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How low-earth-orbit satellites are transforming mobile communications
Direct-to-device satellite technology could transform mobile coverage in Uganda by extending connectivity to areas beyond the reach of terrestrial networks, writes Eng. Jospeh Alfred Bogere
Eng. Joseph Alfred Bogere. (Courtesy)
By: Admin ., Journalist @New Vision
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OPINION
By Eng. Joseph Alfred Bogere
Historically, mobile satellite services (MSS) depended on satellite phones or specialised user terminals. The emergence of low-earth-orbit (LEO) constellations has allowed new services that target end-user devices more directly. Known as direct-to-device (D2D), direct-to-cell, or direct-to-handset services, these services allow smartphones and similar devices to connect directly to satellites without specialised terminals.
LEO satellites function as long-term evolution (LTE/4G) or 5G mobile base stations or cellular towers, which would usually be on the ground, but are now in orbit, transmitting signals and providing coverage directly to mobile devices on the ground.
Newer high-end handsets currently incorporate specialised antennas and chipsets that enable connectivity to existing satellite services using the spectrum bands allocated to MSS, thanks to collaboration between handset manufacturers and MSS operators.
The upcoming World Radiocommunication Conference in November 2027 will address, among other key topics, the allocation of radio frequency spectrum bands for current International Mobile Telecommunications (IMT) systems, especially 4G and 5G, to MSS services.
Depending on its outcomes, the distinction between terrestrial and satellite spectrum use, and thus services, could diminish by 2030, enabling seamless switching between terrestrial and non-terrestrial (such as satellite) networks.
However, for the potential of mobile satellite services to be fully harnessed, technical challenges must be addressed. These include the distance and path-loss effects from LEO satellites in the sky and end-user devices on earth’s surface, reducing bandwidth and reliability. Any additional obstacle could make communication impossible.
Concrete walls, ceilings or metal roofs further degrade signals, making indoor coverage difficult. This explains why satellite dishes and other antennas are mounted outside buildings to maximise reception. Terrestrial mobile networks, on the other hand, often provide indoor coverage through windows. The signal propagates horizontally and can, therefore, reach users far behind the window.
Another challenge to overcome is spectrum — a limited resource with many services vying for more. In Uganda, as elsewhere, terrestrial mobile networks already occupy the frequency bands designated for IMT. Only a few bands have been assigned to MSS, and these are shared among various satellite services. Globally, D2D service providers seek to use IMT bands already supported by smartphones, but in Uganda, most of this spectrum is heavily utilised, especially in urban areas such as Kampala.
According to international best practice, a satellite D2D service provider can acquire spectrum directly from the regulator or purchase it from licensed national operators. However, in Uganda, the 2018 National Broadband Policy recognises spectrum as a national resource and, therefore, cannot be owned by an individual or organisation.
In other jurisdictions, mobile network operators have shown willingness to share unused spectrum with a satellite D2D service in rural areas, provided the satellite does not cause interference in urban areas, where the same spectrum is used for terrestrial services. However, the satellite moves very quickly and can utilise the spectrum over distances of about 500 to 1,000km. It can also use beamforming to target a specific area, but these beams are not very precise. This means that in both cases, there is a risk of signal interference with other terrestrial networks domestically or across borders.
The Starlink constellation operated by SpaceX is currently one of the largest LEO systems. Starlink reportedly has about 9,100 active satellites in orbit and launches about 300 each month. However, most of these offer broadband internet access only to end-users with specialised Starlink antennas. Of the total number of satellites in orbit, only about 650 are currently believed to support D2D services, which is inadequate for D2D services worldwide.
However, for the potential of mobile satellite services to be fully harnessed, technical challenges must be addressed. These include the distance and path-loss effects from LEO satellites in the sky and end-user devices on earth’s surface, reducing bandwidth and reliability. Any additional obstacle could make communication impossible.
Concrete walls, ceilings or metal roofs further degrade signals, making indoor coverage difficult. This explains why satellite dishes and other antennas are mounted outside buildings to maximise reception. Terrestrial mobile networks, on the other hand, often provide indoor coverage through windows. The signal propagates horizontally and can, therefore, reach users far behind the window.
Another challenge to overcome is spectrum — a limited resource with many services vying for more. In Uganda, as elsewhere, terrestrial mobile networks already occupy the frequency bands designated for IMT. Only a few bands have been assigned to MSS, and these are shared among various satellite services. Globally, D2D service providers seek to use IMT bands already supported by smartphones, but in Uganda, most of this spectrum is heavily utilised, especially in urban areas such as Kampala.
According to international best practice, a satellite D2D service provider can acquire spectrum directly from the regulator or purchase it from licensed national operators. However, in Uganda, the 2018 National Broadband Policy recognises spectrum as a national resource and, therefore, cannot be owned by an individual or organisation.
