Direct-to-Device: Satellite’s Breakout Second Act | Microwave Journal

Satellites Go Direct: The New Era of Connectivity in Your Pocket

In a significant shift that's redefining global connectivity, satellite companies are rapidly expanding "direct-to-device" (D2D) services that allow standard smartphones to connect directly to satellites when cellular networks are unavailable Satellite direct-to-device services enable mobile phones and other devices to connect directly to satellites, providing coverage in areas lacking traditional cellular infrastructure. This technology is particularly beneficial for remote regions, emergency situations, and enhancing global connectivity.

Key Developments in Satellite Direct-to-Device Services:

• Starlink and T-Mobile Partnership: SpaceX's Starlink has partnered with T-Mobile to offer satellite connectivity using existing smartphones. This collaboration aims to eliminate mobile dead zones by allowing devices to connect directly to Starlink satellites. The service is expected to begin with text messaging, expanding to voice and limited data services. 

• Lynk Global's Satellite-to-Mobile Service: Lynk Global is developing a satellite constellation to provide mobile phone coverage, especially in underserved areas. They have conducted successful tests, including sending text messages from satellites to standard mobile phones, and are working towards continuous global coverage. 

• AST SpaceMobile's Global Coverage: AST SpaceMobile is building a satellite network to enable smartphones to connect directly to satellites, aiming to provide coverage in regions without reliable cellular service. They are developing a constellation of satellites to deliver global wireless connectivity. 

• Vodafone's Satellite Video Call: Vodafone achieved the first satellite video call using a standard smartphone, demonstrating the potential of satellite connectivity to provide voice, video, and internet services in areas without network coverage. 

Benefits and Considerations:

• Enhanced Coverage: Satellite services can eliminate coverage gaps, providing connectivity in remote and rural areas where building traditional cellular infrastructure is challenging. 

• Emergency Communication: Direct-to-device satellite services can be crucial during emergencies, natural disasters, or in areas with unreliable cellular networks.

• Performance and Accessibility: While satellite connections offer broader coverage, they may have limitations in speed, latency, and data capacity compared to terrestrial networks. 

The development of satellite direct-to-device services represents a significant advancement in global communications, aiming to provide ubiquitous and reliable connectivity across the globe.

This technological advancement means the smartphone in your pocket can now maintain connectivity virtually anywhere on Earth, eliminating dead zones and bringing reliable communication to previously unserved areas.

"Satellite does not have to be this special niche technology; it can always be with you and go everywhere," says Andrew Nuttall, co-founder of Skylo Technologies, a D2D mobile network operator. "It is about drastically increasing the accessibility of satellites in the consumer mobility segment."[^1]

Unlike traditional satellite phones that required specialized, bulky equipment, the new generation of D2D services works with regular consumer devices. Companies like Qualcomm, MediaTek, and Samsung have developed chipsets that enable standard smartphones to communicate with satellites, while manufacturers including Google and Apple have begun incorporating this technology into their latest models.[^1][^2]

Market Competition Intensifies

The D2D market has attracted major players pursuing different technical approaches:

• Apple partnered with Globalstar, investing $450 million to upgrade ground stations and secure satellite capacity for emergency messaging services on iPhone 14 and 15 models across 14 countries.[^3]

• SpaceX's Starlink is collaborating with T-Mobile to provide text messaging via its second-generation LEO satellites, with plans to expand to voice and data services. The companies aim for global texting coverage by the end of the year.[^3]

• AST SpaceMobile recently conducted a successful two-way test call and plans to launch its initial satellite constellation next year, working with carriers including AT&T, Telefónica, and Vodafone.[^3]

• Skylo has partnered with Viasat to deploy 5G NTN NB-IoT messaging services via geostationary satellites, focusing on seamless integration with existing carriers like Verizon.[^2]

Technical Challenges

Despite the promising advances, D2D faces significant technical hurdles. Mobile devices must balance physical limitations like antenna size, power requirements, and heat management while meeting safety regulations.[^2]

Satellite companies are pursuing two main technical approaches: some reuse existing mobile spectrum, which offers compatibility with unmodified devices but faces regulatory challenges regarding potential interference with terrestrial services. Others use dedicated Mobile Satellite Service (MSS) spectrum, which avoids interference issues but requires compatible devices.[^1][^2]

Beyond Emergency Services

While emergency communication represents the initial application for many D2D services, companies envision broader uses including regular messaging, location sharing, IoT connectivity, and eventually voice and data services.

"It is texting your friend that you will be late for dinner because you decided to extend your hike. It is that call in the dead of winter when the snow and ice have brought down the power grid and you need emergency help now," explains Nuttall.[^1]

Industry experts predict a gradual expansion of services, beginning with messaging and IoT applications via geostationary satellites, followed by more advanced broadband capabilities as larger 5G-compatible LEO constellations emerge.[^2]

With approximately 400 million people worldwide lacking mobile broadband coverage and billions more experiencing occasional service gaps, the potential market for satellite D2D connectivity extends far beyond traditional satellite phone users.[^3]

As Peter Kibutu, 5G NTN Market lead at TTP, notes: "The path forward is clear: if the technical pieces come together, D2D will become transformative, finally addressing coverage gaps that have long been out of reach of terrestrial infrastructure."[^2]

[^1]: Nuttall, Andrew. "Direct-to-Device: Satellite's Breakout Second Act." Microwave Journal. microwavejournal.com Direct-to-Device: Satellite’s Breakout Second Act | Microwave Journal

[^2]: Kim, Julia. "What's Next for Direct-to-Device Satellite Communications?" Satellite Today. satellitetoday.com

[^3]: Jarvis, David. "Signals from space: Direct-to-device satellite phone connectivity boosts coverage." Deloitte. www2.deloitte.com