msn presentation
TRANSCRIPT
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A survey on
Sensor NetworksPrabhu Teja G
M.Tech. in Network & Internet Engg.
Dept. Of Computer Science
School of Engg. & Tech.Pondicherry University
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What is SENSOR?
What is SENSOR NODE?
and
What is (Mobile) SENSOR NETWORK?
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From Human senses to devices
Instruments are more precise. They give
us an exact temperature, humidity,
heart rate
You feel COLD
You feel WET
You feel your heart
pumping!
Thermometer Exercise Meter
Heart Monitor
Rain GaugeHumidity Meter
What is a Sensor?
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Some Important Definitions
Sensor:A transducer that converts a physical phenomenon such as
heat, light, sound, or motion into electrical or other signals that maybe further manipulated by other apparatus.
Sensor Node:
A basic unit in a sensor network, with on-board sensors,
processor, memory, wireless modem, and power supply. It is oftenabbreviated as node. When a node has only a single sensor onboard, the node is sometimes also referred as sensor, creatingsome confusion.
Sensor Network:A wireless sensor network consists of a large number of tiny,
low-cost, low-power, sensor nodes, which are capable of observingthe environment, processing data and communicating each other byradio.
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P2P
Wireless
WirelessAd-hoc
Wireless
Mesh
Wireless
Sensor
Mobile
Ad-hoc
MobileSensor
StaticSensor
Wired
hierarchy of
network types
hybrid
iMANETInVANETVANET
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P2P Network:
A network without the notion of clients or servers,but only equal peer nodes that simultaneously function
as both clients and servers
Wireless Ad-hoc Network:
-A wireless ad hoc network is a decentralizedwireless network. The network is ad hoc because it does
not rely on a preexisting infrastructure, such as routers in
wired networks or access points in managed
(infrastructure) wireless networks.
-Each node participates in routing by forwardingdata for other nodes, and so the determination of which
nodes forward data is made dynamically based on the
network connectivity.
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Wireless Mesh Network:
WMNs is a self organized, self configured and
decentralized wireless network. There are two kinds of nodesin WMN:
1. Mesh router. 2. Mobile client.
-Mesh routers with powerful capacities and lower mobility
are automatically setup and maintain wireless connectionforming the backbone of WMNs.
-It provides interconnections among all networked
nodes, where each node can send and receive data directly to
each other
- WMNs are able to automatically discover topologychange and self adaptively modify routing for more efficient
data transmission
- WMNs are teach to achieve load balance by routing
parts of data to gateway nodes with lower load
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Mobile Ad-hoc Networks:
A mobile ad-hoc network is a collection of autonomous mobile
nodes that communicate with each other over wireless links without any
central administration.
In ad-hoc networks, each host has to act as a router for itself to
communicate with hosts outside its transmission range due to the
limited range of each host's wireless transmission.
Types of MANET
Vehicular Ad Hoc Networks (VANETs) are used for communication
among vehicles and between vehicles and roadside equipment.
Intelligent vehicular ad hoc networks (InVANETs) are a kind of
artificial intelligence that helps vehicles to behave in intelligent
manners during vehicle-to-vehicle collisions, accidents, drunken
driving etc.
Internet Based Mobile Ad-hoc Networks (iMANETs) are ad-hoc
networks that link mobile nodes and fixed Internet-gateway nodes.
In such type of networks normal ad-hoc routing algorithms don't
apply directly.
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Wireless Sensor Networks
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Some more Definitions for Sensor Networks:
A sensor network is composed of a large number of sensornodes, which are densely deployed either inside the phenomenon orvery close to it.
or
Sensor Networks (WSN) are usually a set of battery-suppliedsmall devices. A sensor network can be described as a collection ofsensor nodes which co-ordinate to perform some specific action.
or
Sensor networks are dense wireless networks of small, low-cost sensors, which collect and disseminate environmental data.
or
Sensor network (WSN) is a computer network consisting of
large number of small devices distributed in different placesor
A network consisting of spatially distributed autonomousdevices using sensors to cooperatively monitor physical orenvironmental conditions, such as temperature, sound, vibration,pressure, motion or pollutants, at different locations
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My definition for WSN
A wireless sensor network consists of a largenumber of tiny, low-cost, low-power, batteryoperated and coordinated sensor nodes, whichare capable of observing the environment,processing data and communicating each other by
radio, are deployed densely over the monitoringarea to perform a specific task such astemperature, sound, vibration, pressure, motion orpollutants at different locations.
