular network architecture dubbed Kwiizya, to provide local voice and text messaging services in a rural community. Where outbound connectivity is available, Kwiizya can provide global services. While commercial networks are becoming more available in rural areas they are often out of financial reach of rural residents. Furthermore, these networks typically provide only basic voice and SMS services and no mobile data. To address these challenges, our proposed work allows Kwiizya to operate in coexistence with commercial cellular networks in order to extend local coverage and provide more advanced services that are not delivered by the commercial networks. Internet connectivity in rural areas is typically provided through slow satellite links. The challenges in performance and adoption of such networks have been previously studied. We add a unique dataset and consequent analysis to this spectrum of work, which captures the upgrade of the gateway connectivity in the rural community of Macha, Zambia from a 256kbps satellite link to a more capable 2Mbps terrestrial link. We show that the improvement in performance and user experience is not necessarily proportional to the bandwidth increase. While this increase improved the network usability, it also opened opportunities for adoption of more demanding services that were previously out of reach. As a result the network performance was severely degraded over the long term. To address these challenges we employ white space communication both for connectivity to more capable remote gateways, as well as for end user connectivity. We develop VillageLink, a distributed method that optimizes channel allocation to maximize throughput and enables both remote gateway access as well as end user coverage. While VillageLink features lightweight channel probing, we also consider external sources of channel availability. We design a novel approach for estimation of channel occupancy called TxMiner, which is capable of extracting transmitter characteristics from raw spectrum measurements. We study the adoption and implications of network connectivity in rural communities. In line with the results of our analyses we design and build system architectures that are geared to meet critical needs in these communities. While the focus of analysis in this thesis is on rural sub-Saharan Africa, the proposed designs and system implementations are more general and can serve in infrastructure-challenged communities across the world

A strategy to make ICT accessible in rural Zambia: a case study of Macha

The problem discussed in this dissertation is to gather evidence of good practice and derive strategy for the development of ICT access in rural Zambia. Access to ICT services is important, also in rural areas of Africa. The challenges are many. There is a distinct void in tangible descriptions of the realities of ICT Access in rural areas or actionable guidelines for practitioners. This study involves a case study in the rural areas of Zambia. It does so through ethnography involving 10 years of observation of aspects of ICT access in rural Macha, Zambia. In this community, emerging from an articulated vision, ICT access in the form of the Internet arrived in 2004. Macha Works with its ICT unit LinkNet provides the basis for this interpretive approach from within the rural cultural setting. The purpose of the study is to benefit the local rural community, addressing the fundamentals of reality to add to the body of knowledge. The study involves cross cultural interaction and takes a trans-disciplinary view on science. It involves Participative Action Learning and Research aimed at recognising the complex adaptive systems while being aligned with the ethics of the rural African environment. Emphasis is on the needs of the community, rather than of the individual utilising empirical evidence. The good practices in Macha that inform strategy to make ICT accessible in rural areas are: engaging the community, building relationships; workforce development, unlocking productivity; thought leadership, establishing authority

The Shortcomings of Globalised Internet Technology in Southern Africa

Network protocols and applications have mostly been devel- oped in and for a Western context and usually have an embedded set of assumptions about network performance and availability. As a result web-browsing, cloud-based services, live voice and video over IP, desktop applications and software updates often fail or perform poorly in (rural) areas of Southern Africa. This paper uncovers some of the reasons for this poor performance such as Windows TCP failing to reach capacity in high-delay networks, long DNS delays or time-outs and applications such as Office365 assuming constant connectivity to function, and de- scribes them, set in the Southern African contexts. We address the issue of colonisation in ICT context and show the extend of such in the area of networking. These observations provide strong motivation for Africa- based engineering research to ensure that future network protocols and applications are context-sensitive, adaptive and truly global

