---
license: apache-2.0
language:
- en
base_model:
- openai/gpt-oss-20b
datasets:
- att/OTel-LLM
tags:
- telecom
- telecommunications
- gsma
- rag
- full-parameter-fine-tuning
- fine-tuned
pipeline_tag: text-generation
---

# OTel-LLM-20B-IT

**OTel-LLM-20B-IT** is a context-grounded telecom language model full-parameter fine-tuned on OTel telecommunications data. It is part of the [OTel Family of Models](https://huggingface.co/collections/att/otel-10-llm), an open-source initiative to build reference AI resources for the global telecommunications sector.

Across the 17 core OTel LLM baselines, OTel fine-tuning improves context-grounded correctness over the base checkpoints by +3.3 to +9.4 percentage points.

## Community Use

As of May 3, 2026, the released OTel models had been downloaded over 16 million times, and the Open Telco AI project had received 157+ pieces of media coverage worldwide.

## Model Details

| Attribute | Value |
|---|---|
| Base model | [openai/gpt-oss-20b](https://huggingface.co/openai/gpt-oss-20b) |
| Parameters | 20B |
| OTel training dataset | [OTel-LLM](https://huggingface.co/datasets/att/OTel-LLM) |
| Dataset fields | `prompt`, `completion`, `abstention`, chunk-count metadata, token-count metadata |
| Training method | Full-parameter post-training / fine-tuning |
| Language | English |
| OTel release license | Apache 2.0 |

## Model Lineage

`openai/gpt-oss-20b` -> `OTel-LLM` full-parameter post-training -> `att/OTel-LLM-20B-IT`

## OTel vs. Base Model

| Metric | Base model | OTel fine-tuned | Delta | Evaluation split |
|---|---:|---:|---:|---|
| LLM-as-judge correctness | 61.4% | 65.9% +/- 0.8 | +4.5 pp | OTel-LLM held-out 10% |

Standard errors are computed with bootstrap resampling (`n=1000`) over the held-out OTel evaluation partition. LLM correctness is the average score from two judge models, GPT-4o mini and Claude Sonnet 3.5, each judging the answer against the retrieved context and reference answer.

## Evaluation Caveats

- LLM results measure context-grounded answer generation from retrieved context, not unrestricted context-free telecom QA.
- Reported standard errors come from bootstrap resampling over the held-out evaluation partitions.
- Answer quality depends on the retriever, reranker, context window, and prompt policy around the model.
- External benchmark transfer, multilingual performance, and per-subdomain performance should be evaluated separately for production settings.


## Training Data

The model was trained on telecom-focused data curated by 100+ domain experts. The raw corpus contained roughly 1.1M training points and was filtered to 326,767 higher-confidence examples.

| Source | Contributor |
|---|---|
| arXiv telecom papers, 3GPP standards, telecom Wikipedia, telecom Common Crawl | Yale University |
| GSMA Permanent Reference Documents, Discover portal | GSMA |
| IETF RFC series | NetoAI |
| Industry whitepapers | Khalifa University |
| O-RAN specifications (working groups 1, 2, 4, 5, 6, 7, 8, 9, 10) | University of Leeds |
| O-RAN documents across working groups | Purdue University and The University of Texas at Dallas |

Released datasets: [OTel-LLM](https://huggingface.co/datasets/att/OTel-LLM), [OTel-Embedding](https://huggingface.co/datasets/att/OTel-Embedding), [OTel-Reranker](https://huggingface.co/datasets/att/OTel-Reranker), and [OTel-Safety](https://huggingface.co/datasets/att/OTel-Safety).

The OTel datasets release derived QA/retrieval/reranking examples rather than the raw source documents.

Each released dataset includes a dataset card and Croissant metadata with Responsible AI fields for data limitations, biases, sensitive-information considerations, use cases, social impact, synthetic-data status, and provenance.

## Representative Training Row

`OTel-LLM` rows pair a context-grounded telecom RAG prompt with a reference completion.

```json
{
  "anchor": "How can a cell be considered to be operating in MBSFN mode for 3.84/7.68 Mcps TDD?",
  "completion": "A cell shall be considered to be operating in MBSFN mode when individual scrambling codes are assigned to all timeslots via the IE \"TDD MBSFN Information\".",
  "abstention": false,
  "n_positive_chunks": 1,
  "n_negative_chunks": 4
}
```

## Intended Use

This model is intended for context-grounded telecom answer generation in Retrieval-Augmented Generation (RAG) pipelines. It should receive retrieved telecom context and generate an answer grounded in that context.

