Identify the requirements for real world problems in wireless sensor network
Answers
Wireless Sensor Networks and
Issues
The emerging field of wireless sensor networks combines
sensing, computation, and communication into a single tiny
device. Undoubtedly, all communication between nodes is
through the wireless transmission techniques. Sensing is a
technique used to gather information about a physical object
or process, including the occurrence of events. An object
performing such a sensing task is called a sensor.
A sensor network is an infrastructure comprised of
sensing (measuring), computing, and communication. A
WSN consists of distributed nodes that support signal
processing, embedded computing and connectivity. WSNs
typically transmit information to collecting (monitoring)
stations that aggregate some or all of the information .
Due to distributed nature of these networks and their
deployment in remote areas, these networks are vulnerable
to numerous security threats that can adversely affect their
proper functioning.
Generally, sensor nodes are concerned about two major
security issues, which are privacy preserving and node
authentication. Privacy means the data confidentiality is
achieved under security mechanism . While sensor
networks share many similarities with other distributed
systems, they are subject to a variety of unique challenges
and constraints.
Time Synchronization is useful for better communication
among the sensor nodes. The time synchronization problem
is to synchronize the local clocks of sensor nodes in the
wireless network . Many applications of sensor networks
need local clocks of sensor nodes to be synchronized,
requiring various degrees of precision. Since all hardware
clocks are imperfect, local clocks of nodes may drift away
from each other in time. When a node in the network
generates a timestamp to send to another node for
synchronization, the packet carrying the timestamp will face
a variable amount of delay until it reaches. This delay
prevents the receiver from exactly comparing the local clocks of the two nodes and accurately synchronizing to the
sender node.
There are several reasons for addressing the
synchronization problem in sensor networks. Some reasons
are as following: Sensor nods are required to coordinate
their operations to perform a particular task, Life time of
network is depending on power. So to increase the life of
network we need to use power saving schemes.
WIRELESS SENSOR NETWORK
A Wireless sensor network is a distributed network where
autonomous sensors are connected together for various
network operations. WSN consists of multiple detection
stations called sensor nodes, each of which is small,
lightweight and portable. WSNs are bi-directional and its
topology differs from each application. WSN has some
characteristics such as: mobility and heterogeneity of nodes,
large scale of deployment, ease of use, ability to cope with
node failures and more.
The function of a sensor node in a sensor area is to detect
events, perform local data processing, and transmit raw
and/or processed data. Sink node is nothing but a base
station which plays a vital role in wireless environment and
it acts like a distributed controller. Base station is important
for the following reasons: sensor nodes are prone to failure,
better collection of data and provides the backup if the
master node is failure.
CHALLENGES IN WSN
Wireless sensor networks have tremendous
potential because they will expand our ability to monitor
and interact remotely with the physical world. Sensors have
the ability to collect vast amounts of unknown data.
Sensors can be accessed remotely and placed
where it is impractical to deploy data and power lines. To
exploit the full potential of sensor networks, we must first
address the peculiar limitations of these networks and the
resulting technical issues. Although data fusion requires that
nodes be synchronized, the synchronization protocols for
sensor networks must address the following features of
these networks. WSNs to become truly ubiquitous, a
number of challenges and obstacles must be overcome