NB-IoT is another of those mobile segments where China is racking up big numbers.

It has just crossed the 100 million connections mark and according to a Huawei forecast will double that by the end of 2020.

Christian Kim, Omdia senior analyst for IoT and smart cities, said China accounted for more than 90% of global NB-IoT connections at the end of 2019.

But despite that, takeup is falling short of China's own forecasts.

In 2017, the MIIT set a target of 600 million by 2020, while Huawei had forecast 200 million by end-2019.

"NB-IoT connection numbers were disappointing across the globe in 2019," Kim said.

"The Chinese mobile operators – with help from the government – have already made a considerable amount of up-front investment in building their NB-IoT networks. So for them the success of NB-IoT is very important."

NB-IoT promises mass connections, wide coverage and low power consumption. But LTE-M, based on LTE networks, does not require additional investment.

AT&T and Verizon announced national NB-IoT rollouts in the US in mid-2019, but with LTE-M already widely available, adoption has been slow, Kim said.

The Chinese operators are seeing plenty of topline growth from their IoT businesses, but they are still small.

China Unicom says it collected 3 billion yuan (US$423 million), up 46% from 2019, from 190 million connections in 2019. China Telecom, which reports 157 million connections, says IoT revenue rose 21%.

NB-IoT still only accounts for less than 10% of all China cellular IoT connections, however.

According to operator figures, China has 1.23 billion cellular IoT connections – the vast bulk of them over 2G or 3G using some other low-powered technology.

These non-NB-IoT connections are not slowing down. China Mobile last year grew total connections by 60% to 844 million.

But for the China telecom industry and officials, NB-IoT is the focus. At a conference last week Cao Ming, the head of Huawei wireless product line, forecast adoption would double this year to 200 million.

The MIIT also released an NB-IoT industry index to track the growth of the business across China verticals and geographies.

In contrast to China's all-in approach, NTT DoCoMo announced last month it would shut down its 12-month-old NB-IoT service.

The operator didn't give detailed reasons but analysts believe it was simply a result of limited takeup. It continues to offer other LPWAN technologies.

According to Ericsson's 2019 Mobility Report, worldwide 2G and 3G connections make up the vast majority of cellular IoT services. It predicts that by the end of 2025, NB-IoT and LTE-M will account for 52% of all cellular IoT connections.

However, cellular is just a sliver of the total IoT installed base. Short-range technologies, such as Zigbee and Wi-Fi, account for 86% of all connections.

— Robert Clark, contributing editor, special to Light Reading