الفهرس 
Chapter 1: IntroductionOnly 14 pages are availabe for public view
 |  | from | 126 |  |  |
| | | from | 126 | | |
Abstract
Wireless sensor network (WSN) consists of hundreds and even thousands of small tiny devices called sensor nodes distribution autonomously to monitor physical or environmental conditions such as temperature, sound, pressure and motion at different locations. Energy plays an important role in wireless sensor networks because nodes are battery operated. Consequently, many protocols have been proposed in order to minimize the energy consumption of these nodes.
The monitoring of physical phenomena, industrial and military systems is main task of WSNs. Sink nodes collect the sensed information of normal sensor nodes. Batteries are limited energy sources and represent the main power sources for sensor nodes. Therefore, the efficient routing protocol is based on minimizing the amount of energy consumption which leads to increase the network life time. The biggest amount of energy is used for communication. These wireless networks comprised of nodes with limited hardware resources such as processor, memory and communication range.
Many researches try to overcome the challenges in wireless sensor networks by designing efficient routing protocols which have a significant impact on overall life time of the WSN.
In this work, the original LEACH and /or routing protocol was modified .The modification resulted in finding three approaches called VTLE-LEACH, VMC-LEACH and QB-LEACH. The three approaches are considered enhanced versions of LEACH .A comparative study is done among the performance of the original LEACH routing protocol and the modified one.
The proposed mechanisms introduce significant solutions to some limitations of the original LEACH to increase the efficiency of the energy balance. Such mechanisms propose a new energy balance level to prolong the overall network lifetime. In this work, NS2 simulator is used and integrated with Random Way to compare between the original LEACH and the proposed mechanisms.
IV
The simulation results show that the proposed solutions outperform the original LEACH in terms of the average energy consumed and the network lifetime.