Concepts on Train-to-Ground Wireless Communication System for Hyperloop: Channel, Network Architecture, and Resource Management

Abstract

Hyperloop is envisioned as a novel transportation way with merits of ultra-high velocity and great traveling comforts. In this paper, we present some concepts on the key technologies dedicated to the train-to-ground communication system based on some prevailing fifth-generation communication (5G) technologies from three aspects: wireless channel, network architecture, and resource management. First, we characterize the wireless channel of the distributed antenna system (DAS) using the propagation-graph channel modelling theory. Simulation reveals that a drastic Doppler shift variation appears when crossing the trackside antenna. Hence, the leaky waveguide system is a promising way to provide a stable receiving signal. In this regard, the radio coverage is briefly estimated. Second, a cloud architecture is utilized to integrate several successive trackside leaky waveguides into a logical cell to reduce the handover frequency. Moreover, based on a many-to-many mapping relationship between distributed units (DUs) and centralized units (CUs), a novel access network architecture is proposed to reduce the inevitable handover cost by using the graph theory. Simulation results show that this scheme can yield a low handover cost. Then, with regards to the ultra-reliable and low latency communication (uRLLC) traffic, a physical resource block (PRB) multiplexing scheme considering the latency requirements of each traffic type is exploited. Simulation presents that this scheme can maximize the throughput of non-critical mission communication services while guaranteeing the requirements of uRLLC traffic. Finally, in terms of the non-critical mission communication services, two cache-based resource management strategies are proposed to boost the throughput and reduce the midhaul link burden by pre-fetching and post-uploading schemes. Simulation demonstrates that the cache-based schemes can boost the throughput dramatically.

Research on Vehicle-to-Vehicle MIMO Wireless Channels in Various Tunnels

“…It is well known that when we investigate the propagation characteristics of V2V channels, it is necessary to consider different communication scenarios between a transmitter and a receiver, such as streets, tunnels, highways, and so on. To achieve this research goal, we are required to model effective channels to describe the scatterer distributions in V2V communication scenarios [13]. Since the traffic infrastructure throughout the world has been rapidly developed in recent years, wireless communication scenarios behave in a more complicated manner than before, especially the tunnel communications [14,15].…”

A Service-Aware Latency-Relaxed uRLLC Multiplexing Strategy within eMBB Traffic for Hyperloop Communications

“…Related works have proven that the leaky waveguide system can provide a steady received signal under this circumstance. Detailed depicts can be found in our previous work [3,16].…”

“…According to some research like [4], the communication services for Hyperloop have some similarities to the LTE-R and 5G-R. In [3,16], we have already presented detailed analysis on communication services with accurate key performance indicators (KPIs) from the aspects of service type, data rate, end-to-end latency, and bit error rate (BER), which is presented in Table 1.…”

“…In the simulation, the scheduling unit for uRLLC traffics takes up the duration of a mini-slot of 0.1 ms and a subcarrier of 180 kHz, whereas that for eMBB is set to a slot and a Taking the various uRLLC latency and BER requirements into account, we classify these services into 5 different levels with specific demands according to [16], and the corresponding parameters and values are listed in Table 1. To start with, the predominant task is to find an accurate channel model to characterize the propagation scenario.…”

The Hyperloop System and Stakeholders: A Review and Future Directions

“…Several types of communication systems are required, including (1) the communication of the pod's sensor data to and from a centralized data processor and (2) the communication related to the pod's location between the pod and the tube [20]. Certain challenges exist related to the pod communication and the collection of data, as well as the high-speed connection between the pods and the infrastructure [16,20,94,[124][125][126][127][128].…”