Yong-Soo Song

Automatic train control over LTE: design and performance evaluation

Due to technical advances in train control and wireless communications, unmanned train operation has gained in popularity of late. On the other hand, any errors involved in managing the QoS of train control traffic will cause negative consequences such as possible loss of life. Operators therefore naturally wish to scrutinize the specifications so that the wireless communications system is capable of guaranteeing the QoS of the train control traffic. In this article, we propose a feasible QoS management scheme for train control traffic based on the methodology used in a conventional LTE system. Based on the proposed scheme, we evaluate the feasibility of the LTE system using a testbed built in a commercial railway region. The key issues to support the train control services by the LTE system are the design of a QoS policy based on analyzing the characteristics of the train control traffic and the appropriate adjustment of the cell parameters during the cell planning and optimization procedures in order to resolve any network issues that may cause problems with data pause.

Development of Integrated Wireless Network for Railway

This research aims to conduct a study on the feasibility of the LTE communication method for developing a dedicated integrated railway wireless network. An empirical analysis was carried out by establishing a dedicated integrated railway wireless network in an approximately 12km section between Illo station and Daebul station on the Honam line. Korean wireless communication methods for railway safety are different depending on each line, which makes it difficult for railway workers to cooperate with. This causes various problems. There is the ever-present risk of accidents due to call disconnection between wireless communication systems, frequency interference from commercial networks, and crosstalk. This study verified the feasibility of the 4th generation communication system, LTE, over the dedicated integrated railway wireless network as a solution for the above mentioned problems. The result shows this communication system exceeded existing performance standards of Europe GSM-R in every test item despite the location constraint of train tracks on the base station establishment.

Group communication over LTE: a radio access perspective

Long Term Evolution, which has its roots in commercial mobile communications, has recently become an influential solution to future public safety communications. To verify the feasibility of LTE for public safety, it is essential to investigate whether an LTE system optimized for one-to-one communications is capable of providing group communication, which is one of the most important service concepts in public safety. In general, a number of first responders for public safety need to form a group for communicating with each other or sharing common data for collaboration on their mission. In this article, we analyze how the current LTE system can support group communication from the aspect of radio access. Based on the requirements for group communication, we validate whether each LTE-enabled radio access method can efficiently support group communication. In addition, we propose a new multicast transmission scheme, called index-coded HARQ. By applying the index coding concept to HARQ operations, we show that the LTE system can provide group communication that is more sophisticated in terms of radio resource efficiency and scalability. We finally evaluate the performance of LTE-enabled group communication using several radio access methods and show how the proposed transmission scheme enhances performance via system-level simulations.

Long term evolution for wireless railway communications: testbed deployment and performance evaluation

In this article, we show the feasibility of the LTE-R testbed with essentially IP-based network architecture. Specifically, we discuss procedures of deploying LTE-R by describing our construction of a testbed in a commercial railway through cell planning and optimization. Then we demonstrate the performance enabled by the implementation of a testbed for LTE-R. We confirm that not only reliable communications but also multimedia services requiring high data rates are feasible, which gives us some guarantee of the prosperity of various advanced train services. We also discuss a number of valuable technical communication issues related to inherent characteristics of railway communications that are unlike those of commercial wireless communications.

Research of Ride Comfort for Tilting Train Simulator Using ECG

The train transportation has a lot of advantages-energy efficiency is high, it is eco-friendly, safety is better than normal roads and it is possible for people to arrive on time. In these days, the valuation of ride comfort, which is only limited to road transportation, is newly recognized in order to having competitiveness from other transportation. Especially, in the development of the Korean high-speed railroad business, the ride comfort enhancement of tilting train is very important problem to be solved. Currently, there are international standards of ride comfort such as UIC13, ISO2631. In Korea case, although it has own standard like KS R9216, it mainly depends on the physical parameter such as vibration and noise. So recently, in the valuation of ride comfort, the movements of living parameter technique introduction are increasing on the base of Japan and many developed countries of Europe techniques. Presently, the method of train ride comfort is mainly based of vibration, that is, mechanical parameter adding selection of variable acceleration and noise. This paper would like to show biological parameter; heart rate and blood pressure variation. This method is more direct, based on human body response, than mechanical parameter method. In this experiment, the variability of heart rate and blood pressure of passengers according to tilting angle change of TTX, the Korean tilting train, we are supposed to know that the extent of tilting on the simulation has influence on variability of heart rate and blood pressure, which are living parameter of heart’s blood. This research can be the preliminary study to implement e-Health train that provides optimized ride comfort service to passengers and also, proper feedback service according to changed ride comfort situation that can improve passenger’s feeling as well as healthcare service.

