Introduction to SEAMCAT
Example of MCA study
Stella Lyubchenko
European Communications Office
55th CRAF meeting, 3rd - 5th April 2013
(stella.lyubchenko@eco.cept.org)
EUROPEAN
COMMUNICATIONS
OFFICE
Nansensgade 19
DK-1366 Copenhagen
Denmark
Telephone:
Telefax:
+ 45 33 89 63 00
+ 45 33 89 63 30
E-mail: eco@eco.cept.org
Web Site: http://www.cept.org/eco
Outline
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Part 1:
Why SEAMCAT?
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Compatibility/sharing
study tools
• Analytical analysis, usually by worst-case
approach:
– Minimum Coupling Loss (MCL) method, to establish
rigid rules for minimum “separation”
• Statistical analysis of random trials:
– The Monte-Carlo method, to establish probability of
interference for a given realistic deployment scenario
– That is where SEAMCAT comes into picture!
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Purpose
• SEAMCAT is designed for:
– Generic co-existence studies between different
radiocommunications systems operating in same or adjacent
frequency bands
– Not designed for system planning purposes
• Can model any type of radio systems in terrestrial interference
scenarios (mobile, broadcasting, Fixed etc..)
• Used for analysis of a variety of radio compatibility scenarios:
– quantification of probability of interference between various radio
systems (unwanted emissions, blocking/selectivity)
– quantification of throughput and data loss for CDMA and OFDMA
system
• Based on Monte-Carlo generation
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Strategic tool for CEPT
• For performing compatibility/sharing studies
– Used in generating studies for ECC/CEPT Reports
• As a Reference tool
– Recognised at ITU (Rep. ITU-R SM.2028-1)
• As an agreed work platform
– Project Teams (PTs) can focus on the input
parameters and not on the algorithm
– Sharing simulation between proponents ease the
trust in the results
• For educating future generation of spectrum
engineer (Administrations, Industry or University)
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Usage within and
outside CEPT
Source: google analytics on the www.seamcat.org download page (May 2011/2012 period)
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Part 2:
The Graphical User Interface
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Main user interface
• Windows-oriented
• Main element – workspace.sws
Simulation controls:
number of events etc..
Simulations input data – scenario:
Equipment parameters, placement,
propagations settings, etc.
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Simulation results:
dRSS/iRSS vectors,
Pinterference, Cellular
structure
Graphic interface (1/1)
Easy comparison of
workspaces
Easy
view of parameters
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at a glance
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Graphical reminders (tooltip)
Graphic interface (1/2)
Intuitive check of simulation scenario
Shows positions and budget
link information of the victim
and interfering systems
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Overview of results
(dRSS, iRSS)
Part 3:
Flexibility to the User’s need
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Simple and harmonised
interface
Workspaces
Interfering links
On-line Help
Multiple
interferer
generation
Add
Duplicate
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Delete
Welcome + News
History
• Welcome + News
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• History
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Libraries and Batch
• Easy to create workspaces
with predefined libraries
• Edit, import, export
• Easy to run sequentially
workspaces
• Batch operation
• Intuitive use
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Multiple vectors display
Calculated vectors or
external vectors
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Statistics and
signal type
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Propagation model plug-in
• This plug-in may be used to define ANY
kind of propagation model
• No complexity limit
• No limit to the inputs
• Description of inputs
• The plug-in may be inserted at any point
where propagation model is defined in the
scenario
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Comparing propagation
model
Results in linear or
log format
Compare two or more
propagation models
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Part 4:
Systems you can simulate
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System type
Generic
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CDMA
OFDMA
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Generic system
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Cellular modelling
• Modelling of cellular systems as victim,
interferer, or both:
• Quasi-static time within a snapshot
• One direction at a time (uplink or downlink)
• CDMA
• Voice traffic only
• Particular CDMA standard defined
(CDMA2000-1X, W-CDMA/UMTS)
• OFDMA
• LTE
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Part 5:
Calculations in brief
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Interference Calculations
Interfering Modes Interference Criteria
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Unwanted Emissions
• Victim
Receiver Bandwidth
Interferer emission mask
fv
fI
• Interfering System
Interfering emission mask
fI
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Results
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Part 6:
Example of MCA study
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Assumptions for study
• The secondary RAS allocation in the band 2655 – 2690 MHz
• Protection criterion -177dBm in 10MHz which should not be
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exceeded for 2% of time (in SEAMCAT it will be interpreted as a
percentage of snapshots for which criterion is not exceeded)
Telescope height is 50 m.
1 aircraft within 100 km (within a cylinder: 3000 m – 15000 m)
Deployment density considered: 0.0000255 km2
For the secondary RAS allocation in the band 2655 – 2690 MHz;
Max allowed power of IT was calculated -81 dBm in 10 MHz
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Thank you - Any questions?
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