For the first time in the history of the internet, mobile and portable devices will generate more than half of global IP traffic by 2018.

That’s one of the headline findings of Cisco’s latest Visual Networking Index (VNI), which forecasts global IP traffic for fixed and mobile connections between 2013 and 2018.

Cisco finds 33 per cent of all IP traffic originated with non-PC devices in 2013. By 2018, however, that figure shoots up to 57 per cent.

While PC-originated traffic is expected to have a 10 per cent CAGR over the forecast period, other devices/connections are expected to have much higher traffic growth rates. Tablets are slated for an enormous 74 per cent CAGR in traffic, along with smartphones (64 per cent) and M2M modules (84 per cent).

“There’ll be more tablets than PCs by the end of 2018,” Thomas Barnett, director of Cisco’s service provider thought leadership team, told Mobile World Live.

And it’s the overall proliferation of online devices, combined with an increase in internet connections, which will help global IP traffic reach an annual run-rate of 1.6 zettabytes by 2018, according to Cisco. That’s nearly a three-fold increase over the previous four years.

A zettabyte is one trillion gigabytes or, as Cisco explains, the equivalent of everyone on the planet downloading ultra-HD video for 24 hours.

Other boosts to global IP traffic come from faster fixed and mobile broadband speeds, along with more video viewing.

Cisco further predicts there’ll be a boom in the number of devices/connections, nearly doubling to 21 billion by 2018. Around half of devices by 2018, said Cisco, will be mobile-connected.

It means the number of devices per capita worldwide increases from 1.7 to 2.7 over the five-year period (based on a world population of 7.6 billion).

Of course, the average global monthly traffic varies wildly according to device type. In 2013, Cisco found that M2M modules, on average, generated a mere 78MB per month. Smartphones and tablets notched up 1GB and 4GB respectively, while laptops/PCs – although their market share of traffic is expected to decline – still managed an average of 22.7GB.

Cisco is fairly confident that Ultra-HD will have a marked impact on boosting global IP traffic – the nascent market generated 22.9GB per Ultra-HD TV set in 2013, according to Cisco, which includes IP VoD traffic – but recognises that it’s difficult to back technology winners in early stages of development.

“It’s why we only project out as far as five years,” said Barnett, adding that Cisco’s VNI, now in its ninth annual edition, has had a pretty good track record of forecasting with error margins in the single-digit percentage range.

The number of M2M connections is also forecast to expand rapidly, jumping from 2.3 billion to 7.3 billion between 2013 and 2018. That’s about the equivalent of one M2M module per person on the planet.

Within the M2M category Cisco includes the nascent wearable market, although its overall impact on global IP traffic is likely to be minimal. “We expect 177 million wearable devices by 2018, 22 million of which will have embedded cellular connectivity,” said Schruti Jain, senior analyst at Cisco’s service provider thought leadership team.