Starlink Details Data Speed of its Space-based 4G Mobile Network

A few months ago Starlink (SpaceX) announced (here) that it had teamed-up with T-Mobile to launch a new global space-based 4G and 5G mobile network, which would be supported by the former company’s mega-constellation of Low Earth Orbit (LEO) based broadband satellites. More details on the network have now been revealed.

The Starlink network currently has around 3,270 LEO satellites in a low orbit around the Earth (altitude of c. 550 kilometres) and their initial plan is to deploy a total of 4,425 by 2024. Residential customers in the UK normally pay from £75 per month and £460 for the regular home kit (standard dish, router etc.).

However, the new agreement with T-Mobile goes much further, by enabling even regular Smartphones to connect with Starlink’s LEOs using familiar mid-band spectrum for 4G and 5G connections. Under the Coverage Above and Beyond (satellite-to-cellular) solution, both companies initially plan to offer “text coverage” (i.e. SMS, MMS and “participating messaging apps“) – starting in the continental US, Hawaii, parts of Alaska, Puerto Rico and territorial waters.

The first beta services are due to go live in select areas by the end of 2023, which would later be followed by the addition of voice and data (mobile broadband) connectivity on their second generation (V2 or GEN2 if you prefer) satellites. The attraction of all this is obvious, since it could potentially create a simple solution to the otherwise patchy, tedious and costly problem of global roaming (assuming regulators in each country are receptive and ground stations exist etc.).

At the time, SpaceX didn’t reveal a lot about the technical and network setup of all this, except that it would initially use a small slice of their network capacity across a given coverage area (i.e. “2 to 4 Mbits per cell zone“). But we just got some additional details as part of the company’s recent and successful FCC application to deploy a further 7,500 GEN2 Starlink satellites.

The documents reveal that Starlink’s new “direct-to-cell” system will be able to provide voice, messaging and basic website browsing at “theoretical peak speeds of up to either” 3Mbps or 7.2Mbps peak upload (Earth-to-Space) over 1.4MHz or 5MHz bandwidth channels per beam, respectively, and up to either 4.4Mbps or 18.3Mbps on the downlink (Space-to-Earth) over the same bandwidth channels per beam using LTE (4G) technology.

Elon Musk said:

“Important to note that this is *total* bandwidth within a cell, so would be divided among all phones. Starlink will be great for text messages, voice calls & low resolution pictures. If only a dozen phones are active, which is true in remote regions, then video will work.

But the really mind-blowing thing is that this means your phone will work anywhere on Earth, unless blocked by local government!”

The system would be rolled out across a payload deployed on a sub-set of 2,016 GEN2 satellites. Once fully deployed, this would enable SpaceX/Starlink to have full and continuous coverage of the Earth within +58 degrees to -58 degrees latitude by mid-2024.

However, there’s still a question mark over how much T-Mobile will charge for this service. The operator has said that the feature may be included for free on their most popular plans, but others might need to pay a small charge for an add-on (not unlike adding roaming support to your plan, albeit a potentially very powerful form of roaming).