Wireless Sensor Networks
Content
WIRELESS SENSOR NETWORKS
1
INTRODUCTION
Wireless technology has expanded the limits of our world. Through this innovation, people
have been given freedom to work away from their desks or even outside. The newfound
freedom that people are beginning to enjoy with their computers has started making the world
of technology and nature blend. Wireless Sensor Networks are the next stage of this
technology-nature cohesion. Although a young technology, the applications have been varied
and promise to be even more varied. Efficient design and implementation of wireless sensor
networks has become a hot area of research in recent years, due to the vast potential of sensor
networks to enable applications that connect the physical world to the virtual world. By
networking large numbers of tiny sensor nodes, it is possible to obtain data about physical
phenomena that was difficult or impossible to obtain in more conventional ways. In the
coming years, as advances in micro-fabrication technology allow the cost of manufacturing
sensor nodes to continue to drop, increasing deployments of wireless sensor networks are
expected, with the networks eventually growing to large numbers of nodes (e.g., thousands).
Potential applications for such large-scale wireless sensor networks exist in a variety of
fields, including medical monitoring, environmental monitoring, surveillance, home security,
military operations, and industrial machine monitoring. The purpose of this report is to
explain what are wireless sensor networks.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
2
WIRELESS SENSOR NETWORKS
A Wireless Sensor Network is a self-configuring network of small sensor nodes
communicating among themselves using radio signals, and deployed in quantity to sense,
monitor and understand the physical world. A wireless sensor network (sometimes called a
wireless
sensor
and
actuator
network)
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 location.
The more modern networks are bi-directional, also enabling control of sensor activity. The
development of wireless sensor networks was motivated by military applications such as
battlefield surveillance; today such networks are used in many industrial and consumer
applications, such as industrial process monitoring and control, machine health monitoring,
and so on. 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. WSN provide a bridge
between the real physical and virtual worlds. It allows the ability to observe the previously
unobservable at a fine resolution over large spatiotemporal scales. Wireless Sensor Networks,
or WSNs, have been used to enable better data collection in scientific studies, create more
effective strategic military defenses, pinpoint the origin of a gunshot, and monitor factory. All
of these uses depend on the ability to collect data such as light, vibration, moisture,
temperature, and more, as well as the ability to communicate with each other.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
3
WIRELESS SENSOR NODES
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 sensor node might vary in size from that of a shoebox down to the
size of a grain of dust, although functioning "motes" of genuine microscopic dimensions have
yet to be created. Size and cost constraints on sensor nodes result in corresponding
constraints on resources such as energy, memory, computational speed and communications
bandwidth.
Parts of a Wireless Sensor Network Node
PARTS OF WSN NODE (MOTES)
Motes consist of five crucial components. These components include a number of sensors,
such as temperature, moisture, and vibration sensors, a power source, batteries, a radio
transmitter/receiver, and an electric brain.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
4
SENSORS: When motes are under construction, their intended purpose often
dictates the sensors that are added to the mote. The mote contains three types of
sensors: temperature, moisture, and vibration. There are also motes that take
photographs of the surroundings, sense motion, measure light intensity, and much
more. The sensors are attached to the mote base and communicate readings to the
electronic brain.
POWER SOURCE: The power source for the mote also depends the mote’s
intended use. The power sources usually range between a couple of AA batteries, and
a watch battery, but with the new smart-dust motes, also called “Spec,” they can
collect enough energy to sustain themselves from ambient light, or even vibrations. It
provides energy required to run the sensors, electronic brain, and radio.
RADIO: The radio consists of a radio transmitter and a radio receiver. These parts
help a mote to fully communicate with the other motes. The radio, when transmitting,
receives information from the electronic brain and broadcasts the data to other motes
according to the network connections and when receiving, the radio receives
information from another mote’s radio and transmits it to the electronic brain.
THE ELECTRONIC BRAIN: The motes’ brains consist of a microprocessor
and some flash memory. They have connectors to add other processes and sensors.
