Risk assessment
GSM-R blocking
to support the
coordination process
in the Netherlands
Loek Colussi
June 30, 2014
Coordination agreement
• technical committee: UMTS/LTE900 will increase probability of
blocking/intemodulation
• agreement between MNOs, GSM-R operator and regulator
• interim solution  sustainable solution mid 2015
• no legal basis, appeal on social engagement
• single points of contact
• valid until July 1st 2015
June 30, 2014
Coordination process
Before site activation
• information to regulator >1 week prior to activation
• base stations within 500 m from railway track
• probability of blocking  software tool/modeling & field measurements
• impact analysis  ‘severity map’ from GSM-R operator
After site activation
• active monitoring by GSM-R operator
• report interference to MNO and regulator
• severe disturbance  switch off site/sector within 4 hours
• moderate disturbance  mitigation
June 30, 2014
Pre-activation coordination process
June 30, 2014
Post-activation interference management
June 30, 2014
Risk of blocking/intermodulation
Risk = Probability x Impact
Probability of blocking determined by:
• simulations with coordination tool, translated to geografic picture
• measurements from railway
• detailed inspection
• feedback from field
Impact of blocking determined by :
• annoyance/danger to be predicted
• location (station, shunt, port)
• expected train speed
• application of ERTMS
June 30, 2014
Coordination tool
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‘proportional method’
all block of MNO filled with UMTS
GSM-R on highest channel (924.8 MHz)
single MNO basestation (Tier 0)
rural & suburban HATA propagation model
fixed distance between GSM-R basestations
good & bad radios
with & without filters
Tx power of MNO
June 30, 2014
Model GSM-R radio
June 30, 2014
Simulations with coordination tool
rural
suburban
June 30, 2014
Translation to geografic picture
for each 100 m railway bin:
• what is the distance to the nearest
MNO basestation?
• what is the distance to the nearest
GSM-R basestation?
• is the protection distance
jeopardized?
June 30, 2014
Geotool
• GSM-R: all basestations
• MNO: < 500 m from track
• analysis resolution: 100 m
= GSM-R
= KPN
= T-Mobile
= Vodafone
= blocking
June 30, 2014
June 30, 2014
Measurements
June 30, 2014
Risk assessment
Low risk:
• small chance of blocking according to simulation and measurement
• outside area of potential risk
• expected range of disturbance short
• special railway provisions
High risk:
• large chance of blocking according to simulation or measurement
• inside area of potential risk
• expected range of disturbance large
• cumulation of signals
June 30, 2014
Example: high risk
June 30, 2014
Example: low risk
June 30, 2014
Example: high or low risk?
June 30, 2014