Space-based connectivity services operator Univity has announced the success of its first in-orbit technology demonstration mission, uniSpark.
The successful mission saw the company combine onboard regenerative 5G processing, millimetre-wave frequences and Time Division Duplexing (TDD) operation in orbit for the first time. According to Univity, the demonstration could pave the way for new spectrum resources for satellite communications.
Launched in June 2025, uniSpark established a fully bidirectional 5G Non-Terrestrial Network (NTN) connection between a ground terminal and a 5G base station onboard a satellite in orbit. The demonstration was conducted from a CNES site as part of a programme supported by France 2030.
The milestone reportedly validates several critical building blocks of Univity’s future space infrastructure, and could enable telecom operators to extend their networks from space with greater control in the future.
“With uniSpark, we are moving from technological promise to proof in orbit,” said Charles Delfieux, founder and CEO of Univity. “We have demonstrated our ability to operate technologies derived from terrestrial 5G in millimetre-wave frequency bands in a real space environment.
“This is a decisive step toward our ambition: to develop, alongside telecom operators, a space infrastructure that enables them to extend their networks beyond the limits of the ground. Space can finally become a natural extension of terrestrial 5G networks.”
From concept to in-orbit
The uniSpark programme is Univity’s first in-orbit technology demonstration mission, forming the basis of its future high-speed space telecommunications infrastructure. Since the successful launch of the payload in June last year, the test campaign has validated the operation of the various system components.
The mission objective – to establish a ground terminal synchronised and registered as a 5G terminal in the uniSpark network – was achieved in just two years. This connection to a standard 5G core network uses a protocol similar to that of terrestrial 5G TDD networks operating in millimetre-wave frequencies.
The use of TDD in millimeter-wave) frequencies lies at the heart of Univity’s technological approach. Unlike a conventional Frequency Division Duplexing (FDD) architecture, which typically uses two separate spectrum resources for transmission and reception, TDD enables the same spectrum resource to be shared over time between uplink and downlink communications.
“Beyond the performance of the link itself, this demonstration confirms the possibility of building a satellite infrastructure that relies extensively on technologies and developments derived from terrestrial 5G, rather than recreating an entirely separate ecosystem.”
The teams had to deal with several challenging constraints during the mission. With the base station located several hundred kilometres above Earth and travelling at orbital velocity, the distance between uniSpark and the ground terminal was constantly changing. This required additional mechanisms to compensate for propagation delay and the Doppler effect.
TDD also added another layer of complexity, as equipment on the ground and in space must be synchronised with very high precision in terms of time ad frequency to enable alternating transmission and reception.
Successive test campaigns made it possible to adjust these mechanisms, synchronise the equipment, and fine-tune the radio until a complete bidirectional connection was established.
A new 26GHz spectrum resource
The demonstration also shone a spotlight on the use of a new spectrum resource for satellite communications. With Ku and Ka bands becoming increasingly congested, the mission hows the potential to use the 26GHz band for high-speed NTN communications.
By demonstrating a 5G NTN link can operate in TDD mode at these frequencies from space, uniSpark validates the technical feasibility of this approach in order to meet growing satellite connectivity needs.
Looking ahead, Univity is continuing to develop its uniShape project, which features two demonstration satellites representative of the architecture of its future constellation. Designed in-house, uniShape aims to enable Univity to further validate connectivity performance, system architecture and an end-to-end 5G NTN service ahead of industrialisation.
“By hosting the ground equipment for the demonstration, CNES contributed to the success of these in-orbit tests,” added Laurence Clarac, head of innovative concepts and satcom applications at CNES. “This major milestone marks the completion of the first phase of Univity’s roadmap.
“It will be followed by a 5G service demonstration project, supported by CNES under the France 2030 programme and signed in August 2025.” The third stage of Univity’s roll out will be uniSky, which will mark the industrialisation and deployment of the company’s future commercial constellation.