The model is not optimized for unrestricted context-free question answering. For questions where the retrieved context is missing or insufficient, use an abstention-aware prompt or one of the dedicated `-Safety` variants.

## Training Recipe

| Item | Value |
|---|---|
| Framework | ScalarLM |
| Optimizer | AdamW, 8-bit |
| Learning-rate schedule | Cosine decay with warmup |
| Weight decay | 0.01 |
| Warmup steps | 100 |
| Random seed | 42 |
| Maximum sequence length | 1500 tokens |
| Precision | BF16 |
| Attention | Flash Attention 2 |
| Distributed training | Fully Sharded Data Parallel |
| Gradient checkpointing | Enabled |
| Epochs | 3 for LLM/embedding models; 2 for rerankers |
| Compute | AMD MI300X/MI325X/MI355X and NVIDIA A100/H100 GPUs |

## Usage

```python
from transformers import AutoModelForCausalLM, AutoTokenizer
import torch

model_name = "att/OTel-LLM-20B-IT"
tokenizer = AutoTokenizer.from_pretrained(model_name, trust_remote_code=True)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    torch_dtype=torch.bfloat16,
    device_map="auto",
    trust_remote_code=True,
)

prompt = """You are a precise telecom assistant in a RAG pipeline.
Use only the retrieved context to answer.

User Question
What is the purpose of the F1 interface in O-RAN?

Retrieved Contexts
CONTEXT 1
The F1 interface connects the O-RAN Distributed Unit (O-DU) to the O-RAN Central Unit (O-CU).

Answer:"""

inputs = tokenizer(prompt, return_tensors="pt").to(model.device)
outputs = model.generate(**inputs, max_new_tokens=256)
print(tokenizer.decode(outputs[0], skip_special_tokens=True))
```

## Limitations and Responsible Use

- OTel models are domain-specific to telecommunications and should not be treated as general-purpose models.
- The current release is English-only and primarily text-centric.
- The reported OTel performance results use held-out OTel evaluation partitions and should not be interpreted as results from a fully independent external benchmark suite.
- Aggregate scores can hide subdomain variation; collaborator stress tests suggest O-RAN retrieval is comparatively strong, while academic-paper and GSMA PRD examples need further curation.
- Generated telecom content should be verified before operational, customer-facing, regulatory, safety, or network-configuration use.
- Users must comply with both the OTel release license and the upstream base-model license or terms.
- For unrestricted telecom QA without retrieved context, use a separately evaluated context-free QnA model rather than assuming this RAG-oriented checkpoint will behave optimally.

## Related Models

### Language Models
- [OTel LLM 2.0 Collection](https://huggingface.co/collections/att/otel-20-llm)
- [OTel LLM 1.0 Collection](https://huggingface.co/collections/att/otel-10-llm)

### Embedding Models
- [OTel Embedding Collection](https://huggingface.co/collections/att/otel-10-embedding)

### Reranker Models
- [OTel Reranker Collection](https://huggingface.co/collections/att/otel-10-reranker)

## Resources

- [Project Page](https://huggingface.co/att)
- [OTel code](https://github.com/farbodtavakkoli/OTel)
- [OTel Selected Coverage](https://github.com/farbodtavakkoli/OTel/blob/main/docs/OTel-selected-coverage.md)
- [OTel Paper](https://arxiv.org/pdf/2610.07766)
- [OTel 1.0 Coverage](https://github.com/farbodtavakkoli/OTel/blob/main/docs/OTel-1.0-coverage.md)
- [OTel 2.0 Coverage](https://github.com/farbodtavakkoli/OTel/blob/main/docs/OTel-2.0-coverage.md)
- [OTel Docker](https://hub.docker.com/u/farbodatdocker)

## Citation

```bibtex
@inproceedings{tavakkoli2026otel,
  title     = {OTel: Open Telco AI Datasets, Benchmarks, and Models},
  author    = {Tavakkoli, Farbod and others},
  booktitle = {Advances in Neural Information Processing Systems (NeurIPS), Evaluations and Datasets Track},
  year      = {2026},
  url       = {https://github.com/farbodtavakkoli/OTel}
}
```

## Contact

If you have any technical questions, please feel free to reach out to [farbod.tavakkoli@att.com](mailto:farbod.tavakkoli@att.com) or [farbodtavakoli@gmail.com](mailto:farbodtavakoli@gmail.com)