Efficient data consistency in HLA/DIS++

Simulation exercises based on the DIS paradigm are faced with a severe scalability limitation due to the use of time out updates or "heartbeat" messages for maintaining consistency despite message loss. Since they carry information that is redundant and useless in most cases, these messages represent a waste of network bandwidth and computational resources. This paper presents an elegant solution that eliminates heartbeats without compromising consistency. Rather than using additional schemes and software components as others have done, the solution proposed here consists of careful use of reliable and unreliable communications based on a key insight into the communication properties of DIS-based simulations. Not only does our solution eliminate heartbeats, it also minimizes additional resource consumption by using reliable communications minimally. Finally, due to its simplicity, it can be easily incorporated into HLA-compliant simulations.