TV spectrum wireless broadband: Analog back from the dead

Digital TV switch to result in analog services being dropped paving the way for wireless broadband

This week the CSIRO announced it had succeeded in prototyping the transmission of wireless broadband Internet over spectrum reserved for television broadcasts. This makes an interesting broadband option for Australian's about to lose their analog TV signals.

The technology, dubbed Ngara, is capable of delivering wireless data services to houses within a 20 kilometer radius of a broadcast tower.

See this Computerworld report for more details about CSIRO’s TV broadband tech.

The idea of transmitting data over the TV airwaves is nothing new. I remember having a discussion with a friend about the idea at least five years ago.

What makes this recent development interesting is how the technology coincides with the phasing out of analog TV by the Department of Broadband, Communications and the Digital Economy.

If you’ve been following TechWorld’s recent reports, the transition to digital television is potentially disruptive because it mandates the cessation of all analog broadcasts in the process.

See TechWorld’s digital TV coverage online.

People without digital TV tuners (including set-top boxes) won’t be able to view analog signals after the cut-off date in their area, with the final cut-off date for analog across the country being December 31, 2013.

As a result, a significant number of people are opting for satellite TV to fill the digital gaps.

One of the reasons the DBCDE has given to justify the move to digital-only TV broadcasts is by switching off analog more spectrum will be freed for other use, including data.

Perhaps the DBCDE planned it all along, but now we have an intersection of the commercial viability of broadband over analog signals and a move to digital TV.

Throw the NBN project in the mix and there is somewhat of a perfect storm for the adoption of this type of technology.

Before people start getting ready for broadband-over-analog they need to be aware that many of today’s existing analog terrestrial broadcast towers are not being maintained in the conversion to digital.

Whether those broadcast towers will continue to transmit signals for wireless broadband remains to be seen.

If there is a commercial opportunity they might be converted, or if the government decides they are useful for the NBN they could make up the crucial “last mile” access to 7 per cent of the population.

Another thing to consider is cost and practical bandwidth. If those two factors are no better than satellite, then it’s unlikely to take the home market by storm.

I just confirmed with my colleague Tim Lohman that the ratio of “12Mbps per 1000 homes” is correct. That speed, while symmetrical, is not really broadband, it’s dial-up.

Even if you consider a conservative use case of 10 per cent of people on the network concurrently, it’s 100 homes competing for 12Mbps.

By way of comparison people can get 1Mbps satellite to their home for around $50 per month.

Let’s hope the trial of Ngara in Tasmania next month does enough to convince people the technology has potential.

If Ngara can be made to scale like commercial GSM and WiMax systems then the capital cost of the transmission infrastructure should be markedly less than a Greenfield deployment of the aforementioned technologies.

Reaching Australia’s last mile won’t be easy, but the more options people have the better. A mixture of copper, satellite and terrestrial mobile networks should eventually bridge the broadband divide.

Rodney Gedda is Editor of TechWorld Australia. Follow Rodney on Twitter at @rodneygedda. Rodney's e-mail address is Follow TechWorld Australia on Twitter at @Techworld_AU.

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Tags CSIRObroadbandwirelessdigital tvDepartment of Broadband Communications and the Digital Economy (DBCDE)analogue tvdigital tv switchoverngara

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