This is a major project on topic: Uderwater sensor wireless network

1. BY
SUNIL PODDAR
B160078CS
B.Tech Final Year

2. General Idea
Sensor
A Device that receives and respond to a signal
or stimulus.
As human we perceive the world via senses(
we can hear, taste, touch, see and smell).
Machine senses through sensors like
temperature sensors ,pressure sensors and
light sensors.

3. Wireless Sensor Networks (WSNs)
A Wireless sensor network can be defined as a
network of devices that can communicate the
information gathered from a monitored field through
wireless links. The data is forwarded through multiple
nodes, and with a gateway, the data is connected to
other networks like wireless Ethernet.

4. Key Technologies that enable sensor network:
 Micro electro-mechanical systems (MEMS)
 Wireless communications
 Digital electronics

5. INTRODUCTION
Underwater sensor network have the
potential to enable unexplored
applications and to enhance our ability
to observe and predict the ocean(water
body) .
Unmanned or
Underwater
AUVs),equipped
vehicles
with
Autonomous
(UUVs,
underwater
sensors are also envisioned to find
application in exploration of natural
underwater resources and gathering of
scientific data in collaborative
monitoring missions.

6. APPLICATIONS
It enable abroad range of application:
 Ocean Sampling network
 Environmental monitoring
 Undersea Explorations
 Disaster prevention
 Seismic Monitoring
 Equipment monitoring
 Assisted Navigation
 Distributed Tactical Surveillance
 Mine Reconnaissance

7. CHALLENGES IN DESIGN OF
UNDERWATER NETWORK
 The available bandwidth is severely limited.
 The underwater channel is impaired because of
multipath and fading.
 Battery power is limited and usually batteries
cannot be recharged.
 Underwater sensors are prone to failures because
of fouling and corrosion.

8. DIFFERENCES WITH TERRESTRIAL SENSOR
NETWORKS
Underwater Sensor Network has to take care of living beings
that exist in Oceans and to protect their life while using
autonomous vehicles and sensors . Thus these network has to
be developed based on the challenges posed by the
underwater environment.
Beyond that underwater sensor network is different from
terrestrial sensor network in terms of :
 Cost
 Deployment
 Power
 Memory
 Spatial Correlation

9. UNDERWATER SENSOR NETWORK
COMPONENT
For realization of these networks we need different
components as:
UNDERWATER SENSORS
The typical internal architecture of an underwater sensor is shown:
The controller receives data from the
sensor and can store the data in the
on- board memory, process them, and
send them to other network devices
by controlling the acoustic modem.
These devices include sensors to
measure the quality of water and to
study its characteristics.

10. • Examples of Underwater Sensors Node:
(a) (b)
• (a) Aquacomm underwater modem
• (b) LinkQuest underwater sensor nodes.

11. AUTONOMOUS UNDERWATER VEHICLES
Autonomous Underwater Vehicles (AUVs) are programmable,
robotic vehicles that, depending on their design, can drift, drive,
or glide through the ocean without real-time control by human
operators.
In addition to static sensor nodes, several types of AUVs exist as
experimental platforms for underwater experiments.
Examples of existing AUVs :
Odyssey-class AUVs developed at MIT (small scale submarines )
OdysseyAUV

12. Drifters and gliders are oceanographic instruments often used in
underwater exploration(simpler devices that do not encompass
such sophisticated capabilities).
View of a drifter from above (left) and
from below (right)
Spray glider.

13. COMMUNICATON ARCHITECTURE
The network topology is in general a crucial factor in
determining the energy consumption, the capacity, and the
reliability of a network.
The network capacity is also influenced by the network topology.
Since the capacity of the underwater channel is severely limited,
a it is very important to organize the network topology in such a
way that no communication bottleneck is introduced.
 Static 2-D UWSNs for ocean bottom monitoring
 Static 3-D UWSNs for ocean-column monitoring
 The 3-D networks of AUVs

14. Static 2-D UWSNs for ocean bottom monitoring:
• These are constituted by sensor nodes that are anchored to the
bottom of the ocean.
• Typical applications may be environmental monitoring, or
monitoring underwater plates in tectonics.
• Components used :

