Dependable integrated surveillance systems for the physical security of metro railways (POSTER)

Rail-based mass transit systems are vulnerable to many criminal acts, ranging from vandalism to terrorism. Therefore, security systems are employed in order to protect trains, tunnels, stations, lines and depots. In modern security systems, heterogeneous intrusion detection, access control, intelligent video-surveillance and sound detection devices are integrated in a cohesive Security Management System ( SMS ), providing a user-friendly graphical interface to the operators. The visualization of video streams is activated automatically when an alarm is generated by smart-cameras or other sensors, according to an event-driven approach. In case of emergencies, the procedural actions required to the operators involved are orchestrated by the SMS. Redundancy both in sensor dislocation and hardware apparels improve detection reliability, through alarm correlation, and overall system resiliency against both random and malicious threats.

Objectives of the Work:

To present the architecture, the main functionalities and the dependability related issues of a security system specifically tailored to metro railways

To explain novel existing and “in progress” solutions to achieve a measurable level of dependability for the security system and to fulfill the requirements of the specific application

Dependable integrated surveillance systems for the physical security of metro railways R a t i o n a l e Detection Reliability The combination of redundancy and diversity can be exploited to fine tune the POD ( Probability Of Detection ) and FAR ( False Alarm Rate ) parameters according to AND/OR logical relationships. For example: Giovanni Bocchetti, Francesco Flammini, Alfio Pappalardo, Concetta Pragliola C o n c l u s i o n s S y s t e m D e p e n d a b i l i t y S e c u r i t y M a n a g e m e n t S y s t e m System architecture is distributed and hierarchical, with both local and central control rooms collecting alarms according to different scopes and responsibilities. The data provided by heterogeneous sensors are collected by peripheral control centers, located in the stations, and then centralized in line control centers, located close to the traffic management center. Active Infrared Barrier FAR = P 1 F << 1 Intelligent Video Analytics FAR = P 2 F << 1 Infrared barrier AND Intelligent Video Analytics FAR = P 1 AND 2 F ≈ P 1 F · P 2 F ➩ P 1 AND 2 F << P 1 F , P 1 AND 2 F << P 2 F (similarly, POD is negatively affected, but the loss is not relevant as the gain in FAR, so the trade-off is generally advantageous) Future Works The system can integrate CBRNE ( Chemical Bacteriological Radiological Nuclear ) sensors to better face terror attacks. Novel technologies are being investigated using terahertz cameras to provide non intrusive weapon and explosive detection on passengers. It is in course of study the integration in the SMS of advanced mechanisms for event correlation based on expert systems, in order to provide early warning and decision support to detect suspicious behaviors as well as natural hazards (landslides, earthquakes, floods, etc.) by using smart-sensors. Information Security Security devices (e.g. sensors) differ in their capacity of providing information security. This can have an impact on system availability and also on safety, since the SMS is employed in critical infrastructure surveillance applications. Third ACM/IEEE International Conference on Distributed Smart Cameras (ICDSC’09), 30 August - 2 September 2009, Como (Italy)

Discussion of the Results

A modern surveillance system suitable for rail-based mass transit security needs to integrate different subsystems in order to protect users and assets of the infrastructure against threats of different nature.

The security system provides:

deterrent effects (reduction of intentional threats)

reassuring effects (improvement of the perceived security)

investigative support (for post-event analysis)

rationalizing effects (situational awareness in emergency interventions)

During our on-the-field experience, we have obtained a POD of at least the 80% for most video analytics alarms (including motion detection, unattended object, yellow line crossing) and a FAR of less 10 nuisance alarms a day. The target is to approach the 95% for POD with less than 5 nuisance alarms each day.

These issues can be tackled by a dependable middleware which is able to integrate nodes of any nature. Nodes are “wrapped” by homogeneous embedded hardware and software providing information security (i.e. confidentiality, integrity and availability) by different techniques (cryptography, watchdogs, etc.).