SpaceX CEO Elon Musk and T-Mobile US boss Mike Sievert jointly announced the mobile operator plans to offer basic services to mobile phones by using Starlink’s second generation satellites equipped with large antenna arrays to virtually eliminate dead coverage zones across the US.

Speaking at a high profile event at SpaceX’s launch facility near Brownsville, Texas, Sievert stated the service will use the mobile operator’s mid-band PCS spectrum, which he claimed was ubiquitous across its footprint.

The plan is to enable text, MMS messages, and “select messaging apps” wherever users have a clear view of the sky and when there are no traditional terrestrial cell towers nearby.

“This partnership has a vision that is the end of mobile dead zones,” he stated.

Sievert said a beta test would take place in the latter half of next year, and the service will eventually include voice and data services. No specific date for commercial launch was announced.

He also stated it will be offered at no additional charge on T-Mobile’s more expensive unlimited tariffs,  but customers on cheaper plans may need to pay an additional fee.

The service, which is called ‘Coverage above and beyond,’ is compatible with most of T-Mobile’s current mobile phones that already tap into the mid-band spectrum.

Both Musk and Sievert emphasised the satellite to phone coverage would be particularly useful for emergency situations in remote locations without towers nearby.

Musk stated the new Starlink satellites will need much bigger antennas in order to pick up a single cell signal while traveling 17,000 miles per hour across space (Starlink’s current satellites can only connect to the company’s larger Starlink broadband dish receivers on Earth). The second generation SpaceX satellites also require regulatory approval before launch.

Each satellite cell zone will have 2 to 4 Mb/s capabilities, which would support 2,000 simultaneous voice calls that are about 2 kbs each, or hundreds of thousands of text messages depending on the length of the text message, according to Musk.

Depending on the number of users, Musk noted there could be a bit of a lag in the early stages.

“This won’t have the kind of bandwidth that a Starlink [broadband dish] terminal would have,” Musk said. “But it will enable texting, it will enable images. If there aren’t too many people in the in the cell zone, you could even potentially have a little bit of video”.

The service will be available across the continental US, Hawaii, parts of Alaska, Puerto Rico and territorial waters.

Going forward, T-Mobile’s Sievert stated he was open to using Starlink’s satellites for backhaul, especially in rural areas.

Global operator aims
The bigger picture includes striking reciprocal roaming agreements with other mobile operators both here and abroad that would allow them to use the service when they’re in the US. On the flip side, T-Mobile customers could use other operators’ mid-band spectrum in tandem with the satellites when they’re travelling internationally.

“We do want to work with other partners in other parts of the world,” Musk stated.

SpaceX isn’t the only company playing in this space. AST SpaceMobile is aiming to launch a phone-to-satellite service and has deals with AT&T, Rakuten and Vodafone, among others, while startup Lynk is planning to offer commercial services by the end of this year and has signed operators across Central Africa, Mongolia as well as several Pacific and Caribbean nations.

And T-Mobile US’ two big carrier rivals are also making efforts to plug coverage gaps (albeit via different strategies to SpaceX/T-Mobile). Last year AT&T struck a deal with Starlink rival OneWeb to sell broadband services to businesses outside the area of its fibre network while Verizon plans to extend reach to underserved communities via a partnership with Amazon’s planned Project Kuiper LEO satellite network.