The MEMS motes also contain an analog-digital converter. The functions of the
electronic brain are to make decisions and deal with collected data. The electronic
brain stores collected data in its memory until enough information has been collected.
Once this point is reached, the microprocessor portion of the electronic brain then puts
the data in “envelopes,” or packages of data formatted for greatest transferring
efficiency. These envelopes are then sent to the radio for broadcast. The electronic
brain is connected to the base and interacts with the sensors and radio.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
5
THEORY OF OPERATION OF MOTES
Datiscoledbynr Datispedolcrnbhkgfm"v Envelopisaduthrm.
Processes a mote undergoes when communicating data to other motes
Motes collect and transfer data using four stages: collecting the data, processing the data,
packaging the data, and communicated the data. Each mote collects data using its various
types of sensors. After collecting the data, the mote processes the data using its electronic
brain. Once the data has been processed, the brain packages the data into an easily handled
form. This process is known as enveloping. Once the data has been collected and processed to
this point, the mote then begins to interact with other motes.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
6
PROS AND CONS OF WIRELESS SENSOR
NETWORKING
There are many advantages of wireless sensor networking some of important prose’s are: they
can store a limited source of energy, they have no hassle of cables and has mobility, one of its
major advantage is that it can work efficiently under the harsh conditions, and it has
deployment up to large scale etc. Where it has advantages at the same time it also has some
disadvantages which really take the moral of this technology down such as they have very
insufficient speed of communication, it is to disturb the propagation of waves and hack your
networking and the major disadvantage of wireless sensor networking is it is too costly to
use.
ADVANTAGES:
Network setups can be done without fixed infrastructure.
Ideal for the non-reachable places such as across the sea, mountains, rural areas or
deep forests.
Flexible if there is ad hoc situation when additional workstation is required.
Implementation cost is cheap.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
7
DISADVANTAGES:
Less secure because hackers can enter the access point and get all the information.
Lower speed compared to a wired network.
More complex to configure than a wired network.
Easily affected by surroundings (walls, microwavea, large distances due to signal
attenuation.
APPLICATIONS
In the present era there are lot of technologies which are used for monitoring are completely
based on the wireless sensor networking. Some of important applications are environmental
monitoring, traffic control application, weather checking, regularity checking of temperature
etc. Wireless sensor networks can also be used for detecting the presence of vehicles such as
motor cycles up to trains. These are some important wireless sensor networking based
technologies which help us in our daily life. Some of there daily life applications are:
AREA MONITORING - Area monitoring is a common application of WSNs.
In area monitoring, the WSN is deployed over a region where some phenomenon is to
be monitored. A military example is the use of sensors detect enemy intrusion; a
civilian example is thegeo-fencing of gas or oil pipelines.
HEALTH CARE MONITORING - The medical applications can be of two
types: wearable and implanted. Wearable devices are used on the body surface of a
human or just at close proximity of the user. The implantable medical devices are
those that are inserted inside human body.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
AIR POLLUTION MONITORING
8
- Wireless sensor networks have been
deployed in several cities to monitor the concentration of dangerous gases for citizens.
WATER QUALITY MONITORING
- Water quality monitoring involves
analyzing water properties in dams, rivers, lakes & oceans, as well as underground
water reserves. The use of many wireless distributed sensors enables the creation of a
more accurate map of the water status, and allows the permanent deployment of
monitoring stations in locations of difficult access, without the need of manual data
retrieval.
NATURAL DISASTER PREVENTION - Wireless sensor networks can
effectively act to prevent the consequences of natural disasters, like floods. Wireless
nodes have successfully been deployed in rivers where changes of the water levels
have to be monitored in real time.
