CELEOS

Status

Ongoing
Status date

2025-08-05
Activity Code

6A.087

Objectives

The main objective of the CELEOS project is to develop a cost-effective, high-performance satellite channel emulator tailored for multi-orbit constellations. Built on commercial Software-Defined Radio (SDR) and Graphics Processing Units (GPU) architectures, CELEOS delivers real-time, parallelised emulation while maintaining portability and scalability.

Key enhancements include support for:

Digital Intermediate Frequency Interoperability (DIFI) 1.2 digital interfaces for seamless radio frequency (RF) front-end replacement;
SigMF metadata compatibility for standardised signal traceability and integration;
An embedded Digital Spectrum Analyser for real-time signal inspection;
Weather effects and Earth 3D terrain modelling to simulate propagation impairments with greater realism;
Deployment-ready architectures for virtualisation in Amazon Web Services (AWS).

CELEOS is optimised to provide feature parity with legacy solutions while maintaining a significantly smaller form factor, lower cost, and high adaptability to evolving satellite communication standards.

Challenges

Achieving optimal balance among portability, performance and cost, while still covering most of relevant use cases.

Benefits

Lightweight, low-cost, and portable channel emulation solution built on commercial off-the-shelf hardware. It supports comprehensive satellite channel impairments across native satellite, 5G, and Narrowband-Internet of Things (NB-IoT) use cases, while enabling advanced features like DIFI 1.2 integration, digital spectrum analysis, and cloud deployment via AWS, making it ideal for both lab and field environments.

Features

The following features are covered by CELEOS:

Support for multi-orbit constellations;
Relevant satellite channel impairments, including delay, attenuation, Doppler shift, and Doppler spread, can be simulated
Support for TLE synchronisation;
Capability to configure various emulation profiles (interference, noise, weather conditions, etc);
Facilitation of various input waveforms such as: satellite native, 5G-Near-Radio Non-Terrestrial Networks (5G-NR-NTN), NB-IoT, and enhanced Machine Type Communication (eMTC);
Mobility scenarios such as 5G conditional handover and inter-satellite low Earth orbit (LEO) to LEO handover can be emulated;
The Vita49 standard (DIFI) and SigMF signal recording and importing are both supported.
This system enables the emulation of "in-box" movement for geostationary orbit (GEO) satellites

System Architecture

CELEOS is a satellite channel emulator which follows a Software Defined Radio architecture. In terms of hardware, it consists of an SDR (National Instrument Universal Software Radio Peripherals (USRPs)) and a workstation (x86 or arm-based, with Nvidia GPU). This allows a great degree of flexibility and hardware reusability.

Besides the RF interface provided by SDRs, CELEOS also supports the DIFI standard, meaning it can also run fully digitally, by receiving and sending the IQ samples in DIFI format, as IP packets.

CELEOS can be configured in various ways to address use case specific requirements such as number of channels and bandwidth requirements. This ranges from using high-end SDRs such as the USRP X440, together with powerful Dell workstations, to low-end SDRs such as the USRP B210 and small form factor compute such as the arm-based Nvidia Jetson Orin AGX.

Below is an overview of the CELEOS hardware architecture:

In terms of software, the emulator provides key tools necessary to facilitate development:

The real-time emulation program, which streams data to and from the SDR, and performs the signal processing on the GPU;
A channel modelling tool which computes channel characteristics based on the user configuration, such as satellite orbit given via TLE file and ground terminal positions/ movement;
A web-based User Interface allowing control and monitoring of the emulator;
A web-based API, allowing automated use of the emulator via HTTP;
An embedded web-based spectral analyser, allowing real-time monitoring of channel input and output signals.

All these software modules are delivered as part of the same Docker image, making installation quick, simple and reliable. Additionally, this software-based architecture makes CELEOS suitable for cloud deployments, such as on AWS.

Plan

The CELEOS project was initially structured into two main phases: the Definition Phase and the Technology Phase. As the project evolved and its strategic potential became more evident, two Contract Change Notices (CCN1 and CCN2) were introduced to extend its scope and timeline, leading up to the demonstration and commercialisation stages.

Definition Phase

This phase includes a single key milestone: the Project Concept Review (PCR) at T0 + 3 months. This milestone marks the successful delivery of:

System performance requirements;
SDR technology study; and
Satellite channel characteristics analysis.

The PCR represents a critical decision point, confirming the project’s technical direction and readiness to proceed into the development phase.

Technology Phase

The Technology Phase is structured around three successive milestones, each spaced approximately three months apart:

Preliminary Design Review (PDR) at T0 + 6 months: initial channel impairments are implemented, and a first demonstration is conducted to validate early system behavior and identify gaps;
Intermediate Review 1 (IR1) at T0 + 9 months: remaining channel impairments are completed, core functionalities are validated, and the graphical user interface (GUI) is finalised;
Final Review (FR) at T0 + 12 months: marks the end of core development, ensuring that the technology meets initial requirements and is stable for extended feature integration and field testing.

CCN1 – Feature Extension and System Consolidation

To accommodate feature requests and align CELEOS with evolving use cases, CCN1 introduced two additional milestones:

CCN1 Intermediate Review (CCN1-IR) at T0* + 4 months;
CCN1 Final Review (CCN1-FR) at T0* + 7 months.

The primary objective of CCN1 was to enhance and consolidate the system design, incorporating:

Updated system architecture, design documentation, and implementation details;
Refined test and validation plans tailored to the extended features (e.g., weather models, SigMF support, DIFI compliance);
Enhanced emulation profiles and scenario libraries.

These updates were reflected in revised deliverables that ensured CELEOS remained aligned with user needs and integration targets for hybrid TN–NTN testbeds.

CCN2 – Commercialisation and Cloud Deployment

CCN2 focused on preparing CELEOS for market readiness and scalable deployment, especially targeting cloud environments and AAS (as-a-service) models. Spanning 12 months, CCN2 introduced the following milestones:

CCN2 Intermediate Review (CCN2-IR) at T0^ + 6 months;
CCN2 Final Review (CCN2-FR) at T0^ + 12 months.

Key developments in this phase included:

Creation of installation and deployment procedures for both on-premise and virtualised environments (including AWS);
Delivery of user and customer-facing documentation (manuals, configuration guides);
Establishment of licensing models and integration of cloud-readiness features (e.g. containerisation, multi-user access);
Development of internal support tools to facilitate demo deployments and partner onboarding.

Current status

The CELEOS project has successfully completed the development of its initial scope as agreed with ESA, meeting all technical objectives and passing all formal milestones. The product is now commercially available, with several key features validated through internal and external demonstrations.

Building on this foundation, additional functionalities have been integrated based on direct customer feedback, enhancing CELEOS’s flexibility and applicability across diverse TN–NTN and satellite communication scenarios. These include advanced propagation models, DIFI and SigMF support, and integrated diagnostic tools.

The AAS (As-a-Service) deployment model is currently under validation within the AWS cloud environment, positioning CELEOS for scalable delivery and broader adoption in virtualized and cloud-native test infrastructures.

Ongoing development continues to focus on extending CELEOS capabilities in line with emerging market demands and new use cases, ensuring the product remains technically competitive, aligned with industry standards, and relevant to both commercial and institutional users.