Politics

Australia Considers TV Broadband

The government of Australia is looking at VHF and UHF television spectrum as a possible vehicle for the delivery of wireless rural broadband Internet and telephone service.

by Craig Liddell of australia.internet.com [December 10, 2002]

Following submissions from several companies, Australia's Standing Committee on Communications, Information Technology and the Arts recommended that the Australian Communications Authority (ACA) and Australian Broadcasting Authority (ABA) develop a scheme to allow the use of unallocated VHF and low UHF TV channels for rural wireless broadband links.

Further, the committed recommended that they examine the possibility of allocating spectrum in the 400-500 MHz range for CDMA-450 "on, at least, an experimental basis."

Announced in March, the House of Representatives report, Connecting Australia: Wireless Broadband, explores the current and potential use of wireless technologies to provide broadband in Australia.

The recommendation provides a boost for the BushLAN project, which utilises the low VHF TV channels in the 45 MHz to 70 MHz range to provide high speed, long distance Internet in regions with sparse populations. Those frequencies will no longer be used when digital television is phased in.

Developed over the past two years, BushLAN aims to overcome the problematic landline system to deliver Internet via wireless. The team at Australian National University's (ANU) Research School of Physical Sciences and Engineering, who developed the concept, are planning to create a fully operational wireless network.

Since May, says project director, Dr Gerard Borg, "five students at the ANU have just completed their honours projects on BushLAN. One of these is a market analysis, which is available on our Web page, and four were the technical design." ANU is developing the project more or less from scratch to make the network as cheap as possible.

Four new honours students and three postgraduate students will soon begin work with the team. "These will mostly be concerned with advancing the design of the simple transceiver, investigating networking issues and the effects of the channel in over-the-horizon applications," according to Dr Borg. "The latter is a challenging research topic. Much can already be achieved in BushLAN however with 40 kilometres and non-line-of-sight in order accordance with our earlier experiments."

Since Australia's recent 802.11 Planet conference, Dr Borg says he has "established collaborations with two new wireless ISPs and we are looking at trialling BushLAN on their networks as soon as the transceivers are done. The BushLAN team will benefit enormously from their experience and networking knowledge. We have also just received a grant from the ACT Knowledge Fund which is being used to fund the construction of the transceivers."

He says no new major challenges have been encountered in the past six months. "The BushLAN project fits nicely into a university scenario given that the spectrum is not available on an ongoing basis and that some research issues need to be resolved to optimise the system. This makes our situation quite different compared to that of a telco."

"The main challenge here is organization," Dr Borg explains. "We are working on an educational program for students that is also of benefit for regional Australia. Getting where we want to go is a question of time within the constraint that universities have finite resources and making sure that the students derive some educational benefit from the project."

After a couple of years, he concludes, "we are finally attracting students to the postgraduate level where we should be able to build a core of expertise."

The recent inquiry reveals a number of similar projects developing new wireless technologies for rural last mile links.

Nortel Networks proposes the development of a progressively modified 800 MHz CDMA system based on existing CDMA infrastructure. The company expects it to be able to provide both mobile and fixed wireless data access for 97 percent of the Australian population.

Lucent Technologies is focusing on 450 MHz CDMA for large area broadband coverage.

"Throughout Australia," Lucent says in a submission, "much of the 400-500 MHz spectrum has hosted private trunking radio systems, typically serving industries such as construction, taxis, and oil, as well as government agencies. These are primarily low-capacity analog systems providing group voice communications with minimal data capability. Globally, private trunked radio has seen relatively little innovation and growth, at the same time cellular has grown explosively. The migration path for these services may be to a common, more spectrum-efficient, packet mobile solution."

ntl has achieved data rates equivalent to satellite links using an asymmetric system of modem uplink and fast wireless downlink. The so-called "Bushnet" uses vacant VHF and lower UHF using digital TV standards and hardware. The company considers that the main barrier to commercial deployment of such a system is uncertainty about access to vacant TV spectrum.

Finally, Baltech is also researching the use of VHF channels for Internet data transmission.

Four of the projects use frequencies below 500 MHz and would need spectrum presently assigned to other uses. These are Lucent CDMA 450, BushLAN, Baltech, and Bushnet. The CDMA 450 scheme would have to displace or co-exist with mobile radio, while the other schemes are based on using vacant channels in bands presently assigned to TV. Some of which will become completely unused with the advent of digital TV.

Access to spectrum is the main issue blocking further development of these technologies, according to the inquiry.

Dr Borg, who with an ANU colleague was contracted to produce the draft report, says the themes and recommendations reflect "the issues and attempts to resolve most problems brought up in the submissions."

"There was a strong emphasis on the needs of rural Australia," he continues. "ISM band wireless technologies are seen to provide a low infrastructure way of providing broadband, not just to the Internet but also as a way of networking communities. The report suggests eliminating carrier licenses to facilitate this amongst community wireless groups, even those who work for profit."

He believes this will encourage ISPs to go wireless where there is need, such as rural Australia. "The recommendation specifically does not include the limitations of wireline, such as the 500 metre rule, which would be a terrible constraint in regional Australia."

However, Dr Borg does acknowledge problems. "Of course there are still issues such as the potential for RF interference in ISM bands and the competition issues in providing a backbone connection to the Internet. But there are recommendations which go some way to deal with these issues depending on how they may arise."

He is modest about the impact of BushLAN as a factor in the report's recommendation. "The submissions from big companies like NTL, Nortel, and Lucent which provide imprimaturs for the technologies involved as well as the ongoing infrastructure issues facing regional and remote Australia, all taken together, make for an overwhelming endorsement of recommendation number one."

—End

 

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