A Greedy Strategy of Multiplexing uRLLC Traffic Within eMBB Services for HSR

Ultra-reliable low latency communication (uRLLC) services are crucial for the safe operation of high-speed railways (HSRs). However, when multiplexing with enhanced mobile broadband (eMBB) traffics, the multiple types of uRLLC traffics pose a new challenge. To address the scheduling problem of physical resources in the coexistence of heterogeneous traffics, we divide uRLLC traffics into several levels based on the bit error rate (BER) and delay metrics. A latency margin-based physical resource multiplexing concept is proposed based on different allowable latencies of each traffics. Furthermore, we formulate an optimization problem to minimize the total power of uRLLC traffics while guaranteeing the BER and latency requirements, and a greedy strategy is proposed to solve this optimization problem efficiently. The simulation results show that our proposal can not only guarantee the BER and latency requirements but also reduce the power consumption of various uRLLC traffics significantly in the cases of poor channel status, enhancing the safety and reliability of train-ground wireless communication greatly.