Design Issues and Challenges in Wireless Sensor NetworksKhushbooGupta145
Wireless Sensor Networks (WSNs) are composed self-organized wireless ad hoc networks which comprise of a large number of resource constrained sensor nodes. The major areas of research in WSN is going on hardware, and operating system of WSN, deployment, architecture, localization, synchronization, programming models, data aggregation and dissemination, database querying, architecture, middleware, quality of service and security. This paper study highlights ongoing research activities and issues that affect the design and performance of Wireless Sensor Network.
Wireless Sensor Network (WSN) consists of sensor nodes which interact with each other through physical parameters like sunlight, wind, vibration, humidity etc. Routing protocols provide an optimal data transmission route from sensor nodes to sink node to save energy of nodes. From Base Station (BS) Sensor node sends and receives data to or from wireless stations. Clustering mechanism is one of the popular routing mechanisms used in WSN for optimizing the problem in sensor nodes. There are two types of clustering schemes known as homogeneous schemes and heterogeneous schemes. In Homogeneous scheme initial energy is same for each node but in heterogeneous scheme initial energy is different for each node and also used to determine the efficiency of sensor networks. Enhanced Modified LEACH (EMODLEACH) is a reactive protocol which is implemented for homogeneous network model. We have implemented the concept of Efficient Cluster head Replacement scheme and Dual transmitting power level scheme of MODLEACH along with the concept of Efficient Intra Cluster transmission Scheme of TEEN in LEACH. We analyze the PEGASIS protocol and modified the exiting protocol called improved energy balanced routing protocol (IEBRP).This IEBRP is based on cluster formation, cluster routing and other aspects of LEACH protocol.
Low Power Wireless Sensor Network Technologies and Standards for the Internet...Duncan Purves
Presentation on Low Power Wireless Sensor Network Technologies and Standards for the Internet of Things given at Institute of Physics, Sensors & their Applications XVIII Conference, 12 September 2016
Design Issues and Challenges in Wireless Sensor NetworksKhushbooGupta145
Wireless Sensor Networks (WSNs) are composed self-organized wireless ad hoc networks which comprise of a large number of resource constrained sensor nodes. The major areas of research in WSN is going on hardware, and operating system of WSN, deployment, architecture, localization, synchronization, programming models, data aggregation and dissemination, database querying, architecture, middleware, quality of service and security. This paper study highlights ongoing research activities and issues that affect the design and performance of Wireless Sensor Network.
Wireless Sensor Network (WSN) consists of sensor nodes which interact with each other through physical parameters like sunlight, wind, vibration, humidity etc. Routing protocols provide an optimal data transmission route from sensor nodes to sink node to save energy of nodes. From Base Station (BS) Sensor node sends and receives data to or from wireless stations. Clustering mechanism is one of the popular routing mechanisms used in WSN for optimizing the problem in sensor nodes. There are two types of clustering schemes known as homogeneous schemes and heterogeneous schemes. In Homogeneous scheme initial energy is same for each node but in heterogeneous scheme initial energy is different for each node and also used to determine the efficiency of sensor networks. Enhanced Modified LEACH (EMODLEACH) is a reactive protocol which is implemented for homogeneous network model. We have implemented the concept of Efficient Cluster head Replacement scheme and Dual transmitting power level scheme of MODLEACH along with the concept of Efficient Intra Cluster transmission Scheme of TEEN in LEACH. We analyze the PEGASIS protocol and modified the exiting protocol called improved energy balanced routing protocol (IEBRP).This IEBRP is based on cluster formation, cluster routing and other aspects of LEACH protocol.
Low Power Wireless Sensor Network Technologies and Standards for the Internet...Duncan Purves
Presentation on Low Power Wireless Sensor Network Technologies and Standards for the Internet of Things given at Institute of Physics, Sensors & their Applications XVIII Conference, 12 September 2016
LPWAN Technologies for Internet of Things (IoT) and M2M ScenariosPeter R. Egli
Rapid technological advances in the past made possible the miniaturization of network devices to meet the cost and power consumption requirements in IoT and M2M scenarios. What is missing in this picture is a radio technology with both long range capability and a very low cost footprint. Existing radio technologies such as 3G/4G or Short Range Radio do not aptly meet the requirements of IoT scenarios because they are either too expensive or are not able to provide the required range. Other wireless technologies are geared towards high bandwidth which is in most cases not a requirement for IoT.
