NB-IoT, the mobile industry's panicky response to Sigfox and LoRa, has been largely jobless since it was first standardized more than four years ago.

In April 2016, Vodafone predicted that 1.4 billion "Internet of Things" (IoT) connections would use so-called "low-power, wide-area network" (LPWAN) technologies, including NB-IoT, by 2020. But just 100 million connections worldwide were based on NB-IoT or LTE-M, a sister standard, at the end of 2019, according to Ericsson. Gaps between expectation and reality do not yawn much wider.

It is not for lack of interest, according to several European stakeholders that are refusing to give up on the underperforming technology. About 70% of projects handled by Avnet Silica, a chip developer, include a request for NB-IoT connectivity, says Cyrille Saulet, a sales manager at the company. Customers are demanding capabilities that do not come with the non-cellular Sigfox and LoRa, according to BICS, the international carrier unit of Proximus, a Belgian operator.

Saulet and BICS representatives were speaking to reporters on a pre-arranged Zoom call this week. The problem, as they see it, is that NB-IoT has still not ticked some important boxes. International roaming has been overlooked, coverage remains patchy and costs have been too high. SFR, a French operator that weighed in with some written observations after the Zoom call, is in broad agreement.

Not just a software job

Originally touted by Vodafone as a fairly straightforward software upgrade to 4G infrastructure, NB-IoT actually required far more work than LTE-M, according to Benoit Lemaistre, SFR's group head of commercial wholesale roaming. "Contrary to LTE-M, the radio and core data had to be completely redesigned to support the new features," he said in an email sent to Light Reading and other outlets. "It was not just a software upgrade."

The NB-IoT effort has proven too much for some high-profile operators. Japan's NTT DoCoMo gave up on NB-IoT in March, saying it would switch off the service it had launched a year earlier to "concentrate management resources." Dish Network, an operator building a fourth mobile network in the US, quit the technology in May, writing off a $253 million investment. France's Orange has never been convinced, instead building its IoT strategy around LTE-M and LoRa.

Equipment prices have been too high, as well. A typical NB-IoT modem today costs about $5, says Saulet. To be economical for many customers, the average price needs to fall to about half that level, he reckons. Encouragingly, costs do now seem to be dropping as shipment volumes rise. SFR thinks NB-IoT will eventually be cheaper than LTE-M hardware.

But roaming seems to have been a major headache. The absence of agreements between operators has forced customers to engage in several discussions at the same time, says Saulet. The transfer of billing and other customer information between different networks has not been straightforward, according to Talia Goldstein, the head of global roaming at BICS.

In her view, commercial rates have also been off-putting. "The main issue is the monthly fee for a device that might be travelling in five countries when you have to add those together," she says. "It is going to be a challenge to make sure we keep ourselves to a certain level."

BICS to the rescue?

BICS, which has identified IoT as one of its main growth opportunities, could help in its role as a kind of middleman between network operators launching NB-IoT services. It claims to have signed about 20 NB-IoT agreements with service providers this year and is aiming for the same number in 2021. "We have the reach and daily relationships around the world, so we can set up IoT agreements and make sure everything will work seamlessly," said Mikael Schachne, the vice president of mobility solutions for BICS, during a conversation with Light Reading earlier this year.

A tie-up with Avnet Silica should help. Announced in June, it allows the chip maker to piggyback on BICS' global network and recently launched "SIM for Things" service. One feature of that is a virtual SIM, meaning companies do not have to swap hardware in equipment moved from one country to another. "It provides a very flexible possibility to manage and update the profile inside the SIM," says Saulet.

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NB-IoT can boast lots of attractions over rivals. As far as SFR is concerned, it remains the most "efficient" of all the cellular technologies when it comes to energy consumption and "deep indoor coverage." Goldstein agrees, arguing that LTE-M "is not the direction that mobile operators want to go in when usage is very low." On power consumption, NB-IoT is now about 10 times more efficient than 2G, according to Saulet.

But there is no escaping those low customer numbers years after NB-IoT first appeared. Supporters insist it is young and that time is still on its side. The risk they face is that other technologies leave it behind, even if they seem less than ideal. As frank and interesting as this particular Zoom call turned out to be, nobody with a vested interest in NB-IoT would welcome a replay this time next year.

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— Iain Morris, International Editor, Light Reading