الفهرس 
chapter 1Only 14 pages are availabe for public view
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Abstract
A wireless sensor network (WSN) is a collection of nodes organized into a cooperative
network. Network lifetime has become the key characteristic for evaluating sensor networks
in an application specific way. As most WSN nodes are battery powered, their lifetime is
highly dependent on their energy consumption. Then, one of the primary objectives in
WSNs is to enhance energy efficiency.
In this thesis, Weighted Node Selection (WNS) technique in WSNs is proposed. It is
an energy-efficient cooperative technique where selected numbers of sensors at the
transmitting end are used to form a vi1tual MIMO connected wireless with a selected
number of sensors at the receiving end. The proposed technique is based on a weight
selection function that combines geographical location, inter sensor distance in a cluster,
channel estimate energy, power circuit, channel loss, mobility factor, and residual energy of
each sensor. Then, the cluster head can select the sensors with better select ion parameters
that can help to reduce the overall energy consumption.
The numerical results show that the proposed WNS technique achieves a significant
improvement in the energy consumption, delay and network lifetime than the conventional
techniques with and without selection number of sensors..