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SpaceX is showing off the first text messages sent between T-Mobile phones via one of Starlink’s low Earth orbit satellites. “On Monday, January 8, the Starlink team successfully sent and received our first text messages using T-Mobile network spectrum through one of our new Direct to Cell satellites launched six days prior,” a Starlink update said.
SpaceX last week unveiled the first six Starlink satellites capable of delivering cellular transmissions to LTE phones. The service of what Starlink calls “cell towers in space” is expected to provide text messages this year to T-Mobile consumers in the U. S. to U. S. and carriers in other countries, with voice and knowledge service starting in 2025.
SpaceX posted a photo of the two iPhones that exchanged the texts, which included messages such as “Such signal” and “Much wow.” The process that allowed those texts to be sent was pretty complicated, Starlink said.
“Connecting mobile phones to satellites presents several difficult situations that need to be overcome,” Starlink said. “For example, in terrestrial networks, cell towers are stationary, but in a satellite network, they move at tens of thousands of kilometers per hour relative to users on Earth. This requires seamless transfers between satellites and points such as Doppler lag and time delays that challenge the phone for area communications.
Mobile phones have “low antenna gain and low transmit power,” making it “incredibly difficult” with satellites many miles away, the company said. But Starlink’s new satellites “are supplied with state-of-the-art, next-generation silicon-phased array antennas and complex software algorithms that triumph over those demanding situations and deliver the popular LTE service to terrestrial mobile phones. “
Satellite-to-phone service should work almost anywhere on the planet, but it wouldn’t make sense to use it if it can be connected to a mobile tower on the ground. As noted by SpaceX CEO Elon Musk, the limited bandwidth means that “it’s not competitive with existing land mobile networks. “
T-Mobile said last week that box testing of Starlink satellites with the T-Mobile network would begin soon, but announced a start date for the actual service. T-Mobile said Starlink connectivity would be useful in areas of the U. S. In the U. S. , it has no policy “due to land limitations, land-use restrictions” and other factors.
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