Abstract
In modeling and simulating complex systems, such as mobile ad-hoc networks (MANETs), in defense communications, it is a major challenge to reconcile multiple important considerations: the rapidity of unavoidable changes to the software (network layers and applications), the difficulty of modeling the critical, implementation-dependent behavioral effects, the need to sustain larger scale scenarios, and the desire for faster simulations. Here we present our approach in successfully reconciling them using a virtual time-synchronized virtual machine (VM)-based parallel execution framework that accurately lifts both the devices, as well as the network communications, to a virtual time plane while retaining full fidelity. At the core of our framework is a scheduling engine that operates at the level of a hypervisor scheduler, offering a unique ability to execute multi-core guest nodes over multi-core host nodes in an accurate, virtual time-synchronized manner. In contrast to other related approaches that suffer from either speed or accuracy issues, our framework provides MANET node-wise scalability, high fidelity of software behaviors, and time-ordering accuracy. The design and development of this framework is presented, and an actual implementation based on the widely used Xen hypervisor system is described. Benchmarks with synthetic and actual applications are used to identify the benefits of our approach. The time inaccuracy of traditional emulation methods is demonstrated, in comparison with the accurate execution of our framework verified by theoretically correct results expected from analytical models of the same scenarios. In the largest high-fidelity tests, we are able to perform virtual time-synchronized simulation of 64-node VM-based full-stack, actual software behaviors of MANETs containing a mix of static and mobile (unmanned airborne vehicle) nodes, hosted on a 32-core host, with full fidelity of unmodified ad-hoc routing protocols, unmodified application executables, and user-controllable physical layer effects, including inter-device wireless signal strength, reachability, and connectivity.
Original language | English |
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Pages (from-to) | 439-456 |
Number of pages | 18 |
Journal | The Journal of Defense Modeling and Simulation: Applications, Methodology, Technology |
Volume | 12 |
Issue number | 4 |
DOIs | |
State | Published - Oct 1 2015 |
Bibliographical note
Publisher Copyright:© 2015, © The Author(s) 2015.
Keywords
- Network simulation
- ad-hoc networks
- discrete event simulation
- hypervisor
- real time
- scheduling
- synchronization
- virtual machine
- virtual time