Communication and interoperability between different organizations of first responders has been a problem for a long time. There have been examples of failure in communication between different organizations at World Trade Center on 9/11, for example some of the police warnings were not heard by fire fighters that resulted in several lives lost. In most cases, network unavailability or incapability of coordination among networks causes much damage. Therefore, we present a highly reliable communication infrastructure that is suitable at ground zero where the existing communication network is damaged or unavailable. We used Hybrid Wireless Mesh Network (HWMN) as a candidate for communication infrastructure with the capability of working in a heterogeneous environment with different available backhaul technologies. In addition to the use of WMNs, we also present some special requirements for a cellular networks generated by simulation models investigating different scenarios that occur at ground zero. For example, when hurricane Katrina hit New Orleans, people outside the ground zero area could place a call, but were not able to receive phone calls. This happened because the cellular network elsewhere was not able to contact the Home Location Register (HLR), located at New Orleans. We, in this paper, propose a solution in which the important user or network information databases such as HLR and VLR (Visitor Location Register) are replicated to provide a sufficient amount of fault tolerance.
R. B. Dilmaghani, B. S. Manoj, and R. R. Rao. Proceedings of the 3rd International ISCRAM Conference, Newark, NJ (USA), May 2006. Emergency Communication Challenges and Privacy