Abstract:
Wireless sensor networks have been attracting significant research and commercial interest
recently. Since data dissemination is different from traditional ad-hock networks new challenge
arises. The challenges are due to resource constraint nature of wireless sensor networks. Wise
use of wireless sensor nodes resources such as energy, storage and communication capacity will
increase performance of wireless sensor network.
The most effective way of saving sensor node energy in wireless sensor networks is through
sleep wakeup scheduling. Existing Medium access control layer contention based scheduling
technique such as 802.11 IEEE has short coming for wireless sensor networks. Contention based
protocol with features such as idle listening and overhearing waste sensor nodes energy. This
thesis discusses best feature of existing Medium access control protocols for wireless sensor
networks. We develop network size and remaining energy of sensor nodes based Medium access
control protocol for saving sensor node energy while minimizing communication delay between
sensor nodes. Enhancement is made to SMAC (Sensor Medium access control) protocol by
introducing network size as a configurable parameter to adjust contention window instead of
fixed contention window of SMAC (Sensor Medium access control).
To reduce energy consumption of SMAC (Sensor Medium access control) the duty-cycle
adjustment based on remaining energy of nodes is proposed. Performance of SMAC
(Sensor Medium access control) and ESMAC (Enhanced Sensor Medium access control)
is evaluated on Network simulator-2. The combined effect of those two parameters
enables as to enhance the performance of SMAC (Sensor Medium access control) in
power efficiency, delay and throughput.
