Analysis of the Impact of the Evolution Toward 5G Architectures on Mission Critical Push-to-Talk Services

This paper analyzes the impact of the evolution of mobile broadband networks from 4G architectures toward 5G on mission critical push-to-talk (MCPTT) key performance indicators (KPIs). This paper focuses on how the deployment of MCPTT over these architectures affects the service quality. We carry out a comprehensive analysis of the call flows and the contribution of each network segment to the service KPIs defined by the Third Generation Partnership Project (3GPP). A long-term evolution (LTE) architecture will be considered as the baseline scenario; from there on, different core network proposals are evaluated: the LTE multi-access edge computing (MEC) and 5G. We analyze how these strategies for data and control plane distribution affect the service, identifying current performance bottlenecks and exploring latency reduction techniques. Throughout this paper, we show that the current implementation of the MCPTT service according to the standards defined by the 3GPP remains a key challenge in terms of the KPI compliance. Still, the evolution toward 5G architectures, particularly those leveraging the MEC, further improves the KPIs of the MCPTT service, especially the KPI 3 (mouth-to-ear latency) since the services are deployed closer to the end users. These results strengthen the commitment to mobile broadband networks for the deployment of mission critical communications.