On Millimeter Wave and THz Mobile Radio Channel for Smart Rail Mobility

Self Cite

Railway, subway, airplane, and other transportation systems have drawn an increasing interest on the use of wireless communications for critical and noncritical services to improve performance, reliability, and passengers experience. Smart transportation systems require the use of critical communications for operation and control, and wideband services can be provided using noncritical communications. High speed train (HST) is one of the best test cases for the analysis of communication links and specification of the general requirements for train control and supervision, passenger communications, and onboard and infrastructure wireless sensors. In this paper, we analyze in detail critical and noncritical networks mainly using the HST as a test case. First, the different types of links for smart rail transportation are described, specifying the main requirements of the transportation systems, communications, and their applications for different services. Then, we propose a network architecture and requirements of the communication technologies for critical and noncritical data. Finally, an analysis is made for the future technologies, including the fifth-generation (5G) communications, millimeter wave (mmWave), terahertz (THz), and satellites for critical and high-capacity communications in transportation.

Section: Communications For Smart Rail Transportationmentioning

confidence: 99%

“…Therefore, it requires the bandwidth of several GHz to accommodate over 100 Gbps data rates [8]. Such high data rate and huge bandwidth requirements form a strong motivation of exploring the underutilized mmWave and even THz bands [8].…”

Section: Communications For Smart Rail Transportationmentioning

confidence: 99%

Wireless Communications in Smart Rail Transportation Systems

Briso-Rodríguez

Guan

Yin

et al. 2017

Self Cite

“…To enable intelligent transportation system, various high-datarate services are required in this scenario [2][3][4], for example, high definition (HD) video surveillance, and onboard realtime connectivity. For satisfying these services, applying advanced technologies in HST communications, including millimeter-wave (mmWave), mobile relay station (MRS), and smart antennas, has been studied in the literature [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

A Simplified Multipath Component Modeling Approach for High-Speed Train Channel Based on Ray Tracing

Yang

et al. 2017

Self Cite

High-speed train (HST) communications at millimeter-wave (mmWave) band have received a lot of attention due to their numerous high-data-rate applications enabling smart rail mobility. Accurate and effective channel models are always critical to the HST system design, assessment, and optimization. A distinctive feature of the mmWave HST channel is that it is rapidly time-varying. To depict this feature, a geometry-based multipath model is established for the dominant multipath behavior in delay and Doppler domains. Because of insufficient mmWave HST channel measurement with high mobility, the model is developed by a measurementvalidated ray tracing (RT) simulator. Different from conventional models, the temporal evolution of dominant multipath behavior is characterized by its geometry factor that represents the geometrical relationship of the dominant multipath component (MPC) to HST environment. Actually, during each dominant multipath lifetime, its geometry factor is fixed. To statistically model the geometry factor and its lifetime, the dominant MPCs are extracted within each local wide-sense stationary (WSS) region and are tracked over different WSS regions to identify its "birth" and "death" regions. Then, complex attenuation of dominant MPC is jointly modeled by its delay and Doppler shift both which are derived from its geometry factor. Finally, the model implementation is verified by comparison between RT simulated and modeled delay and Doppler spreads.

“…With the mobile data demand exponentially growing [2][3][4][5], wireless communication systems working at millimeter wave (mmWave) have attracted much more attention in many mobile communication scenarios. For mmWave, it potentially contains a large amount of spectrum resources for achieving multi-Giga bps data rate for wireless communication systems [6][7][8].…”

Section: Introductionmentioning

confidence: 99%

On the Feasibility of High Speed Railway mmWave Channels in Tunnel Scenario

et al. 2017

Self Cite

Rail traffic is widely acknowledged as an efficient and green transportation pattern and its evolution attracts a lot of attention. However, the key point of the evolution is how to develop the railway services from traditional handling of the critical signaling applications only to high data rate applications, such as real-time videos for surveillance and entertainments. The promising method is trying to use millimeter wave which includes dozens of GHz bandwidths to bridge the high rate demand and frequency shortage. In this paper, the channel characteristics in an arched railway tunnel are investigated owing to their significance of designing reliable communication systems. Meantime, as millimeter wave suffers from higher propagation loss, directional antenna is widely accepted for designing the communication system. The specific changes that directional antenna brings to the radio channel are studied and compared to the performances of omnidirectional antenna. Note that the study is based on enhanced wide-band ray tracing tool where the electromagnetic and scattering parameters of the main materials of the tunnel are measured and fitted with predicting models.