Infrastructure costs and technical and regulatory hurdles mean it will be some time yet before handsets worldwide are beaming calls and data directly to Earth orbit -- even as firms pile into the field to meet the appetites of mobile operators for the technology.

"Everybody is moving faster because they understand there's a big opportunity out there," said Suman Sharma, senior director of product management at network infrastructure provider Mavenir.

Satellite operators and mobile networks see 5G services over satellite -- what the industry calls a "non-terrestrial network" (NTN) -- as a way to reach around 400 million people worldwide who today have no mobile access, as well as plugging coverage gaps in better-served markets.

"Everyone is working towards" voice and data coverage via satellite, which will likely "be a reality in two or three years time", said Luke Pearce, an analyst at technology research firm CCS Insight.

For now, services available to the public are relatively limited, such as Apple's collaboration with satellite firm Globalstar to allow iPhone users to send emergency messages even without mobile signal.

- Engineering challenges -

At the MWC, California-based startup Skylo was showing off its service allowing 5G phones to send emergency messages and texts via satellite, which it is working on with US operator Verizon and Germany's Deutsche Telekom.

Phones on display at its stand showed how users can answer a set of questions to be bundled into a data packet sent to emergency responders.

Some screens ask users to align the phone's antenna to better communicate with satellites hundreds or thousands of kilometres (miles) up in orbit -- many times further than the usual few kilometres to a cell tower.

To leap that gap with regular handsets, Skylo has managed to "turn a hardware problem into a software problem", CEO Parth Trivedi told AFP.

The company found that it could allow phones' hardware "chipsets" to communicate with satellites through changes "entirely in firmware and in code," he added -- while acknowledging "a lot of engineering challenges to overcome".

Skylo and CCS highlight that there are already hundreds of millions of more recent phones around the world capable of at least some satellite communication under standards developed by the 3GPP mobile industry body.

To get widespread adoption "you need that device ecosystem" -- which is nevertheless proving "a little slow" to saturate the market as consumers increasingly turn to second-hand or refurbished phones, CCS' Pearce noted.

Most handset component makers are looking to 2026 or 2027 to build 5G NTN capability into their chipsets, Mavenir's Sharma said.

But he predicted that with operators pushing hard to offer satellite services as soon as possible, "this traction is going to make the chipset vendor move" faster to market.

- 'Don't even think about it' -

One reason operators are keen to be first to offer satellite services is the scent of a premium price tag for early adoption.

For example, US provider T-Mobile will charge $15 per month for its tie-up with Elon Musk's Starlink satellite network.

Picking such a bespoke satellite provider, rather than wait for standardised offerings based on 3GPP, allows the operator to deploy quicker -- at the cost of tougher challenges.

Set-ups like those involving Starlink or its competitor AST Space Mobile, which is working with European network provider Vodafone, are "sharing (radio) spectrum with operators" of existing mobile networks, CCS' Pearce pointed out.

"There are certain areas where the spectrum is congested, and that causes interference and other problems... they're having to go around each country and each regulator to get that service approved," he added.

Skylo, by contrast, uses radio frequencies already approved and in use for satellite communication.

As the complex picture of different offerings begins to smooth out in the coming years, using a satellite network on your smartphone will "become as seamless as you switching from Wi-Fi to cellular" connection, Trivedi predicted.

"You don't even think about it."

tgb/lth

MAVENIR SYSTEMS

NTN CORP.

Apple

VERIZON COMMUNICATIONS

Deutsche Telekom

Vodafone Group