Emergency response involves the management of several different types of critical infrastructures and resources. Because of the interdependent nature of these systems, it is often very difficult for human decision makers to determine what the second-or third-order effects of their decisions or actions might be. This has resulted in the development of several simulation tools that could be used to evaluate decisions or behaviours and better inform decision makers about the potential impacts of their decisions. One area that remains underdeveloped in this regard is the engagement of communication technologies by human agents, which has the potential to seriously affect delay times in response coordination.Given the size and complexity of simulating the interconnection of heterogeneous systems, developing reduced-order simulation models has become important to maintain reasonable computation times. This paper describes the derivation of the distribution of the total connection time for a communication link where multiple technologies are engaged. Results show that communication link simulation times, which are among the most time-consuming simulation routines can be significantly reduced by using the closed-form distributions. KEYWORDS analytical communication models, complex systems, disaster communications, disaster response simulation, emergency procedures
INTRODUCTIONDisasters affect millions worldwide and cause economic damage in billions of US dollars on a yearly basis. 1,2 Consequently, a large amount of prior preparation goes into building a resilient system, both in terms of structural integrity of physical infrastructures and population education surrounding disasters. Once an event has occurred, however, the ability to properly coordinate the ensuing response effort becomes critical. The system as a whole consists of many different types of resources and infrastructures, all with their own distribution networks, operation procedures, and physical dynamics. Decisions, such as allocating resources to one place instead of another can have noticeable effects on the disaster response. Given the multidimensional nature of the problem, it is extremely difficult for humans to make informed decisions since they are generally unable to assess second-or third-order effects of decisions in a complex interconnected system of systems. 3 To help decision makers understand the potential impacts of their decisions, a number of simulation tools have been developed such as I2Sim, 4 CIPDSS, 5 HAZUS, 6 and ADMS. 7 Complex interdependencies are evident even within the operations of a single infrastructure. The communication system, for example, which is one of the most critical of infrastructures, 8 can be viewed as a highly interconnected Int J Commun Syst. 2018;31:e3500.wileyonlinelibrary.com/journal/dac