Wireless sensor networks (WSNs) are mainlyused in the emergency services. It can also becalled Emergency Services Networks (ESNs).
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Sensor networks Vs Ad hoc networks:
The number of nodes in a sensor network canbe several orders of magnitude higher than thenodes in an ad hoc network.
Sensor nodes are densely deployed.
Sensor nodes are limited in power,computational capacities and memory.
Sensor nodes are prone to failures.
The topology of a sensor network changesfrequently.
Sensor nodes mainly use broadcast, most adhoc networks are based on p2p.
Sensor nodes may not have global ID.
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Sensor Network ApplicationClasses
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Applications of sensor networks
Military applications Enhanced logistics systems to monitor friendly forces, equipment
and ammunition.
Enhanced surveillance systems to detect intruders, chemical or
biological attacks, underwater targets, firing guns and theirlocations.
Enhanced discovery systems that can run in inaccessible or
contaminated terrains and beyond the enemy lines.
Enhanced targeting and target tracking systems.
Enhanced guidance and navigation systems
Reconnaissance of opposing forces and terrain
Battle damage assessment system
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Applications of sensor networks
Environmental applications
Forest fire detection
Bio-complexity mapping of theenvironment
Flood detection
Precision agriculture
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Applications of sensor networks
Health applications Tele-monitoring of human physiological data
Tracking and monitoring patients and doctorsinside a hospital
Drug administration in hospitals
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Applications of sensor networks
Home and other commercial applications
Home automation and Smart environment
Interactive museums
Managing inventory control
Vehicle tracking and detection
Detecting and monitoring car thefts
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Vehicle Tracking
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Some more Interesting Applications
Environmentalmonitoring CENS-UCLA
50 node seismicmonitoring set up
Terrestrial monitoring:based on observingthe biological andchemical cycles ofnature.
Aquatic monitoring:Monitoring of streamsand river
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Habitat Monitoring:
David Culler and his
team at UC Berkeley
have deployed since
2002 a network of more
than 20 motes on the
Great Duck Island2 to
monitor the islands
habitat and the breeding
habits of Leach Storm
Petrels
UC Berkeley project on
monitoring redwood
trees
ExScal: Extreme Scale
Wireless Sensor
Networking (Anish Arora
at Ohio State Univ):
demonstration covered an
area 1.3km by 300m with
about 1000 sensor nodes
and around 200 backbone
nodes
One possible application:
detection & classification of
multiple intruder types over
an extended perimeter.
Some more Interesting Applications
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Some more Interesting Applications
Precision Agriculture Camalie Net
Wireless SensorNetwork at CamalieVineyards - Mt.
Veeder, Napa Valley,California
Accenture incollaboration with Intelhas a WSN at PickberryVineyard in NorthernCalifornia
SPANN Lab., IIT-B atSula Wines
WSN for small agriculturefarms CEDT, IISc
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Disaster Response
CalIT2: Wireless InternetInformation System forMedical Response inDisasters (WIISARD)project is investigatingthe best way to triagecasualties and managecare in chaotic situationsfollowing disasters, suchas a biological attack, abridge collapse or an
earthquake
SPANN-Lab. IITB: EarlyWarning Systems forLandslide Prediction
Some more Interesting Applications
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Introduction & History
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WSN: Brief History
Earliest: In 1994 DARPAfunded research on LowPower Wireless IntegratedMicro sensor
In 2003, Technology Reviewfrom MIT, listed WSN on thetop, among 10 emergingtechnologies that wouldimpact our future WSN can be viewed as a
disruptive technology
So far, a lot work has beendone in this area but still along way to go And the strategy workshop
is still very relevant
Base
Station
Internet
Cloud
Sensor Nodes
Aggregator
A Typical Architecture
Information
Processing
Center
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Sensor Network Architecture
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WSN node components
Low-power processor. Limited processing.
Memory. Limited storage.
Radio. Low-power.
Low data rate.
Limited range.
Sensors.
Scalar sensors:temperature, light, etc.
Cameras, microphones.
Power.
