Résumé
Wireless sensor networks are made up of number of self governing sensors which are spread throughout a large area to examine physical and environmental conditions, such as temperature, humidty and pressure which mutually assist each other to send their data through the network to a user's location. The WSNs are made up of "nodes" with number of nodes varying from just a few to several hundreds or thousands. Each of these sensor nodes has a link to one or various sensor nodes. Each sensor node consist of several parts: a sensor to sense the environmental conditions like temperature, humidity, pressure etc. a radio transceiver with an internal antenna for communication purpose, a microcontroller to process information or data, a battery to power the entire sensor node. In WSNs the sensor nodes operate on battery, which have restricted amount of power or energy. It is observed that about 70% energy in sensor node is consumed only because of transmission and reception of information ie. in communication purposes and remaining 30% is consumed in sensing information and data or information processing. So it is desirable to came up with new protocol which are energy efficient and enhance the network lifetime.
This research work is modeled around introduction of multi hop routing protocol for WSNs based on gateways and is quite energy efficient. which enhances the network lifetime by utilizing minimum amount of energy. In this paper, we assume Base station is installed out of the sensing field and numbers of gateway nodes are deployed at the edge of sensing field. These gateway nodes are rechargeable therefore, it reduces cost. It also reduces traffic problem and reduce distance for reliable transmission of data. Simulation results on MA TLAB R2009a shows that our proposed gateway based protocol is better in terms of network lifetime than traditional protocol like SEP protocol by showing significant improvement in terms of number of half dead nodes, dead nodes, alive nodes and also in terms of remaining energy of sensor node. We also observe that in Gateway based SEP or G-SEP Protocol Throughput is increased in case of packets transmit to CHs and packets transmit to BS respectively over traditional SEP Protocol.