The television “white-spaces” trial in South Africa began at the end of March and has three partners, Google, the Wireless Access Providers’ Association (Wapa) and university network organisation Tenet, which is doing the implementation.

Tenet already provides the backhaul to a not-for-profit schools network in South Africa that is also a partner in the trial. This consortium bulk-buys and resells connectivity to these schools. The holder of the conditional spectrum licence for the trial is government research institute CSIR, which will monitor for interference during the trial. Wapa member Comsol Wireless Solutions is responsible for the installation, configuration and maintenance of the project.

The trial is connecting 10 schools in Cape Town with three base stations located on top of Stellenbosch University Medical School. As Arno Hart, white space manager at Tenet explains, Cape Town is a good place for a trial. It has the combination of being a busy broadcast market and a fairly challenging topography, which means that there are lots of TV transmitters.

The trial has two main objectives: to demonstrate that the managed spectrum technology can operate in this kind of environment without interfering with TV broadcasts and to encourage the Independent Communications Authority of South Africa (Icasa) to accelerate access to managed spectrum.

The majority of Wapa members currently make use of licence-exempt frequencies in accordance with the Icasa frequency licence exemption regulations 2008. It is, however, recognised that this is not a sustainable solution given the pressure under which these bands are being placed.

Wapa is promoting the development of a sustainable frequency-sharing model in South Africa and believes that this is a key intervention in raising spectrum efficiency and providing opportunities for new entrants. This trial is set to demonstrate that white-spaces spectrum represents an immediate win that can be taken advantage of by regulators.

The three base stations in the trial are connected through a 10Gbit/s fibre backbone that connects to one of Tenet’s clients. The base stations used are pre-production models from Carlson, which has software that uses a database of spectrum provided by Google. The software looks for what spectrum is available and chooses it. One of the things about even legally allocated spectrum is that it is only used for a relatively small proportion of the day.

The trial is operating in the 490-550MHz range. There are 10 channels in this range, with the trial using the odd-numbered channels and broadcasters using the even numbered channels.

There are three or four schools per base station, giving download speeds of between 1Mbit/s and 10Mbit/s. According to Hart, a speed test conducted at the launch showed that four schools were getting 5Mbit/s download speeds. Some of the trial schools already have ADSL lines and the trial is therefore delivering a supplementary service. All the schools are primary and secondary government schools and the service is being provided for free to the schools.

The trial will last for six months, but the intention is to keep the network alive and make the business case for future roll-outs. Hart believes that it could contribute to the creation of a “Wi-Fi city”: “I hope the chip-makers will get into this space so that managed spectrum can function in urban areas.”

One aspect of its importance lies in its ability to redeploy unused spectrum for the user almost in real time.

But the really revolutionary possibility for white-spaces spectrum and managed spectrum falls beyond the remit of either trial. There is equipment that has the ability to measure the time used by different operators in each of the different spectrum channels. Imagine a world in which operators hire spectrum on a time basis for a fee. The charging framework for this would be complicated but not impossible. It would need to strike a balance between not punishing the big users and offering minimal entry barriers to new operators. Every operator would pay on a “pay-as-you-go” basis and there would be much higher use of spectrum. It would also ensure that there was no strategic purchase of spectrum to keep out competitors or for onward sale.

The obstacle to this rather different world is that governments everywhere — and African governments are no exception — regard spectrum sales (particularly through auctions) as a tax cash cow. Unfortunately, what they extract in tax from operators is passed on in some way to end users. If a country wants low-cost broadband — both in rural and urban areas — then governments have to realise that charging large amounts of money may simply entrench large players with deep pockets.