A computer simulation analysis of conventional and trunked land mobile radio for a system with a small number of user groups

Trunked land mobile radio (LMR) systems, currently being developed by several companies, allow many groups of LMR users to share a set of channels dynamically, reducing the total number of channels needed to support these groups. These systems also support dynamic regrouping, reassigning individual users to different groups through software in the controlling computer. The authors discuss a computer model of existing military LMR networks on Wright Patterson Air Force Base (WPAFB) and a model of a hypothetical trunked system for the base. Data were collected from the air monitoring of LMR nets and were used to determine numerical values of various parameters. These values were input to the computer models to determine the time required for a user to obtain a channel while traffic load and (for the trunked model) user grouping were varied to simulate various conditions. A five-channel (one data, four voice) trunked system was found to support WPAFB adequately, even with an increase in LMR traffic. With proper user grouping, trunked system performance is shown to be superior to that of the existing conventional system design and suggests a promising network design for military use