Optimizing Resource Allocation and Scheduling towards FRMCS and GSM-R networks coexistence in Railway Systems

2025-02-25

Global Information Infrastructure and Networking Symposium

AI Summary

To address the resource allocation challenge arising from co-channel coexistence between legacy GSM-R and its 5G New Radio (NR)-based successor, the Future Railway Mobile Communication System (FRMCS), this paper proposes a Channel Quality Indicator (CQI)-aware Intelligent Traffic Scheduling and Preemption (ITSP) algorithm. The method uniquely integrates 5G NR’s preemption mechanism with spectrum white space concepts, ensuring strict zero-interference protection for existing GSM-R resources while enabling dynamic, adaptive scheduling of FRMCS safety-critical and performance-sensitive services. Formulated as an integer linear program and guided by CQI-driven channel quality adaptation, ITSP achieves high computational efficiency without compromising real-time constraints. Evaluation results demonstrate significant improvements in FRMCS spectral efficiency and critical service scheduling success rate, fulfilling stringent railway communication requirements. The proposed scheme provides a practical, deployable coexistence framework to support the smooth GSM-R-to-FRMCS transition.

Technology Category

• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Intelligent Robots: Multi-Robot Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Data management and stream processing for Web, mobile and wireless applications
• User Modeling, Personalization and Recommendation: Federated recommendation systems and personalization
• Security and Privacy: Large-scale security measurements

Abstract

The actual railway communication system used in Europe for high-speed trains (HST) is called the GSM-R system, which is a communication system based on 2G infrastructure. This system is meant to be replaced by a new system based on 5G NR infrastructure called the Future Railway Mobile Communication System (FRMCS) by 2030. For the next years, both systems will probably coexist in the same frequency band since the migration from GSM-R to FRMCS is planned to be done progressively until the GSM-R system is completely shut down, mainly due to safety and budget constraints. In this paper, we study the resource allocation for the FRMCS system sharing the same frequency band as the already deployed GSM-R system. We formulate the resource allocation problem as an integer linear problem (ILP), known to be NP-hard. To solve it in a reasonable time, we propose a scheduling algorithm, called Intelligent Traffic Scheduling Preemptor (ITSP), that allocates resources for the different FRMCS traffic types considered (critical traffic and performance traffic) in the same frequency band with the GSM-R system. Our algorithm is channel quality Indicator (CQI) aware and uses the preemption mechanism in 5G NR standards to optimize the resource allocation for the FRMCS system without impacting the actual GSM-R resource allocation in the context of the white space concept.

Problem

• Optimizing resource allocation for FRMCS and GSM-R coexistence
• Developing scheduling algorithm for shared frequency band
• Ensuring FRMCS performance without disrupting GSM-R

Innovation

• Proposes ITSP algorithm for FRMCS scheduling
• Uses CQI-aware preemption in 5G NR
• Solves ILP problem for shared GSM-R band