Amazon Leo files for 5,105-satellite mobile network

Amazon Leo has filed an application with the US Federal Communications Commission to deploy a new low Earth orbit satellite constellation that would provide direct-to-device mobile connectivity using Globalstar's mobile satellite spectrum.

The proposed Amazon Leo Direct-to-Device (D2D) System comprises up to 5,105 satellites designed to deliver voice, messaging, data and emergency services directly to compatible mobile devices. The company said deployment is scheduled to begin in 2028.

The filing follows Amazon's agreement to acquire Globalstar's satellite operations, infrastructure and mobile satellite services spectrum assets. Amazon said the D2D network would operate alongside its existing and planned broadband satellite constellations, as well as Globalstar's HIBLEO and C-3 systems.

Mobile expansion

Amazon said the D2D network is intended to extend mobile connectivity into areas beyond the reach of terrestrial cellular infrastructure.

The company plans to work with mobile network operators to integrate satellite connectivity with existing mobile services. The network is designed to support compatible smartphones and other mobile devices equipped with satellite-capable chipsets.

Amazon said the service will support voice communications, messaging, internet access and emergency connectivity. It also expects the network to support disaster response communications, remote industrial operations, fleet management and internet of things deployments.

The company noted that the D2D service complements its fixed broadband satellite offering, which requires dedicated customer terminals including the Leo Nano, Leo Pro and Leo Ultra antennas.

Amazon also referenced its previously announced agreement with Apple to provide satellite connectivity for supported iPhone and Apple Watch models. The companies plan to support services including Emergency SOS via satellite, Messages, Find My and Roadside Assistance via satellite while collaborating on future satellite capabilities.

Network design

According to the FCC filing, the D2D constellation will be distributed across five orbital shells at altitudes ranging from 510km to 580km.

Three orbital shells with inclinations between 55.7 degrees and 58.2 degrees will provide coverage across mid-latitude regions. A fourth shell at a 73-degree inclination will extend coverage into higher latitudes, while a fifth shell at an 84-degree inclination will serve near-polar regions.

Amazon said the satellites will communicate with mobile devices using L-band and S-band spectrum. Connections between satellites and ground stations will use Ka-band and V-band frequencies to carry aggregated traffic between the satellite network and terrestrial internet infrastructure.

Unlike conventional "bent pipe" satellites that simply relay signals to ground stations, Amazon said the D2D satellites will process signals in orbit before forwarding traffic. The satellites will also incorporate optical inter-satellite laser links to route communications across the constellation.

The company said the satellites will use digital beamforming and beam-hopping technologies to direct radio capacity towards areas where demand is highest while reducing interference.

Amazon also outlined several signal processing capabilities planned for the network, including adjacent-channel interference protection, dual-polarisation reception and adaptive modulation and coding. The company said these technologies are intended to improve spectrum efficiency while maintaining reliable communications under changing signal conditions.

Operator partnerships

Amazon said the D2D system is intended to complement existing terrestrial mobile networks by providing connectivity where cellular infrastructure is unavailable, uneconomical to deploy or disrupted.

The company has already announced partnerships with telecommunications operators including Vodafone, DirecTV, Herotel and Australia's National Broadband Network. It said it intends to continue working with mobile operators to expand space-based mobile connectivity.

Amazon also said the system has been designed to minimise interference with other spectrum users and will operate within domestic and international frequency allocation frameworks. The company said it will continue coordinating with other satellite operators on spectrum use.

Amazon is currently deploying its first-generation broadband satellite constellation and said more than 390 satellites are already in orbit. The company expects those satellites to provide sufficient coverage to begin rolling out fixed broadband services across initial latitude bands later this year.