We present a temperature monitoring and warning system, which is based on wireless communi- cation technology and applied in train switchgear in this paper. The system is consists of three parts, including wireless te...We present a temperature monitoring and warning system, which is based on wireless communi- cation technology and applied in train switchgear in this paper. The system is consists of three parts, including wireless temperature detection module, inter-vehicle transmission networks module and?remote monitoring server. The switchgear contact temperature data are collected via the wireless temperature detection module and exchanged in inter-vehicle wireless networking by Zigbee modules. Then the temperature of train switchgear cabinets can be monitored remotely through the GPRS wireless communication.展开更多
The high-speed railway and high-way networks are now expanding at a phenomenal speed in Chinaand in many other parts of the world. The related broadband wireless communication over high-speed trains and highway vehicl...The high-speed railway and high-way networks are now expanding at a phenomenal speed in Chinaand in many other parts of the world. The related broadband wireless communication over high-speed trains and highway vehicles is a very challenging task due to hostile transmission channel conditions. The demand for such services is growing rapidly, following the proliferation of laptop/tablet computers and smart phones. This motivates the research on wireless communications in the high mobility environments.展开更多
This article describes a new miniaturized omni-directional antenna with quasi-self-complementary structure for wireless communication applications. A novel ground structure composed of five rectangular plates is propo...This article describes a new miniaturized omni-directional antenna with quasi-self-complementary structure for wireless communication applications. A novel ground structure composed of five rectangular plates is proposed to enhance the impedance bandwidth and reduce the antenna size. The proposed antenna is comprised of two patches surrounded by the ground structure. Two metal patches of the antenna are located on two opposite sides of the dielectric substrate. The feed patch is used to excite the radiation patch. This unique design is realized by properly choosing the suitable feed patch shape, selecting similar slot shape on the radiation patch, and tuning their dimensions. The proposed antenna with an extremely small size of 6 mm × 9 mm has an operating impedance bandwidth ranging from 4.5 to 6.1 GHz for S<sub>11</sub> < -10 dB, which also covers the two IEEE 802.11a wireless local area network bands (5.15 - 5.35 GHz and 5.725 - 5.825 GHz). In addition to be very small in size, the antenna exhibits omni-directional radiation patterns in the entire operating bandwidth and low cross polarization. The distortionless time domain performance of the antenna is confirmed by investigation of the phase response and group delay. The obtained results in both frequency and time domain show that the proposed antenna is suitable for use in wireless communication systems.展开更多
With the increasing utilization of High-Speed Trains （HSTs）, the need for a reliable and high-bandwidth Internet access under high-speed mobility scenarios has become more demanding. In static, walking, and low mobi...With the increasing utilization of High-Speed Trains （HSTs）, the need for a reliable and high-bandwidth Internet access under high-speed mobility scenarios has become more demanding. In static, walking, and low mobility environments, TCP/IP （transmission control protocol/Internet protocol） can work well. However, TCP/IP cannot work well in high-speed scenarios because of reliability and handoff delay problems. This is mainly because the mobile node is required to maintain the connection to the corresponding node when it handovers to another access point node. In this paper, we propose a named data networking wireless mesh network architecture for HST wireless communication （NDN-Mesh-T）, which combines the advantages of Wireless Mesh Networks （WMNs） and NDN architectures. We attempt to solve the reliability and handoff delay problems to enable high bandwidth and low latency in Internet access in HST scenarios. To further improve reliability and bandwidth utilization, we propose a Direction-Aware Forwarding （DAF） strategy to forward Interest packet along the direction of the running train. The simulation results show that the proposed scheme can significantly reduce the packet loss rate by up to 51% compared to TCP/IP network architecture. Moreover, the proposed mechanism can reduce the network load, handoff delay, and data redundancy.展开更多
从车地无线通信、车载控制模型、轨旁设备应用等方面有针对性地研究了设计速度在160~200 km/h下基于通信的列车运行控制(CBTC,Communication Based Train Control)系统的高速适应性问题,提出了速度提升后CBTC系统相对应的改进方案。从...从车地无线通信、车载控制模型、轨旁设备应用等方面有针对性地研究了设计速度在160~200 km/h下基于通信的列车运行控制(CBTC,Communication Based Train Control)系统的高速适应性问题,提出了速度提升后CBTC系统相对应的改进方案。从理论上分析,传统CBTC系统在完成适配性改进后,能够满足此速度等级下安全运行的要求。展开更多
车地无线技术方案会直接影响地铁P I S的最终运行效果。随着国内城市地铁线路的不断建设以及技术的不断发展进步,对于PIS中车地无线技术方案的选择成为地铁通信系统从业人员关注的重点。本文着重介绍了当前国内地铁PIS中的车地无线技术...车地无线技术方案会直接影响地铁P I S的最终运行效果。随着国内城市地铁线路的不断建设以及技术的不断发展进步,对于PIS中车地无线技术方案的选择成为地铁通信系统从业人员关注的重点。本文着重介绍了当前国内地铁PIS中的车地无线技术方案,并针对PIS当前及未来业务需求、应用现状及技术原理进行分析,提出了适合于PIS业务需求的技术方案。展开更多
文摘We present a temperature monitoring and warning system, which is based on wireless communi- cation technology and applied in train switchgear in this paper. The system is consists of three parts, including wireless temperature detection module, inter-vehicle transmission networks module and?remote monitoring server. The switchgear contact temperature data are collected via the wireless temperature detection module and exchanged in inter-vehicle wireless networking by Zigbee modules. Then the temperature of train switchgear cabinets can be monitored remotely through the GPRS wireless communication.