Study of Ride Comfort on Train through Physiological Parameter

The train transportation has a lot of advantages-energy efficiency is high, it is eco-friendly, safety is better than normal roads and it is possible for people to arrive on time. In these days, the valuation of ride comfort, which is only limited to road transportation, is newly recognized in order to having competitiveness from other transportation. Especially, in the development of the Korean high-speed railroad business, the ride comfort enhancement of train is very important problem to be solved. Currently, there are international standards of ride comfort such as UIC13, ISO2631. In Korea case, although it has own standard like KS R9216, it mainly depends on the physical parameter such as vibration and noise. So recently, in the valuation of ride comfort, the movements of living parameter technique introduction are increasing on the base of Japan and many developed countries of Europe techniques. Presently, the method of train ride comfort is mainly based of vibration, that is, mechanical parameter adding selection of variable acceleration and noise. This paper would like to show biological parameter; heart rate and blood pressure variation. This method is more direct, based on human body response, than mechanical parameter method. In this experiment, the variability of heart rate and blood pressure of passengers according to tilting angle change of Train, the Korean tilting train, we are supposed to know that the extent of tilting on the simulation has influence on variability of heart rate and blood pressure, which are living parameter of heart`s blood.

Ride Comfort Analysis with Physiological Parameters for an E-Health Train

Transportation by train has numerous advantages over road transportation, especially with regard to energy efficiency, ecological features, safety, and punctuality. However, the contrast in ride comfort between standard road transportation and train travel has become a competitive issue. The ride comfort enhancement technology of tilting trains (TTX) is a particularly important issue in the development of the Korean high-speed railroad business. Ride comfort is now defined in international standards such as UIC13 and ISO2631. The Korean standards such as KSR9216 mainly address physical parameters such as vibration and noise. In the area of ride comfort, living quality parameter techniques have recently been considered in Korea, Japan, and Europe. This study introduces biological parameters, particularly variations in heart rate, as a more direct measure of comfort. Biological parameters are based on physiological responses rather than on purely external mechanical parameters. Variability of heart rate and other physiological parameters of passengers are measured in a simulation involving changes in the tilting angle of the TTX. This research is a preliminary study for the implementation of an e-health train, which would provide passengers with optimized ride comfort. The e-health train would also provide feedback on altered ride comfort situations that can improve a passengers experience and provide a healthcare service on the train. The aim of this research was to develop a ride comfort evaluation system for the railway industry, the automobile industry, and the air industry. The degree of tilt correlated with heart rate, fatigue, and unrelieved alertness.

Ride Comfort Analysis using Physiological Parameters for e-Health Train

When passengers ride in a car of a train, they feel the vibration, which partially defines their degree of comfort. The ISO standards based on existing passenger trains, the Wz evaluation method, UIC standards, and the KS are standards in this area. Based on the vibration of the train car ride, the speed, the noise, and only considering mechanical elements, there is a limit for passengers to feel comfort in these situations, especially because problems related to trains on a curved line have not been evaluated. To evaluate car comfort on a tilting train is challenging. Based on readings of a train car, mechanical elements have an impact on the heart, blood pressure, and body temperature; therefore, these biological parameters are evaluated here using train car ride data. In particular, a tilting train operated on a curved line is used with changes of the tilt level to evaluate the level of comfort felt by passengers. This research can be the preliminary study to implement e-Health train that provides optimized ride comfort service to passengers and also, proper feedback service according to changed ride comfort situation that can improve passenger’s feeling as well as healthcare service.