Location-Aware Cognitive Communication Systems for Public Safety

The introduction of cellular systems and evolution of analog wireless communications systems to digital systems opened an era of hundreds of millions of wireless communications users around the globe. Cellular phones are used in the first place in case of extreme situations or emergency cases and rescue-safety operations can benefit from prevalence of cellular wireless technologies during and just after extreme situations like hurricanes, earthquakes and collapse of buildings or mines. However, events around the world such as unfortunate attacks of 9/11, hurricane Katrina, Indonesian tsunami, and devastating Pakistan floods revealed problems about legacy wireless communications systems from a different aspect: Wireless communications of all kinds cease to work in extreme situations because of the damaged infrastructure, congestion caused by overwhelming request for communicating and abnormal communication parameters e.g. drastic changes in air interface because of whether conditions during natural disasters. Establishing communications under severe conditions of extreme situations to detect and locate survivor communications or to maintain reliable communications between the first responders of various public safety organizations require reconfigurable and intelligent communications techniques. For instance, the radio should sense the operational environment of communication and autonomously adjust its parameters accordingly to execute these tasks. Another important issue is interoperability of public safety organizations or first responders. Wireless communications infrastructure may not satisfy the requirements of large operations that are needed during the spread natural disasters and events because, the number of the first responders increases with increasing population but, allocated resources and technology does not change by the time. Hence, it becomes nearly impossible to communicate even for the first responders of the same organization because of insufficient resources such as frequency spectrum. Besides, if there is no common infrastructure or