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HLA Project Overview
ACIMS LabPrepared by: Saurabh Mittal
To Start with…
• Basic ideas on– Designing network environments with
common parameters (e.g. mean distance, probability of connection, quantized or periodic updates, etx.)
– Modeling various components within these networks
• Preliminary design of router completed
• Basic tests conducted(eg. Ensuring packet routing etx..)
DEVS Simulation Layer(nodes and links being simulated as per DEVS Formalism)
Experimental Frame Layer
Network Modeling Layer
Routing Sub-layer
Topology Sub-layer
Area encompassing components designedusing DEVS Formalism
Topology Designer
VisualizerParameter Controller /
Evaluator Traffic Generator
Layered Architectural Framework
DEVS Modeling & Simulation HLA Network Framework
Development of DEVS:• Modeling API for components in Application
Layer• Routers• Links• Message Passing and other specialized features
related to Application Layer components
System Entity Structure (SES) for Net-Framework
Network Node
Improvise Router (network) Node for HLA implementation
• Develop the router node as shown below and create a network
Payload Traffic
GeneratorRTI
Ambassador
updates
Updates to specific destinations
Routing/Lookup Table
Real-time Routing Engine
Forwarding Engine
Routing Capability Inside every network Node (taken form earlier Version of simulation-based Router)
Message Passing to be implemented
Traffic generatorGenerating packetsOf different classes
M/M/1 queuing system that routes packets based on the information from the forwarding engine. The queuing system characterizes the RTI capabilities
HLA / RTI Implementation
• Centralized and De-centralized versions of network HLA/RTI under consideration
• Different experiments devised to gather information about– Thruput– Network delay– Link utilization
• Transducers being implemented within components (links+routers) to gather individual data in an automated manner.
Conceptual Centralized HLA/RTI network
• Network components– Centralized RTI Executive node
• Receives packets being published• Broadcasts packets being subscribed
– HLA Router• Generates traffic containing packets of different
‘classes’
– Links
Centralized HLA/RTI Network
HLA Router Network
HLA Router 1
HLA Router 2
HLA Router n
RTI EXECUTIVE RTI Executive - a part of the Network - routers publish messages of different ‘classes’ to RTI - broadcasts messages to every other node - those subscribed to particular ‘class’ of messages, attend to it, others ignore
Metrics - end-to-end Delay - average link utilization - thruput - queuing time at RTIExec
‘RouterNode’
‘HLA Router’
‘HLA Router’
‘HLA Router’
DEVS Demowith RTI Executive
Example Topology being modeledRun networkHLAwithRTIExec.java
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RTI Executive
HLARouter
DEVS Network in simView
RTI Exec Router links
RTI Exec links
HLA Routers
Publish-Subscribe functionality
• Each federate– Publishes packets to ‘classes’– Subscribes to particular ‘classes’
If there is RTI Executive present• Packets are published to destination RTI Exec• Packets are broadcasted to other federates thru it• Packets can be multicasted to only those federates who subscribe to those
classes
If there in NO RTI Executive present• Point-to-point network• Packets generated to specific destinations
public class Publish extends entity {
///stores classNames in string format
private ArrayList classes; private ArrayList classesString; private ArrayList classesDouble; public Publish() public Publish(String name) public void publishMsgOfClass(String msgClass) public void publishMsgOfClasses(ArrayList classes_) public int getPublishedClassCount() public String getClass(int i) public boolean isClassOfMsgPresent(String msgClass) public void removePublishedClass(String msgClass) }
Similar is the ‘Subscribe’ class
Benefits:•Can communicate in more than One data-type as opposed to just ‘Strings’Better functionality and encapsulationby creating a Publish or Subscribe object
DEMO 1
Run networkHLAwithRTIExec.java main function
• Visualization of constructed DEVS Network in real-time manner
. • Adjusting of network
parameters for observing behavior of the network
• Modular GUI development and GUI created at run-time during the time the network gets created
• EASY to IMAGINE what you want to achieve with your network
LINK PANEL
ROUTER PANEL
Real-time Simulation
Controller
DEMO 2
• Attractive GUI• Change dynamically,
– Number of nodes
– Distance between nodes
– Link Properties
– Connection-density
• Integrate with Demo 2 in progress
• Run ListSelect.java main function
FAST Mode DEVS simulation inside devsNetworkHLA.java
public void simulate(){ s.s("inside devsNetworkHla.java simulate()"); coordinator c = new coordinator(this); c.initialize(); c.simulate(1000); }
Snapshot of OUTPUT
PACKET RECEIVED AT : HLA Router_node_8Packet_from_0_to_8_cost_5.0_type_0_Class_b_nextHop_8------PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class b ...ignoringPacket_from_0_to_8_cost_5.0_type_0_Class_b_nextHop_8------PACKET RECEIVED AT : HLA Router_node_3Packet_from_8_to_3_cost_5.0_type_0_Class_d_nextHop_3------PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class c ...ignoringPacket_from_1_to_0_cost_5.0_type_0_Class_c_nextHop_0------PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class b ...ignoringPacket_from_0_to_8_cost_5.0_type_0_Class_b_nextHop_8------
PACKET HAS REACHED ITS DESTINATION with the info: I am NOT SUBSCRIBED TO THIS CLASS: Class d ...ignoringPacket_from_1_to_3_cost_5.0_type_0_Class_d_nextHop_3------
Terminated Normally at ITERATION 1001 ,time: 2.191101580114225
Topology Designer
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HLA Routers connected in P2P network and communicating without RTI Executive
HLA Routers connected in P2P network and communicating THRU RTI Executive
Experiment No. 1 Experiment No. 2
Each Federate publishing 3 types of packets and subscribed to 3 different class of packets. The receiver federate attends only to the subscribed packets and ignores other packets.
Simulated Topological setup
P2P Run Time to Stabilize Thruput of Network
INCREASE in Thruput
Plot of Avg Thruput v/s TimeAvg Thruput v/s Time
Further INCREASE in
Thruput
Time to Stabilize
after updating
RTI Delay
Plot of Link Max Q length v/s TimeLink Max Q length v/s Time Plot of
Latency Max v/s Latency Max v/s TimeTime
Increase in Queue Lengths of Network due to Increase in
Load
UPDATED Load
UPDATED Link Capacities Packets in Links
Packets in Routers
Centralized HLA: Broadcast ModeT= 4.461 sec
RESPONSE Time
Thruput Stabilization for
RTI Links
SNAPSHOTTime
Packets in Links
Resulting Q Length for RTI Length during Stabilization
Centralized HLA-Multicast mode
SNAPSHOTTime
Thruput Stabilization for
RTI Links
Resulting Q Length for RTI Length during Stabilization
Link CapacityReduced to
accommodate Stabilized load
RESPONSE Time
Other Simulation Experiments
• Various other case studies were conducted– Benchmarking and Tuning of this DEVS
model based on reported results for RTI latency
• Details can be looked in the Project report.
• Thanks for your Attention !!!