1. SIMTO Project Overview
11/18/2018
The SIMTO Project
A Framework for a Flexible Simulation Toolset for Future IP Networks Project Overview and Status
Thomas Luckenbach
Marc Emmelmann

2. SIMTO Project Overview
11/18/2018
The SIMTO Idea
Home
Car
Satellite
SIMTO
Simulation Tools
Simulation Models
Simulation Results

3. SIMTO Project Overview
11/18/2018
Knowledge Exchange
At GMD FOKUS side SIMTO has established:
research contract with Technical University of Berlin ( , 6 month student, simulation tool analysis)
research contract with CNUCE ( , 12 month scientist, TCP/IP via LEO)
research stay of GMD researcher in Pisa (6/00, 2 weeks., introduction into ATM-Sat, agreement on workplan)
research stay of CNUCE researcher in Berlin (10/00, 1 week, introduction into demonstrator, presentation of results)
Continuation of SIMTO depends on funding

4. SIMTO Project Overview
11/18/2018
Work Items & Topics
Network Environment & Parameters
Evaluation of Simulation Tools
Review of Project Goals
Simulation Results
Network Environment & Parameters:
Overview of target architecture specification
Assumptions made for simulation purposes
Evaluation Tools:
Present tools that were evaluated
Point out reasons for specific choices
Review of Project Goals:
Re-evaluation of envisioned goals and project aspects
Simulation Results:
First simulation results
Presented by CNR/CNUCE

5. Network Environment & Parameters
SIMTO Project Overview
11/18/2018
Network Environment & Parameters
Defined by GMD/Fokus
Based on LEO Satellite project at GMD
Includes definition of:
Satellite Orbit
Bit-Rates
Bit Error Rates
Up- & Downlink Delay
Intra-Satellite Delay
Defined by GMD/Fokus
Based on LEO Satellite project at GMD:
LEO satellite network
ATM based
Multimedia Support: Video, Voice, Data, etc.
Definitions for SIMTO:
(a) Orbit, bit- & error-rates
(b) propagation delay (Up-, Down-, & Intra-Satellte)

6. Satellite Orbit,Bit- & Error- Rates
SIMTO Project Overview
11/18/2018
Satellite Orbit,Bit- & Error- Rates
Feeder Up & Downlink: Mbit/s
BER above MAC 2*10e-8
ISL: Gbit/s
BERs neglected
Service Downlink: Mbit/s
Service Uplink (fixed): Mbit/s
Service Uplink (portable): 384 kbit/s
LEO Satellite
1350 km orbit
45deg inclination
Network Overview: LEO satellite network: orbit hight: 1350 km
inclination: 45 deg
permanent line of sight; 20 deg. min. eleavation
Ground stations:
Service Provider: E.g.: ISP
Large antennas, fixed position
Portable Terminal: E.g. Notebook
Medium antenna, portable
NOT moving during communication
Mobile Terminal: E.g.: Notebook (or handheld)
Medium (or small) antenna, portable
Moving during communication
[Press RETURN]
Bit-Rates & Error-Rates
Downlink: Mbit/s for all types of terminal, shared
Uplink: Feeder Link: Mbit/s
Portable Terminal: Mbit/s
Mobile Terminal: 384 kbit/s
BER: 2*10-8 (above MAC); good wheather
link failure during rain
Mobil Terminal
Portable Terminal
Service Provider

7. SIMTO Project Overview
11/18/2018
Propagation Delays
Up- & Downlink Delay
function of slant range
analytically gained
verified with STK
Intra-Satellite Delay
“routes in the sky” still open
simulation based
forward & backward, “left” & “right” neighbor
Up- & Down-Link
satellite passes observer at 90deg. elevation
min. elevation: 20deg. ==> 12 min. visibility
delay in between 4.5 ms and 9 ms
plotted: slant range / speed of light
Intra-Satellite
affects strongly end-to-end delay for long distance calls
not apliable for “single-hop-scenarios”
Simulation based (STK)
walker orbit: 12 planes, 6 satellites per plane
forward delay: constant
next neighbor:
in between 11.5 ms and 15 ms
period: 40 minutes !!
==> change of 4.5 ms in 40 minutes
==> 1/4 of uplink-delay variation

8. Evaluation of Simulation Tools
SIMTO Project Overview
11/18/2018
Evaluation of Simulation Tools
RESQ
Research Queuing package, developed at IBM
very strong in describing behavior of queues
protocol simulation done by “jobs” passing queus
OPNETmodeler/Radio:
Event oriented; state-machines to describe protocols
support of ATM and wireless scenarios
large networks can be modeled
graphical interface for modeling and simulation
complex statistical results possible
standard tool in commercial projects (Nortel, NASA, Bosch, DLR)
NS:
freely available, c-based simulation tool
rudimental satellite support
neither graphic input nor graphical representation of results
no ATM support at the time of evaluation
STK:
Toolkit to analyzes satellite orbits, slant ranges, and reachability

9. Review of Project Goals
SIMTO Project Overview
11/18/2018
Review of Project Goals
“Real Life” Verification of Simulation Results
Test-Beds
Real Networks
Provision of Demonstration Environment
Network independent
TCP Analyzer
User Application Platform
“Real Life” Verification
Only simulation not enough
Necessary to verify simulation results in the real world using:
Test-Beds
Real Networks
Demonstration Environment
Network independent
consider the network to analyze as a “cloud”
single hop or multiple hop analyzes (entire network)
TCP Analyzer
collection of several tools and programs to evaluate TCP
Tools: DBS -> predefined complex traffic patterns (tcp, upd) FTP: regular ftp-transfer
netperf: single connection, bandwidth & latency
see also RFC 2398
User Application Platform
computer running any “daily life” application
subjective test of network’s QoS

10. Simulation Results & Demonstrator Set-Up
SIMTO Project Overview
11/18/2018
Simulation Results & Demonstrator Set-Up
Will be presented by: Dr. Enrico Gregori & Cristina Foderi CNR / CNUCE

11. SIMTO Project Overview
11/18/2018
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Information about FOKUS
Information about the Competence Center CATS
Information about the project
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