Sensors
Processor
Radio
Storage
P
O
W
E
R
WSN device schematics
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WSN Nodes Sensor nodes have local processing capability
Sensor nodes can be randomly and rapidly deployed even in places
inaccessible for humans
Sensor nodes can self organize to communicate
Sensor nodes can collaboratively work
A sensor node might vary in size from that of a shoebox down to the size of
a grain of dust
The cost of sensor nodes is variable, ranging from hundreds of dollars to a
few pennies, depending on the size of the sensor network and the
complexity required of individual sensor nodes
Size and cost constraints on sensor nodes result in corresponding
constraints on resources such as energy, memory, computational speed and
bandwidth
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Evolution of Sensor nodes
Military Networks of Sensors Early 1950s, long-range acoustic sensors (hy-
drophones), called the Sound Surveillance
System (SOSUS),deployed in the deep basins of
Atlantic & Pacific oceans for submarinesurveillance
Networks of air defense radars
Warning and Control System (AWACS) planes for all-
weather surveillance, command, control, andcommunications.
Air Delivered Seismic Intrusion Detector (ADSID)
system, used by US Air Force in the Vietnam war.
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Evolution of Sensor Networks(Cont.)
Next generation Wireless sensor Nodes WINS from UCLA
In 1996, the Low Power Wireless Integrated
Microsensors (LWIMs) were produced by UCLA and
the Rockwell Science Center. In 1998, the same team built a second generation
sensor node-the Wireless Integrated Network
Sensors (WINS)
The WINS processor board The WINS radio board
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Evolution of Sensor Networks(Cont.) Motes from UC Berkeley
In 1999, the Smart Dust project at UC Berkeley
released the first node, WeC
WeC was built with a small 8-bit, 4 MHz Atmel mi-
crocontroller (512 bytes RAM and 8 KB ash
memory), which consumed 15 mW active power and
45 W sleeping power
WeC also had a simple radio supporting a data rate
up to 10 Kbps, with 36 mW transmitting power and 9
mW receiving power. Later on, Rene and Dot were built in 1999 and2000,
respectively, with upgraded microcontrollers.
Mica family was released in 2001, including Mica ,
Mica2, Mica
2Dot, and MicaZ
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Evolution of Sensor Networks(Cont.)
(a) WeC(b) Mica family
(c) Telos (d) Spec prototype
Motes from UC Berkeley
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Evolution of Sensor Networks(Cont.)
PicoRadio from UC Berkeley In 2003, the Berkeley Wireless Research Center
(BWRC) presented the first radio transmitter,PicoBeacon, purely powered by solar andvibrational energy sources.
BWRC also produced SoC based sensor nodesinstead of using COTS components
In 2002, PicoNode II was built using two ASIC chipsthat implemented the entire digital portion of theprotocol stack
the chip set consumed an average of 13 mW when threenodes were connected.
PicoNode III integrate a complete PicoNode into asingle small aspect-ratio package.
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Evolution of Sensor Networks(Cont.) AMPS from MIT
AMPS I AMPS II- highly integrated sensor node comprised of a
digital and an analog/RF ASIC
interesting feature of AMPS-II is that the node will be ableto operate in several modes-
Either as a low-end stand-alone guarding node, a fully functionalnode for middle-end sensor networks,
or a companion component in a more powerful high-end sensorsystems.
it favors a network with heterogeneous sensor nodes formore efficient utilization of resources.
AMPS-I from MIT
Q
Q
Q
Q
Q
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Evolution of Sensor Networks(Cont.)
Other commercial products and testbeds for
Sensor Networks
Ember products
Sensoria WINS
Pluto mote
PC104 testbed and
Gnome testbed
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Why Microscopic Sensor Nodes?
The transition from large to small scale sensor nodes has several
advantages.
(1) Small sensor nodes are easy to manufacture with much lower cost
than large scale sensors.
(2) With a mass volume of low cost and tiny sensor nodes, they can be
deployed very closely to the target phenomena or sensing field at an
extremely high density.
(3) Since computing and communication devices can be integrated with
sensors, large-sample in-network and intelligent information fusion
becomes feasible. The intelligence of sensor nodes and the
availability of multiple onboard sensors also enhances the flexibility of
the entire system.
(4) Due to their small size and self-contained power supply, sensor nodescan be easily deployed into regions where replenishing energy is not
available, including hostile or dangerous environments. The
survivability of nodes also increases with reduced size.
(5) The high node density enables system-level fault tolerance through
node redundancy.