Emerging LPWAN technologies such as ETSI LTN or LoRAWAN are poised for filling the gap by providing long range (up to 40km) and low power connectivity. These technologies allow low cost radio devices and operation thus enabling scaling up IoT applications.
sensors are what we experience the most in our life. they are even working in our body in different aspects. they may be as eyes, ears, skin, tongue etc. when we combine them they make a network. it may be a human sensor network. but i have shared something interesting about wireless sensor networks.
This presentation is all about the wireless sensor networks, how they collect data using aggregation, and how they evaluate or calculate the parameters
Comprehensive Review on Base Energy Efficient Routing ProtocolIJRES Journal
With the faster growing in electronics industry, small inexpensive battery powered wireless sensors have made an impact on the communications with the physical world. The Wireless Sensor Networks (WSN) consists of hundreds of sensor nodes which are resource constrained. WSN nodes monitor various physical and environmental conditions very cooperatively. WSN uses various nodes for the communication. WSN has become one of the interested areas in the field of research from last few years. To enhance the lifetime of the whole networks energy reduction is the necessary consideration for design and analyse of the clustering and routing protocols. This paper describes the study of various energy efficient routing protocols in WSNs which are important for their designing purpose so as to meet the various resource constraints.
International Journal of Computational Engineering Research (IJCER) is dedicated to protecting personal information and will make every reasonable effort to handle collected information appropriately. All information collected, as well as related requests, will be handled as carefully and efficiently as possible in accordance with IJCER standards for integrity and objectivity.
A review of Hierarchical energy Protocols in Wireless Sensor Networkiosrjce
IOSR Journal of Computer Engineering (IOSR-JCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of computer engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in computer technology. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
The development of the wireless sensor networks (WSNs) in various applications like Defense, Health,
Environment monitoring, Industry etc. always attract many researchers in this field. WSN is the network
which consists of collection of tiny devices called sensor nodes. Sensor node typically combines wireless
radio transmitter-receiver and limited energy, restricted computational processing capacity and
communication band width. These sensor node sense some physical phenomenon using different
transduces. The current improvement in sensor technology has made possible WSNs that have wide and
varied applications. While selecting the right sensor for application a number of characteristics are
important. This paper provides the basics of WSNs including the node characteristics. It also throws light
on the different routing protocols.
Secure and Efficient DiDrip Protocol for Improving Performance of WSNsINFOGAIN PUBLICATION
Wireless Sensor Networks consists of a set of resource constrained devices called nodes that communicate wirelessly with each other. Wireless Sensor Networks have become a key application in number of technologies. It also measures the unit of vulnerability to security threats. Several Protocols are projected to make them secure. Some of the protocols within the sensor network specialize in securing data. These protocols are named as data discovery and dissemination protocols. The data discovery and dissemination protocol for wireless sensor networks are utilized for distributing management commands and altering configuration parameters to the sensor nodes. All existing data discovery and dissemination protocols primarily suffer from two drawbacks. Basically, they are support centralized approach (only single station can distribute data item).This approach is not suitable for multiple owner-multiple users. Second, the protocols are not designed with security in mind. This Paper proposes the first distributed knowledge discovery and dissemination protocol called DiDrip which is safer than the existing one. The protocol permits multiple owners to authorize many network users with altogether totally different priorities to at an equivalent time and directly flow into data items to sensor nodes.
Wireless Sensor Networks UNIT-1
You can watch my lectures at:
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Concepts and evolution of research in the field of wireless sensor networksIJCNCJournal
The field of Wireless Sensor Networks (WSNs) is experiencing a resurgence of interest and a continuous evolution in the scientific and industrial community. The use of this particular type of ad hoc network is becoming increasingly important in many contexts, regardless of geographical position and so, according to a set of possible application. WSNs offer interesting low cost and easily deployable solutions to perform a remote real time monitoring, target tracking and recognition of physical phenomenon. The uses of these sensors organized into a network continue to reveal a set of research questions according to particularities target applications. Despite difficulties introduced by sensor resources constraints, research contributions in this field are growing day by day. In this paper, we present a comprehensive review of most recent literature of WSNs and outline open research issues in this field.
