European Space Agency
European Space Agency
Preliminary analysis have shown that the NB-IoT standard can be used by satellite systems in non-geostationary orbits under certain constraints. However, to enable the integration of user sensors employing this technology, it is necessary to develop an on-board evolved node B (eNB) capable of using a standard not originally conceived for satellite communications with adaptation and additional features dictated by the scenarios. Moreover, the eNB is preferably compatible with small satellites platforms in terms of mass, power and volume since these platforms are usually the ones selected to provide M2M/IoT services. Finally, it is also important to develop and propose UU (radio interface between UE and eNB) adaptations that would allow maximizing the efficiency of a satellite system.
The goal of the project is the development of a demonstrator in which communication between an NB-IoT User Equipment (UE) and an eNB adapted for satellite communications is functionally verified.
The state-of-the-art technology for NB-IoT is critically revised, referring to integration with satellite systems and associated technical requirements expected by the demonstrator.
The project aims at developing a demonstrator where the communication between a NB-IoT UE and the adapted eNB is functionally verified. The main challenges are:
Development and validation of the adaptations to the UU’s protocol stack (e.g., PHY, MAC, RLC, PDPC, and RRC layers) to make the NB-IoT radio standard viable over satellite.
Development of an on board eNB capable of supporting the adapted 3GPP NB-IoT standard within the mass, power and volume constraints of a small platform (<12U). The demonstrator is capable of emulating different scenarios as well as the main limiting factors in the telecommunications channel, with reference to Doppler shift/rate, mobility, possible shadowing/multipath, in order to assess performance under realistic conditions.
The project features include:
An high level and preliminary architecture is shown in the following picture:
The main sub-systems are:
The main planning of the general tasks is reported below:
With the following relevant milestones:
The activities have been started on April 1st 2020.
The milestone MS1 has been achieved with the completion of the WP1, where feasible scenarios have been analysed, challenges have been identified, and trade-off choices have been indicated, in order to select plausible and consistent applications of NB-IoT in a satellite context adapted to CubeSat platforms. Currently, the Team is concluding the activities in WP2 and WP3 (i.e., milestone MS2), in order to fully define the necessary UU interface modifications and the testbed requirements. Finally, the Team is starting the WP4 activities, devoted to the design and the implementation of the NB-IoT testbed.
