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Showing posts with label Internet. Show all posts
Showing posts with label Internet. Show all posts

Thursday, June 12, 2008

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.


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Sunday, May 25, 2008

ALBRECHT WLAN radio


I guess i found something interesting that is an ALBRECHT DR-315 from http://www.albrecht-online.de/ . A small radio with powerfull capabilities. It support 802.11 b/g, 54 Mbps, DAB/FM Tuner also can connect to any internet radio station.


I just wonder when this technology will come to my country, Indonesia. Our research here about DAB/DVB or a digital communication even on product is still less than enough. We plotted by some big country just to be a consumer country, not a producent. But I still interest on how this small machine can work based on OFDM modulation technique. May be later after Wimax really deploy here that dream will be come true.
Also, if cognitive radio technology has grown to mature level I also can enjoy this product. I only hope that it won't be take a long enough time. Only government regulation can force that, i guess. So is their polotical will.
This product has been sell about 272 CHF(it's Switzerland Currency) or about 181 Euro or 2,654,752.8 Indonesian Rupiahs not included shipping cost. The price is not to high for such technology we will got. Hmmmm......
but maybe i still cannot use this thing because of there's no network here and the station's coverage. Using a common acces point only cover about 100 m, but if we use wimax maybe we can got a full coverage. So I really hope the government can deploy Wimax soon. So I can take benefit from this product.
It's really nice to dedicate our life to something worthed.
Good night everybody, i think it's time for me to get sleep....see u later


Read more!
TCP/IP Quick Guide 3G Wireless Quick Guide (electronic and printed bundle)