What is White Space?
Locations where spectrum is unutilized appear as white areas in system coverage maps. Therefore they are referred to as White spaces. TV white space (TVWS) is the unused spectrum on TV broadcasting frequencies (UHF and VHF bands) in an arbitrary location. TV shite spaces are created especially by efficient spectrum utilization of the digital broadcasting. TVWS is currently the first area that is considered for white space devices (WSD).
Geolocation database
The use of white spaces is controlled with geolocation database containing information of the incumbent use. In TV frequencies 470-790 MHz they are TV signals and wireless microphones. White space device queries available frequencies and transmission powers by sending the location and devices parameters to the database.
WISE Project (2011-2012) achievements on TV white space work are the following:
• Operative TV white space testbed as presented TVWS Testbed
• Interference measurements as reported in Documents
• Software tools to validate geolocation database operations including the implementation of PAWS protocol as presented Software
CEPT ECC SE43 group has published following documents on the utilization of TV white spaces:
• ECC Report 159. Technical and operational requirements for the possible operation of cognitive radio systems in the “white spaces” of the frequency band 470-790 MHz. 2011. http://www.erodocdb.dk/docs/doc98/official/Pdf/ECCRep159.pdf
• ECC Report 185. Complementary Report to ECC Report 159 Further definition of technical and operational requirements for the operation of white space devices in the band 470-790 MHz. 2013. http://www.erodocdb.dk/docs/doc98/official/Pdf/ECCRep185.pdf
• ECC Report 186. Technical and operational requirements for the operation of white space devices under geo-location approach. 2013. http://www.erodocdb.dk/docs/doc98/official/Pdf/ECCRep186.pdf
In WISE2 project the utilization of test environment was extended for piloting following use case scenarios with TVWS technology:
• Rural broadband: TVWS can be used as a last mile connection to provide broadband access for rural areas, since TV frequencies have good propagation properties.
• Video surveillance: Wireless video surveillance systems utilize WLAN or cellular networks. These systems have issues with capacity and cost. TVWS could provide a cost efficient way for extra capacity.
• Smart grid: TVWS is tested for communication between control stations. Data rates are very low but delay requirements are strict. TVWS is considered for replacing satellite link. The transmission link considered is several tens of kilometres.
• ITS in public transport: Public transport has many wireless applications. For TVWS wireless ticket purchasing and connection between bus and information screen at the bus station are piloted before devices supporting mobility and handover are available.