Cost 286 Hamburg, 25-26/11/2004 1/16

Budapest University of Technology and EconomicsFaculty of Electrical Engineering and Informatics

Department of Electric Power Engineering

Possibility of wireless communication in a railway carriage

Ferenc GAZDAG, assistant lecturer

János LÖCHER, research engineer

György VARJÚ, professor

Cost 286 Hamburg, 25-26/11/2004 2/16

IntroductionUsing Wireless LAN in a railway carriage

- Presenting the place of measurements

- Result of the measurement

- Conclusions

- Future plans (realisation)

- Introducing the used devices

- Why we need this?

Cost 286 Hamburg, 25-26/11/2004 3/16

Internet on the trainThe reasons to deal with WLAN inside a carriage

-plan for managers to use their notebooks during the travel

-mainly based on IC and EC (Inter and European City train)

-the wired solution has too many problemsphisycal connection (can be damaged)fixed number of users

Cost 286 Hamburg, 25-26/11/2004 4/16

Used devicesWe need an Access Point, WLAN card, spectrum analiser

-Access point (router), IEEE 802.11g

SMC 2804WBR, 100mW-WLAN card in the notebook

SMC 2835W (802.11g)HP PCMCIA (802.11b)

-spectrum analyser (HP8594E) with an antenna

Cost 286 Hamburg, 25-26/11/2004 5/16

Place of measurementWest-Hungary, Sopron

Main railway station of GYSEV/ROeEE

Cost 286 Hamburg, 25-26/11/2004 6/16

Environment

Cost 286 Hamburg, 25-26/11/2004 7/16

Trains

Bp type IC carriage

Bpy type 1st & 2nd class carriage

Cost 286 Hamburg, 25-26/11/2004 8/16

Seat locationBp type carriage (1

part)

Bpy type carriage (3 part)

Cost 286 Hamburg, 25-26/11/2004 9/16

Measurements (Bp)

Num# Carriage Seat OrienationLink qualityspeed [kByte/s]

0 Bp 11 back to 100% 12531 Bp 21 back to 85% 15002 Bp 22 face to 86% 14003 Bp 41 back to 85% 14834 Bp 42 face to 80% 14135 Bp 61 back to 73% 13406 Bp 62 face to 75% 14107 Bp 91 back to 65% 14508 Bp 92 face to 72% 13609 Bp 102 face to 67% 1300

10 Bpy 21 back to 30% 65011 Bpy 22 face to 40% 65312 Bp 21 back to 45% 1300

Bp type carriage (1 part)

Cost 286 Hamburg, 25-26/11/2004 10/16

Measurements (Bpy)Bpy type carriage (3

parts)

Num# Carriage Seat OrienationLink qualityspeed [kByte/s]

13 Bpy 11 face to 60% 120014 Bpy 36 back to 65% 114015 Bpy 45 face to 100% 115016 Bpy 72 face to 80% 126017 Bpy 97 back to 60% 120018 Bpy 112 face to 60% 1211

Cost 286 Hamburg, 25-26/11/2004 11/16

Some spectrum

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2390 2400 2410 2420 2430 2440 2450 2460 2470 2480 2490

f [MHz]

E [

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/m]

Cost 286 Hamburg, 25-26/11/2004 12/16

Some spectrum

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Cost 286 Hamburg, 25-26/11/2004 13/16

Some spectrum

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Cost 286 Hamburg, 25-26/11/2004 14/16

Some spectrum

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Cost 286 Hamburg, 25-26/11/2004 15/16

Conclusions

-it can be work, with some restrictionsavoid two AP-s workin in each other range, HW/SWfind possible EM noise sources

-the field is strong enough outside the carriage

-the transfer rate is not a real function of the field strength

-the effect of the human presence must be investigate

Cost 286 Hamburg, 25-26/11/2004 16/16

Thank you for your attention!

Cost 286 Hamburg, 25-26/11/2004 17/16

Next step

Internet

Downlink: from satelliteUplink: GSM/GPRS – for test only

450 MHz data link