A Survey on Security Issues to Detect Wormhole Attack in Wireless Sensor Networkpijans
Sensor nodes, when deployed to form Wireless sensor network operating under control of central authority
i.e. Base station are capable of exhibiting interesting applications due to their ability to be deployed
ubiquitously in hostile & pervasive environments. But due to same reason security is becoming a major
concern for these networks. Wireless sensor networks are vulnerable against various types of external and
internal attacks being limited by computation resources, smaller memory capacity, limited battery life,
processing power & lack of tamper resistant packaging. This survey paper is an attempt to analyze threats
to Wireless sensor networks and to report various research efforts in studying variety of routing attacks
which target the network layer. Particularly devastating attack is Wormhole attack- a Denial of Service
attack, where attackers create a low-latency link between two points in the network. With focus on survey of
existing methods of detecting Wormhole attacks, researchers are in process to identify and demarcate the
key research challenges for detection of Wormhole attacks in network layer.
Marker Controlled Segmentation Technique for Medical applicationRushin Shah
Medical image segmentation is a very important field for the medical science. In medical images, edge detection is an important work for object recognition of the human organs such as brain, heart or kidney etc. and it is an essential pre-processing step in medical image segmentation.
Medical images such as CT, MRI or X-Ray visualizes the various information’s of internal organs which is very important for doctors diagnoses as well as medical teaching, learning and research.
It is a tough job to locate the internal organs if images contains noise or rough structure of human body organs.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
2024.06.01 Introducing a competency framework for languag learning materials ...Sandy Millin
http://sandymillin.wordpress.com/iateflwebinar2024
Published classroom materials form the basis of syllabuses, drive teacher professional development, and have a potentially huge influence on learners, teachers and education systems. All teachers also create their own materials, whether a few sentences on a blackboard, a highly-structured fully-realised online course, or anything in between. Despite this, the knowledge and skills needed to create effective language learning materials are rarely part of teacher training, and are mostly learnt by trial and error.
Knowledge and skills frameworks, generally called competency frameworks, for ELT teachers, trainers and managers have existed for a few years now. However, until I created one for my MA dissertation, there wasn’t one drawing together what we need to know and do to be able to effectively produce language learning materials.
This webinar will introduce you to my framework, highlighting the key competencies I identified from my research. It will also show how anybody involved in language teaching (any language, not just English!), teacher training, managing schools or developing language learning materials can benefit from using the framework.
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
How to Make a Field invisible in Odoo 17Celine George
It is possible to hide or invisible some fields in odoo. Commonly using “invisible” attribute in the field definition to invisible the fields. This slide will show how to make a field invisible in odoo 17.
2. Basics of
Wireless Sensor Network
Unit 2
Wireless Ad Hoc and Sensor Networks
2
]RushiN $hah
February 27, 2014
3. 1.1 Introduction
A sensor network is an infrastructure :
-- comprised of sensing (measuring), computing, and
communication elements
that gives an administrator
-- the ability to instrument, observe and react to
events & phenomena in a specified environment.
The
administrator
typically
is
a
civil, governmental, commercial, or industrial entity.
The environment can be the physical world, a
biological system or an information technology (IT)
framework.
3
]RushiN $hah
February 27, 2014
4. 1.1 Introduction
There are Four Basic Components in a sensor network:
An assembly of distributed or localized sensors;
An interconnecting network (usually, but not always,
wireless-based);
A central point of information clustering; and
A set of computing resources at the central point (or
beyond) to handle
- data correlation,
- event trending,
- status querying, and
- data mining.
4
]RushiN $hah
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5. 1.1 Introduction
Because of the potentially large quantity of data
collected, algorithmic methods for Data Management
play an important role in sensor networks.
The computation and communication infrastructure
associated with sensor networks is often specific to
this environment and rooted in the device and
application-based nature of these networks.
5
]RushiN $hah
February 27, 2014
6. 1.1.1
Background of Sensor Network Technology
Researchers see WSNs as an
--‘‘exciting emerging domain of deeply networked
systems of low-power wireless motes
-- with a tiny amount of CPU and memory, and
-- large federated networks for
-- high-resolution sensing of the environment’’
Sensors in a WSN have a variety of purposes,
functions, and capabilities.
The field is now advancing under the push of recent
technological advances and the pull of a myriad of
potential applications.
6
]RushiN $hah
February 27, 2014
7. 1.1.1
Background of Sensor Network Technology
The radar networks used in air traffic control,
the national electrical power grid, and
nationwide weather stations deployed over a regular
topographic mesh are all examples of earlydeployment sensor networks.