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Mobile Sensor Networks
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Definition A mobile wireless sensor network owes its name to the
presence of mobile sink or sensor nodes within the network.
A mobile sensor network is composed of a distributedcollection of nodes, each of which has sensing, computation,
communication and locomotion capabilities
The mobile sensor node is in fact an enhanced sensor node.It not only has all the capabilities of the static sensor node, butalso realizes mobility by adding a robotic base and a driverboard.
Networks are capable of self-deployment; i.e., starting fromsome compact initial configuration, the nodes in the networkcan spread out such that the area covered by the network ismaximized.
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Sensors Vs. Mobile Sensors Mobile sensor networks have more powerful network
capabilities such as self-deployment, network repair andevent tracking.
In Static Sensor Network, the sensor nodes localize onlyfirst time during deployment. In case of Mobile Sensor
Network, nodes collect the data by moving from oneplace to another place hence localization is needed.
Mobile sensor networks are more energy efficient, bettertargeting and provide more data fidelity than Static
Sensor Network
The advantages of mobile WSN over static WSN arebetter energy efficiency, improved coverage, enhanced
target tracking and superior channel capacity
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System Overview The complete system architecture of a mobile sensor
network includes a group of mobile sensor nodes, abase station, upper communication networkinfrastructures and clients
A base station is used to bridge the sensor network toanother network or platform, such as Internet.
A mobile sensor network is well suited for distributed
measurement and control applications.
The sensor nodes are scattered in the targetenvironment and they form a multi-hop meshnetworking architecture
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Architecture
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Its architecture can be divided into three layers:
Node layer-consists of all the sensor nodes that can beeither static or mobile. This layer is directly embeddedinto the physical world to get all kinds of data.
Server layer-includes a personal computer or a singleboard computer running server software.
Client layer-includes local clients and remote clients.The devices of the client layer can be any smart
terminals, such asP
Cs,P
DAs,P
ocketP
Cs and smartphones.
The server layer and the client layer communicate witheach other and they form a typical example of Internet.
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Mobile Node Design Mobile sensor node is in fact a mobile robot that can
communicate with other nodes wirelessly in the multi-hopsensor network
Add various locomotion modules to the sensor nodes sothat they can move from place to place.
Propose a wheel-based mobile node architecture that canbe regarded as a simple differential drive robot
Wireless sensor node is a resource-constrained device.
When we add mobility to it, we cannot expect it to be aspowerful as conventional mobile robots
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Structure Decomposition
Exploded view of the proposed mobile node structure
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A prototype of the mobile sensor node
-The mobile node, which isnamed as RacemoteZ
-Provides a novel robotic
platform for adding controlled
mobility to wireless sensor
-The size of RacemoteZ is
105 mm90 mm80 mm.
-Easy to assemble or
disassemble the node
-System up-gradation is
possible
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Software Architecture of Mobile Node
The software environment for the sensor nodes isTinyOS, an open-source operating system designed for
wireless embedded sensor networks
The embedded software modules of the mobile node.
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MSNs Type 1: Robots with Sensors
Type 1: Successors of Stationary WSNs.
Artifacts created by the distributed robotics and lowpower embedded systems areas.
Characteristics
Small-sized, wireless-capable, energy-sensitive, as theirstationary counterparts.
Feature explicit (e.g., motor) or implicit (sea/air current)mechanisms that enable movement.
CotsBots (UC-
Berkeley)
MilliBots (CMU) LittleHelis
(USC)
SensorFlock (U
of Colorado
Boulder)
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MSN Type 1: Examples
Example: Chemical Dispersion Sampling
Identify the existence of toxic plumes.
SensorFlock: An Airborne Wireless Sensor Network of Micro-Air Vehicles
Micro Air Vehicles (UAV
Unmanned Aerial Vehicles)Ground Station
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MSN Type 1: Examples
SenseSwarm: A new framework where data acquisition is
scheduled at perimeter sensors and storage at core
nodes.
PA Algorithm for finding the perimeter
DRA/HDRA Data Replication Algorithms
s1
s2 s3
s4s5
s6
s7
s8
Perimeter-Based Data Replication and Aggregation in Mobile Sensor Networks
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MSN Type 1: Advantages
Advantages of MSNs
Controlled Mobility
Can recover network connectivity.
Can eliminate expensive overlay links.
Focused Sampling
Change sampling rate based on spatial
location (i.e., move closer to the physicalphenomenon).
