Million Entity Distributed Simulations

1. Million Entity Distributed Simulations Improving network load by eliminating broadcast interest groups Presented by: David Prody

2. State of the Art • In 2005 the Institute for Defense Analysis conducted a million plus entity simulation. • Joint Semi Autonomous Force (JSAF) was used as the driver for entities inside the simulation • Scalable Parallel Processor (SPP) where use to provide the horsepower for the simulation • These nodes where spread out across the country including several supercomputer sites • Maui High Performance Computing Center • Aeronautical Systems Center Major Shared Resource Center • High Performance Computing Modernization Program (DOD)

3. How they did it • Tree of Meshes Routing • Groups of nodes used mesh overlays to communicate with other local nodes • One node in each local mesh was connected to backbone mesh connecting the 5 primary simulation sites • Interest declaration • Modified Runtime Infrastructure version s (RTI-s) • Simulation nodes specify what data they are interested in. • Publish Subscribe model • Sender side quelch • Original RTI-s used multicast to handle interest groups • Smarter routers not only send out data to nodes that have requested it • Limited “active entities” • Most entities (one million) where civilian “clutter) • Only 1000 combat entities total • No combat entities used emiiters (no radar or laser)

4. The Problem • Simulation did not contain enough combat elements to effectively model theater wide combat. • More active entities are needed. • Modern combat vehicles make extensive use of EMF spectrum. • Radar and laser is a major component of a modern battlefield • Precision guided weapons • Active Radar Tracking/Radar Countermeasures

5. Problem with Emitters • Under the current RTI-s interest declaration protocol there is only one emitter interest group • If you an interested in any emission you must receive all emissions • This is not a scalable solution.

6. Proposed Solution • Break up emitter interest group into geographic regions. • Simulations nodes will be allowed to specify specific geographic regions of interest and only receive emitter traffic from those regions • This forces receivers to compute the regions they are able to receive from before they can receive any traffic. • This implementation will be done the same as entity position interest groups are handled • Battle space is broken in a grid and each grid point is given a unique identifier • Receivers publish a list of grid square that they are interested in.

7. Test Bed • Computer simulation based on the 2005 large simulation run and personal experience with battlespace simulations • 100 nodes in Mesh network • Entities distributed evenly throughout nodes • This is done for real simulations to prevent computational “hotspots” • Only Emitter traffic monitored • 4 different distributions of emitter entities “locations” modeled • Broadcast – This is the current method. Entity location is irrelevant because controlling node will broadcast to all nodes • Random distribution – Entities in each node are randomly assigned a grid location • Host Cluster – Entities in the same node have a high probability of being in the same grid. • This is closest to how real simulations work • Two different distributions where tried. The probability of entities grouping was changed • 50% probability – half of the entities on the node where in the same grid • 30% probability – 30 % of the entities on the node where in the same grid

10. Thank You for Listening Any question? Write: dprody@gmail.com