scholarly journals QoS-Aware Resource Allocation for Network Virtualization in an Integrated Train Ground Communication System

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Li Zhu ◽  
Fei Wang ◽  
Hongli Zhao
Keyword(s):  
Resource Allocation ◽  
Communication System ◽  
Communication Systems ◽  
Network Virtualization ◽  
Base Station ◽  
Urban Rail Transit ◽  
Normal Operation ◽  
Rail Transit ◽  
Resource Allocation Algorithm ◽  
Urban Rail

Urban rail transit plays an increasingly important role in urbanization processes. Communications-Based Train Control (CBTC) Systems, Passenger Information Systems (PIS), and Closed Circuit Television (CCTV) are key applications of urban rail transit to ensure its normal operation. In existing urban rail transit systems, different applications are deployed with independent train ground communication systems. When the train ground communication systems are built repeatedly, limited wireless spectrum will be wasted, and the maintenance work will also become complicated. In this paper, we design a network virtualization based integrated train ground communication system, in which all the applications in urban rail transit can share the same physical infrastructure. In order to better satisfy the Quality of Service (QoS) requirement of each application, this paper proposes a virtual resource allocation algorithm based on QoS guarantee, base station load balance, and application station fairness. Moreover, with the latest achievement of distributed convex optimization, we exploit a novel distributed optimization method based on alternating direction method of multipliers (ADMM) to solve the virtual resource allocation problem. Extensive simulation results indicate that the QoS of the designed integrated train ground communication system can be improved significantly using the proposed algorithm.

scholarly journals Reliability Evaluation for LTE Based CBTC Train Ground Communication Systems

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Shuo Wang ◽  
Li Zhu ◽  
Kun Xu ◽  
Lin Zhang ◽  
Xuan Wang
Keyword(s):  
Information Transmission ◽  
Communication Systems ◽  
High Speed ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Local Networks ◽  
Urban Rail ◽  
Train Operation ◽  
Time Requirements ◽  
Actual Operation

Nowadays, most communication based train control systems (CBTC) use Wireless Local Networks (WLAN) technology for information transmission. However, because of the high running speed of the train in urban rail transit, WLAN technology cannot fully satisfy the information transmission under the condition of train operation at a high speed. Long term evolution (LTE) technology has a high transmission speed, which can better meet the real-time requirements of train and ground information transmission. Therefore, LTE technology has become an emphasis on the research of communication technology in today’s urban rail transit. Although there is a lot of research on the application of LTE technology in urban rail transit, there is little research on the reliability of LTE based train ground communication systems using experimental data. In this paper, the reliability of train ground communication is firstly defined. Then the train ground communication environment was established in the laboratory, and the performance parameters of train ground communication based on LTE technology were obtained in the test. Finally, the reliability is calculated and analyzed according to the experimental results, and a storage method of train data in actual operation is proposed, which can be used to analyze the reliability of train information transmission. The results show that the reliability of train ground communication based on LTE technology meets CBTC requirements.

Research on Urban Rail Transit Resource Allocation Based on K-Shortest Paths Algorithm

2013 ◽  
Vol 748 ◽  
pp. 1285-1289 ◽  
Author(s):  
Ju Mei Shen ◽  
Yong Sheng Shen ◽  
Lin Xu
Keyword(s):  
Resource Allocation ◽  
Search Algorithm ◽  
Shortest Paths ◽  
Flow Distribution ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Rail Network ◽  
Assignment Model ◽  
Urban Rail ◽  
Major Factors

This paper considers the major factors of passenger flow distribution and the running cost of train, explains and demonstrates how to sove the problem of urban rail transit resource allocation. The paper at first constructs urban rail network assignment model in the multiple operating lines based on the k-shortest paths algorithm, then proposes the k shortest paths search algorithm, finally the effectiveness of the model and algorithm are verified with the data from the Beijing urban rail transit network.

Research on the Key Issues of the Civil Communication Resource Management for Urban Rail Transit

2014 ◽  
Vol 505-506 ◽  
pp. 410-414
Author(s):  
Jian Xun Zhang ◽  
Bao Ming Han
Keyword(s):  
Communication System ◽  
Information Service ◽  
Value Added ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Urban Rail ◽  
Key Issues ◽  
The One ◽  
Maintenance Personnel ◽  
Urban Rail Transit Network

The civil communication system in urban rail transit network is the one which can provide the passenger value-added service. It can meet underground needs of information service for passengers, and be the alternate means of communication for drivers, equipment maintenance personnel, the stations duty officers, and so on. When the wireless systems for rail transit comes malfunction, the civil communication system can provides smooth information channel for rail transit participants to ensure the safety of personnel and rail transit dispatching.