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MSN Type 2: Smartphones
Type 2: Smart phones, the successors of our
dummy cell phones Mobile:
The owner of the smart-phone is moving!
Sensor: Proximity Sensor (turn off display when getting close to ear)
Ambient Light Detector (Brighten display when in sunlight)
Accelerometer (identify rotation and digital compass)
Camera, Microphone, Geo-location based on GPS, WIFI, Cellular
Towers,
Network: Bluetooth: Peer-to-Peer applications / services
WLAN, WCDMA/UMTS(3G) / HSPA(3.5G): broadband access.
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MSN Type 2: Smart phones
Type 2: Smart phones, the successors of ourdummy cell phones
Actuators: Notification Light, Speaker.
Programming Capabilities on top of LinuxOSes: OHAs Android (Google), Nokias
Maemo OS, Apples OSX,
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MSN Type 2: Examples
Intelligent Transportation Systems with VTrack
Better manage traffic by estimating roads taken by
users using WiFi beams (instead of GPS) .
Graphics courtesy of: A .Thiagarajan et. al. Vtrack: Accurate, Energy-Aware Road Traffic Delay Estimation using
Mobile Phones, In Sensys09, pages 85-98. ACM,(Best Paper) MITs CarTel Group
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MSN Type 2: Examples
BikeNet: Mobile Sensing for Cyclists.
Real-time Social Networking of the cycling community
(e.g., find routes with low CO2 levels)
Left Graphic courtesy of: S. B. Eisenman et. al., "The BikeNet Mobile Sensing System for Cyclist Experience
Mapping", In Sensys'07 (Dartmouths MetroSense Group)
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MSN Type 2: Examples
Mobile Sensor Network Platforms
SensorPlanet*: Nokias mobile device-centric large-
scale Wireless Sensor Networks initiative.
Underlying Idea:
Participating universities (MITs CarTel, DartmouthsMetroSense,etc) develop their applications and share the
collected data for research on data analysis and mining,
visualization, machine learning, etc.
Manhattan Story Mashup**: An game where 150 players
on the Web interacted with 183 urban players in
Manhattan in an image shooting/annotation game
First large-scale experiment on mobile sensing.
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MSN Type 2: Examples
Other Types of MSNs?
Body Sensor Networks (e.g., Nike+): Sensor in shoes
communicates with I-phone/I-pod to transmit the distance
travelled, pace, or calories burned by the individual wearing
the shoes.
Vehicular (Sensor) Networks (VANETs): Vehicles communicate
via Inter-Vehicle and Vehicle-to-Roadside enabling Intelligent
Transportation systems (traffic, etc.)
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Design Challenges
Why are Sensor Networkschallenging/unique from a research point of
view?
Typically, severely energy constrained. Limited energy sources (e.g., batteries).
Trade-off between performance and lifetime.
Self-organizing and self-healing. Remote deployments.
Scalable. Arbitrarily large number of nodes.
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Design Challenges (Cont.)
Heterogeneity. Devices with varied capabilities.
Different sensor modalities.
Hierarchical deployments. Adaptability.
Adjust to operating conditions and changes inapplication requirements.
Security and privacy. Potentially sensitive information.
Hostile environments.
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Technical Issues
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Sensor Deployment
Sensors positioned far from the phenomena
Several sensors deployed near the phenomena and sending time
series to a central system
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Deployment and Self-organization
Most sensor nodes are deployed in regions which have no
infrastructure at all. A typical way of deployment in a forest would be tossing the
sensor nodes from an aero plane. In such a situation, it is up to
the nodes to identify its connectivity and distribution.
Self organization of ad hoc networks includes both
communications self-organization and positioning self-organization.
The nodes must wake up, detect each other, and form a
communication network
Localization
In most of the cases, sensor nodes are deployed in
an ad hoc manner. It is up to the nodes to identify
themselves in some spatial co-ordinate system. This
problem is referred to as localization.
