TelecomGPT-R1: A Unified Open-Source Reasoner for the Telecom Stack

Researchers released TelecomGPT-R1-9B, an open-source telecom reasoning model that ranks first among open-source telecom LLMs on the GSMA open telco leaderboard and achieves a seven-axis mean comparable to state-of-the-art closed-source frontier reasoners. The model, built on Qwen3.5-9B with a 67,427-example supervised fine-tuning corpus and a two-stage post-training recipe, targets protocol, knowledge, modeling, and fault reasoning axes.

arXiv:2608.26126v1 Announce Type: new Abstract: Telecommunications is a high-leverage domain for large language model LLM -based reasoning because routine engineering workflows require joint grounding in normative specifications, operational telemetry, vendor-specific fault evidence, and exact RF/network calculations. However, current LLM integration in telecom remains bottlenecked by a two-sided capability gap: generic reasoners often lack telecom-specific grounding, while domain-specific telecom LLMs remain limited in structured, multi-step reasoning. To bridge this gap, we release TelecomGPT-R1-9B, a unified open-source telecom reasoner that ranks top-performing on the GSMA open telco leaderboard. Specifically, we curate a 67,427-example supervised fine-tuning SFT corpus organized around four complementary reasoning axes: protocol, knowledge, modeling, and fault. The corpus is built from axis-matched public web sources and enhanced through axis-specific chain-of-thought CoT generation and prefix-continuation self-validation. Starting from Qwen3.5-9B, we further develop a two-stage post-training recipe. First, multi-teacher low-rank adaptation LoRA -based SFT injects telecom knowledge and induces axis-specific reasoning formats. Second, group relative policy optimization GRPO , stabilized by decoupled clip and dynamic sampling policy optimization DAPO , optimizes the policy using four axis-aligned binary verifier rewards. Across seven public telecom benchmarks, TelecomGPT-R1-9B ranks first among open-source telecom LLMs and achieves a seven-axis mean comparable to state-of-the-art closed-source frontier reasoners.