Clash over TV white space

There is a bone of contention between Internet service providers and telecommunication companies on the one hand, and broadcasters on the other over the use of TV white spaces.

During the TV White Space Spectrum workshop, held in Johannesburg this week, broadcasters seemed uncomfortable with the allocation of white spaces, arguing that this would interfere with their services.

White spaces are vacant frequencies between occupied (licensed) broadcast or broadcast auxiliary services. “If you have ever used an old TV, the unoccupied channels that just show 'snow' are the white spaces,” said Sascha Meinrath, director of the New American Foundation, speaking during the workshop.

“In essence, white spaces are an enormous, underutilised resource that the media and arts community, along with the rest of the general public, could be using for the next-generation digital media and low-cost communications,” Meinrath explained.

However, Independent Communications Authority of SA (ICASA) councillor William Stucke said South African broadcasters have not expressed any specific worries. “In the US, where they have some 800 broadcasters, compared to the 20 or so that we have, including community TV, there is a real shortage of broadcast spectrum. That will not apply here, once the digital TV migration is complete.”

One of the outcomes of the workshop was that Africa should lead the way in making use of the TV white spaces, as the majority of nations are sitting on hundreds of megahertz of underused frequency spectrum.

Most speakers agreed that white spaces can be ideal for Africa, especially because of the ability to reach rural communities, which are dominant on the continent. Professor Hyacinth Nwana, Ofcom's group director of spectrum policy, said TV white space can provide broadband connections between rural areas.

“TV white space is a cost-effective means to provide broadband to areas that would otherwise be expensive to serve by other means,” he said.

Meinrath concurred, saying the highly favourable propagation characteristics of TV broadcast spectrum allow for wireless broadband deployment with greater range of operation at lower power levels.

“Thus, the TV white spaces could be used to provide better broadband service in less densely populated areas, or as a first broadband service in many underserved areas, including rural and other remote areas.”

Meinrath explained that TV frequencies are a valuable data networking tool for the same reasons they are for television broadcasts. “They easily penetrate obstacles such as buildings and trees, and can reach longer distances than the higher frequencies used by WiFi devices.”

He also argued that local communities could use white space devices to enable mobile video and audio services and citizen journalism.

Also speaking during the workshop, Heink Kleynhans, chairman of the Wireless Access Providers' Association, revealed that white space capacity is waiting to be unleashed on the market. He said it can help bring broadband services to many more South Africans over the next few years.

“The spectrum being referred to is the so-called 'white space' between television channels on the VHF and UHF frequency bands - several hundred megahertz of sub-900MHz spectrum frequency ready to be put to good use by telecoms entrepreneurs. This precious resource is currently being wasted by virtue of the fact that it is underutilised,” said Kleynhans.

He also pointed out that white space frequency comes bundled with a number of benefits that have led some to speculate that it could be used to provide a new class of “super WiFi” services.

“It can travel longer distances, provide higher download speeds and penetrate walls better than the 2.4GHz and 5GHz bands currently used to provide WiFi services. This makes it suitable as a last mile solution that will help to affordably connect more people to the Internet in places where fibre is too expensive to be viable.”

It also emerged during the workshop that in the US last year, the Federal Communications Commission approved TV white space spectrum use for unlicensed use, while Nwana indicated that UK regulator Ofcom has authorised TV white space trials in Cambridge.

Speaking on behalf of ICASA, Dumisa Ngwenya, GM for engineering, said the body is involved in white space technology research with two local universities, as well as the Council for Scientific and Industrial Research.

Ngwenya acknowledged that TV white spaces provide lots of opportunities, especially in the rural communities of SA. “ICASA is looking at piloting a geolocation database when moving ahead with TV white spaces.”

Stucke pointed out that there are a considerable number of unused channels due to the old requirement to keep gaps free between analogue transmissions, plus the reuse distance before the same frequency can be reused, which is several hundred kilometres.

“After migration, far fewer channels will be used for digital transmission. Also, no empty 'guard band' channels will need to be left between active TV channels. Both of these free up spectrum to be used for BWA [Broadband Wireless Access], for example. That's what we're calling the 'digital dividend'.”

However, he added, we will still have to leave a large distance before reusing the same frequency, so white spaces will still exist. “The white spaces are areas where a specific frequency is not actively used, and could possibly be used by a low power transmitter,” Stucke explained.

During the African Round Table discussion at the workshop, the majority of representatives from African states also indicated they are still weighing the pros and cons of making use of the TV white spaces.

Americo Muchanga, director of INCM, the Mozambican telecoms regulator, said his country had not yet done anything in as far as TV white spaces are concerned. He noted that he had come to learn from others on how the technology works.

Alice Munyua, of Kictanet in Kenya, also pointed out that the East African nation was still in the consideration stage.