Key points:
- T-Mobile announced beta test signups for Starlink's "Direct to Cell" service, which will allow T-Mobile customers to send and receive texts via newer Starlink V2 satellites.
- The beta will begin in early 2025 and will be limited to approved participants with "optimized" phones. The number of participants will expand as more satellites enter orbit.
- This direct-to-cell service is NOT high-speed Starlink broadband to your phone - it's intended to fill coverage gaps in T-Mobile's network for basic texting with the future potential of voice and limited data service.
T-Mobile and SpaceX have a partnership to provide limited cellular service from space, and the FCC recently approved this direct-to-cell (DTC) service for commercial use. T-Mobile is launching a beta test for this capability in early 2025 and plans to expand service as more satellites with direct-to-cell capability are orbited.
This is NOT Starlink high-speed broadband to your cell phone - it is a secondary payload on newer Starlink satellites that broadcasts a cellular signal (using T-Mobile spectrum in the USA) that provides limited connectivity and coverage where cellular towers cannot reach.
Because the satellite constellation that supports this is not fully deployed and there are still technical details to work out, T-Mobile and Starlink cannot open up service to all T-Mobile customers. Therefore, the initial launch will be a beta test using a limited number of customers.
So what is this beta test about, and what capabilities will direct-to-cell have at launch and potentially in the future? Read on for the details...
Table of Contents
Video Overview
What Is Direct-to-Cell Satellite Service?
Space-related technology can be very confusing, especially regarding commercial services for consumers and businesses. There are several ways for people on Earth (and people flying in planes or traveling on boats) to get connectivity from space via satellites, and direct-to-cell is the latest iteration. The FCC (Federal Communications Commission) also calls this technology Supplemental Coverage from Space (SCS).
In a nutshell, SCS/DTC is a system in which satellites expand the footprint of terrestrial mobile cellular networks, especially in underserved or remote areas that lack cell service. Direct-to-cell technology allows satellites to send and receive signals on cellular frequencies, like a system of cell towers in space.
This type of satellite-based cellular coverage comes with some advantages, disadvantages, and technical challenges, however:
The biggest advantage is that direct-to-cell provides cellular coverage where nothing else can. In many areas of the US (and worldwide), it is not affordable, practical, or even legally possible for cell carriers to build cell towers to provide complete coverage. A space-based system is perfect for filling these gaps.
But there are some significant downsides and technical challenges:
- This isn't a full-featured cell tower in space. It only supports a single cellular band with limited bandwidth that must be shared over a much wider area than a typical cell tower. Additionally, the satellites are much further away from the user than a typical cell tower. This means much slower speeds compared to a terrestrial cell tower. And, due to the limited number of Starlink satellites that support this technology, the T-Mobile/Starlink service will only initially support text messaging. Elon Musk stated that initially, "Bandwidth per beam is only ~10Mb, but future constellations will be much more capable." That is not a lot of bandwidth to serve all users over a wide area and is tiny compared to a cell tower or Starlink broadband.
- Because the satellites are so much further away than a cell tower and up in the sky, the service will not work well (or at all) indoors. You'll need to be outdoors with a clear view of the sky.
- A big technical challenge for Starlink and T-Mobile is ensuring that signals from satellites do not cause interference with terrestrial cellular networks operating on the same frequencies. This is another factor that, at least for now, ensures that performance will be limited, although that may change in the future.
Finally, it's important to note that this service is completely different from Starlink's satellite broadband service. Starlink broadband uses completely different frequencies and is designed to provide broadband speeds from space. To accomplish that, Starlink service needs large (compared to a cell phone) antennas, along with other technical details that are not part of the direct-to-cell/SCS service.
DTC/SCS service is actually provided by what is called a "secondary payload" on Starlink's V2 satellites. A secondary payload is carried alongside the primary payload on a satellite to provide other capabilities beyond the primary payload. Starlink broadband service is the primary payload and purpose for Starlink satellites—it's the secondary payload on V2 satellites that provides the DTC capability.
Direct-To-Cell FAQ
Here are some answers to common questions about this technology, which is often confusing:
- Will routers be able to connect through Starlink via DTC? Theoretically, most cellular routers can connect to the cellular frequency (Band 2) used for T-Mobile/Starlink DTC service—assuming the router has antennas with a clear sky view. However, T-Mobile is limiting initial access to smartphones. It's not known if or when other device types will be supported in the future. Additionally, if a cellular tower is in range, it will always take precedence and outperform the satellite connection.
- Is the Starlink broadband service with a Starlink dish obsolete? No. The cellular coverage provided by SpaceX and T-Mobile is an entirely separate technology from the high-speed connection supported by a Starlink dish using Starlink's broadband service. The Starlink dish is much larger than a cell phone, provides more bandwidth and faster speeds, and the hardware is (relatively) power-hungry. The cellular capabilities of the Starlink V2 satellites will be able to provide a limited cellular connection that is MUCH slower and specifically intended to fill gaps in cellular coverage - not provide broadband service like Starlink.
