There is considerable interest in vacant TV white space frequencies released by analogue switch off but European regulators still do not allow their use for telecoms.
Their reluctance stems from concern over possible interference with existing television bands.
British regulator Ofcom is working on legislation to overcome such fears: “Searching and recycling unused gaps in airwaves could prove critical in averting a global spectrum capacity crunch, as consumers demand more bandwidth over different devices,” explained Ed Richards, CEO, Ofcom.
These lower frequency white space radio waves are ideal for long-range, low-powered connectivity.
Possible applications, in what France-based research institute CEA-Leti, describes as the ‘golden frequencies’ (470-790MHz), include campus networks, smart cities, home networking, M2M and public safety applications.
Dominique Noguet, head, Communication/Security Technology Department, CEA-Leti told Mobile Europe: “Making such devices available in Europe requires all regulators to agree about spectrum polity and how white space frequencies can be harmonised across international borders.”
CEA-Leti is the first research centre in France to be granted a government licence to conduct field experiments to quantify improvements in system capacity and co-existence with incumbent radio systems.
It follows from wireless cognitive radio systems developed by Leti’s Communication and Security Department in which cognitive radios dynamically allocate and exploit spectral resources to optimise wireless capacity and QOS.
CEA-Leti’s research focuses on resolving issues related to free-channel detection and flexible high-spectrum-efficiency communications systems with low power leakage in adjacent channels.
White space devices cannot transmit until they have clearance from a dynamic geo-location database which shows where devices/frequency spaces are and the appropriately restricted power levels at which devices can operate.
Noguet suggests dynamic databases may be combined with spectrum sensing technologies to help detect devices using specific frequencies.
An Ofcom spokesperson told Mobile Europe the dynamic spectrum access database prevents any possible interference as devices will log into a database of users to determine available spectrum.
In the University of Strathclyde’s new Centre for White Space Communications in Scotland, industry (including BT, Microsoft and the BBC) and academic researchers, working with government backing are developing and applying dynamic spectrum technologies using white space spectrum.
Professor Sir Jim McDonald, Principal, University of Strathclyde said: “The aim of the centre is to improve wireless broadband access thereby supporting a plethora of smart rural developments and maximizing the technical, economic and social yield from spectrum.”
Proving the technology viable and harmless for existing technologies, Nouget believes booming consumer demand for content on-the-go, operators, device manufacturers and content providers will drive adoption.
Ofcom will notify the EC of proposed technical regulations later this year and finalise arrangements for databases and the technical parameters required to ensure devices operate harmoniously with existing spectrum users.
It is possible white space devices and technologies may be launched in Britain by year-end.