"Polite" dynamic spectrum access could lead to innovation spurt

Features

Spectrum is the lifeblood of the mobile industry, with operators ever eager to get their hands on more. But a former Ofcom executive has claimed that instead of suffering from a bandwidth deficit, huge amounts of their holdings go unused every day.

Professor H. Nwana is now Executive Director of the Dynamic Spectrum Alliance, which lobbies for a new approach to spectrum usage.

He argues as much as 100MHz of spectrum lies unused at any time in the United Kingdom. He says: "Most spectrum is unused in most spaces most of the time."

He describes the auction-led approach to dishing out spectrum as outdated and claims if regulators were starting with a blank slate, they would replace auctions with an approach that supports dynamic access.

He says: "The only reason there is to auction spectrum is when the demand is significantly exceeding supply. In that case there's no other objective way of determining what the pricing should be.

"It allows the people who value the spectrum the most to acquire it. If spectrum gets into the wrong hands and isn't properly used, then consumers and businesses will lose out."

He says regulators are trying to balance different industries trying to pull spectrum in their direction, no easy job when well funded lobbying departments from the telecoms and broadcasting industries are jostling for the resource. Nwana says: "When both industries are crying foul, you are probably doing something right."

The DSA, which boasts the likes of Google, Microsoft and Mediatek among its members, conducted tests in the UK last year across zoos, flood defence networks and ships. Members used the 470MHz to 790MHz band, which Nwana identifies as rife with potential for spectrum sharing.

Nwana says dynamic sharing works once a set of base stations send their GPS to a database requesting access. The database then compares the request to what existing users of the spectrum, television in this case, are doing before granting or rejecting access. The base stations make the request every 24 hours, ensuring there is no interference with other users. Nwana says: "By allowing the spectrum to be used on a secondary basis, it will allow more use of the resource."

Nwana advises sceptics of the potential of dynamic sharing should look to Wi-Fi, "the classic secondary service" that also uses unlicensed spectrum. He says the high levels of Wi-Fi offload and enduring popularity are something to be celebrated. He says: "Wi-Fi is the most ubiquitous technology out there today."

But some Wi-Fi players are leery at telcos trying to muscle onto their turf. LTE-U, which uses a mix of 4G and unlicensed spectrum, has been greeted with horror in some quarters and been seen as a land grab by operators.

Nwana disagrees. "The Wi-Fi guys should be flattered about the invention of LTE-U. Imitation is the best form of flattery and all that. They shouldn't overplay their hands as LTE-U is the best acknowledgement of the status of Wi-Fi. From my perspective, LTE-U and LAA are innovations that are good and no different to the likes of Bluetooth."

He says the "politeness" of Wi-Fi, or how it co-exists with other players, is something dynamic spectrum access matches and something LTE-U will have to do as well. Nwana predicts dynamic spectrum access will be just one of a new wave of technologies using mobility in different ways. He says: "DSA not only enables more efficient use of spectrum but will also lead to more competition within the industry." As long as they are polite, of course.