Towards a sustainable business model for rural telephony

This paper presents the work done thus far towards designing a sustainable business model for rural telephony in the community of Mankosi, located in the Eastern Cape province of South Africa. The pillars of the model are sustainability and community ownership to design both the wireless mesh network providing the telephony service and its business model. Given the airtime consumption pattern in the community, the model is based only on the provision of calls inside the community and for using solar power to charge mobile phones. Some scenarios with different usage of the telephony services and different pricing rates are explored in order to find the break even point of the network, or in case the CAPEX was provided externally, to calculate the revenues expected. These revenues could be used for projects that benefit the community at large. Although the project is in its initial phase and the community has some particularities that make it unique, the sustainable business model presented here is intended to showcase innovative ideas that could serve similar projects in other parts of the world.Telkom, Cisco, Aria Technologies, THRI

Alternative networks: toward global access to the Internet for all

It is often said that the Internet is ubiquitous in our daily lives, but this holds true only for those who can easily access it. In fact, billions of people are still digitally disconnected, as bringing connectivity to certain zones does not make a good business case. The only solution for these unsatisfied potential users is to directly undertake the building of the infrastructure required to obtaining access to the Internet, typically forming groups in order to share the corresponding cost. This article presents a global classification and a summary of the main characteristics of different Alternative Network deployments that have arisen in recent years with an aim to provide Internet services in places where mainstream network deployments do not exist or are not adequate solutions. The Global Access to the Internet for All Research Group of the Internet Research Task Force, where all authors actively participate, is interested in documenting these emerging deployments. As an outcome of this work, a classification has converged by consensus, where five criteria have been identified and, based on them, four different types of Alternative Networks have been identified and described with real-world examples. Such a classification is useful for a deeper understanding of the common characteristics behind existing and emerging Alternative Networks

A Comparison between the Wickström Compartment Fire Model with Experiments and other Calculation Methods

An Excel spreadsheet application has been developed for calculating pre-flashover compartment fire temperature according to the method described in the book ”Temperature Calculation in Fire Safety Engineering” written by Wickström 2016. Here called the Wickström Compartment Fire Model, WCFM, which is a model where the surrounding structure can be assumed either as lumped heat or as semi-infinite.The excel spreadsheet is user friendly and time efficient. The model has been used to calculate temperature of gas layer which is compared with results from experiments and calculations made with the alternative calculation methods MQH, FDS and CFAST. The compartment fire chosen for comparisons were performed in a normal sized room with a door opening. The walls, floor and ceiling of the room consisted of the same material but changed between the tests. Four materials were used: light weight concrete, uninsulated steel and insulated steel on inside or outside.   The results of the comparison show that the temperature calculated with WCFM follows both the experiments and FDS temperature curves well for three of the tests. The test with light weight concrete differs from the results where WCFM in the end stabilises at a lower temperature. The difference that occurred between WCFM, the experiments and FDS, for the other three tests is mainly in the beginning of the tests. WCFM predicts temperatures which are as an average 100 ℃ higher or lower than what measured depending on test setup. In the end of the test WCFM, the experiments and FDS coincide and give essentially the same final temperatures. The temperature from MQH and CFAST differ considerably from the experiments in all the tests.