01-05-2012, 04:50 PM
WIRELESS SENSOR NETWORKS
wireless_sensor_network.ppt (Size: 585 KB / Downloads: 414)
INTRODUCTION
WSN are used to collect data from the environment.
They consists of large number of sensor nodes and one or more Base Stations.
The nodes in the network are connected via Wireless communication channels.
Each node has capability to sense data, process the data and send it to rest of the nodes or to Base Station.
These networks are limited by the node battery lifetime.
ADVANTAGES
It avoid lot of wiring.
It can accommodate new devices at any time.
Its flexible to go through physical partitions.
It can be accessed through a centralised monitor.
DISADVANTAGES
It is very easy for hackers to hack it as we cant control propagation of waves.
Comparitively low speed of communications.
Gets distracted by various elements like Blue-tooth.
Still costly at large.
Base Station
Data storage for the collection of sensor patches
WAN connectivity will be wireless
Base-Remote link connection to the internet
Communication Protocols
Headers.
Each message generally has a header identifying its source node, destination node, length of the data field, and other information.
This is used by the nodes in proper routing of the message. In encoded messages, parity bits may be included.
In packet routing networks, each message is broken into packets of fixed length.
The packets are transmitted separately through the network and then reassembled at the destination.