CSIRO scales 50 Mbps wireless broadband to 16 nodes
Top wireless boffin too diplomatic to recommend for NBN
Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO) has revealed that new trials of its Ngara wireless broadband system have scaled a single base station from six to 16 users.
Speaking at the Physics in Industry Day hosted by the Australian Institute of Physics, Dr Iain Collings, Research Director, wireless and networking technologies lab, outlined recent enhancements to Ngara, which was first demonstrated in the Tasmanian town of Smithton in December 2010.
That location was provocative because Smithon was one of the first locations in all of Australia to be offered NBN connections.
Ngara is contentious because it’s design aims to achieve symmetrical speeds of 50 Mbps, greater bandwidth than offered by the fixed wireless components used for regional deployments of Australia's national broadband network (NBN). While CSIRO has never suggested outright that Ngara would be a better fit than the technologies selected by NBNco for fixed wireless deployments, the language CSIRO uses to describe the technology leave little doubt that it is keen for comparisons to be drawn.
This press release , for example, is titled ‘Fewer towers for CSIRO rural broadband wireless’ and features a quote from CSIRO ICT Centre Director Dr Ian Oppermann to the effect that ”Analysis we’ve commissioned shows other wireless technologies, which typically operate at higher frequencies, would require four times as many towers.”
That comment is telling in light of an oft-advanced anti-NBN argument that promotes wireless networks over the current fiber-to-the-remises plan, as wireless is said to be faster, cheaper and less disruptive to deploy. Opponents of that argument point out that enormous quantities of radio towers would be achieved to deliver an all-wireless NBN on national scale, and that beyond the scars such a scheme would leave on the landscape the resulting radio frequency challenges would be very tricky indeed.
Collings spent much of his speech debunking both of those arguments, asserting that the “spatial dimension” of wireless networks can see daintily-sized antennae multiple-input and multiple-output antennae (MIMO) used to deliver data services to small areas. “If you use space, each cell can have a different frequency without interference,” Collings explained, going on to say smaller cells than currently used, plus MIMO, mean more antennas-per-tower, plus more antennas on the ground to either service a specific user or to act as very local relays.
“It used to be one tower with one antenna,” he explained. “Now you have distributed antennas throughout the cells. They can be low power, so it can be a small antenna bolted to side of building.” Other advances, including dynamic spectrum allocation in real time, also make denser wireless deployments possible.
The results, he said, are a wireless network with greater capacity. “LTE is only a 2x improvement” he said at the event. “Small cells deliver 12x.”
Collings also expects antennas to be embedded in buildings, saying he expects NBN fibres to meet local networks that include wireless access points pre-installed in ceiling spaces in order to ensure MIMO-using wireless networks can provide interference-free coverage for many tenants of a commercial or residential building.
Collings has talked up such ideas for at least five years, as evident in this CSIRO list  of his publications. CSIRO’s most recent tests of Ngara put some of that work into practice. Billed  as aiming to achieve 50 Mbps for 12 simultaneous users, Collings told a sparse Industry Day crowd that recent tests of Ngara have scaled the technology to 16 simultaneous users.
That scale was achieved using an array of 16 antennas, using MIMO to achieve 60 bits per second per hertz per antenna.
Colings said Ngara could be used to deliver broadband to locations where fibre cannot provide backhaul for other fixed wireless networks. “We could do that connection with Ngara,” he said. Another scenario for the technology is providing small pockets of coverage. “There could be an antenna on a bus stop for the people at a bus stop.”
CSIRO is in discussions with several companies about commercialising Ngara, he said, without naming any names.
The researcher also stopped short of saying Ngara, or CSIRO’s MIMO-fied view of networks, is an appropriate or superior technology for the NBN. In response to a question from The Reg, Collings said he would not comment on policy.
But after hearing Collings speak for 45 minutes, it was hard to draw a conclusion other than that he feels disquiet that policy may not be resulting in the best-possible NBN. ®