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Sensor Network Technology
Sensor nets often wireless towards sensors-May use Wi-fi 802.11
-Often use ZigBee 802.15.4 (low-power)
-Other technology under development and use
Sensor net gateways often use Web access
-Is good standard for heterogeneity
Sensor net gateways may use differenttechnologies towards Internet
-Often wired with normal technologies
-Often wireless e.g. cellular or Wi-fi
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Sensor Network Topology
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Software Issues
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Operating System
Typically less complex than the general purposeoperating systems, because
special requirements of sensor network applications
resource constraints in sensor network hardwareplatforms
Embedded operating systems such as eCos oruC/OS for sensor networks can be used
Wireless sensor network hardware is not differentfrom traditional embedded systems
Embedded operating systems are often designedwith real-time properties
Operating systems specifically for sensor networksdo not have real-time support
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Operating System(Cont.)
TinyOS is perhaps the first operating systemspecifically designed for wireless sensornetworks
TinyOS is based on an event-drivenprogramming model instead of multithreading
TinyOS programs are composed into eventhandlers and tasks with run to completion-semantics
Programs written for TinyOS are written in aspecial programming language called nesC extension to the C programming language
NesC is designed to detect race conditionsbetween tasks and event handlers.
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Software
What is the role of software in sensornetworks?
Energy is the scarcest resource of
WSN nodes, and it determines the lifetime of
WSNs
WSNs are meant to be deployed in
large numbers in various environments,
including remote and hostile regions
Ad-hoc communications as key
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Software(Cont.)
Algorithms and protocols need to address the followingissues:
Lifetime maximization
Robustness and fault tolerance
Self-configuration
Some of the "hot" topics in WSN software research are:
Security
Mobility (when sensor nodes or base stations aremoving)
Middleware: the design of middle-level primitivesbetween the software and the hardware
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Algorithms And Protocols
An algorithm for a Sensor Network is
implicitly a distributed algorithm.
Algorithmic research in Sensor Networksmostly focuses on
Energy Efficiency
Localization & Time Synchronization
Routing
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MAC for Energy Efficiency
Medium Access Control (MAC) protocolsdesigned for ad hoc networks primarily focused on optimizing fairness and
throughput efficiency, with less emphasis on energyconservation
MACs for sensor network are enhanced Protocols such as MACAW and IEEE 802.11
eliminate the energy waste caused by collidingpackets in wireless networks
MAC protocols for sensor networks is to reducethis idle power
consumption by setting the sensor radios into asleep state
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MAC protocols
Sensor MAC(S-MAC) First MAC for Sensor Networks
nodes create a sleep schedule for themselvesthat determines at what times to activate their
receivers and when to set themselves into asleep mode.
Timeout-MAC (T-MAC) Solution for limitations of the original S-MAC
protocol T-MAC to eliminate idle energy further by
adaptively setting the length of the active portionof the frames
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MAC protocols
DMAC By staggering the wakeup times, DMAC
reduces the large delays observed in packets
that are forwarded for more than a few hops
TRaffic-Adaptive Medium Access
(TRAMA)
TRAMA attempts to reduce wasted energy
consumption caused by packet collisions
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Localization(Cont.)Localization algorithms can be roughly
classified into two categories(Depending on whetherabsolute range measurements
(point-to-point distances, angles, etc.) are used or not)
range based and
range-free.
Range-basedalgorithms usually need somespecial hardware to obtain accurate absoluterange measurements can achieve higher localization accuracy than
range-free algorithms. Range-free algorithms do not need special
hardware and are low costly more attractive in recent years.
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Localization Algorithms for MSNs
All are based on the Sequential Monte
Carlo (SMC) method
SMC method provides simple simulation-based
approaches to estimating the distribution
Weighted Monte Carlo Localization (WMCL)
Energy efficient algorithm
.
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Time Synchronization
To enable applications such as target
tracking, sensor networks require time
synchronization
Romers Algorithm
Reference-Broadcast Synchronization (RBS)
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Routing protocols
It is a great challenge for routing in a WSN,because since it is not easy to grasp the whole network
topology, it is hard to find a routing path
sensor nodes are tightly constrained in terms ofenergy, processing, and storage capacities. Thus,they require effective resource management policiesto increase the overall lifetime of sensor networks
Routing Protocols for WSNNetworkStructure BasedProtocolsProtocol Operation BasedProtocols
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Routing Protocols(cont.)
1.Network Structure Based protocols Depend on the system architecture of
the network.
These protocols are classified again
into three categories:
Data centric or flat routing protocols,
Hierarchical routing protocols, and
Location based routing protocols.
