For those who are not familiar with the term, cognitive radio (also sometimes described as white-space radio) describes a way of using radio spectrum in which unlicensed devices do not use particular assigned frequencies but rather constantly assess the available spectrum, determine which parts of it are currently unused and make use of that spectrum to transmit information. There has been significant publicity concerning the US’s pro-white-space policy, leading to some concern within Europe that the US may be stealing a march on Europe.
Last week the European Radio Spectrum Policy Group (a high-level advisory group that assists the European Commission in the development of radio spectrum policy), published responses to its November 2010 consultation on its Draft Opinion on Cognitive Technologies. The draft opinion being consulted on recommended that:
- “implementing measures to introduce the CR technologies in some bands could be left to Member states as long as border coordination issues are addressed and the following recommends [SIC] are taken into account
- a platform shall be created to allow researchers, academia and regulators to coordinate research activities
- Administrations, when implementing CR technologies that require to utilise databases should (possibly with guidance developed in the CEPT):
a. indicate how the databases should be certified or accredited, supplied and updated by national regulatory bodies, and to supply relevant information to CR systems
b. provide information to database managers on algorithms;
c. provide information on incumbents directly or through a designated entity;
- Administrations and the EC should request ETSI to study the relevant means that could be implemented in order to secure the access from CR devices to the relevant database and the exchange of information between them;
- Administrations, in relation with the EC and TCAM, should give to ETSI relevant information on suitable data elements, equipment behaviour and output signal radio characteristics which will allow ETSI to develop harmonised standards
that any Cognitive Radio harmonised standard developed by ETSI should include:
a. compliance testing instructions under R&TTE Directive;
b. relevant information on how CR device could access only certified or authorised databases;
c. HS information that should be given to CR devices from the database for a given period of time;
d. information to be supplied by the CR device to the database including appropriate geolocation information;
e. means needed to secure transmission between the database and the CR device;
- TCAM should keep Notified Bodies up to date regarding specific requirements under the R&TTE Directive for CR devices;and
- in order to provide some confidence to all stakeholders, EC should investigate if JRC facilities can be made available.”
As with any technological development capable of disruptive change, the responses were predictably mixed. The strongest adverse reactions came from current users of licensed spectrum, mobile operators and broadcasters, who have most to lose not only from any potential interference by cognitive radio with their licensed spectrum use but who also from the potential diminution in value of existing licensed spectrum were unlicensed cognitive radio to be widely deployed. Vendors, for whom cognitive radio represents both a market opportunity, but also a risk if new entrants exploit the technology, remained on the fence by recognising the potential, but also the risks.
At this stage it is unlikely that much beyond ‘co-ordinate and play nicely’ will come out of the RSPG process in the short-term, but the issue is also being considered at national level. In the UK, Ofcom has been considering potential new uses for the digital dividend since 2005. In 2007 Ofcom concluded that cognitive devices could use white spaces without requiring individual licences, provided that there was no harmful interference to licensed spectrum use, such as digital terrestrial television and programme-making and special events (‘PMSE’). At the same time, Ofcom decided that any liberated spectrum should be auctioned off, with one package reserved for auction to PMSE users. None of the spectrum will be expressly reserved for unlicensed use by cognitive devices.
Ofcom is now working with industry to establish whether white spaces can be used without causing harmful interference. Ofcom recently consulted on the proposed parameters for such use, concluding that cognitive devices should sense the presence of other signals or use a geolocation database to discover unused spectrum. Geolocation is being further considered after studies showed that the signal levels devices would need to sense down to, in order to ensure no harmful interference, are extremely low.
Ofcom consulted on geolocation to seek feedback on the following issues:
- Whether there should be just one database or several;
- The type and format of information to be provided by the device to the database(s) and to be returned from the database(s) to the device;
- The frequency of update of the database(s) and the periodicity with which devices will need to re-consult;
- The modelling algorithms and device parameters to be used to populate the database(s); and
- The maintenance of the database(s): who should be responsible for hosting and maintaining the database(s), and who should incur the associated costs?
Responses to the consultation were broadly supportive of Ofcom’s proposals. Ofcom concluded that no competition will be held to select a database. Organisations can apply at any time to become database operators, but operators will be regulated and each database will need to be registered.
Ofcom’s focus is on technological capability, and wants industry to take the lead before regulating. In any case, white spaces cannot be utilised until switch-over completes in 2012. Ofcom also intends to cooperate with the rest of Europe in seeking international agreement, which may cause further delay. No European solution is likely to be implemented until complete analogue switch-off is achieved; whether the 2012 deadline will actually be met is uncertain.