Successful Japan-Europe Joint Experiment on Integration of Satellite Links in Japan-Europe Long Distance 5G Network

In 5G/Beyond 5G, “non-terrestrial networks (NTN)” are attracting attention from the perspective of scalability and a wide range of communication. The NTN is a system that connects different spaces, such as the sea, sky, and space, without barriers via various platforms, such as satellites, high-altitude platform stations (HAPS), and drones. In addition, by connecting NTN and 5G/Beyond 5G terrestrial systems, users will be able to communicate wherever they are. The Third Generation Partnership Project (3GPP) is studying the standardization for the interconnection of NTN and 5G, which is expected to improve performance in conventional use cases and realize new use cases.

Based on this background, NICT and ESA signed and updated a Letter of Intent (LoI) in 2018 and 2020, and planned a joint experiment between Japan and Europe. In this experiment, we aimed to connect satellite links and 5G over long-distance networks to contribute to the realization of 5G/Beyond 5G with long-distance communications between international locations, including communications involving global movement, such as aircraft and international roaming.

We built a testbed for the Japan-Europe joint experiment connecting the Ku-band satellite (12GHz/14GHz band frequency), local 5G systems, and JGN operated by NICT between Japan and Europe. Figure 1 shows the configuration of the constructed testbed. Figure 2 shows a gateway station and a very small aperture terminal (VSAT) station for the construction of the satellite link. Figure 3 shows the gNB (5G base station) which was used for 5G communications. In this experiment, 4K video and IoT data transmission was conducted as a basic experiment for future international long-distance communications, which targeted the use cases of transmitting video contents and monitoring data obtained in remote areas.

We successfully transmitted both 4K video and IoT data using the testbed. In this experiment, we verified that even under the influence of latencies caused by long-distance transmission, including satellite and Japan-Europe terrestrial links, it was possible to establish a communication session using 5G control signals exchanged between the customer-premises equipment (CPE, 5G gateway) in Japan and the 5G core in Europe; subsequently, the data acquired by the 4K camera and IoT sensor in Japan were transmitted to a PC and data server in Europe. Furthermore, we measured the network quality of each transmission segment and evaluated the network performance by connecting satellite links and 5G. Figure 4 shows that the 4K video image was transmitted from Japan to the Europe without any problems. Figure 5 shows a time-series graph of the sensor data acquired in Japan and received by the data server in Europe (in this case, temperature and humidity information). The results of this joint experiment confirmed that the integration of satellite links in 5G networks via international long-distance communication can be realized in terms of specific application transmission.

It is expected that the technology obtained from this joint experiment will contribute to extending 5G network coverage and constructing a global 5G/Beyond 5G network that includes satellite links.

JRC and SKY Perfect JSAT will continue to cooperate with Europe across borders to establish the technologies necessary for the seamless integration of terrestrial and satellite systems in Beyond 5G.

The NICT will continue to promote international collaboration between Japan and Europe. Furthermore, utilizing the results of this experiment will lead to the development of technology to connect multiple nodes, such as satellites, HAPS, and drones, as well as the realization of a three-dimensional network that connects multiple layers from the terrestrial to the sea, air, and space. The NICT aims to realize diverse communication so that people will communicate in all areas.

A contractor of the European/ESA side. In charge of coordinating the ESA partner organizations in this experiment.

A contractor of the European/ESA side. In charge of providing 5G core software and satellite edge network development support in this experiment.

A project between standardization bodies to study and develop specifications for mobile phone networks

A high-speed R&D network testbed for the development of ICT technology operated by NICT. The JGN is designed to provide a testing environment for researchers of advanced networking technologies and to deliver strong support for researchers and empower them.

Communication equipment used for communication services, such as broadband routers, are installed in subscribers' homes and facilities.

A part of 5G that handles the connection, routing processes.