This article is about the advancement of the Wireless Sensor Networks (WNSs). Their usage in various fields making them the most fast evolving technology. The wireless sensor network consist of a large number of sensor nodes, Sink and the Actuator. These sensor networks use broadcast communication paradigm but most of the networks depends on point-to-point communication. The sensor networks does not have a global identification because of large in number.
The communication architecture of sensor networks has three phases 1. Sensor node 2.Sink 3.User. The sensor node collects data sends it to the sink, where the sink compute the data and finally sends it to the user.
The design topology of sensor networks depends on the user requirement. The basic system consists of the power unit, processing unit, sensing unit and the transceiver. Depending on the requirement some other components can be added to the network which are like location finding ...view middle of the document...
The network layer is the layer which helps us to establish a network link in the network. Depending on the importance of data this layer uses different types of routes to send the data which are 1. Minimum PA route 2. Minimum Energy route 3. Minimum hop route 4. Maximum Minimum PA node route.
The sensor networks also use MAC protocol which helps in establishing and transferring data to sink. The main work of the MAC protocol is to establish a link between the node and also the fairly and efficient in sharing the communication resources (data). The main use of the MAC protocol in the sensor systems it to provide a high quality of service and band width efficiency.
As the sensor nodes consist of many components which are in built in the node it uses a high power for operation which means the power supply is the major task. To save the power the node is operated in different modes which helps us in saving power in the node for future use. To solve the above power issue the Small Minimum Energy Communication Network is proposed which works as different subnetwork constructed which is smaller than the minimum energy communication network.
There are also different routing techniques like Flooding which uses broadcast for transmitting data which sends data to all the nodes and these nodes send the data to the Sink. The other form of routing technique is gossiping which means the node sends data to a selected neighbor which intern sends the data to the sink. There is another form routing which is the Sequential Assignment Routing where the nodes select their neighbors by sending a packet and connects to it. In the above cases the power consumption of the network is high but the transmission of data would be safe and secure.
Above discussed layers the network and the data link layers are responsible for establishing the network and the secured link between the node and the sink. Now the transport and the application layer responsible for the transmission of the data in the established links.
The application layer uses three different protocols which are 1.Sensor Management Protocol 2.Task Assignment and Data Advertisement Protocol 3. Sensor Query and Data Dissemination Protocol. All these protocols are open research issues