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. Connecting cell phones to satellites has several major challenges to overcome. For example, in terrestrial networks cell towers are stationary, but in a satellite network they move at tens of thousands of miles per hour relative to users on Earth. This requires seamless handoffs between satellites and accommodations for factors like Doppler shift and timing delays that challenge phone to space communications. Cell phones are also incredibly difficult to connect to satellites hundreds of kilometers away given a mobile phone’s low antenna gain and transmit power. Starlink satellites with the Direct to Cell payload are equipped with innovative new custom silicon, phased array antennas, and advanced software algorithms that overcome these challenges and provide standard LTE service to cell phones on the ground. As the global leader in rocket and satellite launch and manufacturing, SpaceX
is uniquely positioned to rapidly scale our Direct to Cell network and will rapidly launch a constellation of hundreds of satellites to enable text service in 2024 and voice, data, and Internet of Things (IoT) services in 2025.
https://api.starlink.com/public-files/DIRECT_TO_CELL_FIRST_TEXT_UPDATE.pdf