Most public safety agencies (fire, law enforcement, and EMS) in the U.S. and Canada do fairly well in using their communication tools, e.g., land mobile radios and wireless devices, for the day-to-day emergency incidents to which they respond. Those same entities, however, can experience real communications challenges when faced with a large-scale or complex emergency events that require the response of additional resources from multiple agencies. Those scenarios imply multiple different technologies and challenges mais appear when merging them to communicate easily.