Wireless sensor network
- 1. Wireless Sensor Network By:Shubham Takkar Reg.Id: (DD1711401010)
- 2. Introduction • Wireless sensor networks (WSN), are similar to Wireless ad hoc network (WANET) in the sense that they rely on wireless connectivity and spontaneous formation of networks so that sensor data can be transported wirelessly. • A WSN system incorporates a gateway that provides wireless connectivity back to the wired world and distributed nodes. • WSN are spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, pressure, etc. and to cooperatively pass their data through the network to a main locations . • The WSN is built of "nodes" – from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors.
- 3. History • The origins of the research on WSN can be traced back to the Distributed Sensor Networks (DSN) program at the Defense Advanced Research Projects Agency (DARPA) at around 1980. By this time, the ARPANET (Advanced Research Projects Agency Network) had been operational for a number of years, with about 200 hosts at universities and research institutes ( Chon & Kumar, 2003). A demonstrative application of DSN was a helicopter tracking system (Myers et al., 1984), using a distributed array of acoustic microphones by means of signal abstractions and matching techniques, developed at the Massachusetts Institute of Technology (MIT). • Even though early researchers on sensor networks had in mind the vision of a DSN, the technology was not quite ready (Size is large). • Further, the earliest DSN were not tightly associated with wireless connectivity. Recent advances in computing, communication and micro electromechanical technology have caused a significant shift in WSN research and brought it closer to achieving the original vision. • The new wave of research in WSN started in around 1998 and has been attracting more and more attention and international involvement. Further, the sensor nodes have been much smaller in size (i.e. pack of cards to dust particle) and much cheaper in price, and thus many new civilian applications of sensor networks such as environment monitoring, vehicular sensor network and body sensor network have emerged.
- 4. Working • The WSN is built of "nodes" – from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors. • Each such sensor network node has typically several parts: a radio transceiver with an internal antenna or connection to an external antenna, a microcontroller, an electronic circuit for interfacing with the sensors and an energy source, usually a battery or an embedded form of energy harvesting. A transceiver is a device comprising both a transmitter an da receiver that are combined and share common circuitry or a single housing. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Program memory in the form of Ferroelectric RAM or OTP ROM is also often included on chip, as well as a small amount of RAM.
- 5. Working • The SensiNet® Services Gateway is a powerful appliance based on the Intel® Atom ™ processor and provides network management, user interface, data logging, trending, alarming and communications without any complicated software to install. A standard browser and network connection is all that’s required to access and configure the system. The GWAY-2100 also operates as stand-alone data logger with real time views, trending and e-mail alerts.
- 6. Classification Of Routing Protocols Routing techniques are required for sending data between sensor nodes an the base stations for communication. Routing Protocols can be classified : • Based on Mode of functioning and type of target applications into Proactive, Reactive and Hybrid. • Based on Participation style of the nodes into as Direct Communication, Flat and Clustering Protocols . • Depending on the Network Structure as Hierarchical, Data Centric and Location based
- 7. Direct Communication, Flat and Clustering Protocols • In Direct Communication Protocols, any node can send information to the BS directly. • When this is applied in a very large network, the energy of sensor nodes may be drained quickly. • Its scalability is very small. • SPIN is an example of this type of protocol. • In the case of Flat Protocols, if any node needs to transmit data, it first searches for a valid route to the BS and then transmits the data. Nodes around the base station may drain their energy quickly. • Its scalability is average. • Rumor Routing is an example of this type of protocol. • According to the clustering protocol, the total area is divided into numbers of clusters. • Each and every cluster has a cluster head (CH) and this cluster head directly communicates with the BS. • All nodes in a cluster send their data to their corresponding Cluster Head. • The Threshold sensitive Energy Efficient sensor Network (TEEN) is an example of a clustering protocol.
- 8. Advantage/Disadvantage Advantages • Wireless sensor networks are used in those harsh and hostile environments where wired networks can't be deployed. For example in a forest, wireless sensor nodes are dropped from the air because going down there and deploying a wired setup is not possible. • Another advantage is that the wireless sensor networks are scalable. That is why they are actively being used in applications such as Structural Health Monitoring where there is a need of dense deployment and with a dense wired set up, it may lead to a chaos at the time of deployment. Moreover a dense wired set up will prove to be very costly. On the other hand, wireless sensor nodes can easily be deployed without any hustle. Disadvantages • Limited computation and communication resources are the only disadvantages in wireless sensor networks. They have limited battery power, limited storage and computation capabilities, prone to the security attacks and have limited bandwidth to communicate. • Less but still human interaction is their. • Despite of the above disadvantages, sensor networks are being used widely and considered to be the backbone of the phenomenon we call “Internet of Things”.
- 9. Future of WSN Presently! What if this happened?
- 10. References • www.wikipedia.org/wiki/Wireless_sens or_network • www.elprocus.com/introduction-to-wireless-sensor-networks-types-and-application On date:- 09/10/2017 3:49PM