Network everywhere, all the time: direct satellite connectivity
The entire cell phone and space industry is now aware of the need to have connectivity, however limited, everywhere on the planet. In fact, it’s one of the 6 objectives of 6G (IMT-2030), on a par with improved speed, capacity, and latency performance. However, without waiting for 6G, standardization organizations already included the functionalities that will allow smartphones to connect to non-terrestrial networks (NTNs) in 5G. NTN refers not only to satellites of course, but also to high-altitude platforms, drones or stationary balloons above air traffic at an altitude of around 20 kilometres. For such platforms, the conditions to meet to use frequencies, including the protection of mobile networks and other services in neighbouring countries, were established by WRC-23 (item 1.4).
Existing services
Solutions already exist, such as the service proposed by Apple, which allows iPhone 14 and later versions to send short messages to a satellite for emergency calls, to request for roadside assistance or to share their position. To receive and relay these messages, Apple uses the Globalstar constellation, which has been operating for 25 years in specific frequency bands for traditional mobile satellite services (voice and data). Another example is Mediatek, which has built a function into its chips that allows messages to be exchanged in bands used by geostationary satellites, such as the Inmarsat satellites. In both cases, the functions are reserved for smartphones that include a component they can use to interact with the corresponding frequencies. For some users, this satellite emergency call function outside mobile coverage may become a new purchase criterion when they replace their smartphones.
Ongoing projects
The other direct satellite connectivity solution opened up by the NTN standardisation is to use the frequency bands already used on the ground by networks open to the public. That has the advantage of working with any smartphone capable of using all the frequencies operated by its mobile operator. It then becomes possible to provide true connectivity for everyone, everywhere, including when roaming. But in that case, the operator must agree to give up a block of frequencies from its terrestrial network. It’s not possible to use the same frequency for a cell tower and a satellite because of the resulting interference. That’s why in the United States, in order to provide a service with Starlink, T-Mobile has agreed to reserve a 2x5 MHz block for which it holds a licence to operate a mobile network throughout the country for satellite communications. Since the beginning of the year, Starlink has been deploying satellites that will make it possible to launch the service as early as 2025. Two other US companies, AST Space Mobile and Lynk, have also launched satellites and carried out experiments to provide a similar service. They are currently negotiating with mobile operators around the world for access to frequency resources compatible with the capabilities of their satellites. New Chinese projects have also been announced. Nevertheless, data rates per user will remain limited: for a 5 MHz block, a 10 Mbit/s resource will have to be shared between all users likely to be active in a 20 to 40 km diameter area.
Europe: a regulatory framework and ambitions
In Europe, there are fewer "white" spots without mobile coverage. As a result, the direct smartphone-satellite connection market is uncertain as operators may not want to use an expensive block of frequencies for a limited number of uses. However, many other parts of the world, including in the USA, are not covered by mobile networks at all, not to mention the oceans!
For the ANFR, a prerequisite is to provide an appropriate international regulatory framework, given that the bands in question are not currently assigned to the mobile satellite service under the Radiocommunications Regulations. Although the first satellites were launched without an appropriate framework, the Agency worked to include item 1.13 on the WRC-27 agenda which will make it possible to decide on a new mobile satellite service allocations in those bands accompanied by all the necessary conditions to protect the terrestrial mobile networks and the other services. That involves determining the border constraints to be respected by any satellite covering a country, for example, to protect the mobile networks in neighbouring countries, as well as any other services that may be assigned and used in those bands. But there are also other highly interesting regulatory issues, such as the framework applicable in international waters and coordination between the various satellite networks.
If some European countries want to authorise such services without waiting for WRC-27, the question of drawing up a provisional European framework will arise. Furthermore, these new uses raise issues relating to national authorisations, which in France are governed by the Arcep and the ministry for electronic communications: coexistence with other networks, competition, emergency calls and the possibility of legal interception.
To address spectrum policy issues, at the request of the European Commission, the RSPG has initiated the drafting of an opinion that should clearly define the issues raised by those services in terms of spectrum management and recommend how Europe should deal with these innovative services.