With the continuous development of heavy haul railways

traditional ground-based monitoring systems and track inspection methods relying on dedicated inspection vehicles have gradually revealed their limitations. To meet modern operational maintenance requirements

deploying onboard monitoring systems in freight wagons and establishing real-time vehicle-to-ground (V2G) data transmission channels to ground monitoring centers has become a crucial direction for enhancing railway safety and operational efficiency. Against this background

this paper designs and implements a centralized V2G communication platform utilizing commercial mobile communication networks. Serving as the communication hub for onboard monitoring systems

the platform enables unified management and control of data transmission processes. To address frequent network interruptions along heavy haul railway lines

a breakpoint continuation transmission method based on packet segmentation is proposed to ensure data continuity and integrity. Furthermore

a service-prioritized data transmission strategy is developed to adapt to low-speed sections and manage sudden data surges

optimizing service quality for efficient and stable data transfer. Developed using the QT framework

the communication platform has been installed in onboard subsystems and functionally validated. Experimental results demonstrate that the implemented centralized communication platform fully satisfies all functional requirements of heavy haul freight wagon monitoring systems

significantly contributing to enhanced railway safety and operational efficiency.