What type of system is used for in-building emergency radio communication?

The Auxiliary Radio Communication System (ARCS) is specifically designed to enhance in-building emergency radio communication. This system ensures that first responders have reliable communication access within structures, where typical radio signals may be obstructed or weakened due to building materials and layout. ARCS operates to facilitate clear and consistent communication during emergencies, enabling personnel to receive timely updates and instructions essential for safety and coordination.

In contrast, other systems listed may have different functionalities. A Public Address System is typically used for general announcements rather than emergency communications. The Central Monitoring System generally focuses on monitoring alarms and alerts rather than facilitating direct communication with first responders. A Smart Alarm System is designed for automatic notifications and alerts rather than as a dedicated communication tool for emergency responders. Hence, the distinct purpose and design of ARCS position it as the correct choice for in-building emergency radio communication.