Malawi and South Africa pioneer unused TV frequencies for rural broadband

Abstract

At Mulanje Secondary School, in Malawi’s verdant tea-growing district, something remarkable is happening: Students and teachers now have broadband access to the Internet for the first time, thanks to an over-the-air network that connects the school with a telecom provider in a nearby town. Installed last year, the network transmits signals over unused portions of the television spectrum—known as TV white spaces—from a high-gain antenna mounted atop the sturdy brick-and-stucco building to a radio tower owned by Malawi Telecommunications, 2.6 kilometers away. Inside the school, in a new computer lab, students check email, do homework, and hang out on social media, just like teenagers the world over. At the network’s launch in May 2015, Kondwani Nankhumwa, who was then Malawi’s minister of information, tourism, and culture, listed the many ways in which the new broadband link would aid the community. Local residents, he said, “will be able to communicate to relatives who are working abroad. Small-holder growers will be able to access the prices of crops on the global market. Tourists interested in visiting Mulanje Mountain will be able to book accommodations, transport, and tour guides.” What’s more, he predicted, the same TV white space technology could help lift Malawi’s Internet penetration from less than 10 percent today to around 70 percent by 2019. TV white space technology has also been explored for use in more populated areas. Cape Town, South Africa, has the distinction of having the fewest vacant TV channels in the country, and hence it’s the toughest South African site for deploying the technology. Yet in our trial, 10 schools—several of them in impoverished areas on the outskirts of the city—were connected with base stations at Tygerberg Hospital. The radio equipment was provided by Carlson Wireless, and the trial was operated by TENET (the Tertiary Education and Research Network of South Africa) with sponsorship from Google; the Meraka Institute of the Council for Scientific and Industrial Research (CSIR, where coauthor Johnson works) performed the field measurements to ensure that no radio interference occurred. In contrast to the trials in Malawi, the Cape Town network relied on both spectrum scans and predictions of signal propagation to match available TV channels with the GPS coordinates of devices in the network.