Apple Inc. has been secretly working with SpaceX and T-Mobile US Inc. to add support for the Starlink network in its latest iPhone software, providing an alternative to the company’s in-house satellite-communication service.

Right now, iPhones use Apple’s own satellite service, but it’s pretty basic—just emergency calls, texting, and location sharing.

T-Mobile and Elon Musk’s SpaceX are currently testing the Starlink cell network on a trial basis after receiving approval from the Federal Communications Commission in November last year. The trial offers “text via satellite”, while voice and data features will be added in the future, according to the T-Mobile website.