The latest "Mobile Economy" report from GSMA estimates that 4G's share of global mobile connections will climb from less than one-third last year to more than half by 2025.

5G networks, meanwhile, are expected to account for 1.2 billion connections — 14 percent of overall connections — by 2025 after their expected debut later this year. 4G, the report added, is expected to take over as leading network technology this year.

In total, two-thirds of the world's connections will be either 4G or 5G by the end of the study window.

The annual report also noted that the mobile industry surpassed 5 billion unique subscribers last year and that total subscribers would approach 6 billion by 2025. Five billion mobile phone users will access the internet on their devices by that year compared to 3.3 billion in 2017.

GSMA analysts attributed the growth primarily to developing nations in Asia — namely Bangladesh, China, India, Indonesia and Pakistan — Latin America and sub-Saharan Africa.

In addition, the report said that 23 operators launched 41 mobile Internet of Things networks to date and that the number of IoT connections would more than triple between 2017 and 2025.

"We are at the dawn of a new era in mobile with the imminent launch of the first 5G networks and the Internet of Things poised to further transform the way we live and work," GSMA Director General Mats Granryd said in a statement.

The study estimated that the mobile industry accounted for 4.5 percent of global GDP last year — which equates to $3.6 trillion in economic value added — and directly or indirectly supported 29 million jobs.

By 2022, its share of global GDP should climb to 5 percent, or $4.6 trillion.

"As the mobile industry moves into the 5G era, the need for pro-investment, pro-innovation policies and modernized regulatory regimes has never been greater," Granryd said.