Zohaib Ur RehmanMuhammad Muneeb Bin JamilMuhammad Suleman2019-01-312019-01-312018https://escholar.umt.edu.pk/handle/123456789/3633Dr. Tahir Mushtaqfaced serious challenges from large scale natural disasters. In October, 2005 earthquake occurred in Kashmir. It was centered near the city of Muzaffarabad, and also affected Kyber Pakhtunkhwa province. In 2010 floods due to heavy monsoon affected about 20 million people in different areas of Pakistan. Natural disaster results into communication failure So, licensed band communication cannot help in these types of situation. A free licensed band communication can help us during disasters. Offline communications systems during a natural disaster can be dangerous for affected. One of the quick and huge effects of flooding and cataclysmic events is the sudden and wide-scale breakdown of communications infrastructure. When local communication networks fails, the effect can be broadly felt and can wipe out access to standard versatile or landline telecommunications, notwithstanding Internet and even satellitebased crisis specialized devices. And one more application of this system can be, that there are different companies and organizations that user their own private branch exchange systems. This system can replace that old private branch exchanges.enSubscriber Identity Module, Private branch exchange, Voice Over ip SIP Session Initiation ProtocolBSThesis