By
Lakmi Ray
C.S.E. Dept. , 4th Year
13003410043

A wireless sensor network (WSN) consists of
spatially distributed autonomous sensor to monitor
physical or environmental conditions, such
as temperature, sound, pressure etc. and to
cooperatively pass their data through the network to a
main location.

The more modern networks are bi-directional, also
enabling control of sensor activity.

The WSN is built of “NODES" – where each node is
connected to one (or sometimes several) sensors. Each
such sensor network node has typically several parts:-
 Radio
transceiver- with an internal antenna or
connection to an external antenna.
 Microcontroller- an electronic circuit for interfacing
with the sensors
 Energy source, usually a battery or an embedded form
of energy harvesting.

A sensor node might vary in size .
 Size
and cost constraints on sensor nodes result in
corresponding constraints on resources such as
energy, memory, computational speed and
communications bandwidth
 The
topology of the WSNs can vary from a
simple star network to an advanced multi-hop
wireless mesh network. The propagation technique
between the hops of the network can be routing or
flooding.

Forest monitoring application using WSN has various
uses, most importantly: Temperature or weather change detection.
 Forest fire.
 Oil spills.

Habitat and environmental monitoring represent a class
of sensor network applications with enormous potential
benefits for scientific communities.

Life scientists are increasingly concerned about the
potential impacts of direct human interaction in
monitoring plants and animals in field studies. At best,
it is possible that chronic human disturbance may
distort results by changing the behavioral patterns of
the animal.

Habitat monitoring studies install one or a few
sophisticated weather stations an “insignificant
distance” (as much as tens of meters) from the area of
interest.

Instead of large data loggers, weather stations, and
invasive physical monitoring, a revolution for
biologists would be the ability to monitor the
environment on the scale of the organism, not on the
scale of the biologist by deploying sensors. In order to
deploy sensors densely to monitor a habitat, the sensors
must be small in size to minimize the disturbance
effects caused by traditional methods.
Presently such forest monitoring using WSN is being done in Great
Duck Island, Maine, on Atlantic. Some of the related data graph
made on basis of Habitat and weather information collected are:

Some other such are as follows:-
Sensor nodes being setup for weather monitoring
in the Forests.
System Level Architecture for the habitat
and weather monitoring

The system architecture for habitat monitoring applications is a
tiered architecture. Samples originate at the lowest level that
consists of sensor nodes. These nodes perform general purpose
computing and networking in addition to application-specific
sensing. Sensor nodes will typically be deployed in dense sensor
patches that are widely separated. Each patch encompasses a
particular geographic region of interest. The sensor nodes
transmit their data through the sensor patch to the sensor network
gateway. The gateway is responsible for transmitting sensor data
from the sensor patch through a local transit network to the
remote base station that provides WAN connectivity and data
logging. The base station connects to database replicas across the
Internet.
SYSTEM ARCHITECTURE FOR HABITAT AND
WEATHER MONITORING


