South Korea’s already impressive internet speeds are about to pull even farther ahead of the rest of the world with plans to introduce a next-generation 5G wireless service capable of downloading full-length

films in a second.

The country’s science ministry said on Thursday it would invest 1.6t won ($1.5bn) with local firms in the service, with a view to making it commercially available by the end of the decade.

The 5G network will enable users to download an 800-megabyte movie in one second, compared with 40 seconds on the current 4G network – already the fastest in the world.

That would mean passengers on high-speed trains would be able to access the internet even at speeds of 500kmh (310mph), compared with the current limit of 300kmh.

"Bullet trains around the world keep getting faster, with some in China running as fast as 500kmh and 600kmh," a ministry official, who declined to be named, told AFP in Seoul. "If we have the technology to allow fast internet access in these trains, it can open new opportunities for us globally.”

South Korea is determined to protect its position as a global leader in super-fast internet connections. More than 78% of South Korea's 50 million people use smartphones; among 18-24 year olds, the proportion rises to a staggering 97%.

Regular upgrades to the country’s mobile network have been instrumental in fuelling economic growth, starting with the 2G service in the 1990s through to the introduction of the 4G service in 2010.

"Countries in Europe, as well as China and the US are making aggressive efforts to develop 5G technology ... and we believe there will be fierce competition in this market in a few years," the science ministry said in a statement.

The ministry estimates the project will generate about 331t won in 5G-related mobile devices and infrastructure between 2020 and 2026, with a focus on new features such as ultra-HD and cutting-edge social networking services. The new network will generate a domestic telecom market worth 68t won, it said.

The ministry said it would develop 5G with expertise and investment from mobile carriers and handset makers such as LG and Samsung, the world’s biggest maker of smartphones.

While South Korea, led by Samsung, dominates the global mobile device market with a 30% stake, its share of the telecom infrastructure market is just 4.4%. The ministry said it hoped increase that share to one-fifth by the end of the decade. Rivals such as the Chinese firm Huawei, which also plans to roll out a 5G service by 2020, have much bigger shares of the telecom infrastructure market.

The 5G service will be tested on social networking services as early as next year before expanding to include 3D images and cloud services in 2017, the ministry said. The full range of services will be tested at the Winter Olympics in PyeongChang in 2018.

In a test of 5G technology last year, Samsung said it had successfully sent and received data over a distance of two kilometres at a download speed of one gigabit per second.