Revisão sistemática sobre o acesso à internet em propriedades rurais

O desenvolvimento tecnológico propiciou o uso crescente da computação nos mais diversos setores da sociedade moderna. Entretanto, uma parcela da população mundial, devido a problemas de conexão e mesmo de acesso ao conhecimento, ainda possui sérias dificuldades para usufruir do potencial disponibilizado pela tecnologia, em especial ferramentas de acesso à Internet. Nesse contexto, o trabalho realiza uma revisão sistemática da literatura. Foram selecionados 14 artigos dos 101 retornados pela ACM Digital Library referentes aos temas de uso da computação e o acesso à Internet nos estabelecimentos rurais, levando em consideração pesquisas de caráter técnico e social. Além disso, os estudos selecionados contemplam países dos mais diferentes padrões econômicos, estruturais e geográficos, demonstrando assim as diversidades e semelhanças entre os mesmos. O objetivo do estudo é identificar problemas e dificuldades no uso de Internet e software em estabelecimentos agrícolas das zonas rurais em nível mundial. Dessa forma foi possível propiciar uma reflexão sobre o quanto as novas tecnologias impactam fora das grandes áreas urbanas.Sociedad Argentina de Informática e Investigación Operativ

Understanding internet usage and network locality in a rural community wireless mesh network

© 2015 ACM. Community networks owned and operated by local communities have recently gained popularity as a low cost solution for Internet access. In this paper, we seek to understand the characteristics of Internet usage in community networks and provide useful insights on designing and improving community networks in rural areas. We report the results of a socio-technical study carried out during a three month measurement of a community wireless mesh network (CWMN) which has been operating for two years in a rural area of northern Thailand. An on-site social interview was also conducted to supplement our analysis. The results reveal several interesting findings: rural users do use online social networks, instant messaging applications and online games similarly to urban users; they install unnecessary applications on their mobile phones and are completely obvious to their side effects - the traffic from these applications accounts for a major share of the traffic leading to numerous network anomalies. Finally our analysis uncovers the characteristic of locality in community networks where users in close geographical proximity interact with each other.TakNet was achieved thanks to sponsorship from THNIC Foundation. Part of this work was also supported by EU H2020 UMobile Project (Grant agreement no: 645124)

Investigating wireless network deployment configurations for marginalized areas

In recent years, immense effort has been channelled towards the Information and Technological development of rural areas. To support this development, telecommunication networks have been deployed. The availability of these telecommunication networks is expected to improve the way people share ideas and communicate locally and globally, reducing limiting factors like distance through the use of the Internet. The major problem for these networks is that very few of them have managed to stay in operation over long periods of time. One of the major causes of this failure is the lack of proper monitoring and management as, in some cases, administrators are located far away from the network site. Other factors that contribute to the frequent failure of these networks are lack of proper infrastructure, lack of a constant power supply and other environmental issues. A telecommunication network was deployed for the people of Dwesa by the Siyakhula Living Lab project. During this research project, frequent visits were made to the site and network users were informally interviewed in order to gain insight into the network challenges. Based on the challenges, different network monitoring systems and other solutions were deployed on the network. This thesis analyses the problems encountered and presents possible and affordable solutions that were implemented on the network. This was done to improve the network‟s reliability, availability and manageability whilst exploring possible and practical ways in which the connectivity of the deployed telecommunication network can be maintained. As part of these solutions, a GPRS redundant link, Nagios and Cacti monitoring systems as well as Simple backup systems were deployed. v Acronyms AC Access Concentrators AMANDA Automatic Marylyn Network Disk Archiver CDMA Code Divison Multiple Access CGI Common Gateway Interface

A Distributed Caching Approach for Improved Data Availability in Rural Wireless Mesh Networks

The performance of wireless mesh networks (WMNs) deployed for Internet access in rural settings is affected by several factors. Typically, deployments in African domains use cheap and computationally constrained devices with challenges such as power fluctuations, gateway congestion, VSAT communications asymmetry and low bandwidth, which affects throughput under dynamic scenarios. Caching methods can offer improvement for content availability to ensure a reliable quality of experience (QoE) for rural dwellers. Primarily, we integrate a modified multicast technique and overhearing for object caching and cache dissemination. We proposed a Distributed Overheard-object Caching Approach (DOCA) and evaluated the performance employing simulations. The outcome shows significant improvements over the random-path-cache-request (RPCR) strategy with increased data availability and reduced communication cost regarding response time for the outlined rural scenarios. Moreover, the optimization of gateway load helps to conserve network resources such as bandwidth and nodal energy considerably