Modeling MCPTT and User Behavior in ns-3

To support the advancement of public safety communications technology, the Third Generation Partnership Project (3GPP) has created several standards to define Mission Critical Push-To-Talk (MCPTT) over Long Term Evolution (LTE) networks. As this is a new service that can be used in dire situations, it is imperative that the behavior and performance meet the expectations of first responders. This paper introduces an extension to the network simulator, ns-3, that models MCPTT and user Push-To-Talk (PTT) activity, so that researchers can gain insights and evaluate the performance of this service. In this paper we will describe MCPTT based on 3GPP definitions, the implementation of the MCPTT model in ns-3, and some results, including Key Performance Indicators (KPIs), that can be extracted from this model.