INDUSTRIAL MACHINE MONITORING - Wireless sensor networks
have been developed for machinery condition-based maintenance (CBM) as they offer
significant cost savings and enable new functionality. Wireless sensors can be placed
in locations difficult or impossible to reach with a wired system, such as rotating
machinery and untethered vehicles.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
9
CONCLUSION
Wireless sensor networks are still uncommon. This is still a young technology, allowing wsns
great growth potential. It is this potential that captures the attention of those who interact with
wsns. The question that is constantly asked is “what new use can we come up with for this?”
There have been many answers to this question, including: data collection, strategic mine
placement, machinery monitoring, and much more. The way that motes are made is a huge
part of the success of WSN in such different situations. Another reason they are successful is
the way that the motes work together to form a network. Using MEMS technology, motes
have been becoming smaller and more efficient. The uses and capabilities of WSN are varied,
and the only way to fully understand the extent to which they can be adapted will be to wait
and see what happens. The future of WSN is bright, as increasing attention is brought to their
uses. Wireless sensor networking has a bright future in the field of computer networking
because we can solve the monitoring problems at an advanced level in the future with the
help of such technology of networking. Who knows, wsns may become as commonplace as
the PC.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
10
BIBLIOGRAPHY
SITES:
http://wireless.ictp.it/wp-content/uploads/2012/02/Zennaro.pdf
http://www.ece.rochester.edu/courses/ECE586/readings/perillo.pdf
http://ceng.usc.edu/~bkrishna/research/talks/WSN_Tutorial_Krishnamachari_ICISIP0
5.pdf
http://www.wifinotes.com/how-wireless-sensor-networks-works.html
REFERENCE BOOKS:
Silva, D.; Ghanem, M.; Guo, Y. (2012). "WikiSensing: An Online Collaborative
Approach for Sensor Data Management". Sensors12
Culler, D. E., & Mulder, H. (June, 2004). Smart Sensors to Network the World.
Scientific American, 290, 52-59.
I. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, “A Survey On Sensor
Networks”, IEEE Communications Magazine, Volume 40, Number 8, pp.102-114,
2002.
ECE Department, SRMGPC, Lucknow
1
INTRODUCTION
Wireless technology has expanded the limits of our world. Through this innovation, people
have been given freedom to work away from their desks or even outside. The newfound
freedom that people are beginning to enjoy with their computers has started making the world
of technology and nature blend. Wireless Sensor Networks are the next stage of this
technology-nature cohesion. Although a young technology, the applications have been varied
and promise to be even more varied. Efficient design and implementation of wireless sensor
networks has become a hot area of research in recent years, due to the vast potential of sensor
networks to enable applications that connect the physical world to the virtual world. By
networking large numbers of tiny sensor nodes, it is possible to obtain data about physical
phenomena that was difficult or impossible to obtain in more conventional ways. In the
coming years, as advances in micro-fabrication technology allow the cost of manufacturing
sensor nodes to continue to drop, increasing deployments of wireless sensor networks are
expected, with the networks eventually growing to large numbers of nodes (e.g., thousands).
Potential applications for such large-scale wireless sensor networks exist in a variety of
fields, including medical monitoring, environmental monitoring, surveillance, home security,
military operations, and industrial machine monitoring. The purpose of this report is to
explain what are wireless sensor networks.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
2
WIRELESS SENSOR NETWORKS
A Wireless Sensor Network is a self-configuring network of small sensor nodes
communicating among themselves using radio signals, and deployed in quantity to sense,
monitor and understand the physical world. A wireless sensor network (sometimes called a
wireless
sensor
and
actuator
network)
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 location.
The more modern networks are bi-directional, also enabling control of sensor activity. The
development of wireless sensor networks was motivated by military applications such as
battlefield surveillance; today such networks are used in many industrial and consumer
applications, such as industrial process monitoring and control, machine health monitoring,
and so on. 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. WSN provide a bridge
between the real physical and virtual worlds. It allows the ability to observe the previously
unobservable at a fine resolution over large spatiotemporal scales. Wireless Sensor Networks,
or WSNs, have been used to enable better data collection in scientific studies, create more
effective strategic military defenses, pinpoint the origin of a gunshot, and monitor factory. All
of these uses depend on the ability to collect data such as light, vibration, moisture,
temperature, and more, as well as the ability to communicate with each other.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
3
WIRELESS SENSOR NODES
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 sensor node might vary in size from that of a shoebox down to the
size of a grain of dust, although functioning "motes" of genuine microscopic dimensions have
yet to be created. Size and cost constraints on sensor nodes result in corresponding
constraints on resources such as energy, memory, computational speed and communications
bandwidth.
