Onboard trains, customer surveillance could be done via various networked cameras. These cameras can be controlled centrally and used to identify any suspicious or potentially dangerous incidents during travel. Embedded systems within trains can now be now used to control the display of advertisements whilst monitoring the activity of passengers for anti-social or criminal behaviour. When the train arrives at a train station, the embedded system establishes a wireless connection with the local server. Video surveillance footage is then uploaded and the train is ready for the following trip.

Embedded applications often require a compact rugged computer capable of front-end data processing. Traditional air-cooled systems cannot achieve the desired MTBF necessary for critical applications. Leading edge designs now utilise aluminium casing, which are thermally bonded to internal heat generating components. Ambient conditions could vary, hence this rugged computer needs to withstand; a high amount of shock and vibration, wide temperature and humidity variations, reasonable levels of ambient dust and particles. At the heart of each CCTV system is a rugged embedded computer that must be capable of withstanding the high degree of shock and vibration transmitted through the chassis of the train carriage. Wide temperature, 24/7 operation and direct DC powering capabilities also makes this unit suitable for the ambient conditions in this environment.

A power over Ethernet switch distributes data between cameras and the central PC and removes the need to supply power to each of the cameras. Power over Ethernet reduces the cost and complexity of camera installation. Amplicon have recently released a unique Ethernet switch designed for PoE applications in the security market - the AES-208P.

A wireless LAN card added via an expansion slot in the rugged embedded computer provides an automatic connection to the wired network when the train returns to base or a selected train station. Using a WLAN card with an external connector allows the appropriate length of co-axial cable and antenna to be added. WPA encrypts the transferred data providing end to end security.

The generic hardware platform described above requires software to transform it into a customised CCTV solution. System integrators may choose to develop their own software or off-the-shelf packages such as 'Milestone' can be installed, removing software development overhead and facilitating a shorter time to market.