In this work we study the wireless networks without infrastructure especially in emergency situations where groups of rescuers must be on site to accomplish emergency tasks, which is necessary to establish a wireless communication in real time between individuals or groups. The nature of MANET (Mobile Ad Hoc network) makes it suitable to be used in the context of emergencies and that, when the existing infrastructure is down or severely overloaded. In emergency cases Ad Hoc networks can be used to deploy quickly small spontaneous networks. Since nodes are mobile, the network topology may change rapidly and randomly.
The increasing mobility of terminals makes them progressively dependent on their autonomy from the power source; this is illustrated by introducing many mobility models and using many scenario of mobility in emergency situation. Energy efficiency in emergency scenario is the main objective of this paper, achieved by the combination of a low-power mode algorithm and a power-aware routing strategy. A selected set of simulation studies indicate a reduction in energy consumption and a significant increase in node lifetime whereas network performance is not affected significantly. This is the big interest of our works in emergency situation, by increasing life time of nodes individuals can communicate longer and give more chance to rescuers to find them.