Over at its Africa Blog, Google has just posted up the results of its TV White Spaces (TVWS) trial in Cape Town in which it was testing mobile broadband delivery in radio frequencies set aside for analogue TV broadcast. The six month project has been declared a success by policy manager Fortune Sibanda, who says there was no interference with TV reception, as verified by a team from the Council for Scientific and Industrial Research (CSIR).
TVWS is a potential technique for getting thousands of South Africans online, by using unlicensed radio spectrum and low cost hardware to provide bandwidth between fixed points. For example, in areas where a school is a long way from the nearest fixed line infrastructure, TVWS frequencies can provide a low cost way of beaming bits cleanly to a building over relatively long distances without line of sight.
The difficult part of TVWS is that – as the name suggests – broadband signals co-exist in the same freqencies as television signals. Clever technology is required to hunt out those parts of the spectrum not being used for TV channels – the gaps between the channels on your dial that are filled with static – and adapt the broadband signals to use them.
After six months, the trial has been a success. The participating schools, which previously had slow or unreliable Internet connections, experienced high-speed broadband access for the first time. Teachers were able to use videos in their lesson plans, make Skype calls to other schools, update school websites, and send regular email updates to parents. Students could use educational videos for research. Because the service was better and faster, teachers and learners used the web to enrich the classroom experience.
The full report is published here.
As promising as TVWS is as a potential solution to South Africa’s lack of bandwidth issues, it’s not without its controversial aspects. The International Telecoms Union, ITU, recently published a report with the support of several mobile operators that called for TVWS use to be restricted to licensed operators. Many others, including Google, Microsoft and the World Wide Web foundation, want to make it easier for newcomers to access TVWS spectrum in order to speed-up broadband deployment in underserved areas. There’s an excellent essay on the subject over here.