PAGE CONTENTS
Objectives
Preliminary analyses 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 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.
Challenges
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:
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identification of the scenarios suitable for NB-IoT via NTN and what are their impacts in terms of key architectural strategies;
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identification of adaptations needed to enable the operation of satellite links for NB-IoT for both Access Stratum (AS) and Non-Access Stratum (NAS);
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development of a satellite RAN, including a User Equipment (UE), an RF and baseband processing unit and an eNB;
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Functional and performance verification of NB-IoT over satellite.
System Architecture
The System Architecture is shown in the following picture:
The main sub-systems are:
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NB-IoT Traffic Emulator: to emulate the traffic generated by several UEs.
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NB-IoT Adapted UE: is an NB-IoT terminal emulator based on an SDR with UU interface adaptations.
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Channel Emulator: to emulate all the impairments caused by LEO satellites. In particular, is able to introduce variable delay, variable Doppler Shift, Phase Noise, Fading.
Plan
The project foresees the following relevant milestones:
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MS1: Preliminary Operation Scenario Requirements and acceptance of all related deliverables.
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MS2: Technical Requirements (traffic emulator, NB-IoT UE, Channel Emulator, On-board eNodeB Prototype) and acceptance of all related deliverables.
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MS3: Testbed Implementation and acceptance of all related deliverables.
MS4: Results, Roadmap and acceptance of all related deliverables.
Current Status
The activities started on 1st April 2020.
The milestone MS1 has been achieved with the completion of WP1 relating to scenarios definition and challenge identification.
The milestone MS2 has been achieved with the completion of work packages WP2 and WP3, concerning UU Interface and Testbed Requirements.
The milestone MS3 has been achieved with the completion of the activities concerning the Testbed Design, Development and Verification and the Test Plan definition.
The Final Review has been achieved at the end of the overall activities.
