1. Energy Efficiency Energy consumption is the most important factor to determine the life of sensor network. since sensors networks has low power resources, it make energy optimization more complicated. Prolonging the life of network can be done by energy awareness.

2. Energy Efficiency ( Continued ) Sensor network usually contain four subsystems: 1- Computing subsystem. 2- Communication subsystem. 3-Sensing Subsystem. 4- Power supply Subsystem.

3. Energy Efficiency ( Continued ) Computing subsystem: - It consists of microcontroller unit (MCU). - MCU is responsible for the control of the sensor & execution of communication protocols. - MCU works under various operating mode of power consumption.

4. Energy Efficiency ( Continued ) Computing subsystem: - Shuttling between different modes of operations involves consumption of power. - energy consumption level of the various modes should be considered at each node.

5. Energy Efficiency ( Continued ) Communication subsystem: - It consists of short range radio system. - It used to communicate with neighboring nodes and the outside world. - Transmitting and receiving operation consume high energy.

6. Energy Efficiency ( Continued ) Communication subsystem: - Energy can be reduced by shutdown (sleep mode) the radio when there is no need to communication.

7. Energy Efficiency ( Continued ) Sensing subsystem: - It consists of group of sensors and links to the outside world. - Energy consumption can be reduced by using low power components.

8. Energy Efficiency ( Continued ) Power supply subsystem: - It consists of a battery which supplies power to the node. - Energy can be reduced by reducing the amount of current drawn from the battery.

9. Energy Efficiency ( Continued ) Sensor node acts a router. - Intelligent hardware that helps in redirecting packets which need to be forwarded reduce power consumption. - No overheads computing processes are needed.

10. Energy Efficiency ( Continued ) Updating the health of network would serve as a warning. - This warning could save energy in case of failure or malfunction.

11. Sensor VS Ad-Hoc Networks One gateway node. Communication between pair of nodes is not specific.

12. Sensor VS Ad-Hoc Networks Not Dynamic (i.e. sensors are not mobile). - In some applications WSN can contain some mobile/robotic nodes with moving capabilities. - Generally, dynamic of WSN involves nodes the network because of system failure or power depletion.

13. Routing Protocols in Sensors Network WSN use the same Protocols in Ad-Hoc Network. Routing Algorithms can be classified into two main categories : 1- Proactive Protocols. 2- Reactive Protocols.

14. Routing Protocols in Sensors Network Proactive Protocols: - Destination Sequenced Distance Vector routing protocol (DSDV). - Path-Finding Algorithms (PFA). - Wireless Routing Protocols (WRP).

15. Routing Protocols in Sensors Network Reactive Protocols: - Gafni and Bertsekans’s algorithm. - Dynamic Source Routing protocol (DSR). - Temporally Ordered Routing Algorithm Routing protocol (TORA). - Associative-Based Routing protocol (ABR).

16. Routing Protocols in Sensors Network Reactive Protocols: - Ad-Hoc On demand Distance Vector (AODV). - Signal Stability-Based Routing protocol (SBR). - Location Aided Routing algorithm (LAR). - Power Aware Routing protocol (PAR).