---
license: llama3.1
base_model:
- meta-llama/Llama-3.1-8B-Instruct
tags:
- satcom
- satellite
- satellite communications
- space
- esa
- artes
- llm
- fine-tuned
- question-answering
language:
- en
model_name: esa-sceva/llama3-satcom-8b
pipeline_tag: text-generation
library_name: transformers
datasets:
- esa-sceva/satcom-qa
- esa-sceva/satcom-mcqa
- esa-sceva/satcom-synth-qa
- esa-sceva/satcom-synth-qa-cot
---

# LLama3 SatCom 8B

**LLama3 SatCom 8B** is a fine-tuned open Large Language Model (LLM) developed under the **ESA ARTES** programme as part of the **SatcomLLM / SCEVA (SatCom Expert Virtual Assistant)** project.  
It is designed to support **satellite communications (SatCom)** experts, engineers, and mission planners through domain-specialised reasoning, question answering, and document-based assistance.

---

## Model Description

- **Base model:** `meta-llama/Llama-3.1-8B-Instruct`  
- **Fine-tuning type:** Instruction fine-tuning (IFT)  
- **Training data:** Domain-specific question–answer datasets (manual, synthetic, and multiple-choice)  
- **Architecture:** Decoder-only transformer, 8 billion parameters  
- **Languages:** English  
- **License:** LLama-3.1 Communiy License Agreement  

The model has been fine-tuned on curated SatCom-related corpora to enhance its understanding of technical language, protocols, and reasoning processes common to satellite communications, including 5G/6G non-terrestrial networks, link budget evaluation, and mission engineering tasks.

---

## Training Datasets

| Dataset                           | Description                                                                            |
| --------------------------------- | -------------------------------------------------------------------------------------- |
| **esa-sceva/satcom-synth-qa**     | Synthetic QA data generated via agentic pipelines using large teacher models           |
| **esa-sceva/satcom-synth-qa-cot** | Chain-of-thought annotated QA used to improve reasoning depth and factual traceability |

---


## Intended Use

**Primary use cases:**
- Technical Q&A and reasoning on SatCom systems  
- Support for link budget and RF engineering questions  
- Guidance for 5G/6G NTN (Non-Terrestrial Network) operations  
- Mission design, planning, and anomaly detection support  
- Educational and research use within the SatCom sector  

**Intended users:**  
- ESA engineers and project officers  
- SatCom and aerospace researchers  
- SMEs and technical operators in satellite communication  
- Academic and educational users  

---

## Limitations

- The model does **not access real-time mission data** or proprietary ESA documents.  
- Answers are based on training data and may require expert validation for operational use.  
- It should not be relied upon for flight-critical or safety-critical decisions.  
- Limited context window (base 8B configuration) may constrain long-document reasoning.

---

## Technical Details

| Parameter | Value |
|------------|--------|
| Base Model | Llama 3.1 8B Instruct |
| Parameters | 8 billion |
| Context length | 8k tokens |
| Precision | bfloat16 / fp16 |
| Framework | Lit-GPT (Lightning AI) |
| Training infra | EuroHPC MareNostrum5 + AWS EC2 |
| Optimisation | LoRA fine-tuning, cosine LR schedule |

---

## Evaluation

### Evaluation Datasets

The model was benchmarked on both general-purpose and domain-specific QA tasks. Regarding Satcom-specific datasets:

| Dataset                   | Subset             | Description                                                                                          |
| ------------------------- | ------------------ | ---------------------------------------------------------------------------------------------------- |
| **esa-sceva/satcom-qa**   | **Open SatCom QA** | Conceptual and reasoning-based questions on SatCom workflows, regulations, and mission/system design |
|                           | **Math SatCom QA** | Quantitative and formula-based questions derived from system design and orbital mechanics topics     |
| **esa-sceva/satcom-mcqa** | **Open MCQA**      | Conceptual multiple-choice questions on RF systems, communication protocols, and architecture        |
|                           | **Math MCQA**      | Numerical and link-budget-focused multiple-choice questions testing applied calculations             |

### Results

<table>
  <thead>
    <tr>
      <th rowspan="2">Model</th>
      <th colspan="3">MCQA (Accuracy)</th>
      <th colspan="3">Satcom-QA</th>
      <th colspan="3">EVE-QA</th>
    </tr>
    <tr>
      <th>Satcom</th>
      <th>EVE</th>
      <th>TeleQnA</th>
      <th>Norm.</th>
      <th>Bin.</th>
      <th>WR</th>
      <th>Norm.</th>
      <th>Bin.</th>
      <th>WR</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>Llama-3.1-8B-Instruct</td>
      <td>78.59</td>
      <td><strong>81.35</strong></td>
      <td>68.40</td>
      <td>75.44</td>
      <td>70.40</td>
      <td>—</td>
      <td>61.47</td>
      <td>65.20</td>
      <td>—</td>
    </tr>
    <tr style="border-top: 1px dashed #999;">
      <td><code>llama3-satcom-8b</code></td>
      <td><strong>80.15</strong></td>
      <td>80.95</td>
      <td><strong>68.80</strong></td>
      <td><strong>77.75</strong></td>
      <td><strong>73.62</strong></td>
      <td><strong>51.49</strong></td>
      <td><strong>62.90</strong></td>
      <td><strong>68.12</strong></td>
      <td><strong>51.41</strong></td>
    </tr>
  </tbody>
</table>

**Table:** Evaluation results (%).  
 - **Norm.** denotes the normalized score obtained by averaging 1–5 ratings from a panel of LLM judges (Qwen3, gpt-4.1-mini, Mistral-Large-2512, and DeepSeek-V3.2) and scaling to [0,1].  
 - **Bin.** is the binary accuracy computed from correctness judgments.  
 - **WR** (Adjusted Win Rate) is defined as (wins + 0.5 × ties) / total, based on pairwise comparisons with randomized answer order.  
Multiple-choice performance is measured using standard accuracy.  
All results are averaged over 3–5 runs; standard deviation ≤ 0.25 pp for open-ended QA and ≤ 0.10 pp for MCQA.

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