Parts of a Wireless Sensor Network Node
PARTS OF WSN NODE (MOTES)
Motes consist of five crucial components. These components include a number of sensors,
such as temperature, moisture, and vibration sensors, a power source, batteries, a radio
transmitter/receiver, and an electric brain.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
4
SENSORS: When motes are under construction, their intended purpose often
dictates the sensors that are added to the mote. The mote contains three types of
sensors: temperature, moisture, and vibration. There are also motes that take
photographs of the surroundings, sense motion, measure light intensity, and much
more. The sensors are attached to the mote base and communicate readings to the
electronic brain.
POWER SOURCE: The power source for the mote also depends the mote’s
intended use. The power sources usually range between a couple of AA batteries, and
a watch battery, but with the new smart-dust motes, also called “Spec,” they can
collect enough energy to sustain themselves from ambient light, or even vibrations. It
provides energy required to run the sensors, electronic brain, and radio.
RADIO: The radio consists of a radio transmitter and a radio receiver. These parts
help a mote to fully communicate with the other motes. The radio, when transmitting,
receives information from the electronic brain and broadcasts the data to other motes
according to the network connections and when receiving, the radio receives
information from another mote’s radio and transmits it to the electronic brain.
THE ELECTRONIC BRAIN: The motes’ brains consist of a microprocessor
and some flash memory. They have connectors to add other processes and sensors.
The MEMS motes also contain an analog-digital converter. The functions of the
electronic brain are to make decisions and deal with collected data. The electronic
brain stores collected data in its memory until enough information has been collected.
Once this point is reached, the microprocessor portion of the electronic brain then puts
the data in “envelopes,” or packages of data formatted for greatest transferring
efficiency. These envelopes are then sent to the radio for broadcast. The electronic
brain is connected to the base and interacts with the sensors and radio.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
5
THEORY OF OPERATION OF MOTES
Datiscoledbynr Datispedolcrnbhkgfm"v Envelopisaduthrm.
Processes a mote undergoes when communicating data to other motes
Motes collect and transfer data using four stages: collecting the data, processing the data,
packaging the data, and communicated the data. Each mote collects data using its various
types of sensors. After collecting the data, the mote processes the data using its electronic
brain. Once the data has been processed, the brain packages the data into an easily handled
form. This process is known as enveloping. Once the data has been collected and processed to
this point, the mote then begins to interact with other motes.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
6
PROS AND CONS OF WIRELESS SENSOR
NETWORKING
There are many advantages of wireless sensor networking some of important prose’s are: they
can store a limited source of energy, they have no hassle of cables and has mobility, one of its
major advantage is that it can work efficiently under the harsh conditions, and it has
deployment up to large scale etc. Where it has advantages at the same time it also has some
disadvantages which really take the moral of this technology down such as they have very
insufficient speed of communication, it is to disturb the propagation of waves and hack your
networking and the major disadvantage of wireless sensor networking is it is too costly to
use.
ADVANTAGES:
Network setups can be done without fixed infrastructure.
Ideal for the non-reachable places such as across the sea, mountains, rural areas or
deep forests.
Flexible if there is ad hoc situation when additional workstation is required.
Implementation cost is cheap.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
7
DISADVANTAGES:
Less secure because hackers can enter the access point and get all the information.
Lower speed compared to a wired network.
More complex to configure than a wired network.
Easily affected by surroundings (walls, microwavea, large distances due to signal
attenuation.
