White Space Radio using 802.11af Demoed

Posted by Sam Churchill on

Japan’s National Institute of Information and Communications Technology (NICT) says they have developed the world’s first WiFi prototype in the TV White Spaces (470 MHz~710 MHz) that is based on the IEEE 802.11af draft specification.

Their access points integrate the 802.11af draft (D2.0) together with a traditional 802.11a/b/g/n wireless router operating in the 2.4 GHz and 5 GHz bands. When the traffic in the 2.4 GHz or 5 GHz is congested, it can use unused television frequencies. The system automatically identifies busy channels by interrogating a database, with vacant channels chosen by the access points so no interference is generated.

IEEE 802.11af is the task group (TG) under the IEEE 802.11 working group (WG) for White Space radios. The prototype verifies the physical (PHY) and media access control (MAC) layer design of the draft specification, following the worldwide trend of prompting the TVWS for wireless communication systems.

Carlson and Neul worked together to develop RuralConnect, which uses unused portions of UHF spectrum. It is designed for use in both the US and the UK. With approval from both the FCC and Ofcom (the UK’s spectrum regulatory entity), the companies plan to introduce the product to the open market by year’s end.

The Wireless Innovation Alliance (WIA) hopes to use spectrum in the television band using unlicensed radios (similar to WiFi), that would be available a electronic stores.

TV White Spaces (TVWS) are vacant frequencies not being used by licensed television broadcasters. This spectrum is located in the VHF (54-216 MHz) and UHF (470-698 MHz) bands in the United States. In white spaces radio, each Base Station (BS) would have a GPS receiver which would allow its position to be reported. This information would be sent back to centralized servers (in the USA these would be managed by the FCC), which would respond with available TV channels in the area.

On September 23, 2010 the FCC released a Memorandum Opinion and Order that determined the final rules for the use of white space (pdf). The new rules removed mandatory sensing requirements which greatly facilitates the use of the spectrum with geolocation based channel allocation and adopted a proposal from the White Spaces Coalition for very strict emission rules that prevent the direct use of IEEE 802.11 (Wi-Fi) in a single channel effectively making the new spectrum unusable for Wi-Fi technologies.

According to a major study by PolicyTracker, the defining year for TV white spaces will be 2014 as a series of major standardization efforts will be completed resulting in new white space devices (WSD) reaching the market.

The FCC is planning spectrum auctions in the 600 MHz television band to enable licensed use of the current TV band by cellular providers. Where television channels are not auctioned off or used (White Spaces), unlicensed radios may enable WiFi-like connectivity. It’s seen as particularly useful for providing connectivity for rural users since lower frequencies can penetrate foliage and can travel further.

The spectrum will be in the 600MHz band and the FCC plans to implement 6MHz “guard bands” to protect remaining broadcasting services from the new mobile broadband services.

Related Dailywireless articles include; FCC: TV Auction in 2014 , Spectrum Bridge Partners with Carlson Wireless, Microsoft Announced Narrow Channel Whitespace, FCC Authorizes White Space Service in Wilmington, FCC Gets Unlicensed White Spaces in Payroll Tax Bill, Mobile: The New Television, FCC Moves on TV Frequency Auction, FCC Makes TV Spectrum Sharing Official, FCC Gets White Space Autonomy, White Space Show Down, Genachowski Lobbies for Unlicensed White Spaces, Universal Service Reform Passed, Microsoft Announced Narrow Channel Whitespace, FCC Authorizes White Space Service in Wilmington, White Space Legislation Goes Dark, White Space War, Bills to Kill Unlicensed White Space?, White Space Trial Completed, White Space Trialed, Huawei to Trial White Space TD-LTE, NTIA “Finds” 1.5 GHz of Federal Spectrum, UK Delays 4G Auction Ofcom: White Spaces by 2013, UK Gets Free Public WiFi, Europe’s Digital Divide Auction,

Posted by Sam Churchill on Wednesday, October 17th, 2012 at 8:49 am .

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