MiXiM - CCS Labs

MiXiM
Michele Segata and Bastian Bloessl
University of Innsbruck
Problem
▪ Map wireless network simulation to DES paradigm
Compound Module
Simple Module
Simple Module
Simple Module
Gate
vs.
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MiXiM
▪ Combines several module libraries
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Mobility Framework (MF)
Channel Simulator (ChSim)
MacSimulator
Positif framework
▪ Goal: accurate and fast modeling of PHY-Layer operations
▪ Targets
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Modeling propagation and transmission delay
Frame synchronization / frame detection
SINR calculation / bit error analysis
RSSI / channel state estimation
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The Challenge
channel attenuation (in dB)
▪ Example: frequency selective fading
Source: S. Valentin, "ChSim -- A wireless channel simulator for OMNeT++", TKN TU Berlin Simulation workshop, September 2006
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Connection Modeling
▪ Transmission channel is (thin) air
▪ Need more than a single connection
▪ Single transmission impacts multiple (but not all) nodes
▪ MiXiM approach:
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Connect sender to all affected nodes
“Affected” := within maximum interference distance
Manipulate transmissions to include path effects etc.
Receiving nodes can individually reason about signal quality
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The Signal Concept
▪ Model message as electromagnetic
wave (“Signal”)
▪ Time
▪ Frequency
▪ Space
▪ Model signal effects as mapping: 𝑀 𝑡, 𝑓
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Pathloss
Shadowing
Fading
Antenna gain
MIMO
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▪ Apply gain effects to signal:
▪ 𝑃𝑅𝑋 = 𝑀 𝑡, 𝑓 ∙ 𝑃𝑇𝑋
Source: K. Wessel, M. Swigulski, A. Köpke, D. Willkomm, “MiXiM – The Physical Layer:
An Architecture Overview”, 2nd International Workshop on OMNeT++, Rome, Italy, March 2009
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The “Analogue Model” Concept
▪ Mappings applied by chain of “Analogue Models”
▪ e.g.: path loss
▪ e.g.: attenuation by buildings
Source: C. Sommer, D. Eckhoff, R. German and F. Dressler, "A Computationally Inexpensive Empirical Model of IEEE 802.11p
Radio Shadowing in Urban Environments," 8th IEEE/IFIP WONS 2011, Bardonecchia, Italy, January 2011
Source: C. Sommer and F. Dressler, "Using the Right Two-Ray Model? A Measurement based Evaluation of PHY Models in VANETs,"
17th ACM International Conference on Mobile Computing and Networking (MobiCom 2011), Las Vegas, NV, September 2011
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The “Decider” Concept
▪ Receiving PHY will reason about reception using “Decider”
▪ e.g.: SNR threshold decider
▪ Vote NO on frames with SNR dropping below threshold
▪ Vote YES otherwise
Time
Source: K. Wessel, M. Swigulski, A. Köpke, D. Willkomm, “MiXiM – The Physical Layer: An Architecture Overview”,
2nd International Workshop on OMNeT++, Rome, Italy, March 2009
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Configuring AnalogueModels and Deciders
▪ **.phy.analogueModels = xmldoc("config.xml")
▪ **.phy.decider = xmldoc("config.xml")
<root>
<AnalogueModels>
<AnalogueModel type="SimplePathlossModel">
<parameter name="alpha" type="double" value=“2.0"/>
<parameter name="carrierFrequency" type="double" value="2.4e+9"/>
</AnalogueModel>
</AnalogueModels>
<Decider type="Decider80211">
<parameter name="threshold" type="double" value="0.10"/>
</Decider>
</root>
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MiXiM – The Physical Layer
Source: K. Wessel, M. Swigulski, A. Köpke, D. Willkomm, “MiXiM – The Physical Layer: An Architecture Overview”,
2nd International Workshop on OMNeT++, Rome, Italy, March 2009
[C2X-PS] Summer 2013 - MiXiM
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