Running short of dramatically new phone designs, leaders of the world's wireless industry showcased their next big idea 5G, shorthand for the fifth generation of networks they expect to have up and running by 2020, at the Mobile World Congress in Barcelona.

But first the industry will have to decide what 5G needs to do that the current, fourth generation of wireless networks, don't offer.

With discussions on setting 5G technical standards yet to begin, a final standard is expected in 2019, experts say.

That will not stop network equipment makers such as China's Huawei and France's Alcatel and dozens of newer players from touting projects as ready for 5G. Most industry experts expect the first commercial deployments of 5G in the run-up to the Tokyo Olympics in 2020.

Huawei and other companies will use software to power 5G, relying less on hardware than in the past.

"For the 5G architectures, what they do is with just one physical infrastructure to enable different network licences for different industry applications. How it will work? It will be based on SDN-NFV (Software Defined Network and Network Functionality Virtualisation technology), to enable that," Daisy Choo, marketing director for 5G at Huawei said.

In that vein, Sweden's Ericsson and Finland's Nokia, will join a parade of equipment makers expected to unveil their latest 5G demonstration projects with telecom operators at Mobile World Congress, the largest annual trade show for the global wireless industry.

"I think we will see the early launches by 2020," Kester Mann, an analyst at CCS Insight, said. "Docomo, the leading Japanese operator, looking at a solution to the Tokyo Olympic Games in 2020. I know SK Telecom, the South Korean operator talked about by 2018 for the winter Olympics in South Korea, but the reality is that it will be later than that, certainly for European markets and other parts of the world."

Major vendors predict a 100 to 1,000 fold increase in network capacity over 4G

But the technology will also have to grapple with a new challenge: the fact that much of the world's spectrum in lower frequency bands is used up. What remains is higher frequency spectrum that can only carry traffic over shorter distances.

Ericsson, the world's leading maker of mobile network equipment, has forecast 50 billion connected objects by 2020.

"5G in terms of the capacity will enable these huge numbers of objects to be connected. Say 50 to 100 billion objects potentially by 2020 is a huge number and we need technology in place to enable that. Alongside extremely good reliability, faster speed and of course very, very low latency to enable this to happen," Mann added.

That's the vision, but then the mobile industry has a history of over-promising what it actually delivers with each G.

The GSMA estimates operators will spend $1.7 trillion on equipment upgrades between now and 2020. Most of that is simply to add 4G network capacity and improve coverage in densely trafficked areas.