CSR, Microsoft and Nokia to push dynamic spectrum allocation
"We are actively involved in multiple initiatives including Weightless," said Les Smith, a consultant on antennas and propagation working with CSR. "We don’t have a chip on our forward roadmap but we’ve got an engineer looking at a MAC [media access controller] and we are doing some work there," he said.
CSR has an official statement on its position with regard to whether it is going to start making Weightless transceiver ICs, with their characteristic asymmetric reception signal budget.
That statement reads: "CSR is actively involved in most of the standards and related regulatory activity in the wireless industry focused on spectrum sharing in the TV White Spaces, including Weightless, IEEE P802.11af and TD-LTE. CSR is working alongside many organisations and trade bodies to ensure that the Weightless standard is as fully developed as possible when it comes to market, as we do see the applications that the technology will enable in the future as significant."
CSR’s high levels of activity but lack of a definite chip roadmap may be due to the fact that official standardization of such radio frequency issues often takes many months, even years. While the U.K. government’s regulatory office Ofcom and startup Neul Ltd. (Cambridge, England) have been doing much pioneering of TVWS via licensed trials any Weightless standard will still have to be harmonized with work starting within ETSI’s Broadband Radio Access Networks (BRAN) committees, Smith said.
There is also some divergence on what the primary use case should be for additional bandwidth liberated by spectrum sharing. While Neul has emphasized the potential for dedicted machine-to-machine communications many other bodies are interested in TVWS as means of delivering rural broadband at acceptable cost.
Nonetheless there is growing interest in TVWS both within the U.K. and the European Commission and a sense that previous academic work on software-defined radio and cognitive radio could soon be put to work, Smith said. CSR is not alone in this view. Companies such as Microsoft, the BBC, BT Group, Arqiva and Neul are working with CSR in the UK Program Group for Dynamic Spectrum Access (DSA), a body created by UK digital TV association the Digital TV Group (DTG) to promote spectrum sharing enabled by appropriate standards and the use of cognitive radio techniques.
The creation of the body was announced by Ed Vaizey M.P., a U.K. politician, as he opened a research institute called the Centre for White Space Communications at the University of Strathclyde in Glasgow, Scotland.
Jim Beveridge, senior director of Microsoft’s technology policy group, welcomed the initiative, saying: "We believe tapping unused spectrum will help support innovation in the UK’s tech sector and extend the broadband access needed by rural and unserved communities not only in the UK but globally and essentially transform the local economies and create opportunities for ambitious SMEs."
Many of the same companies are working at the European level and within ETSI. According to ETSI documentation work on the proposed standard EN301598 for white space devices and wireless access systems operating in the 470-MHz to 790-MHz frequency band is being supported by Ofcom, Nokia, BT Group, Microsoft, CSR, Sky Interactive and Research in Motion UK. The draft ETSI standard is described as "stable" and is due to be finalized by June 1, 2013 and then begin an approval process with a view to delivery to the European Commission by June 2014.
As is common in matters of wireless communication standards the situation is inherently complicated. In the matter of TVWS itself there are issues related to wireless microphones that already share television broadcast spectrum. "They are a licensed user and they have to be protected," said Robin Heydon, responsible for global standards at CSR.
Heydon made the point that spectrum is a finite resource but that demand to use it is set to grow exponentially. "Cognitive radio is a way of managing spectrum in the future. That’s why we are excited," he said, adding that might be done either by way of the current method, a database look-up, or autonomous radio sensing.
Heydon made it clear that the opportunity for dynamic spectrum allocation extends beyond television white space. Heydon gave the example of radar used to check railway level crossings "Railways have radar to check for obstructions. Before we start sharing that spectrum we need a non life-critical application to demonstrate white-space. TV is non safety-critical application."
While U.K. and European trials have to be specially licensed to use otherwise licensed and allocated frequencies the situation in the U.S. is more liberal. On March 1, 2013 the Federal Communications Commission announced that is had authorized approved TVWS database systems to provide services to unlicensed radio devices that operate in the unused spectrum in the TV as defined by the database.
www.csr.com
www.etsi.org
www.fcc.gov/encyclopedia/white-space-database-administration
www.wirelesswhitespace.org
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