scholarly journals The QoS Indicators Analysis of Integrated EUHT Wireless Communication System Based on Urban Rail Transit in High-Speed Scenario

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xiaoxuan Wang ◽  
Hailin Jiang ◽  
Tao Tang ◽  
Hongli Zhao
Keyword(s):  
Wireless Communication ◽  
Communication System ◽  
High Speed ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Transit System ◽  
Wireless Communication System ◽  
Handoff Latency ◽  
Urban Rail ◽  
Set Up

Nowadays, in urban rail transit systems, train wayside communication system uses Wireless Local Area Network (WLAN) as wireless technologies to achieve safety-related information exchange between trains and wayside equipment. However, according to the high speed mobility of trains and the limitations of frequency band, WLAN is unable to meet the demands of future intracity and intercity rail transit. And although the Time Division-Long Term Evolution (TD-LTE) technology has high performance compared with WLAN, only 20 MHz bandwidth can be used at most. Moreover, in high-speed scenario over 300 km/h, TD-LTE can hardly meet the future requirement as well. The equipment based on Enhanced Ultra High Throughput (EUHT) technology can achieve a better performance in high-speed scenario compared with WLAN and TD-LTE. Furthermore, it allows using the frequency resource flexibly based on 5.8 GHz, such as 20 MHz, 40 MHz, and 80 MHz. In this paper, we set up an EUHT wireless communication system for urban rail transit in high-speed scenario integrated all the traffics of it. An outdoor testing environment in Beijing-Tianjin High-speed Railway is set up to measure the performance of integrated EUHT wireless communication system based on urban rail transit. The communication delay, handoff latency, and throughput of this system are analyzed. Extensive testing results show that the Quality of Service (QoS) of the designed integrated EUHT wireless communication system satisfies the requirements of urban rail transit system in high-speed scenario. Moreover, compared with testing results of TD-LTE which we got before, the maximum handoff latency of safety-critical traffics can be decreased from 225 ms to 150 ms. The performance of throughput-critical traffics can achieve 2-way 2 Mbps CCTV and 1-way 8 Mbps PIS which are much better than 2-way 1 Mbps CCTV and 1-way 2 Mbps PIS in TD-LTE.

Multi-Train Movement Simulation Research for Urban Rail Transit under Sudden Failure

2011 ◽  
Vol 97-98 ◽  
pp. 523-530
Author(s):  
Zhi Qiang Wang
Keyword(s):  
Urban Rail Transit ◽  
Normal Operation ◽  
Rail Transit ◽  
Emergency Plan ◽  
Simulation Research ◽  
Safety Control ◽  
Sudden Failure ◽  
Urban Rail ◽  
Transit Operation ◽  
Movement Simulation

Analyze the sudden failure influence to urban rail transit normal operation, has important significance to grasp the key of failure emergency treatment. This paper take moving block mode for example, first by use of multi-particle traction model, general consider the passenger comfort, safety control and other factors, design the multi-train tracking calculate model. Then according to the different influence to urban rail transit operation, classify the sudden failure into two kinds: sudden train failure and sudden section break off failure, analyze the multi-train movement simulate arithmetic under the two kinds of failure, based on this, design the simulation system’s workflow, build the urban rail transit multi-train movement simulate system under sudden failure. Finally, by analyze the calculate results of two kinds of failure, verified the system’s validity. Simulate urban rail transit multi-train movement process under sudden failure can master the detail instance about failure influence operation, deeply analysis the infect’s diffusion process caused by failure or delay, provide a powerful assist analyze tool to analysis the network’s operation reliability, constitute correlative emergency plan.

Crash Recovery for Embedded Main Memory Database

2012 ◽  
Vol 195-196 ◽  
pp. 1122-1124 ◽  
Author(s):  
Yi Bing Li ◽  
Shuang Wang ◽  
Fang Ye
Keyword(s):  
Real Time ◽  
Communication System ◽  
Communication Systems ◽  
Base Station ◽  
Main Memory ◽  
Normal Operation ◽  
Recovery Algorithm ◽  
Main Memory Database ◽  
Efficient Data ◽  
Crash Recovery

In the last years, the deployment of embedded real-time communication systems has increased dramatically. At the same time, the amount of data that needs to be managed by embedded real-time main memory databases is increasing, thus requiring an efficient data management. However, system crash will cause data loss in main memory, which will seriously affect the normal operation of the entire communication system. This paper introduces an algorithm of system crash recovery applied in main memory database of embedded real-time communication system. This paper expatiates the software architecture of SDR base station, the cause of crash occurring, and proposes the flash recovery algorithm using for system recovery. A main memory database using this algorithm has been applied in a real communication systemmultimode SDR base station communication system.

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