A broadcast distribution system for delivering emergency bulletins to user equipment outside of eNBs coverage

When base stations in cellular networks break down due to a disaster, users may not be able to use mobile services such as calls, mail and SNS, and may have difficulty gathering information necessary for their protection and safety. It is therefore important to build an alternative network for delivering emergency bulletins about earthquakes and tsunamis. We propose a broadcast distribution system integrating the ETWS (Earthquake and Tsunami Warning System) and ProSe (Proximity Services) on LTE that delivers emergency bulletins to UEs outside eNB coverage and incorporates DTN to maximize the message arrival rate. We showed the effectiveness of our proposed system by carrying out an evacuation simulation using the system.