Enabling Mission-Critical Communication via VoLTE for Public Safety Networks

With the development of mobile broadband technologies, such as LTE, Voice over LTE (VoLTE) has become a feasible solution to provide mission-critical voice services in the public safety (PS) networks. Conventional Land Mobile Radio (LMR) systems are reliable for voice communication but not suitable for supporting bandwidth-demanding data services or providing sufficient interoperable capacity for modern-day first responders. With national and regional authorities moving towards broadband-enabled emergency services, VoLTE is being identified as an important enabler, as it inherently supports Quality of Service (quality of service), precedence access, and preemption, and is integrated with the IP Multimedia Subsystem (IMS) architecture. This paper examines how VoLTE systems can be deployed to meet the high demands of mission-critical communication, including low latency, high availability, secure end-to-end communication, and seamless interconnection across agencies. The focus is on commercial LTE network customisation to support public safety requirements, including: QCI mapping, evolved packet core (EPC) enhancements, and dynamic policy control enforcement.