All of these systems, however, use specialized
computers and communication protocols and
consequently, are very expensive.
Much less expensive WSNs are now being planned
for novel applications in physical security, healthcare,
and commerce.
7
]RushiN $hah
February 27, 2014
8. 1.1.1
Background of Sensor Network Technology
Sensor networking is a multidisciplinary area that
involves:
Radio and Networking,
Signal Processing,
Artificial Intelligence,
Database management,
Systems architectures for operator-friendly infrastructure
administration,
Resource optimization,
Power management algorithms, and
Platform Technology (hardware and software, such as
operating systems)
The applications, networking principles, and
protocols for these systems are just beginning to
be developed.
8
]RushiN $hah
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9. 1.1.1
Background of Sensor Network Technology
The technology for sensing and control includes
Radio-wave frequency sensors;
Electric and Magnetic field sensors;
Optical-, Electro optic-, and Infrared sensors;
Radars;
Lasers;
Location / Navigation sensors;
Seismic and Pressure-wave sensors;
Environmental parameter sensors (wind, humidity,
heat);
Biochemical national security–oriented sensors.
9
]RushiN $hah
February 27, 2014
10. 1.1.1
Background of Sensor Network Technology
Sensor devices, or wireless nodes (WNs), are also
(sometimes) called ‘motes’.
Sensors are typically deployed in a high-density
manner and in large quantities:
A WSN consists of densely distributed nodes that
support sensing, signal processing, embedded
computing, and connectivity;
Sensors are logically linked by self organizing
10
]RushiN $hah
February 27, 2014
11. 1.1.1
Background of Sensor Network Technology
WNs typically transmit information to collecting
(monitoring) stations that aggregate some or all of
the information.
WSNs have unique characteristics, such as, but not
limited to, power constraints and limited battery life
for the WNs, redundant data acquisition, low duty
cycle, and, many-to-one flows.
11
]RushiN $hah
February 27, 2014
12. 1.1.1
Background of Sensor Network Technology
A current research and development (R&D)
challenge is to develop low-power communication
with low-cost on-node processing and self organizing
connectivity or protocols.
Another critical challenge is the need for extended
temporal operation of the sensing node despite a
(typically) limited power supply (and/or battery life).
Low power consumption is a key factor in ensuring
long operating horizons for non-power-fed systems
(some systems can indeed be power-fed and/or rely
on other power sources).
12
]RushiN $hah
February 27, 2014
13. 1.1.1
Background of Sensor Network Technology
Power efficiency in WSNs is generally accomplished
in three ways: *
1) Low-duty-cycle operation.
2) Local/in-network processing to reduce data volume
(and hence transmission time).
3) Multihop networking reduces the requirement for
long-range transmission since signal path loss is
an inverse exponent with range or distance.
Each node in the sensor network can act as a
repeater, thereby reducing the link range coverage
required and, in turn, the transmission power.
13
]RushiN $hah
February 27, 2014
14. Classification of Sensor Network
Sensor Networks and Systems taxonomies into two
categories:
Category 1 WSNs (C1WSNs): almost invariably meshbased systems with multi-hop radio connectivity among
or between WNs, utilizing dynamic routing in both the
wireless and wire-line portions of the network.
Military-theater systems typically belong to this
category.
Category
2 WSNs (C2WSNs): Point-to-point or
multipoint-to-point (star-based) systems generally with
single-hop radio connectivity to WNs, utilizing static
routing over the wireless network; typically, there will be
only one route from the WNs to the companion terrestrial
or wire-line forwarding node (WNs are pendent nodes).
Residential control systems ]RushiN $hah February 27, 2014 this
typically belong to
14
category.
15. 1.1.1
Background of Sensor Network Technology
C1WSNs
C2WSNs
support highly distributed high- support
node-count applications
spaces
confined
short-range
e.g., environmental monitoring, e.g. home, a factory, a building, or
national security systems
the human body.
different in scope and/or reach for
short-range
low-data-rate
from evolving wireless
wireless applications
RFID
(radio-frequency
identification)
systems,
light
switches, fire and smoke
detectors, thermostats, and, home
appliances
tend to deal with large-scale tend to focus on short-range pointmultipoint-to-point systems with to
point,
source-to-sink
massive data flows
applications with uniquely defined
transaction-based data27, 2014
15
]RushiN $hah February flows.