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Routing protocols(Cont.)2.Protocol operation based protocols
These are classified into five categories:
Negotiation based routing protocol
Multi-path based routing protocol
Query-based routing protocol
QoS-based routing protocol and
Coherent-based routing protocol
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Factors influencing sensor
network design
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Factors influencing sensor network
design
Fault Tolerance
Scalability
Hardware Constrains Sensor Network Topology
Environment
Transmission Media Power Consumption
F i fl i k
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Factors influencing sensor network
design
Fault tolerance
Fault tolerance is the ability to sustain sensornetwork functionalities without any
interruption due to sensor node failures.
The fault tolerance level depends on theapplication of the sensor networks.
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Factors influencing sensor
network design
Scalability
Scalability measures the density of the
sensor nodes.
Density = (R) =(N R2)/AR Radio Transmission Range
Q T
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Factors influencing sensor network
design
Production costs
The cost of a single node is very important to
justify the overall cost of the networks.
The cost of a sensor node is a very
challenging issue given the amount offunctionalities with a price of much less than a
dollar.
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Factors influencing sensor network
designHardware constraints
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Factors influencing sensor network
design
Sensor network topology
Pre-deployment and deployment phase
Post-deployment phase
Re-deployment of additional nodes phase
F t i fl i t k
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Factors influencing sensor network
designEnvironment Busy intersections
Interior of a large machinery
Bottom of an ocean Surface of an ocean during a tornado
Biologically or chemically contaminated field
Battlefield beyond the enemy lines
Home or a large building
Large warehouse Animals
Fast moving vehicles
Drain or river moving with current.
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Factors influencing sensor network
designTransmission media
In a multi-hop sensor network,
communicating nodes are linked by awireless medium. To enable global operation,the chosen transmission medium must beavailable worldwide.
Radio infrared
optical media
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Factors influencing sensor network
design
Power Consumption
Sensing Communication
Data processing
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Communication Architecture
Communication architecture of
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Communication architecture of
sensor networks
Combine power androuting awareness
Integrates date with
networking protocols Communicates power
efficiently through thewireless medium
Promotes cooperative
efforts among sensornodes.
Sensor Network Protocol stack
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Communication architecture of sensor
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Communication architecture of sensor
networks
Propagation Effects
Minimum output power
(dn 2=
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Communication architecture of
sensor networksOpen research issues
Modulation schemes
Strategies to overcome signal propagation
effects
Hardware design: transceiver
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Communication architecture of
sensor networks
Data link layer:
The data link layer is responsible for themultiplexing of data stream, data frame detection,
the medium access and error control.
Medium Access Control Power Saving Modes of Operation
Error Control
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Communication architecture of sensor
networksMedium access control
Creation of the network infrastructure
Fairly and efficiently share communication
resources between sensor nodes
Existing MAC protocols (Cellular System,
Bluetooth and mobile ad hoc network)
Communication architecture of sensor
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Communication architecture of sensor
networks
MAC for Sensor Networks
Self-organizing medium access control for sensor networks
and Eaves-drop-and-register Algorithm
CSMA-Based Medium Access Hybrid TDMA/FDMA-Based
Communication architecture of
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Communication architecture of
sensor networks
Power Saving Modes of Operation
Sensor nodes communicate using short data
packets The shorterthe packets, the more dominance
of startup energy
Operation in a power saving mode is energy
efficient only if the time spent in that mode is
greater than a certain threshold.
C i ti hit t f
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Communication architecture of
sensor networks
Error Control
Error control modes in Communication Networks(additional retransmission energy cost)
Forward Error Correction (FEC)
Automatic repeat request (ARQ)
Simple error control codes with low-complexity encodingand decoding might present the best solutions for sensor
networks.
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Communication architecture of
sensor networksOpen research issues
MAC for mobile sensor networks
Determination of lower bounds on theenergy required for sensor network self-
organization
Error control coding schemes. Power saving modes of operation
C i ti hit t f
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Communication architecture of
sensor networksNetwork layer:
Power efficiency is always an important
consideration. Sensor networks are mostly data centric.
Data aggregation is useful only when it does not
hinder the collaborative effort of the sensor nodes.
An ideal sensor network has attribute-basedaddressing and location awareness.