基金supported by the Major State Basic Research Development Program of China(973 Program No.2012CB316100)the National Natural Science Foundation of China(NSFC No.61032002)the Innovative Intelligence Base Project(111 Project No.111-2-14)
文摘The high-speed railway and high-way networks are now expanding at a phenomenal speed in Chinaand in many other parts of the world. The related broadband wireless communication over high-speed trains and highway vehicles is a very challenging task due to hostile transmission channel conditions. The demand for such services is growing rapidly, following the proliferation of laptop/tablet computers and smart phones. This motivates the research on wireless communications in the high mobility environments.
文摘This article describes a new miniaturized omni-directional antenna with quasi-self-complementary structure for wireless communication applications. A novel ground structure composed of five rectangular plates is proposed to enhance the impedance bandwidth and reduce the antenna size. The proposed antenna is comprised of two patches surrounded by the ground structure. Two metal patches of the antenna are located on two opposite sides of the dielectric substrate. The feed patch is used to excite the radiation patch. This unique design is realized by properly choosing the suitable feed patch shape, selecting similar slot shape on the radiation patch, and tuning their dimensions. The proposed antenna with an extremely small size of 6 mm × 9 mm has an operating impedance bandwidth ranging from 4.5 to 6.1 GHz for S<sub>11</sub> < -10 dB, which also covers the two IEEE 802.11a wireless local area network bands (5.15 - 5.35 GHz and 5.725 - 5.825 GHz). In addition to be very small in size, the antenna exhibits omni-directional radiation patterns in the entire operating bandwidth and low cross polarization. The distortionless time domain performance of the antenna is confirmed by investigation of the phase response and group delay. The obtained results in both frequency and time domain show that the proposed antenna is suitable for use in wireless communication systems.
基金supported by the National Natural Science Foundation of China (No. 61309025)the Hunan Provincial Natural Science Foundation of China (No. 2017JJ2332)+1 种基金the National Key Technology R&D Program (No. 2015BAH05F02)the Fundamental Research Funds for the Central Universities of Central South University (No. 2017zzts146)
文摘With the increasing utilization of High-Speed Trains （HSTs）, the need for a reliable and high-bandwidth Internet access under high-speed mobility scenarios has become more demanding. In static, walking, and low mobility environments, TCP/IP （transmission control protocol/Internet protocol） can work well. However, TCP/IP cannot work well in high-speed scenarios because of reliability and handoff delay problems. This is mainly because the mobile node is required to maintain the connection to the corresponding node when it handovers to another access point node. In this paper, we propose a named data networking wireless mesh network architecture for HST wireless communication （NDN-Mesh-T）, which combines the advantages of Wireless Mesh Networks （WMNs） and NDN architectures. We attempt to solve the reliability and handoff delay problems to enable high bandwidth and low latency in Internet access in HST scenarios. To further improve reliability and bandwidth utilization, we propose a Direction-Aware Forwarding （DAF） strategy to forward Interest packet along the direction of the running train. The simulation results show that the proposed scheme can significantly reduce the packet loss rate by up to 51% compared to TCP/IP network architecture. Moreover, the proposed mechanism can reduce the network load, handoff delay, and data redundancy.
文摘从车地无线通信、车载控制模型、轨旁设备应用等方面有针对性地研究了设计速度在160~200 km/h下基于通信的列车运行控制(CBTC,Communication Based Train Control)系统的高速适应性问题,提出了速度提升后CBTC系统相对应的改进方案。从理论上分析,传统CBTC系统在完成适配性改进后,能够满足此速度等级下安全运行的要求。
文摘车地无线技术方案会直接影响地铁P I S的最终运行效果。随着国内城市地铁线路的不断建设以及技术的不断发展进步,对于PIS中车地无线技术方案的选择成为地铁通信系统从业人员关注的重点。本文着重介绍了当前国内地铁PIS中的车地无线技术方案,并针对PIS当前及未来业务需求、应用现状及技术原理进行分析,提出了适合于PIS业务需求的技术方案。
