Burak Demirel
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AI-Native Link Adaptation

Production AI system for real-time 5G link adaptation under sub-100μs latency constraints.

PyTorchGraph Neural NetworksPolicy DistillationDomain RandomizationDistributed RL

Problem

Traditional link adaptation in radio access networks relies on heuristic control loops (e.g., OLLA) and coarse feedback signals, which struggle under rapidly changing channel conditions and heterogeneous traffic patterns.

While reinforcement learning methods demonstrate strong performance in simulation, they rarely transfer to production due to stringent system constraints:

  • Sub-100μs inference latency requirements
  • Non-stationary and partially observable environments
  • Tight integration with baseband hardware and protocol stacks
  • Strict reliability and stability guarantees in live networks

The core challenge is not learning a better policy, but deploying it reliably in real-time network infrastructure.

Contribution

Designed and deployed an AI-native link adaptation system replacing heuristic control with learned policies under real-time baseband constraints.

The system bridges RL research and production through a unified pipeline for training, compression, and deployment — enabling continuous adaptation in live 5G networks.

System Architecture

Learning to Deployment Pipeline

SimulationenvironmentRL TrainingGNN policyDistillationcompressionCompact Model<1 MBBaseband<100μsLive 5Gproduction

RL policies are trained in high-fidelity simulation environments capturing radio dynamics.

Policies are then distilled into compact models optimized for deterministic, low-latency inference.

The distilled model is deployed directly in the baseband pipeline, enabling real-time decisions under sub-100μs constraints.

Continuous validation in live networks ensures robustness under non-stationary conditions.

Design Decisions

  • Policy Distillation — Compress high-capacity RL policies into models meeting strict latency budgets.

  • Simulation-Driven Training — Train in system-level simulators approximating real-world radio conditions.

  • Latency-Constrained Design — Prioritize deterministic execution and predictable runtime over model complexity.

  • Closed-Loop Integration — Embed inference directly into the link adaptation control loop.

  • Robustness to Non-Stationarity — Handle distribution shifts in dynamic network environments.

  • Stability-Aware Optimization — Use conservative updates to ensure reliable production behavior.

Results

  • +20% throughput in live 5G networks
  • +10% spectral efficiency
  • <100μs latency on baseband hardware
  • Deployed with Tier-1 operators

Impact

This system demonstrates that reinforcement learning can operate reliably in real-world communication infrastructure.

By replacing static heuristics with adaptive policies, it improves efficiency, responsiveness, and robustness in live networks — enabling AI-native radio systems.

Lessons Learned

  • Deployment is the bottleneck — Reliability under real-world constraints dominates performance.

  • Simulation–reality gap dominates — Strong simulation results do not guarantee production success.

  • Latency reshapes model design — Sub-100μs constraints require aggressive compression and simplification.

  • Stability > peak performance — Production favors predictable behavior over aggressive optimization.

  • System integration defines success — ML performance depends as much on infrastructure as on algorithms.