16. MANETs
There is considerable research in the area of mobile
ad hoc networks (MANETs).
MANETs are similar to WSNs in some ways; for
example, both involve multi-hop communications.
But the applications and technical requirements for
the two systems are significantly different in several
respects.
The typical mode of communication in WSN is
from multiple data sources to a data recipient or
sink rather than communication between a pair of
nodes.
In other words,
16 Sensor
]RushiN $hah February 27, 2014
Nodes use multicast or broadcast
17. MANETs
In
most scenarios the sensors themselves are not
mobile; this implies that the dynamics in the two
types of networks are different.
Because the data being collected by multiple
sensors are based on common phenomena, there is
potentially a degree of redundancy in the data
being communicated by the various sources in
WSNs; this is not generally the case in MANETs.
The number of sensor nodes in a sensor network
can be several orders of magnitude higher than the
nodes in a MANET.
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]RushiN $hah
February 27, 2014
18. MANETs
Because
the data being collected by multiple sensors are
based on common phenomena, there is potentially some
dependency on traffic event generation in WSNs, such
that some typical random-access protocol models may
be inadequate at the queuing-analysis level; this is
generally not the case in MANETs.
A critical resource constraint in WSNs is energy; this is
not always the case in MANETs, where the
communicating devices handled by human users can be
replaced or recharged relatively often.
The scale of WSNs (especially, C1WSNs) and the
necessity for unattended operation for periods reaching
weeks or months implies that energy resources have to
be managed very judiciously. This, in turn, precludes
high-data-rate transmission.
18
]RushiN $hah
February 27, 2014
19. Comparison between WSN and WAN *
The
number of nodes in sensor network can be
several orders of magnitude larger than the wireless
ad hoc network
Sensor nodes are more prone to failure and
energy drain and their battery resources are usually
not replicable or rechargeable.
Sensor nodes may not have global identifiers, so
unique addressing is not feasible in sensor network.
Sensor nodes are data centric, while ad hoc
wireless network is address centric.
Sensor network require different mechanism for
routing & answering queries.
19
]RushiN $hah
February 27, 2014
20. 1.1.2
Applications of Sensor Networks
Traditionally, sensor networks have been used in the
context of high-end applications such as:
Military applications
20
Monitoring inimical forces
Monitoring friendly forces and equipment
Military-theater or battlefield surveillance
Targeting
Battle damage assessment
Nuclear, biological, and chemical attack detection
]RushiN $hah
February 27, 2014
21. 1.1.2
Applications of Sensor Networks
Environmental applications
Microclimates
Forest fire detection
Flood detection
Precision agriculture
Health applications
21
Remote monitoring of physiological data
Tracking and monitoring doctors and patients inside a
hospital
Drug administration
Elderly assistance
]RushiN $hah
February 27, 2014
22. 1.1.2
Applications of Sensor Networks
Home applications
Home automation
Instrumented environment
Automated meter reading
Commercial applications
22
Environmental control in industrial and office buildings
Inventory control
Vehicle tracking and detection
Traffic flow surveillance
]RushiN $hah
February 27, 2014
23. 1.2.1
Basic Sensor N/W Architectural Elements
A sensor network is composed of a large number of
sensor nodes that are densely deployed.
sensor nodes may be deployed in an open space;
on a battlefield in front of, or beyond, enemy lines; in
the interior of industrial machinery; at the bottom of a
body of water; in a biologically and/or chemically
contaminated field; in a commercial building; in a
home; or in or on a human body.
A sensor node typically has embedded processing
capabilities and onboard storage; the node can have
one or more sensors operating in the acoustic,
seismic, radio (radar), infrared, optical, magnetic,
and chemical or biological domains. (Sensor Types
and Technology)
23
]RushiN $hah
February 27, 2014
24. 1.2.1
Basic Sensor N/W Architectural Elements
The node has communication interfaces, typically
wireless links, to neighbouring domains.
The sensor node also often has location and
positioning knowledge that is acquired through a
global positioning system (GPS) or local positioning
algorithm.
Sensor nodes are scattered in a special domain
called a sensor field.
Each of the distributed sensor nodes typically has
the capability to collect data, analyze them, and
route them to a (designated) sink point.
