White Paper on Satellite Direct-to-Device Services

As commercial carriers roll out new services, consumers may have questions about the capabilities of satellite direct-to-device (D2D). To get a better understanding of the capabilities and constraints of the service, WIA commissioned a white paper by Telecom, Media and Finance Associates (TMF), which was updated in October 2025. In the paper, Tim Farrar, President of TMF, explains the current capabilities of satellite D2D services, as well as constraints such as lower speeds, limited capacity, and limited coverage in obstructed areas.  

Satellite D2D White Paper, October 2025 | Key Takeaways

Satellite Direct-to-Device (D2D), also called Direct-to-Cell (DTC), is an emerging complement to terrestrial wireless networks, extending basic connectivity to areas where tower construction is not practical. While promising, D2D is not a replacement for traditional cellular infrastructure—it serves as a fallback option for remote and emergency use. The TMF’s white paper provides in-depth analysis of (1) the state of satellite connectivity; (2) technical and performance limits; and (3) satellite’s role in the wireless ecosystem.

What is the current state of play for satellite direct-to-device connectivity?

Function: Satellite D2D connects standard smartphones directly to satellites with no special hardware needed.

Technology Evolution: D2D builds on the success of space-based fixed broadband systems (e.g., Starlink for home internet) but is designed for mobile devices.

Industry Activity: The market is very active with both commercial device manufacturers and wireless carriers announcing partnerships with satellite operators for D2D services including:

• Apple is partnered with Globalstar and offers emergency and non-emergency text messaging on iPhones.
• T-Mobile is partnered with Starlink and offers texting, limited app data, and low-bandwidth voice/video on modern smartphones.
• AT&T and Verizon are partnered with AST SpaceMobile, which has demonstrated voice and video calls and is in the process of launching satellites.
• Starlink is acquiring additional spectrum that will potentially allow it to perform at 4G LTE levels, once a second generation constellation is constructed and compatible handsets are available, and assuming that the spectrum sale is approved. This capability is not expected for at least two years. 

What are the technical and performance limits of satellite direct-to-device?

Signal Strength and Coverage: Satellite D2D signals are much weaker than those from terrestrial towers. D2D also requires a line-of-sight between the phone and the satellite, so indoor and urban service remains limited.

Capacity Constraints: Only a few tens of megahertz of spectrum is available for D2D and each satellite beam covers huge areas (typically hundreds of square miles), which forces users to share limited bandwidth.

Speed: Current performance for satellite D2D is below 1 Mbps download. Future systems are expected to reach 4G LTE-like speeds outdoors, not 5G, and any connections indoors will be even slower.

Spectrum Challenges: Suitable frequency bands for satellite D2D are scarce and costly, constraining scale and affordability. Sharing terrestrial spectrum has proved challenging, prompting operators to focus on the limited bands of spectrum that are already allocated for Mobile Satellite Services (MSS).

What is satellite direct-to-device’s role in the wireless ecosystem?

Purpose and Value: Satellite D2D serves as a supplemental capability to fill gaps in remote, rural, or disaster-affected areas. It enhances reliability, coverage, and emergency response in these hard-to-cover areas.

Limitation: D2D cannot deliver the capacity or performance needed for everyday mobile use, in line with the expectations of today’s 5G cellphone users.

Bottom Line: D2D strengthens network reach and resilience, but remains a complement, not a substitute, for terrestrial towers and small cells.