Wireless & Telecommunication

Biography

Biography: Chitra Sudhakaran, Dr. M. Suganthi

Abstract

Evolution of digital wireless communication systems from the analog systems and the introduction of cellular systems brought valuable opportunities to millions of users around the world. However, during events like earthquakes, tsunamis and floods all kinds of wireless devices might be ceased through serious spectrum and traffic jam due to the collapse of network infrastructures. Even the emergency calling services would be interrupted due to its dependency on network infrastructure and congestion due to capacity limit. Thus, the public safety (PS) responders are not able to reach the affected victims in such extreme cases. So there is a need for a reconfigurable and intelligent emergency communication system to detect and locate survivor communications or to maintain reliable communication between various public safety organizations. Here, we envision the usage of cognitive radio for emergency communication in disaster scenarios to re-establish the connectivity among isolated devices. Cognitive radios are fully programmable wireless devices that can sense their environment and dynamically adapt their transmission waveform, channel access method and networking protocols. The major spectrum management functionalities are spectrum sensing, spectrum decision, spectrum sharing and spectrum mobility. Spectrum mobility can alert the spectrum sensing function on detected changes in the environment . These spectrum sensing functions supports the flexibility needed in disaster management. The enabling technologies of self-organizing wireless systems includes Mobile Adhoc Networks (MANETs) , emergency networks with dynamic spectrum reconfiguration capabilities (Cognitive Radio) and emergency networks with autonomous mobility (Vehicular Networks) . In the proposed system, we introduce a relay assisted dual core cognitive radio vehicles in which hybrid sensing technique is used. The main objective for choosing vehicles in such scenario is that the localized radio on these vehicles does not require infrastructural changes at the public handsets. In dual core cognitive radio which acts as a relay, one core is dedicated to interference based sensing in underlay network which constantly senses the nearby primary channel. The other one is a decision making core, in which it cooperatively senses the spectrum with its neighboring CRV’s when there occurs spectrum mobility. Two scenarios are investigated i.e. Victim to victim and victim to personnel communication and identified the criteria which is to be solved for the real time implementation of the system. An interference alignment based technique is proposed for accessing the spectrum database by CRVs to enable the location estimation of the victims.