White space: SA's broadband white knight - TechCentral

White space: SA’s broadband white knight

[By Henk Kleynhans]

The department of communications and the Independent Communications Authority of SA (Icasa) are sitting on the digital equivalent of millions of hectares of fertile but fallow land in the form of several hundred megahertz of underused frequency spectrum.

This capacity is waiting to be unleashed on the market and 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.

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 Wi-Fi” 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 Wi-Fi 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.

The beauty of white-space frequency is that other countries have already started to work out the business models and benefits for us — our legislators and regulators simply need to learn from the best practices they are establishing. The Federal Communications Commission (FCC) in the US last year released this white space to anyone who wants to use it. Ofcom in the UK and other European regulators look set to follow its example.

The FCC’s goal is quite simply to “promote the use of an underused resource to spur on innovation and economic development”. The US regulator has even developed a model that allows for equitable use of this resource in a way that protects spectrum in use from interference, and with no need for a spectrum frequency allocation or bidding process.

In the US model, which Ofcom also looks set to adopt, white-space devices will have geo-location capabilities and access to a spectrum database. If a device finds that no other device in the database is using the band it wants to use in a particular location, it can make use of the spectrum.

This is an elegant solution that ensures that white-space usage doesn’t descend into anarchy while rewarding those companies that were first to move into the market with access to the frequency they need to provide services to their clients.

Using Wi-Fi technology, Wireless Access Providers’ Association members have already helped countless consumers, businesses, schools and hospitals to connect to the Internet. What we could achieve with white-space frequency is simply staggering.

In rural areas our members could extend the range of their access points by 300% or more. They would no longer need line of sight to provide coverage to a subscriber. Suddenly, it becomes viable to provide broadband where there was none before. Community or municipal networks in poor urban areas will also be more economically sustainable since it will be possible to reach more people with fewer access points.

Does this sound too good to be true? As Cambridge Consultants, a wireless consulting firm, points out, the last time such a significant allocation of spectrum was set free was in 1985 when the 2,4GHz band was dismissed as “junk frequency”. This led to some of the most significant developments in wireless technology in recent times.

The release of 50MHz of junk frequency led directly to the spawning of the multibillion-dollar baby monitor, cordless phone, Bluetooth and Wi-Fi businesses. There is a not-to-be-missed opportunity for SA’s telecoms industry to get an early start in what is sure to grow into a huge global industry within the next five years.

And for Icasa and the department of communications, releasing white-space frequency is about as quick a win as they could hope for in their mandate to make the broadband market more competitive and services more affordable and accessible to consumers around the country.

  • Henk Kleynhans is the chairman of the Wireless Access Providers’ Association
  • I was interested to read your post about white spaces. I just wanted to add that the FCC has recently been promoting the idea of an incentive auction for broadcast spectrum that would significantly reduce or even eliminate the white spaces that you refer to in your article. I was particularly interested to learn that the consumer electronics industry in the US is pushing the idea of the incentive auctions.

  • Very nice thinking, but I think we all should stretch our collective technological imaginations even more. Certainly “White Spaces” can do a lot to bring broadband to some of the 45-million South Africans excluded from the information age, but how about, for example, innovations around white spaces to leverage the expected “Digital Dividend” even more? If some of the available “White Spaces” real estate could be assigned to provide a cost-effective up-link tied to set-top boxes whatever the digital broadcasting standard, it would bring at least another 10 million South Africans closer to the information age utopia – there are that many more television sets than fixed telephone lines (Voice or VoIP) and PCs combined. And there are many more new technological applications just waiting for a few enterprising South Africans, supported by their government and regulator, to think outside their age-old boxes that confined their imaginations to the 5 million or so South Africans who already have much, and dangerously forget the 45 million who have far too little and want much more.
    By the way, any ideas why they were called “White Spaces”? A far more appropriate name would have been “Black Holes” – lots and lots of invisible broadband communications energy in very large uninhabited regions of the radiofrequency universe.

  • Of course, the government could think short-term and auction off this frequency, make some good money for government to spend on parties and beemers and then leave the country behind the rest of the world.

    That is an option.. but they wouldn’t do that. Surely?

  • Boyan S

    @Walter. The reason it’s called a ‘white’ space is because in the imperfect, practical world there exists a noise floor for every transmitter and receiver (attributed to many effects such as thermal noise in electronics, cosmic radiation, etc.). Thus unused spectrum does not look completely void of any power, but rather has as uniform power spectral density of low power (usually around -90 to -120 dBm for your average commercial receiver). Since it’s uniform, this is why it is referred to as white (all frequency components are of the same power).

    In terms of the article, I think the authors should clear up the dangerous ambiguity of the term “white spaces between TV channels”. This could be taken to mean the guard-bands which are present between two adjacent channels (impossibly stupid and illegal if one were to transmit there as it would cause great interference to the TV channels themselves) or it could be correctly rephrased as “unused TV channels”. White spaces in spectral terms just means “frequency where nothing is transmitted intentionally”, some are left white on purpose to mitigate adjacent channel interference (non-ideal filters) while others are unusued due to their low transmission utilization.

    In terms of the whole ‘super wi-fi’ technology, it’s effectively a less intelligent implementation on the currently-worked-on cognitive radio systems (IEEE 802.22 working group is one example) where spectrum sensing is not implemented.

  • Good article Henk: As an additional point of clarity we need to understand that having these so-called White Spaces available depends on SA getting a move on with the TV digital migration. It is when this is completed that this part of the spectrum becomes usable due to less spectrum being used in digital terrestial broadcasting. I very much doubt we have the logistical, technical and organisational capabilities to use any of the White Spaces before then.

    What would be great is if ICASA stated that the move to digital terrestrial TV would see the 700 MHz band becoming available for telecommunications and maybe having the telecommunications operator only funded Universal Service Agency’s funds to help subsidise the digital TV set top boxes. There is a logic to this: currently, this TV frequency (and the reason why they were chosen for TV initially) projects signals for kilometres, if the band is wide enough, carry a lot of data and less influenced by line of sight, trees and walls. This dratically reduces the physical tower infrastructure needed.

    The key lesson from the FCC is that the slightly less valuable (due to other propogation characteristics) is that the spectrum below 700MHz is to be made freely available on for unlicensed basis to the public.

    @ Boyan, you’re right about 802.22 v 802.11 but WiFi is an open standard with way more development happening in this standard so, despite, limitations it ought to be the applicable standard for any new unlicensed/free/ISM frequency that could be made available in the so-called White Spaces. Makes sense, we can ride in on the coat tails of all this free and largely open source development.

  • Boyan S

    @Dirk, valid points you have (i.t.o. the transmission properties of 700 MHz) but with respect to 802.22 and 802.11: their standards are both maintained and developed by the relevant IEEE working groups, which usually comprise of leading, academic researchers. There will be just as much development (if not more) of the 802.22 as there is in the 802.11. 802.11 is more ubiquitous because 1) it’s a finalised standard and 2) 2.4 GHz is an ISM band throughout the world (whereas 433 MHz, 868 MHz, etc. vary). The whole point of 802.22 is to be license exempt (i.e. has no fixed channel location) and later on, DSA devices will be completely exempt for most of the spectrum (save for military/emergency purposes) and not just UHF TV.