Non-cellular low-power wide area (LPWA) networks like Ingenu and Sigfox will outnumber cellular networks in terms of Internet of Things (IoT) connections by more than 12 percent by 2021, according to an ABI Research report.

Although both cellular and non-cellular networks will benefit from the growth in IoT applications, non-cellular LPWA connections will see particular strength in Europe and Asia-Pacific where operators have been aggressively rolling out nationwide networks.

However, ABI adds that cellular LPWA network technologies like narrowband-IoT and LTE-M (also known as LTE CAT-M) will also see strong growth particularly in 2018 and onward as network operators become more aggressive in their deployments of those technologies. Operators like Japan’s SoftBank and Korea’s SK Telecom have both said they will deploy LoRa networks, which are non-cellular and use unlicensed spectrum, in 2016 and 2017 and then deploy NB-IoT and LTE-M later.

In the U.S. Verizon has said it will deploy LTE CAT-M throughout its network by year-end, and AT&T is piloting the technology in San Francisco this quarter.

ABI adds that IoT customers that require service level agreements will gravitate toward cellular networks because of the higher quality of service those networks can offer.

ABI also believes that proprietary machine-to-machine (M2M) networks that are specifically for metering like Itron, Sensus, and Aclara will continue to benefit from strong growth in utility metering because they offer a reliable solution. However, they may eventually see more competition from public LPWA networks as their coverage areas expand nationwide.

ABI’s study is good news for networks like Sigfox and Ingenu, which some have criticized because they use proprietary technology. Sigfox has been on an expansion kick recently. The company recently received $159 million in Series E funds that it will use to expand its network to 60 countries by 2018. The French IoT firm also said it will have its network in 100 markets in the U.S. by year-end.