15. Static 3-D UWSNs for ocean column monitoring
• These include networks of sensors whose depth can be
controlled by means of various techniques.
• May be used for surveillance applications or monitoring of
ocean phenomena (ocean bio/geo/chemical processes, water
streams, pollution).
• Components:

16. 3-D Networks ofAUVs
• These include networks of sensors whose depth can be
controlled by means of various techniques.
• May be used for surveillance applications or monitoring of
ocean phenomena (ocean bio/geo/chemical processes, water
streams, pollution).
AUV

17. Sensor network protocol stack
Physical Layer :Until the beginning of the last decade, due to the
challenging characteristics of the underwater channel, underwater
modem development was based on non-coherent frequency Shift
Keying (FSK) modulation, since it relies on energy detection and
thus does not require phase tracking, which is a very difficult task
mainly because of the Doppler-spread in the UW-A channel. In FSK
modulation schemes developed for underwater, the multi-path
effects are suppressed by inserting time guards between successive
pulses to ensure that the reverberation, caused by the rough ocean
surface and bottom, vanishes before each subsequent pulse is
received.

18. Data Link Layer :Channel access control in UW-ASNs poses
additional challenges because of the peculiarities of the
underwater channel, in particular limited bandwidth, and high
and variable delay.
Frequency Division Multiple Access (FDMA) is not suitable for
UW-ASNs due to the narrow bandwidth in UW-A channels and
the vulnerability of limited band systems to fading and multi-
path.
Time Division Multiple Access (TDMA) shows a limited
bandwidth efficiency because of the long time guards required
in the UW-A channel. In fact, long time guards must be designed
to account for the large propagation delay and delay variance of
the underwater channel.

19. Carrier Sense Multiple Access (CSMA) prevents collisions with
the ongoing transmission at the transmitter side. To prevent
collisions at the receiver side, however, it is necessary to add a
guard time between transmissions dimensioned according to the
maximum propagation delay in the network. This makes the
protocol dramatically inefficient for UW-ASNs.
CONTINUED…

20. Network Layer :The network layer is in charge of determining the
path between a source (the sensor that samples a physical
phenomenon) and a destination node (usually the surface station).
In general, while many impairments of the underwater acoustic
channel are adequately addressed at the physical and data link
layers, some other characteristics, such as the extremely long
propagation delays, are better addressed at the network layer.
The existing routing protocols are usually divided into three
categories, namely proactive, reactive and geographical routing
protocols.

21. Transport Layer :A transport layer protocol is needed in UW-
ASNs to achieve reliable transport of event features, and to
perform flow control and congestion control. Most existing TCP
implementations are unsuited for the underwater environment
since the flow control functionality is based on a window-based
mechanism that relies on an accurate estimate of the Round Trip
Time (RTT). The long RTT, which characterizes the underwater
environment, would affect the throughput of most TCP
implementations. Furthermore, the variability of the underwater
RTT would make it hard to effectively set the timeout of the
window-based mechanism, which most current TCP
implementations rely on.

22. Application Layer :Channel access control in UW-ASNs poses
additional challenges because of the peculiarities of the
underwater channel, in particular limited bandwidth, and high
and variable delay.
The purpose of an application layer is multi-fold: i) provide a
network management protocol that makes hardware and software
details of the lower layers transparent to management
applications;
ii) provide a language for querying the sensor network as a
whole;
iii) assign tasks and advertise events and data.

23. SOURCES
 Underwater Acoustic Sensor Network
-edited by Yang Xiao
 http://nopr.niscair.res.in/bitstream/123456789/6203/1/IJMS
%2038%283%29%20267-273.pdf
 Wireless Sensor Networks
By Ian F.Akyildiz, Mehmet Can Vuran
 https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web
&cd=6&cad=rja&uact=8&ved=0CDIQFjAF&url=http%3A%2F%2
Fwww.ece.rutgers.edu%2F~pompili%2Fpaper%2Fpompili_dario_2
00708_phd.pdf&ei=yPdAVbSLKcbauQT1mYHoDg&usg=AFQjCN
FTfU1ebFGjgxlnhN0PgeAsOb06Xw&sig2=_-
zC3vVa5TZW98TyGFxRmA&bvm=bv.92189499,d.c2E

24. THANK YOU

25. QUERIES???