The architecture of the precision Forest fire detection
system based on wireless sensor networks consists of
the monitoring nodes, base stations, communications
systems, Internet access and the structure of
monitoring hardware and software system.
A large number of the different sensors can be placed
in the field and constructed a self-organized network
to monitor the value change including temperature,
humidity, smoke or gas detector etc. The collection
data is send to the sink by wireless mode. The control
center can send the control information to any node
in the network.
Forest Fire
To control forest fire
sensor Nodes being set
up.
Basic structure for
WSN for
forest fire control.
Hardware design of
sensor nodes
Fire Characteristics
diagram
Various parts of the
hardware system used
for fire detection
process are:1)Understanding fire
characteristics
2) Temperature and humidity sensors-The capacitive humidity and
temperature sensors provide digital and fully calibrated output which
allows for easy integration without the need for additional calibration.
3) Optical smoke detector -A smoke detector is a device that detects
smoke,
typically as an indicator of fire. When smoke enters the
optical chamber across the path of the light beam, some
light is scattered by the smoke particles, directing it at the
sensor.
Smoke detector diagram
1)
2)
3)
4)
5)
Optical chamber
Cover
Case molding
Photo diode
Infra red LED
4) Microcontroller Unit- Microcontroller like ARM (LPC 2148) performs
tasks,
processes data and control the functionality with other
components in the sensor node. This also sends the data to
the RF transceivers for the transmission of data to the base
station. The microprocessor has a number of functions
including:
1) Managing data collection from the sensors
2) Performing power management functions
Interfacing the sensor data to the physical radio layer.
5) RF Tranceivers- Zig-Bee is a Technological Standard Created for Control
and Sensor Networks based on the IEEE 802.15.4
The main features of this standard are network flexibility, low cost, very low
power consumption, and low data rate in an ad-hoc self-organizing network
among inexpensive fixed, portable and moving devices.
Software design of the
sensor node
Details of software design of
Sensor nodes used in fire
detection.
1) Software Architecture: The software architecture of sensor node is
divided into embedded OS kernel layer and API layer. Embedded
module provides tasks, power management and
communication protocol. The kernel also provides a
low-level node driver of all hardware devices. API layer
provides sensor acquisition module and RF communication
module.
2)The Function of WSN Protocol- Wireless network communication
protocol provides the wireless communication standards between
the cluster-head nodes and nodes. It achieves registration,
sleep the node, data acquisition, device controller, parameter
Settings and debugging.
1) Registration:- When the nodes work on, the node
registers MAC to the cluster-head node and accesses to the
network subnet number. It is assigned to a node ID.
2) The Node Sleep- The cluster-head node sends a data
packet to notify the next node sleep time.
3) Data Collection:- According to testing requirements, the
cluster-head node assigns the task of data collection, such
as temperature, humidity, light intensity and gas
concentration.
4) Equipment Control: The cluster-head node analyzes the
data and makes decision. The packet of control instructions
is sent to the node
5) Parameter Settings: The cluster-head node sends the
modified equipment parameters to the child nodes.
6) Debugging: It is the equipment development and
debugging functions.
3) Wireless Sensor Network Protocol Stack-Software component
is the gateway and sensor nodes. The function of gateway
software is processing and management data from sensor nodes.
The operating system is Tiny OS.
Wireless Sensor
Network
Protocol Stack
The software of sensor node is to receive the instruction from the
cluster-head node and send the data to the sensor gateway. There are
the wireless sensor network protocol stack consists of the
the physical layer, medium access control layer, network layer
and other components.
Prospect and challenges faces by this system:Due to a larger monitoring area of forest , the
sensor network has a large number of nodes while it ensures
the cost of the network. Because the sensor node energy
is limited, the possibility of node failure is very large. In short the following
problems needs to be resolved:
i) The Large-scale High-density Network Structure-The network
Nodes must be a large-scale, high-density deployment method to
keep monitoring the area coverage and connectivity.(contd.)
A large number of nodes in the network will inevitably
increase the cost which will affect the network in the
practical application. The premise of agriculture application
is to design an available and economic deployment
mechanism for WSN.
ii) Data Processing and Node Energy-Communication is the
maximal energy consumption. Each node has data
independent processing ability. It reduces network
transmission cost by processing and extracting the original
data. A well-designed network networking, data transfer
and data integration algorithms are important to the
lifetime of the network.
iii) Network redundancy and tolerance-Network fault
tolerance includes node failure detection and failure
recovery. Node failure needs to locate. If each node has the
portable GPS devices, it will inevitably increase the cost of
the entire network.
From scalar field to discreted , WSN approximation.
Latest Report on Fire detection System in forest using WSN:-This project is
designed the hardware and software based on WSN protocol which includes
Sensors such as temperature, smoke, humidity along with the processor
LPC 2138 and Zigbee as a RF device. Our hardware works on battery operated
system, in future we will use solar power for the same. The forest fire
monitoring system was developed which detects fire in the forest.
OIL SPILL CONTROL IN FORESTS USING
WSN
•Dynamic geographic phenomena, such as forest fires and oil spills,
can have dire environmental, sociopolitical, and economic consequences.
Mitigating, if not preventing such events requires the use of advanced
Spatio -temporal information systems.
•One such system that has gained
widespread interest is the wireless sensor network (WSN), a deployment of
sensor nodes – tiny unethered computing devices, which run on batteries
and are equipped with one or more commercial off-the-shelf or
custom-made sensors and a radio transceiver.
•This research deals with initial attempts to detect topological changes to
geographic phenomena by an environmentally deployed wireless sensor
network (WSN).
•After providing the mathematical and technical preliminaries,
we define topological change and present in-network algorithms to detect such
changes and also, to manage the WSN’s resources efficiently.
•The algorithms are compared against a resource-heavy continuous monitoring
approach via simulation. The results show that two topological changes,
hole loss and hole formation, can be correctly detected in-network and that
energy is greatly saved by our event-driven approach.
•In future work, we hope to test the algorithms over a broader range of topological
changes and to relax some of the network assumptions.
CONCLUSION
The aspects of using wireless sensor networks for forest tree
monitoring and alerting using rare event detection with ultra low power
consumption. In this prototype, two sensors (mercury sensor & temperature
sensor) which work well for the detection of fire and tree theft were selected
and mesh protocol was used for alert routing and event detection. Network
lifetime and latency estimation for the deployment scenario
showed the implementation feasibility of such a monitoring system for
deforestation application. However, as the sensor nodes are battery powered,
issues related to battery life and ease of battery replacement are major concerns
for WSN applications that involve long term monitoring of vast area especially
hostile areas. It is therefore necessary to have some means of recharging the
batteries of the sensor node to increase the network lifetime. For this, one of the
most common ways is to extract the energy from the surrounding environment.
Life time of network is increased by adopting RF energy harvesting technique
for recharging the sensor nodes. In addition to RF technique various other
energy harvesting techniques are available that can be used for this purpose.
The various energy
sources which can be used for this prototype implementation have been
explored here. A detailed description of solar and RF energy harvesting is
given which can be used to charge the batteries and hence increase the lifetime
of the deployed WSN system.
Forest Monitoring System using WSN