ACORDE - Broadband Railway Internet Access on High Speed Trains Via Satellite Links

BROADBAND INTERNET ACCESS ON HIGH SPEED TRAINS

ACORDE's railway Internet access communications system (ACVSAT-Train-Ku) combines a bidirectional satellite link with a distribution system on the train. The distribution system (wireless LAN and optical fibre) is also bidirectional within the train itself, linking the satellite terminal and the train users.

The ACVSAT-Train-Ku establishes a connection with a stationary GEO satellite, assuring data rates of at least 4Mbit/s in the downlink and at least 2Mbit/s in the uplink. These data rates are functions of both HUB and satellite transponders, and can be improved by increasing transmit power. These data rates have been successfully tested with the train running at 350km/h.

The satellite link should be provided by a satellite operator which will rent the required bandwidth (for example: 7Mhz for 2+4Mbit/s) to the railway operator. Should the data-rate required by the services provided to each train be lower than 2+4Mbit/s, the 7MHz bandwidth rented from the satellite operator could be shared by several trains without additional HW nor SW modification.

The Internet connection should be provided by an ISP (Internet Service Provider); the railway operator should become the ISP to keep control of the system and increase the business revenue.

SYSTEM DESCRIPTION

The ACVSAT-Train-Ku is composed of a communications subsystem, a pointing subsystem and a distribution subsystem.

COMMUNICATION SUBSYSTEM

The communications subsystem possesses:

• Antenna
• Transmitter
• Modem
• Router IP connectivity

POINTING SUBSYSTEM

This subsystem performs the satellite acquisition and tracking. Three axes can be moved in order to maximise the received or transmitted signal, i.e., azimuth, elevation and feeder polarisation. Several elements are required in the pointing subsystem:

• IMU (Inertial Measurement Unit)
• AGC (Automatic Gain Control)
• Control unit

  

DISTRIBUTION SUBSYSTEM

An optical fibre connection is established between the central server and each train car where the conversion from optical to radio domain, and vice versa, takes place. The signal is eventually distributed to the passengers by means of WiFi IEEE802.11g / WiMax IEEE 802.16 access points.

Based on ACORDE's solution, both passengers and rail operators can benefit from the following services:

WIRELESS ACCESS TO BROADBAND INTERNET FOR THE DURATION OF THE TRIP

Via the Internet:

• Web surfing
• MSN
• Voice over IP connectivity (Skype)
• Email

Via railway operator's Intranet:

• On line games
• Trip maps and facts
• Ticket reservations and sales
• Video streaming
• Electronic newspapers

Passengers willing to use the Internet access service should purchase a prepaid card on the train. Together with the prepaid card users will be provided with a username and password to log on to the system.

IP-BASED VIDEO SURVEILLANCE SYSTEM (CCTV)

The recorded picture on our high speed train CCTV system can be centralised and monitored from a control room. Staff can receive silent alarm messages or even pictures with regard to passenger incidents.

Other specifically anti-terrorism technologies, such as chemical sniffers and radiation detectors, can also be combined into the system.

RAILWAY MEASUREMENT SYSTEM

ACORDE's communications system allows railway operators to implement real-time telemetry services for the railway system by means of a 'laboratory car' carrying the measurement equipment for rail wheels, overhead power cable checks, acceleration on train axles, vibrations, etc.