At the Cambridge White Space Conference, last month, companies involved in the UK White Space trial gathered to discus white space standards and approaches. The sponsoring partners ran their technology up a proverbial flag pole, including Microsoft, BBC, BT, Cambridge Consultants, Neul and Arqiva.
Ofcom has decided to make White Space devices licence exempt. Devices will be allowed to operate without the need for an Ofcom licence on the condition that they do not cause harmful interference to existing users. The UK regulator expects that White Space technology could be launched in 2013.
An expert panel gave their views on the risks, challenges and opportunities. One key issue is whether a primary licensee has exclusive use of their spectrum when they need it. Arqiva, which develops UK broadcast infrastructure, has been asked to estimate the value of some 56MHz of TV channels, starting at 550MHz. The band could be opened for unlicensed use, like the slots at 433 and 868MHz which already exist for short range devices. Ofcom may auction it off, according to The Register.
The first UK white space tests, run by BT, were in the radio wastelands of the remote Scottish Isle of Bute. Neul’s trials in Cambridge may be more interesting.
California’s Carlson Wireless will team up with Cambridge, England-based telecoms start-up Neul to develop a white space radio networking system using unused television frequencies and a new “open” protocol. Neul is promoting a wireless broadband service based on white space technology designed to boost coverage in rural areas. It has received approval from Ofcom in the UK, and is expected to hit the market before the end of the year.
Neul favors their own Weightless industry standard (video), which is said to define a very wide range of data rates, from 16Mb/s for wireless broadband to 1kb/s for M2M. Neul hopes to unify the fragmented world of Machine-to-Machine (M2M) communications using white spaces and their new, open M2M “Weightless standard”. Their NeulNET, includes a basestation unit and a portable battery-powered terminal and is said to deliver speeds of up to 16Mbs with a 10km radius.
Meanwhile, at the recent Super WiFi Summit held in Austin, TX, Xg Technology delivered a presentation on the suitability of TV white spaces for mobile services. Formed by Spectrum Bridge founder Rick Rotondo in Florida, he says their xMax cognitive radio technology delivers on the FCC’s vision of opportunistic spectrum use for both licensed and unlicensed bands.
Cognitive Radio and beam forming can also be incorporated into associated products. NetBlazr places routers and three directional 802.11n radios by Ubiquity to create a “node.” Each node then creates short-range, point-to-point radio connections to other nodes.
One concern is the possibility of TV white spaces spectrum becoming reallocated. Although it is too soon to tell what will happen, as Google’s FCC representative, Rick Whitt put it, “the sooner we can prove the technology, the sooner we can prove the value of white spaces.”
According to Whitt, “There’s considerable interest from what we can gauge in developing the devices, developing the services and building out networks, at least in some places. I think the challenge we see, as we discussed with FCC in our advocacy around the white spaces, is to ensure that the rules allow for enough flexibility in terms of the power limits so that you have access to enough white space channels across the country so that you can [then] build and operate a ubiquitous, nationwide broadband network.”
The FCC has started a 45-day trial on Sept. 19 (pdf) with the first of nine databases that will allow new devices using the white spaces to operate without interfering with existing broadcasters.” The trial started on September 19, 2011 and ends on November 2, 2011.
The FCC requires that unlicensed White Space devices contact an authorized database system to obtain a list of channels that are available at each location. The first trial will use the Spectrum Bridge database.
In the United States, unused “white space” television frequencies are primarily in the UHF band. The White Spaces Coalition consists of eight large technology companies that includes Microsoft, Google, Dell, HP, Intel, Philips, Earthlink, and Samsung. Various proposals, including IEEE 802.11af, IEEE 802.22 and those from the White Spaces Coalition, have advocated different standards for the United States.