Mobile operators that have made investments in LoRa networks are now looking at using licensed spectrum to support the technology, according to a spokesperson for the LoRa Alliance .

LoRa has so far relied on unlicensed spectrum to provide connectivity for sensors used in smart meters, asset-tracking devices and other "Internet of Things" (IoT) networks. Running the technology over licensed spectrum could help operators overcome one of the main drawbacks of the technology -- the interference and congestion that can occur in unlicensed airwaves.

It might also have implications for a crop of cellular standards that have emerged in response to LoRa and other unlicensed-spectrum technologies, including France's Sigfox . At the forefront of those cellular standards is NB-IoT, which a number of mobile operators plan to launch in the coming months. (See Vodafone Ireland to Launch NB-IoT in Jan 2017 and Telia 'Betting' on NB-IoT Over LoRa, Sigfox.)

The cellular community has been split in its approach toward LoRa. The UK's Vodafone Group plc (NYSE: VOD), for example, has avoided dabbling in the technology whatsoever, preferring to wait for the arrival of NB-IoT before making any big moves in the market for low-power, wide-area (or LPWA) connectivity. (See Vodafone to 'Crush' LoRa, Sigfox With NB-IoT.)

Others, including South Korea's SK Telecom (Nasdaq: SKM), France's Orange (NYSE: FTE) and KPN Telecom NV (NYSE: KPN) of the Netherlands, have announced major commitments to LoRa, seeing the technology as a means of satisfying existing demand for a range of IoT services. (See SK Telecom Sees LTE-M, LoRa as Its 'Two Main IoT Pillars'.)

Orange, however, has previously expressed concern about LoRa's reliance on unlicensed spectrum. That concern is partly why cellular alternatives such as NB-IoT also figure in the French operator's IoT plans. (See LoRa May Not Be for Long Haul at Orange.)

According to a spokesperson for the LoRa Alliance, an association that promotes LoRa technology, the quality of service that comes with licensed spectrum represents the only real advantage that cellular technologies have over LoRa and Sigfox.

"The only benefit carriers have is that they can guarantee quality of service because it's a licensed band," he says. "The only move that LoRa and Sigfox can make to counter that is to put the technologies in licensed bands and I predict that will happen at some point."

So what has stopped it from happening before now?

For one thing, much of the early interest in LoRa has come from players outside the traditional telco sector that lack their own spectrum resources. "Squeezing NB-IoT into an existing band is a different game from having to acquire spectrum and build an IoT business case on top of that," says the LoRa Alliance spokesperson.

Telcos such as Orange, KPN and SK Telecom do not face this problem, however, and the LoRa Alliance says it has already carried out tests with operators to show that LoRa works effectively in licensed spectrum bands.

One of the main obstacles in this scenario is securing the approval of regulatory authorities that may harbor reservations about an unfamiliar technology. "There is a difference between technically proving it and going around the world and getting it certified," says the LoRa Alliance's spokesperson.

Nevertheless, if they could use licensed spectrum to negate any concerns about interference, operators could offer different tiers of service, charging more for higher-quality connectivity, according to the LoRa Alliance. "KPN, say, could provide an unlicensed-band subscription of $2 per year and a licensed-band subscription of $4 per year," says the group's spokesperson.

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The big question, perhaps, is whether operators have sufficient incentive to dedicate costly spectrum resources to LoRa given the growing momentum behind NB-IoT.

Orange and KPN were approached by Light Reading about their interest in using licensed spectrum to support LoRa but had not answered questions at the time this story was published.

LoRa's opponents say the technology is not as "open" as the LoRa Alliance makes out. Although the LoRa ecosystem is growing, and features players from all parts of the value chain, a Californian chipmaker called Semtech Corp. (Nasdaq: SMTC) still appears to control the intellectual property behind LoRa. Nor is equipment likely to work in some of the licensed spectrum bands that operators have at their disposal.

On the other hand, LoRa's backers claim it enjoys major technical and cost advantages over cellular. For a start, NB-IoT consumes about ten times more power than either LoRa or Sigfox, they say, making it unsuitable for a wide range of applications.

Until volumes grow, NB-IoT modules are likely to be much costlier than LoRa ones, too. The LoRa Alliance reckons that an NB-IoT module will cost somewhere between $10 and $15 next year and says the current cost of a LoRa module is just $5.

Vodafone has argued that NB-IoT represents an economical network option because about 80% of its existing basestations need only a software upgrade to support it.

Yet the LoRa Alliance reckons this NB-IoT software upgrade costs about the same as building a LoRa network from scratch. In a market like France, it says, a full installation of LoRa hardware and software costs about $5,000 per site. "For Orange, 4,000 sites in France at $5,000 per site is about $20 million," says the association's spokesperson.

Depending on the number of sites in question, fees for an NB-IoT software upgrade are likely to cost at least $5,000 per site, he says.

Light Reading asked Vodafone how the costs of an NB-IoT software upgrade compared with the expense of installing new hardware but had yet to receive an answer at the time of publication.

NB-IoT has too many powerful backers to be derailed by a licensed-spectrum version of LoRa. But the cellular standard may find the going much tougher if LoRa does go licensed.

— Iain Morris, , News Editor, Light Reading