The UK communications regulator Ofcom recently presented a tutorial on white space devices in the UHF TV band. The report was made to the EU Radio Spectrum Committee (RSC) at its October 5 meeting. The RSC is chaired by the European Commission and involves spectrum regulators from all EU member states.
"White spaces" are geographical areas where spectrum is not used by the licensee. The Ofcom material, presented by its technical policy director Professor Reza Karimi, says that white spaces could be used for such applications as Wi-Fi devices, rural broadband, and machine to machine communications. Ofcom has decided to proceed with enabling access to TV white spaces, among other reasons, as a "stepping stone to future access" to white spaces in other bands. It believes this approach could satisfy some of the "huge demand" for spectrum for wireless data applications.
The regulator nevertheless recognizes the challenges, first and foremost being the protection of incumbent licensees. It also believes that harmonized regulatory standards are crucial. The presentation identifies several specific areas for technical harmonization, including the radio interface and communication protocols. Perhaps just as important, it also identifies what does not need standardization, including the technical algorithm that specifies available TV channels, which in Ofcom's view should be country-specific to permit flexibility and reflect national circumstances.
The topic of white spaces already has come up in several Ofcom consultations, which are catalogued in the presentation. The regulator is investigating how to create the database(s) that would be required to permit access to white spaces, which in large part will depend on cognitive access (also known as intelligent radio).
The UK is moving ahead on these concepts. Professor Karimi's presentation notes that the UK already is creating voluntary national specifications for regulating white space devices. There remains some uncertainty whether the same type of specifications can be created for white space databases, as those are not technically telecommunications equipment, so the UK is examining other approaches.
Being in the forefront of these developments, the Ofcom presentation to the RSC likely provided a strong challenge to other spectrum managers to examine their national approaches towards white space devices. The entire topic remains controversial, with concerns being raised over the technical ability to protect incumbent users and the economic model for white space devices in general.