There is a priority communication service which is applied to an authorised user (e.g. government, emergency responder) using priority mechanisms such as special access class (i.e. access classes 11 to 15) allocation and high priority level allocation of eMLPP. The service is effective in giving an important direction in disasters (e.g. earthquakes) which direction is to lead to saving life. This direction should be transferred even if terminating side is in congestion caused by traffic used for confirmation of the safety of people in the disaster areas because the authorised users orders some agencies or people in the disaster areas to take an action for saving life. Use-cases are described below. (Note: not exclusive)

• Case1: Disaster risk management office in government calls to emergency responder within disaster areas in order to supply temporary service to the disaster areas.
• Case2: Ambulance attendant who gets to a rescue site in the disaster areas but does not found out a person calling for help because of unexpected destruction calls to him/her in order to make sure where he/she is.

Case3: Firefighter at a fire of high-rise apartment in the disaster areas calls to a person losing his/her way in order to give out directives on the evacuation.

Following considerations are identified from subscription aspect. In the case1 both of the originating users and the terminating users are the authorised users. Whereas in the case2 and 3 the originating users are the authorised users and the terminating users are not the authorised users.