Optimum speed of NAD scheduler on a fragmented tactical network

A Taguchi robust design process was applied to both a fully connected and a fragmented 16-member company level network topologies for the optimization of the V-NAD scheduler and Type 4 message parameters, as specified in the MIL-STD-188-220B protocol. We applied Taguchi's robust design method to the ITT TIDB Phase III OPNET/sup TM/ network model associated with the IOT&E, over a set of seven fragmented net configurations, in order to investigate mutual interference in the tactical Internet. The results demonstrated that the most critical control factors among MIL-188-220B parameters pertained to the voice activity net access delay (V-NAD) scheduler algorithm. Other control factors were found to have little or no affect on net performance. From these results, three optimum V-NAD scheduler sets (specified as "fast", "moderate", and "slow") were selected for investigating net performance over the seven fragmented net configurations. This paper presents an analysis of network behavior in various fragmented configurations over a range of optimum V-NAD sets. In addition, the performance results of the selected V-NAD parameter sets are compared against the current default scheduler algorithm (L-NAD). It is demonstrated that the "slow" V-NAD scheduler set represents a robust solution in the fragmented net environment.