Shipments of smartwatches with mobile connectivity will hit 7.5 million units in 2016, increasing to 53.6 million in 2020, according to Canalys.

The company said that in the short term, shipments are likely to be driven by a new Apple Watch which includes cellular connectivity. Samsung and LG have also already offered connected smartwatches, and will play a major role.

“The phase 2 eSIM specification will enable more independent smartwatches with a smoother user experience around cellular connectivity. Users will soon be able to easily choose among cellular providers and pay for monthly service,” said analyst Daniel Matte.

Also playing a role will be evolutions of 4G technology targeting machine-to-machine applications, which could be suitable for wearables. At the recent Mobile 360 Europe event, ARM strategist David Maidment said that low-power wireless technology could reduce the ties between wearables and smartphones.

The integration of additional health and fitness sensors, expanded activity tracking and battery life improvements will further drive growth over the next few years. The app ecosystems around watchOS and Android Wear are also set to pick up pace.

Canalys noted that the biggest impact for mobile-connected wearables will come in 2017, after a full year of availability.