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20.4.2012
1
Communication Network Simulations Using OPNET
Juho Markkula
521365A Simulations and tools for telecommunications
24.4.2012 klo 12.15TS133
1
Network simulations
• Simulations are used for
– Application
– Equipment
– Protocol (algorithm)
– Network security
functionality verification and implementation comparison
• Modeling of a real communication network
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Things that are simulated
• Packet transmission.
– Capacity
• Packet formation.
– Packet length and distribution
• Terminal entering and exiting networks
• Communication link setup between terminals
• Mobility
• Effect of disturbance of other transmissions
• Energy consumption
3
Results
• End to end delay
• Throughput
• Packet loss
• Congestion and lost connections
• Network utilization
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Throughput
00.020.040.060.080.1
0.120.140.160.180.2
0
0.00
78125
0.01
5625
0.03
125
0.06
250.
125
0.25 0.
5 1 2 4
G
S
ALOHA
5
End to end delay
G
dela
y6
Network simulators
• OPNET (www.opnet.com)
• NS2 (http://www.isi.edu/nsnam/ns/)
• OMNeT++ (http://www.omnetpp.org/)
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OPNET
• Event based discrete time simulator.
• Packet level simulations
• Developped for wireline simulations
• Currently also supports wireless system simulations
– Radio channel modelled accurately
• Contains a large library of accurate models
(network hardware and protocols)
• For R&D
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Modelling
•Network
•Sub nets, topologies, geocraphical modelling, mobility
•Node
•Routers, servers, clients, mobile terminals etc.
•Process
•Protocols (TCP/IP), data generation, algorithms, etc
External processeing possible
(Matlab)
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Tools in OPNET• Network model editor
• Node model editor
• Process model editor
• Source code editing environment
• Antenna pattern editor
• Modulation curve editor (SNR –BER behavior)
• Packet format editor
• Analysis configuration tool
• Simulation tool
• ICI editor (Interface Control Information)
• Probe model tool (organization of result collection)
• Link model editor (properties of fixed link models)
• Path model editor (for routing and modeling virtual circuits)
• Demand model editor (wide scale application modeling)
• OPNET Animation viewer
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Network modeling
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Network modeling (2)
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Node modeling
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• Node structure
• OSI –like presentation
Node modeling (2)
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Process modeling
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Process modeling (2)
• Process models determine the functionality of the node model
• State machines
• Conditional transitions from state to another determined by external events (e.g. packet arrival), or self interrupts (e.g. packet generation)
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Process modeling (3)
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Process modeling (4)Editor to help C/C++ code writing.
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Simulation toolParametrized simulations
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Simulation tool (2)
• Simulations as a function of time
• Not enough for determining the full statistics of a phenomenon
• Several simulations needed with different seeds
• Typical results are averaged combinations of different iterations.
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Analyze tool
• Tool for inspection of results
• Published results can be done with Matlab where there are more possibilities for editing the results
• Numerical values of the simulation results also available
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Physical link (Radio)
• Physical link is presented with a connection where all the issues present in the physical layer are described.
• When a packet travels inside the simulation, the effect of all the states of the PHY layer is calculated
• The effect of other users also taken into account.
• All the states are presented with editable C/C++ code
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Physical link (Radio)(2)
• Used connection components are determined by the transceiver attributes.
• The attributes can be altered during the simulation
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Physical link (Radio)(3)
BER for a BPSK moddulation
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Antenna modeling
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Packet editor
• Packet editor can be used for describing the transmission packets used for the simulation
• Length and content can be determined according to one’s needs
• Data transmission among the simulation entities.
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OPNET productsNetwork R&D
– OPNET Modeler –The main simulation & development tool+
Wireless suite and Defense additions
Capacity management
– IT Guru (network and system capacity planning for enterprises)
– SP Guru (network planning and engineering for service providers)
Network operations
– IT Sentinel (network audit, security, and policy compliance for
enterprises )
– SP Sentinel (network audit, security, and policy compliance for
service providers)
– IT and ST Netcop (unified network views and situational awareness)
Application performance management
– ACE Analyst (analytics for networked applications)
– ACE Live (enduser experience monitoring & realtime network
analytics)
– SLA Commander (application service level monitoring)
– OPNET Panorama (realtime application monitoring and analytics)27
Options for OPNET Modeler
• 3G LTE
• UMTS (WCDMA)
• WiMAX (802.162004, 802.16e2005)
• DOCSIS (Data Over Cable Service Interface Specification)
• IPv6 + Mobile IPv6
• MPLS (MultiProtocol Label Switching)
• PNNI (Private NetworkNetwork Interface)
• Terrain Modeling
• TIREM (propagation modeling calculation)
• Satellite Capability (dozens of models for satellite systems)
• Joint Communications Simulation System (JCSS) (Military orientated
models)
• Vendor Devices (Dozens of vendor specific devices)
• Integration with 3rd Party Products (several modules)
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Summary
• OPNET is an event based (discrete time) communication network simulator software
• OPNET contains a large library of accurate models
(network hardware and protocols)
• Networks modeled in three levels; network , node, process (c-code).
• Large number of additional features and tools to ease the problem solving
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References
• OPNET Modeler + Wireless (version 16.0 (14.0))
• OPNET (versions 16.0 (14.0)) Documentation
• OPNET Technologies, Inc. WWW page, http://www.opnet.com
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Opnet Demo: 3G LTE
• The network is composed of 10 UEs, NobeB, EPC and server.
• Voice, Video conference, HTTP and FTP-traffic is delivered in network.
• Table presents traffic per UEApplication type Interval [s] duration Direction
Voice Ip telephony and Silence supressed 5 min UL, DL
Video conference 128×120 pixels 0.1 1 min UL, DL
HTTP 11-51 kB/page 10 10 pages DL
FTP 2670.5 kB/file 1 file DL