Communication architecture of
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Communication architecture of
sensor networks
Maximum available power (PA) route:
Route 2
Minimum energy (ME) route: Route 1
Minimum hop (MH) route: Route 3
Maximum minimum PA node route:
Route 3
Minimum longest edge route: Route 1
Energy Efficient Routes
Communication architecture of
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Communication architecture of
sensor networksInterest Dissemination
Sinks broadcast the interest
Sensor nodes broadcast the advertisements
Attribute-based naming
The areas where the temperature is over 70oF
The temperature readbya certain node
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Communication architecture of
sensor networks
Data aggregation
Solve implosion and overlapProblem
Aggregation based on same
attribute of phenomenon
Specifics (the locations ofreporting sensor nodes) should
not be left out
Communication architecture of
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Communication architecture of
sensor networks
Several Network Layer Schemes for Sensor
Networks
Communication architecture of
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Communication architecture of
sensor networks
Open research issues
New protocols need to be developed to addresshigher topology changes and higher scalability.
New internetworking schemes should be developed
to allow easy communication between the sensor
networks and external networks.
Communication architecture of
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Communication architecture of
sensor networks
Transport layer:
This layer is especially needed when the system is
planned to be accessed through Internet or otherexternal networks.
TCP/UDP type protocols meet most requirements
(not based on global addressing).
Little attempt thus far to propose a scheme or todiscuss the issues related to the transport layer of a
sensor network in literature.
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Communication architecture of
sensor networksOpen research issues
Because acknowledgments are too costly,
new schemes that split the end-to-end
communication probably at the sinks may
be needed.
Communication architecture of sensor
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networks
Application layer:
Management protocol makes the hardware andsoftware of the lower layers transparent to the
sensor network management applications. Sensor management protocol (SMP)
Task assignment and data advertisement protocol(TADAP)
Sensor query and data dissemination protocol(SQDDP)
Communication architecture of
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sensor networks
Sensor management protocol (SMP)
Introducing the rules related to data aggregation, attribute-basednaming, and clustering to the sensor nodes
Exchanging data related to the location
finding algorithms
Time synchronization of the sensor nodes
Moving sensor nodes
Turning sensor nodes on and off
Querying the sensor network configuration and the status ofnodes, and reconfiguring the sensor network
Authentication, key distribution, and security in datacommunications
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Some Other Interesting
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g
Applications
MIT d'Arbeloff Lab The ring
sensor
Monitors the physiological status of
the wearer and transmits theinformation to the medical
professional over the Internet
Oak Ridge National Laboratory
Nose-on-a-chip is a MEMS-based
sensor
It can detect 400 species of gases
and transmit a signal indicating the
level to a central control station
iB tt
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iButton
A 16mm computer chip armored in a stainless
steel can
Up-to-date information can travel with aperson or object
Types of i-Button
Memory Button
Java Powered Cryptographic iButton
Thermochron iButton
iB tton Applications
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iButton Applications
Caregivers Assistance Do not need to keep a bunch of keys. Only one
iButton will do the work
Elder Assistance They do not need to enter all their personal
information again and again. Only one touch of
iButton is sufficient They can enter their ATM card information andPIN with iButton
Vending Machine Operation Assistance
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iBadge - UCLA
Investigate behavior of children/patient
Features:
Speech recording / replaying Position detection
Direction detection / estimation(compass)
Weather data: Temperature, Humidity,
Pressure, Light
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iBadge - UCLA
Some Application work in India
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Some Application work in India DRDO project on theoretical aspect, mote
development and deployment (IISc.) WSN for critical emergency applications (Amirta
Univ., IIT-Bombay, IIT-Delhi, IIT-Kgp)
WSN for tracking and monitoring in undergroundmines (Central Mining Research Institute)
Underwater wireless sensor networks (NPOL)
WSN for Agriculture (IISc, IIT-Bombay)
Pollution monitoring (IIT-Delhi, IIM-Kolkata, IIT-Kgp)
WSN for Biomed (IIT-Bombay)
Many IITs have WSN test beds Many other theoretical and application work in India
The above list is by no means complete, it is only illustrative
Academic Research to Industry
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Academic Research to Industry
WSN is transiting fromactive academic researchto industry.
Start-up companies suchas:
Crossbow Technologies Dust Networks
Ember
Millennial Net
Tendril Networks
Scalable NetworkTechnologies
Airbee Wireless (India;will be giving a demo)
Virtualwire (Delhi, India)
WSN can be a greatenabler for component
manufacturers
system integrators
software servicesproviders
OEMS
application developers
and other end users.
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gracias