In modern rail transport systems, balises are widely used to exchange track–train information via air-gap interface. In this paper, we first present the vulnerabilities on the standard balise air-gap interface, and then conduct vulnerability simulations using the system parameters that were specified in the European Train Control System. The simulation results show that the vulnerabilities can be exploited to launch effective and practical attacks, which could lead to catastrophic consequences, such as train derailment or collision. To mitigate the vulnerabilities and attacks, we propose to implement a challenge–response authentication process in the air-gap interface in the existing transport infrastructure.

https://ink.library.smu.edu.sg/cgi/viewcontent.cgi?article=4819&context=sis_research

Vulnerabilities, Attacks, and Countermeasures in Balise-Based Train Control Systems

Balise is a popular wayside device to provide accurate location information for subway station parking by sending telegrams to passing trains. By craftily disturbing wireless signals of balise telegrams, this paper proposes three attacks that may make passengers fall and even cause injury. Concretely, the first attack is to jam telegrams such that balises cannot be detected by a passing train; the second attack changes the location of transmitting telegrams by jamming and replaying; and the third attack is to change the total time of transmitting telegrams. All the attacks exploit the train localization mechanism such that a passing train localizes its position inaccurately and then takes improper control actions. Furthermore, since these attacks are independent, they can be launched at the same time to achieve advanced attacks. As the attacks do not require to tamper with the balises, they can be launched easily. Our simulations demonstrate the effectiveness of the proposed attacks. To defeat these attacks, the received telegrams need be verified by a train based on fidelity of telegram data.

https://ink.library.smu.edu.sg/cgi/viewcontent.cgi?article=5225&context=sis_research

Position Manipulation Attacks to Balise-Based Train Automatic Stop Control

In this paper, beamforming design based on a novel coverage model of high-speed railway (HSR) to improve the coverage in HSR communication systems is investigated. A dedicated coverage model, where the coverage cell is ellipse rather than the traditional circular is considered. Based on the elliptical coverage cell, an optimization problem for beamforming design is formulated to maximize the percentage of rail coverage for a given railway length, which is defined as the percentage of coverage distance that the signal-to-noise ratio (SNR) exceeds a desired SNR threshold for the given railway length, subject to the equal average received power on the elliptical line constraint. Considering that the percentage of coverage can be improved by increasing the received power, the problem can be recast to maximizing the expected average received power. A semidefinite relaxation (SDR) method is developed to solve the optimization problem. Through numerical results, the proposed elliptical coverage cell based beamforming can increase the covering railway distance and reduce the transmission power consumption compared with the circular coverage cell. It is also found that the larger eccentricity of the ellipse with appropriately chosen BS location can provide further coverage distance.

Design and Coverage Analysis of Elliptical Cell Based Beamforming for HSR Communication Systems

With the rapid development of wireless communications, passengers are able to surf the internet on the subway trains through mobile communication systems, even wireless local area networks (WLAN). That leads to communications-based train control (CBTC) systems interfered by WLAN equipments in the carriage due to working on the same frequency (2.4GHz frequency band). In this paper, we evaluate the interference from WLAN equipments for the spatial deployment for CBTC systems. To investigate the impact of the carriage to radio propagation, the test on the shielding effectiveness of the carriage is carried out and also verifies the simulation results based on ray-tracing method. Then, multiple spatial deployment scenarios for access points (APs) and mobile radios (MRs) of CBTC systems are investigated on anti-interference to WLAN equipments, respectively. From the analysis, the suggestions of the deployment for APs and MRs are provided.

Evaluation on anti-interference to WLAN equipments for spatial deployment of CBTC systems in tunnels

The invention relates to the technical field of information interaction, in particular to a client information interaction method and system. The client information interaction method includes that corresponding interaction codes and corresponding business information are generated according to received client information, and the interaction codes are sent down to a client; the client sends the obtained interaction codes to an interaction terminal; a business request sent by the interaction terminal is received and carries the interaction codes; the business request is verified according to the interaction codes in the business request, and when the business request is verified to be legal, business information meeting the business request is sent to the interaction terminal. The client information interaction system comprises a server, the client and the interaction terminal. By means of the client information interaction method and system, leakage of client information in an information interaction process can be prevented.

Client information interaction method and system

A new portable and mobile relay device called MiFi which can provide personal Wi-Fi access with the aid of the cellular networks as the backhaul becomes increasing popular. However, as MiFi can be deployed without operators' planning, the devices can cause interference problems when they are brought in subway carriages. Hence, to investigate the interference on the Communication Based Train Control (CBTC) system imposed by MiFi devices, the coexistence scenario and system models are proposed. Based on the models, the performance loss of the CBTC downlink and the effectiveness of a proposed anti-interference algorithm with the Constant Contention Window (CCW) Distributed Coordination Function (DCF) protocol are studied. Research results show that the metro train indeed may be forced to stop by MiFi devices with the growth of the MiFi devices and the MiFi Data Frame Length (DFL). Additionally, our anti-interference algorithm can reduce the performance loss of the CBTC system without any change of the existing CBTC hardware equipments.

Study on coexistence and anti-interference solution for subway CBTC system and MiFi devices

The invention provides a method for preventing information from being leaked on the basis of separation of right to use and right to know. The method needs to be assisted by a third party, the third party provides a method for separation and management of the right to know and the right to use of the information, and simultaneously the third party provides a method enabling users to use the information without being informed fully according to arrangement of the right to know and the right to use of the information by an owner.

Method for preventing information from being leaked on basis of separation of right to use and right to know of information

Recently, the High-speed Railway Private Network (HRPN) is increasingly being recognized as the most promising approach to realize high quality communication for high-speed trains. However, research into modeling coexistence between HRPN and Co-located Cellular Networks (CCN), an essential issue of this approach, is still at its infancy and far too immature to guide the deployment of HRPN. Furthermore, the widely used Monte Carlo static simulation method is not quite applicable to HPRN due to the dynamic nature of this communication scenario. In this paper, we first considerably improve the modeling of HPRN by introducing a new topology which can completely cover the long and narrow railway, new statistics which can precisely analysis every position's performance during trains' forward process, and finally a new shadow fading model with spatial correlation which can decrease the fluctuation between two adjacent positions. Subsequently, we propose two new anti-interference approaches to solve the serious problem of downlink interference between HPRN and CNN. Extensive simulation studies are performed which show that compared to existing approaches our improved modeling results in a more realistic and precise description of HPRN. It is also shown that the proposed anti-interference approaches are very effective.

Improved Performance Modeling and Anti-Interference Approaches for the Coexistence Problem in High-Speed Railway Scenario

The invention discloses a method and device for operation of a public network base station. The method comprises the steps that current path loss between the device and a communication device in a high-speed rail train is determined according to a preset period; according to the current path loss and the maximum transmitting power determined in advance, current interference power generated by the communication device is calculated; when a specific value of the current interference power and the maximum borne interference power capable of being borne by the communication device is smaller than or equal to a first preset threshold value, communication is conducted through the maximum public network bandwidth determined in advance, wherein the first preset threshold value is a constant larger than 0 and smaller than 1. Compared with the prior art, the method and device for operation of the public network base station can effectively improve the use rate of frequency band resources.

Citing Song

Papers

Study on coexistence and anti-interference solution for subway CBTC system and MiFi devices

Method for preventing information from being leaked on basis of separation of right to use and right to know of information

Improved Performance Modeling and Anti-Interference Approaches for the Coexistence Problem in High-Speed Railway Scenario

Method and device for operation of public network base station