South Korea launches the world's first fully-fledged 5G mobile networks Friday, a transformational leap that already has superpowers sparring for control of an innovation that could potentially change the day-to-day lives of billions of people.

The superfast communications heralded by fifth-generation wireless technology will ultimately underpin everything from toasters to telephones; from electric cars to power grids.

But while the South has won the race to be first to provide the user experience, that is only one part of a wider battle that has pit the United States against China and ensnared giants including Huawei.

Hyper-wired South Korea has long had a reputation for technical prowess, and Seoul has made the 5G rollout a priority as it seeks to stimulate stuttering economic growth.

The system will bring smartphones near-instantaneous connectivity -- 20 times faster than the existing 4G -- allowing users to download entire movies in less than a second.

In the same way that 3G enabled widespread mobile web access and 4G made new applications work ranging from social media to Uber, 5G will herald a new level of connectivity, empowered by speed.

It is crucial for the future development of devices ranging from self-driving vehicles that send data traffic to one another in real time, industrial robots, drones and other elements of the Internet of Things.

That makes it a vital part of the infrastructure of tomorrow, and the 5G standard is expected to bring about $565 billion (S$764 billion) in global economic benefits by 2034, according to the London-based Global System for Mobile Communications, an industry alliance.

'ONE MILLION DEVICES' 

But the implications have pitted Washington against Beijing in an increasingly bitter standoff.

The US has pressed its allies and major economies to avoid 5G solutions from Chinese-owned telecom giant Huawei, citing security risks that technological backdoors could give Beijing access to 5G-connected utilities and other components.

But Chinese firms dominate 5G technology.

Huawei, the global leader, has registered 1,529 5G patents, according to data analysis firm IPlytics.

Combined with manufacturers ZTE and Oppo, plus the China Academy of Telecommunications Technology, Chinese entities own a total of 3,400 patents, it says -- more than a third of the total.

South Korea comes next, with its companies holding 2,051 patents.

In contrast, US firms have 1,368 altogether, IPlytics said -- 29 fewer than Finland's Nokia alone.

All three of South Korea's mobile networks -- KT, SK Telecom and LG UPlus go live with their 5G services.

"5G's hyper speed can connect one million devices within a one square kilometre zone simultaneously," KT said in a report.

On the same day, Samsung Electronics will release the Galaxy S10 5G, the world's first available smartphone using the tech, with rival LG following with the V50s two weeks later.

COST BARRIER

More than three million South Koreans will switch to 5G by the end of this year, predicted KT vice-president Lee Pil-jae.

Until now, no mobile networks have offered nationwide 5G access. In the US, hotspots in a few selected cities have offered 5G speeds but over wifi only, while Qatari firm Ooredoo says it offers 5G services in and around Doha, but does not have devices available to use them.

US network carrier Verizon will launch fifth-generation services for mobile users in Chicago and Minneapolis next week, with more than 30 cities due to follow this year.

Japan is also expected to roll out a limited deployment in 2019 before full services start in time for next year's Tokyo Olympics.

But cost is likely to be a barrier for user uptake initially, analysts say: the cheapest version of the new Galaxy handset will be 1.39 million won (S$1,623).

"While there are many cheap 4G smartphones under $300, Samsung's 5G phones are well over $1,000, which could be a major minus point for cost-savvy consumers," a KT representative told AFP.

None of South Korea's three network operators would say how much they have invested in 5G -- but Seoul's economy minister Hong Nam-ki put it at at least $2.6 billion this year alone.

"If 5G is fully implemented," he said, "it will greatly improve people's lives".