The present document addresses the requirements for communications between the authorized representatives who can be involved in the responses and actions when handling an emergency. It describes the functional requirements for communications between the authorized representatives involved in the responses and actions when handling an emergency. The level of precision has been chosen to avoid interaction with the specific local, regional or national organizations and diagrams of relations between authorized representatives. It follows from this that adaptations will have to be done when implementing the present document at a local level. Furthermore, the scope of the present document also encompasses various types of services that can bring an added value to this basic scenario or add new scenarios, such as the services brought by other technologies e.g. IoT devices that support communications between authorities during emergencies.