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]RushiN $hah
February 27, 2014
26. 1.2.1
Basic Sensor N/W Architectural Elements
The following are important issues pertaining to
WSNs: sensor type; sensor placement; sensor
power
consumption,
operating
environment,
capabilities
and
signal
processing, connectivity, and telemetry or control of
remote devices.
It is critical to note that node location and finegrained time (stamping) are essential for proper
operation of a sensor network.
26
]RushiN $hah
February 27, 2014
27. 1.2.1
Basic Sensor N/W Architectural Elements
Embedded sensor networks are predicated on three
supporting components: Embedding, Networking,
and Sensing.
Embedding implies the incorporation of numerous
distributed devices to monitor the physical world and
interact with it.
The devices are untethered nodes of small form
factors that are equipped with a control and
communication subsystem.
Spatially- and Temporally-dense arrangements are
common.
27
]RushiN $hah
February 27, 2014
28. 1.2.1
Basic Sensor N/W Architectural Elements
Networking implies the concept of physical and
logical connectivity.
Logical connectivity has the goal of supporting
coordination and other high-level tasks.
Physical connectivity is typically supported over a
wireless radio link.
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]RushiN $hah
February 27, 2014
29. 1.2.1
Basic Sensor N/W Architectural Elements
Sensing implies the presence of these capabilities in
a tightly coupled environment, typically for the
measurement of physical-world parameters.
Some of the characteristic features of sensor
networks include the following
Sensor nodes are densely deployed.
Sensor nodes are prone to failures.
The topology of a sensor network changes very
frequently.
Sensor nodes are limited in power, computational
capacities, and memory.
Sensor nodes may not have global identification because
of the large amount of overhead and the large number of
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sensors.
30. Sensor networks require sensing systems that are
long-lived and environmentally resilient.
Unattended, untethrered, self-powered low-dutycycle systems are typical.
In most instances, communication circuitry and
antennas are the primary elements that draw most of
the energy.
Sensors are either passive or active devices.
Passive sensors in element form include seismic-,
acoustic-, strain-, humidity-, and temperaturemeasuring devices.
Passive sensors tend to be low-energy devices.
Active sensors include radar and sonar; these tend
to be high-energy systems. ]RushiN $hah February 27, 2014
30
32.
The components of a (remote) sensing node include
(see Figure 1.3) the following:
32
A sensing and actuation unit (single element or array)
A processing unit
A communication unit
A power unit
Other application-dependent units
]RushiN $hah
February 27, 2014
33. Categorization of issues related to sensor and
their communication/computing architecture
Categorization of issues related to sensor and their
communication/computing architecture
Sensors
33
Size: Small [e.g., nanoscale electromechanical systems
(MEMS)], medium [e.g., microscale electromechanical
systems (MEMS)], and large (e.g., radars, satellites):
cubic centimetres.
Mobility: stationary (e.g., seismic sensors), mobile (e.g.,
on robot vehicles)
Type: passive (e.g., acoustic, seismic, video, infrared,
magnetic) or active (e.g., radar, ladar)
]RushiN $hah
February 27, 2014
34. Categorization of issues related to sensor and
their communication/computing architecture
Communication
Processing Architecture
Networking: wired (on occasion) or wireless (more
common)
Bandwidth: high (on occasion) or low (more typical)
Centralized (all data sent to central site), distributed or innetwork architecture (located at sensor or other sides), or
hybrid.
Operating Environment
34
Monitoring requirement: distributed (e.g., environmental
environment monitoring) or localized (e.g., target tracking)
Number of sites: sometimes small, but usually large
(especially for C1WSNs)
]RushiN $hah
February 27, 2014
35. Categorization of issues related to sensor and
their communication/computing architecture
35
Spatial coverage: dense, spars: C1WSN: low-range
multi-hop or C2WSN: low-range single-hop (point-topoint)
Deployment: fixed and planned (e.g., factory networks)
or ad hoc (e.g., air-dropped)
Environment: benign (factory floor) or adverse
(battlefield)
Nature: cooperative (e.g., air traffic control) or non
cooperative (e.g., military targets)
Composition: homogeneous (same types of sensors) or
heterogeneous (different types of sensors)
]RushiN $hah
February 27, 2014
36. Software (Operating Systems and Middleware)
To support the node operation, it is important to have
open-source operating systems designed specifically
for WSNs.
Such operating systems typically utilize a
component-based architecture that enables rapid
implementation and innovation while minimizing
code size as required by the memory constraints
endemic in sensor networks.
