The portion of the spectrum that is freed up as terrestrial television broadcasting is being replaced by cable and internet-based TV should be opened up for unlicensed use to stimulate innovation, German scientists argue.

In the 2000s Wi-Fi started competing with cellular networks. The latter were maintained by large telco's who had spent billions on licensing spectrum and maintaining and upgrading infrastructure to provide primarily voice communication services for paying customers. As mobile data communication grew in popularity Wi-Fi technology, operating in the unlicensed spectrum and rolled out one device at a time from the bottom up, became a serious competitor for the 3G cellular networks.

Wi-Fi overtakes cellular
Wi-Fi was so successful “unlicensed communication even overtook licensed communication in terms of the volume of bits transmitted. In the end, unlicensed was even used to offload traffic from licensed operations”, Jens Elsner of the Munich Innovation Group and Arnd Weber of the Karlsruhe Institute of Technology write in their paper Beachfront Commons.

Promoting innovation
To spark a similar innovation boom Elsner and Weber propose to make the lower UHF bands used for over-the-air TV freely available to the public. Wi-Fi using the 2.5GHz and 5GHz bands is limited in its range, whereas “the UHF bands have very good propagation characteristics, that is, their electromagnetic waves pass through walls with low attenuation but do not travel beyond the radio horizon.” Opening up the spectrum would promote the development of “long-range wireless applications that are not feasible given today's regulation of spectrum”.

Spectrum congestion
The authors address two arguments against turning UHF bands of the into spectrum commons. The first is a technological one. Opponents argue that unlicensed transmission can't work for long-range communications because of spectrum congestion. Elsner and Weber counter there are sufficient technological and regulatory mechanisms to prevent congestions, such as a listen-before-talk protocol to ensure a channel is free before transmitting. To add weight to their argument they present a spectrum sharing use case and explain in detail how congestion can be prevented technically.

The second objection against sharing is economical. Governments make astronomical amounts of money of auctioning off spectrum access. Spectrum commons opponents argue that the best way to collectivize a scarce resource is to collect the highest price and let the revenues flow back to public funds. The two Germans disagree with this line of reasoning saying that it is very well possible that the economic value of the commons could be greater than instant cash in hand. Wi-Fi, for instance, has significantly lowered the cost of mobile communications and an innovation frenzy has seldom hurt an economy.

Image: Nickolay Lamm