A Hybrid Semantic RAN Protocol Stack Design for 6G System and Its Implementation

2025-04-10

AI Summary

To address the incompatibility between semantic communication (SC) and traditional non-semantic communication under 6G multi-service coexistence, this paper proposes a Hybrid Semantic Cellular Radio Access Network (HSC-RAN) protocol stack. Methodologically, it introduces the first PDSCH transmission mechanism jointly supporting SC and non-SC, along with a configurable DCI format, enabling dynamic, real-time, dual-mode scheduling and transmission of semantic representations and bit streams over a unified OFDM air interface. At the physical layer, integrated semantic encoding/decoding modules support concurrent end-to-end semantic reconstruction and conventional bit-level transmission. Experimental results demonstrate that the scheme simultaneously ensures high-quality parallel delivery of SC-based AR/VR video and non-SC industrial control text. Under high-fidelity semantic reconstruction constraints, it significantly improves spectral efficiency and service adaptability.

Technology Category

• Planning, Routing, and Scheduling: Scheduling
• Search and Optimization: Mixed Discrete/Continuous Search
• Multiagent Systems: Agent Communication

Application Category

• Search and Retrieval-Augmented AI: Retrieval-Augmented Generation (RAG) and multi-modal RAG
• Systems and Infrastructure for Web, Mobile and WoT: Web applications in cross-disciplinary domains and verticals such as mixed reality, smart cities, and digital health
• Semantics and Knowledge: Methods to enhance, augment, integrate or synergize semantic models such as knowledge graphs and LLMs

Abstract

Recently, Semantic Communication (SC) has been recognized as a crucial new paradigm in 6G, significantly improving information transmission efficiency. However, the diverse range of service types in 6G networks, such as high-data-volume services like AR/VR/MR and low-data-volume applications requiring high accuracy, such as industrial control and data collection, presents significant challenges to fully replacing the fundamental technologies with SC. Therefore, we design a Hybrid Semantic Communication Ratio Access Network (HSC-RAN) protocol stack demo for 6G systems to achieve compatibility and smooth transition between SC and non-SC. Specifically, we take the Physical Downlink Shared Channel (PDSCH) as an example, to efficiently integrate SC with Orthogonal Frequency Division Multiplexing (OFDM). Furthermore, we introduce a novel Downlink Control Information (DCI) format that jointly supports SC and non-SC, enabling real-time video transmission via SC and text transmission through non-SC. Experimental results demonstrate that our approach allows simultaneous transmission of semantic and non-semantic information while maintaining high-quality reconstruction at the receiver.

Problem

• Hybrid protocol stack for 6G SC and non-SC compatibility
• Efficient integration of SC with OFDM in PDSCH
• Novel DCI format supporting real-time SC and non-SC transmission

Innovation

• Hybrid Semantic RAN protocol for 6G
• Integrates SC with OFDM in PDSCH
• Novel DCI format supports SC and non-SC