APPLICATIONS
In the present era there are lot of technologies which are used for monitoring are completely
based on the wireless sensor networking. Some of important applications are environmental
monitoring, traffic control application, weather checking, regularity checking of temperature
etc. Wireless sensor networks can also be used for detecting the presence of vehicles such as
motor cycles up to trains. These are some important wireless sensor networking based
technologies which help us in our daily life. Some of there daily life applications are:
AREA MONITORING - Area monitoring is a common application of WSNs.
In area monitoring, the WSN is deployed over a region where some phenomenon is to
be monitored. A military example is the use of sensors detect enemy intrusion; a
civilian example is thegeo-fencing of gas or oil pipelines.
HEALTH CARE MONITORING - The medical applications can be of two
types: wearable and implanted. Wearable devices are used on the body surface of a
human or just at close proximity of the user. The implantable medical devices are
those that are inserted inside human body.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
AIR POLLUTION MONITORING
8
- Wireless sensor networks have been
deployed in several cities to monitor the concentration of dangerous gases for citizens.
WATER QUALITY MONITORING
- Water quality monitoring involves
analyzing water properties in dams, rivers, lakes & oceans, as well as underground
water reserves. The use of many wireless distributed sensors enables the creation of a
more accurate map of the water status, and allows the permanent deployment of
monitoring stations in locations of difficult access, without the need of manual data
retrieval.
NATURAL DISASTER PREVENTION - Wireless sensor networks can
effectively act to prevent the consequences of natural disasters, like floods. Wireless
nodes have successfully been deployed in rivers where changes of the water levels
have to be monitored in real time.
INDUSTRIAL MACHINE MONITORING - Wireless sensor networks
have been developed for machinery condition-based maintenance (CBM) as they offer
significant cost savings and enable new functionality. Wireless sensors can be placed
in locations difficult or impossible to reach with a wired system, such as rotating
machinery and untethered vehicles.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
9
CONCLUSION
Wireless sensor networks are still uncommon. This is still a young technology, allowing wsns
great growth potential. It is this potential that captures the attention of those who interact with
wsns. The question that is constantly asked is “what new use can we come up with for this?”
There have been many answers to this question, including: data collection, strategic mine
placement, machinery monitoring, and much more. The way that motes are made is a huge
part of the success of WSN in such different situations. Another reason they are successful is
the way that the motes work together to form a network. Using MEMS technology, motes
have been becoming smaller and more efficient. The uses and capabilities of WSN are varied,
and the only way to fully understand the extent to which they can be adapted will be to wait
and see what happens. The future of WSN is bright, as increasing attention is brought to their
uses. Wireless sensor networking has a bright future in the field of computer networking
because we can solve the monitoring problems at an advanced level in the future with the
help of such technology of networking. Who knows, wsns may become as commonplace as
the PC.
ECE Department, SRMGPC, Lucknow
WIRELESS SENSOR NETWORKS
10
BIBLIOGRAPHY
SITES:
http://wireless.ictp.it/wp-content/uploads/2012/02/Zennaro.pdf
http://www.ece.rochester.edu/courses/ECE586/readings/perillo.pdf
http://ceng.usc.edu/~bkrishna/research/talks/WSN_Tutorial_Krishnamachari_ICISIP0
5.pdf
http://www.wifinotes.com/how-wireless-sensor-networks-works.html
REFERENCE BOOKS:
Silva, D.; Ghanem, M.; Guo, Y. (2012). "WikiSensing: An Online Collaborative
Approach for Sensor Data Management". Sensors12
Culler, D. E., & Mulder, H. (June, 2004). Smart Sensors to Network the World.
Scientific American, 290, 52-59.
I. Akyildiz, W. Su, Y. Sankarasubramaniam, and E. Cayirci, “A Survey On Sensor
Networks”, IEEE Communications Magazine, Volume 40, Number 8, pp.102-114,
2002.
ECE Department, SRMGPC, Lucknow
