The European Commission announced this week it will take steps to free up radio frequencies for emerging technologies.With wireless data traffic exploding the demand on the already crowded radio spectrum will dramatically increase in the coming years. The EC sees low access barriers to the spectrum (PDF) as the breeding ground for wireless innovation but it fears overcrowding the finite resource may grind innovation to a hold.
To address the problem the EC proposes to share radio spectrum.
In its Radio Spectrum Policy Program the EC proposes different modes of spectrum sharing which are explained in more detail in a report by the Radio Spectrum Policy Group (PDF), an advisory group assisting the EC.
The most open form of sharing is the Collective Use of Spectrum (CUS). Here the frequency band is open to any user, without needing a license (license-exempt frequency bands) for a wide variety of technologies. An example is the 863 – 870 MHz band where Short Range Devices like remote controls, hearing aids, access controls and audio transceivers happily coexist. One of the difficulties of CUS is the risk of harmful interference.
A regulatory-based mode of sharing is Licensed Shared Access (LSA). Currently, specific bands of the spectrum are auctioned off to a single party. This brings in revenue for governments but often leads to the underutilization of the frequency band. An industry consortium including Nokia and Qualcomm proposed to the RSPG to allow for secondary licensing to one or more parties by the incumbent licensee. The RSPG ran with it and coined it LSA. LSA is mostly about making the necessary regulatory changes to allow for secondary licensing.
A technologically more complex mode of sharing is Shared Use Of Spectrum. The spectrum is unitized into temporal and geographical timeslots and several technologies or services share the same range of frequencies.
To make this possible next-generation radio technologies are put into play like Dynamic Spectrum Access. DSA is a set of techniques that optimizes spectrum use by making individual devices cooperate with each other. These techniques include: monitoring airwaves to detect unused frequencies; communication between devices to reach an agreement on which frequency should be used and switching frequency bands and adjusting power if this is needed to avoid interference.
The EC hopes that freeing up the radio spectrum acts as an incentive for innovators to develop radio technologies better capable of sharing.
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