In other jurisdictions, mobile network operators have shown willingness to share unused spectrum with a satellite D2D service in rural areas, provided the satellite does not cause interference in urban areas, where the same spectrum is used for terrestrial services. However, the satellite moves very quickly and can utilise the spectrum over distances of about 500 to 1,000km. It can also use beamforming to target a specific area, but these beams are not very precise. This means that in both cases, there is a risk of signal interference with other terrestrial networks domestically or across borders.
The Starlink constellation operated by SpaceX is currently one of the largest LEO systems. Starlink reportedly has about 9,100 active satellites in orbit and launches about 300 each month. However, most of these offer broadband internet access only to end-users with specialised Starlink antennas. Of the total number of satellites in orbit, only about 650 are currently believed to support D2D services, which is inadequate for D2D services worldwide.
Nevertheless, Starlink remains one of the leading organisations in driving the D2D concept to reality, collaborating with mobile terrestrial operators, including Rogers in Canada and T-Mobile in the US. Other companies engaged in satellite services include AST SpaceMobile, Lynk Global, Eutelsat OneWeb, and Amazon Leo. Some newer smartphones offer D2D services that make use of the spectrum allocated to MSS.
In 2022, the iPhone 14 introduced emergency SOS services in co-operation with Globalstar. Google launched satellite direct-to-device connectivity with the Pixel 9 in 2024, and Samsung with the Galaxy S25 last year, primarily for emergency SOS.
Meanwhile, standards development is advancing under the 3rd Generation Partnership Project. Release 17, completed in 2022, incorporated support for non terrestrial networks into 5G standards, including advanced Doppler correction mechanisms to account for the high speeds of satellites, thereby enabling direct 5G satellite connectivity.
Allocating the current mobile terrestrial spectrum bands to mobile satellite services could be a vital step toward enabling and accelerating the expansion and adoption of D2D services. International Telecommunication Union (ITU) member states, including Uganda, will then need to review and potentially revise the regulations governing spectrum assignment and use to reflect the new situation.
The availability of satellite D2D services will inevitably prompt fresh debates over coverage and universal service obligations, as well as national connectivity strategies in many countries, once they are adopted globally. This could also impact debates on coverage obligations, universal service access strategies, and national connectivity planning.
In conclusion, D2D will undoubtedly revolutionise mobile communication, particularly by bridging coverage gaps and eliminating dark zones that remain in terrestrial mobile networks, supporting connectivity along rural highways and in national parks in Uganda. It will also enable the extension of services over offshore waters and enable roaming applications in aviation and maritime environments. D2D could also create new revenue streams and strengthen network resilience for emergency and disaster responses.
Furthermore, where the satellite-enabled coverage reduces the marginal cost of reaching the remaining unserved regions of Uganda, universal service access funds could be redirected to more pressing priorities, such as digital skilling and demand-side adoption programmes to tackle digital usage disparities. The promises mentioned above remain to be seen, as challenges related to the effective deployment of LEO D2D networks and their wider adoption remain active topics in ongoing technical and regulatory studies at the ITU and regionally.
The writer is the director of engineering and communications infrastructure services at Uganda Communications Commission
In 2022, the iPhone 14 introduced emergency SOS services in co-operation with Globalstar. Google launched satellite direct-to-device connectivity with the Pixel 9 in 2024, and Samsung with the Galaxy S25 last year, primarily for emergency SOS.
Meanwhile, standards development is advancing under the 3rd Generation Partnership Project. Release 17, completed in 2022, incorporated support for non terrestrial networks into 5G standards, including advanced Doppler correction mechanisms to account for the high speeds of satellites, thereby enabling direct 5G satellite connectivity.
Allocating the current mobile terrestrial spectrum bands to mobile satellite services could be a vital step toward enabling and accelerating the expansion and adoption of D2D services. International Telecommunication Union (ITU) member states, including Uganda, will then need to review and potentially revise the regulations governing spectrum assignment and use to reflect the new situation.
The availability of satellite D2D services will inevitably prompt fresh debates over coverage and universal service obligations, as well as national connectivity strategies in many countries, once they are adopted globally. This could also impact debates on coverage obligations, universal service access strategies, and national connectivity planning.
In conclusion, D2D will undoubtedly revolutionise mobile communication, particularly by bridging coverage gaps and eliminating dark zones that remain in terrestrial mobile networks, supporting connectivity along rural highways and in national parks in Uganda. It will also enable the extension of services over offshore waters and enable roaming applications in aviation and maritime environments. D2D could also create new revenue streams and strengthen network resilience for emergency and disaster responses.
Furthermore, where the satellite-enabled coverage reduces the marginal cost of reaching the remaining unserved regions of Uganda, universal service access funds could be redirected to more pressing priorities, such as digital skilling and demand-side adoption programmes to tackle digital usage disparities. The promises mentioned above remain to be seen, as challenges related to the effective deployment of LEO D2D networks and their wider adoption remain active topics in ongoing technical and regulatory studies at the ITU and regionally.
The writer is the director of engineering and communications infrastructure services at Uganda Communications Commission