SKA wants larger share of spectrum


The Square Kilometre Array (SKA) project in the Northern Cape wants a large allocation of the digital dividend, to bolster SA’s chances of winning the right to host the telescope.

SA and Australia are both in the running to host the multibillion-rand project, and a decision is expected from the international community in the middle of next year. So far, seven telescopes are running as a trial.

The SKA wants to use additional spectrum in the area, and have current broadcast reworked, so that SA can bolster its competitive advantage. Spectrum is set to be freed up when SA switches off analogue television and moves to digital at the end of 2013.

SKA radio frequency interference manager Adrian Tiplady says the project wants to be granted the digital dividend – the spectrum that will be freed up when SA goes digital – to benefit SA’s bid.

In addition, argues Tiplady, there are ways of optimising frequency use in the area. He explains that replacing broadcasting towers with low-power transmitters would improve the SKA’s position as there would be less radio interference.

Tiplady was addressing industry members at the Independent Communications Authority of SA’s (ICASA’s) workshop on the digital dividend last week. The workshop was held so the industry could submit its views on how the additional spectrum should be allocated.

The SKA is a mega telescope, about 100 times more sensitive than the biggest existing radio telescope. It will cost about €1.5 billion, with construction possibly starting as early as 2016, and is expected to be completed by 2024.

The telescope array will comprise about 3 000 dish-shaped antennae and other hybrid receiving technologies, with a core of about 2 000 antennae and outlying stations of 30 to 40 antennae each, spiralling out of the core.

These stations will be spread over a vast area of up to 3 000km in the Northern Cape province. Tiplady points out that only 2% of SA’s population lives in the province.

The SKA is working with stakeholders in the sector, including Sentech, the South African Broadcasting Corporation and ICASA, to look at how to optimise spectrum use in the region, notes Tiplady.

The project is protected by legislation that limits the amount of radio frequency interference. Tiplady says, as a result, any new broadcasting needs to be approved to make sure it doesn’t interfere with the SKA.

This is because the area, which covers large parts of the Northern Cape province, has been declared an “astronomy advantage area”. Based on a 2010 measurement, the area is a good environment for the SKA; however, any improvements would make SA’s case much stronger, adds Tiplady.