Tiny OS is one such example of a de facto standard,
but not the only one.
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37. Software (Operating Systems and Middleware)
Tiny OS’s component library includes network
protocols, distributed services, sensor drivers, and
data acquisition tools; these can be used as-is or be
further refined for a specific application.
Tiny OS’s event-driven execution model enables
fine-grained power management, yet allows the
scheduling flexibility made necessary by the
unpredictable nature of wireless communication and
physical world interfaces.
A wide community uses Tiny OS in simulation to
develop and test various algorithms and protocols,
and numerous groups are actively contributing code
to establish standard interoperable network services
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February 27, 2014
38. Standards for Transport Protocols
The goal of WSN engineers is to develop a costeffective standards-based wireless networking
solution that supports low to medium data rates, has
low power consumption, and guarantees security
and reliability.
The position of sensor nodes does not have be
predetermined, allowing random deployment in
inaccessible terrains or dynamic situations; however,
this also means that sensor network protocols and
algorithms must possess self-organizing capabilities.
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39. Standards for Transport Protocols
For military and / or
national security
applications sensor devices
must be amenable to rapid
deployment, the
deployment must be
supportable in an ad hoc
fashion, and the
environment is expected to
be highly dynamic.
Figure 1.5 depicts a
generic protocol stack
model that can be utilized
to describe the
communications apparatus.
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February 27, 2014
40. Possible WSN Protocol Stack
Upper
layers
Layer 4
In-network applications, including application
processing,
data
aggregation,
external
querying query processing, and external
database
Transport, including data dissemination and
accumulation, caching, and Storage
Layer 3
Networking, including adaptive topology
management and topological Routing
Layer 2
Link layer (contention): channel sharing (MAC),
timing, and locality
Layer 1
Physical medium: communication channel,
sensing, actuation, and signal Processing
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February 27, 2014
41. Possible Lower-Layer WSN Protocols
GPRS/GSM
IEEE
1xRTT/CDMA 802.11b/g
IEEE
802.15.1
IEEE
802.15.4
Market name
for standard
2.5G/3G
Wi-Fi
Bluetooth
Zig-Bee
Network
target
WAN/MAN
WLAN and
hotspot
PAN and DAN WSN
(desk area
n/w)
Application
focus
Wide area
voice and
data
Enterprise
applications
(data and
VoIP)
Cable
replacement
Monitoring &
control
Bandwidth
(Mbps)
0.064–0.128+
11–54
0.7
0.020–0.25
Transmission
range (ft)
3000+
300+
30+
300+
Design factors Reach and
41
transmission
Enterprise
support, cost
Cost, ease of Reliability,
]RushiN $hah February 27, 2014
use
power, cost
42. Issues:- relate to Networking
Physical connectivity and coverage: How can one
interconnect dispersed sensors in a cost-effective and reliable
manner, and what medium should be used (e.g., wireless
channels)?
Link characteristics and capacity, along with data
compression.
Networking
security and communications reliability
(including naturally occurring phenomena such as noise
impairments,
and
malicious
issues
such
as
attacks, interference, and penetration)
Physical-,
link-,
network-,
and
transport-layer
protocols, with an eye to reliable transport, congestion
detection and avoidance, and scalable and robust
communication.
Communication mechanisms in what could be an
environment with highly correlated and time-dependent
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]RushiN $hah February 27, 2014
arrivals (where many of the queuing assumptions used for
43. Sensor Network Technology
The basic functionality of a WN generally depends
on the application, but the following requirements are
typical :
Determine the value of a parameter at a given
location. For example, in an environment-oriented
WSN, one might need to know the temperature,
atmospheric pressure, amount of sunlight, and the
relative humidity at a number of locations. This
example shows that a given WN may be connected
to different types of sensors, each with a different
sampling rate and range of allowed values.
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44. Sensor Network Technology
44
Detect the occurrence of events of interest and
estimate the parameters of the events. For
example, in a traffic-oriented WSN, one would like
to detect a vehicle moving through an intersection
and estimate the speed and direction of the
vehicle.
Classify an object that has been detected. For
example, is a vehicle in a traffic sensor network a
car, a minivan, a light truck, a bus?
Track an object. For example, in a military WSN,
track an enemy tank as it moves through the
geographic area covered by the network.
]RushiN $hah
February 27, 2014