World's First TV White Space Wi-Fi Prototype Developed
Published on: 17th Oct 2012
Note -- this news article is more than a year old.
By: Ian Mansfield
The world's first Wi Fi prototype using TV White Space has been developed by Japan's National Institute of Information and Communications Technology (NICT). The prototype is based on the IEEE 802.11af draft specification using 470 MHz 710 MHz radio spectrum.
The developed system is the first prototype that verifies the physical and media access control (MAC) layer design of the draft specification, following the worldwide trend of prompting the TVWS for wireless communication systems.
IEEE 802.11af TG was formed in 2009 under IEEE 802.11 WG. The target is to define modifications to both the 802.11 PHY and MAC layers to meet the legal requirements for channel access and coexistence in the TVWS. It is widely considered as one of the most promising technologies for the TVWS. In September 2012, the 802.11af released its first stable draft standard (Draft 2.0).
The prototype also has an interface and co-works with the Registered Location Secure Server (RLSS) that is defined in the 802.11af draft standard to avoid interference with other white space users (secondary users). NICT has developed the RLSS server. It is approved that the primary users and secondary users operating in the co-channels can be sufficiently protected.
There are said to be many benefits of 802.11af systems compared with other current Wi-Fi technologies. Firstly, in view of the fact that 802.11af systems operating the TVWS use frequencies below 1 GHz, it would allow for much longer distances to be achieved. Current Wi-Fi systems use frequencies in the ISM bands -- the lowest band is 2.4 GHz and the signals are easily absorbed. Secondly, by operating in the TVWS, the usable spectrum is much broader than that of ISM bands when efficiently aggregated.