- Can I stream video from space? Not yet. Direct-to-cell has minimal bandwidth and will initially only support text messaging. Video streaming might be possible in the future with a more robust satellite network and regulatory changes.
- Will satellite-based cellular replace terrestrial cellular? - No. Land-based cell towers will always have significant advantages over space-based cellular. Supplemental coverage from space is meant to be exactly that - supplemental coverage for terrestrial cellular networks.
- Will it work indoors or inside my boat/RV? - Likely not, at least initially. Getting a signal on a cell phone from a Starlink satellite will require a clear view of the sky, though Elon Musk noted that it should still work in your pocket. It is unlikely that the cellular signal from space will be strong enough to penetrate indoors. Metal RV/boat roofs will certainly block the signal, though fiberglass and rubber roofs might let just enough in to work inside an RV - that remains to be seen.
The T-Mobile Beta Program
T-Mobile previously rolled out this service in areas affected by hurricanes Milton and Helene, thanks to temporary approval by the FCC. However, the FCC has formally approved the service in the US, and now T-Mobile is ramping up by starting with a beta program that T-Mobile postpaid consumers and business customers can sign up for.
Only some people who sign up for the beta test will be accepted at first. The direct-to-cell system's capabilities are still limited, and it needs further testing and more satellites in orbit before it will be ready for prime-time use.
T-Mobile states that first responders will be prioritized when choosing who to offer beta access, and T-Mobile will also look for users with "optimized" devices:
In time, T-Mobile Starlink is expected to work with most modern mobile phones. During the beta, to ensure a great customer experience we are optimizing the experience on select smartphones and will expand the beta to more customers and phones as more satellites launch. We’ll provide more details on optimized phones when we open the beta in early 2025.
Unfortunately, we'll have to wait for the beta test rollout to see what T-Mobile considers an "optimized" phone.
The service will initially only support text messaging on smartphones, but the announcement states that T-Mobile plans to offer voice and data in the future.
Postpaid customers can get further details and get on the sign-up list here.
The Future of T-Mobile Direct-To-Cell Service
The currently approved capability is still in its infancy, which is why T-Mobile is starting with a beta test. But as Starlink orbits more satellites to increase coverage and capacity, and as testing works out any technical kinks, the service will expand and improve.
One big question is if this service will cost extra. For now, the answer is no - the service is free for participants in the beta test. When the T-Mobile/Starlink partnership was originally announced back in 2022, T-Mobile CEO Mike Sievert stated that satellite-based messaging would be included for no additional charge with the most popular T-Mobile plans and be available for basic plans for a modest fee. However, two years is a long time in the cellular industry, so T-Mobile's plans for monetizing the service could have changed.
T-Mobile also has big plans to increase direct-to-cell bandwidth to allow for higher speeds and more capabilities, but this will require a regulatory waiver from the FCC. T-Mobile currently has a waiver request with the FCC to allow for reduced "Out-of-Band Emissions" limits that would allow for improved performance, but it has not been approved, and there is a lot of opposition from Starlink and T-Mobile competitors.
The future upper limit of performance capabilities of direct-to-cell systems generally - and the T-Mobile/Starlink service specifically - will significantly depend on what regulators allow.
Concluding Thoughts: Satellite and Cellular Finally Merge
Satellite and cellular connectivity have long been completely separate connection technologies. Now, with the FCC approval and early 2025 rollout of T-Mobile's beta test of "supplemental coverage from space" with partner Starlink, the lines between satellite and cellular are blurred.
While spaced-based cellular service can never compete directly with standard terrestrial cellular, it is a great compliment by filling gaps in cellular coverage and providing redundant, if limited, connectivity when cell towers go down due to a disaster like the hurricanes earlier this year.
Cellular has always come with coverage gaps, which can be annoying but also dangerous for those who need emergency services. We may now be witnessing the beginning of the end of coverage gaps as we've known them, allowing cellular coverage just about everywhere.
T-Mobile and Starlink are the first to provide direct-to-cell satellite coverage, but other companies, like AST Mobile, Lynx, and others, are working to provide similar capabilities. Apple and Android have similar features that don't supplement cellular networks but can interface compatible smartphones with other satellite networks for messaging and basic communications. Additionally, Starlink has partnered with cellular providers in other countries to offer the same type of supplemental coverage to other cellular networks.
Overall, it's an exciting time for satellite technology and the ability to get connected just about anywhere.
Further Reading
- Mobile Satellite Internet Options - Our featured guide on all the current and future satellite internet options of interest to RVers and cruisers.
- All our our Satellite Internet Resources - Our collection of guides, gear center entries and news coverage on satellite internet.
- Industry Update: Mobile Satellite Internet for RVers & Boaters – Early 2024 Update: Starlink, Kuiper, Direct To Cellular, and Beyond! - Our deep dive into the state of the satellite internet world.
And here is all of our recent Starlink & T-Mobile coverage: