EC8702 – Unit 1.pptx

EC8702 – Ad Hoc and Wireless
Sensor Networks
SEMESTER VII
DEPARTMENT Electronics and Communication
Engineering
STAFF NAME/ DESIGNATION Ms. Rock Feller Singh Russells P/
AP

Course Syllabus
2
UNIT 1 ADHOC NETWORKS – INTRODUCTION AND ROUTING
PROTOCOLS
Elements of Ad hoc Wireless Networks, Issues in Ad hoc wireless
networks, Example commercial applications of Ad hoc networking, Ad hoc
wireless Internet, Issues in Designing a Routing Protocol for Ad Hoc
Wireless Networks, Classifications of Routing Protocols, Table Driven
Routing Protocols - Destination Sequenced Distance Vector (DSDV), On–
Demand Routing protocols –Ad hoc On– Demand Distance Vector Routing
(AODV).
UNIT 2 SENSOR NETWORKS – INTRODUCTION & ARCHITECTURES
Challenges for Wireless Sensor Networks, Enabling Technologies for
Wireless Sensor Networks, WSN application examples, Single-Node
Architecture - Hardware Components, Energy Consumption of Sensor
Nodes, Network Architecture - Sensor Network Scenarios, Transceiver
Design Considerations, Optimization Goals and Figures of Merit.
EC8702 - Ad hoc and Wireless Sensor
Networks

Course Syllabus
3
UNIT 3 WSN NETWORKING CONCEPTS AND PROTOCOLS
MAC Protocols for Wireless Sensor Networks, Low Duty Cycle Protocols And
Wakeup Concepts - S-MAC, The Mediation Device Protocol, Contention based
protocols - PAMAS, Schedule based protocols – LEACH, IEEE 802.15.4 MAC
protocol, Routing Protocols- Energy Efficient Routing, Challenges and Issues in
Transport layer protocol.
UNIT 4 SENSOR NETWORK SECURITY
Network Security Requirements, Issues and Challenges in Security
Provisioning, Network Security Attacks, Layer wise attacks in wireless sensor
networks, possible solutions for jamming, tampering, black hole attack,
flooding attack. Key Distribution and Management, Secure Routing – SPINS,
reliability requirements in sensor networks.
UNIT 5 SENSOR NETWORK PLATFORMS AND TOOLS
Sensor Node Hardware – Berkeley Motes, Programming Challenges, Node-level
software platforms – TinyOS, nesC, CONTIKIOS, Node-level Simulators –
NS2 and its extension to sensor networks, COOJA, TOSSIM, Programming
beyond individual nodes – State centric programming.
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UNIT 1 – Ad hoc Networks –
Introduction and Routing Protocols
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Unit I-ADHOC NETWORKS INTRODUCTION
AND ROUTING PROTOCOLS
Elements of Ad hoc Wireless Networks, Issues in Ad hoc
wireless networks, Example commercial applications of Ad
hoc networking, Ad hoc wireless Internet, Issues in
Designing a Routing Protocol for Ad Hoc Wireless Networks,
Classifications of Routing Protocols, Table Driven Routing
Protocols - Destination Sequenced Distance Vector (DSDV),
On–Demand Routing protocols –Ad hoc On–Demand
Distance Vector Routing (AODV).
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Introductio
n
• Introduction -Ad Hoc Network definition
• Characteristic/features and application
• Heterogeneity in Mobile Devices
• Wireless Sensor Networks
• Traffic Profiles
• Types of Ad Hoc Mobile Communications
• Types of Mobile Host Movements
• Challenges Facing Ad Hoc Mobile Networks
• Issues and Challenges Facing Ad Hoc Mobile
network
• Ad Hoc wireless Internet
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A BSS without an AP is called an ad hoc
network; a BSS with an AP is called an
infrastructure network
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What Is an Ad Hoc
Network?
• An ad hoc wireless network is a collection of two or
more devices equipped with wireless
communications and networking capability.
• Such devices can communicate with another node
that is immediately within their radio range or one
that is outside their radio range.
• For the latter scenario, an intermediate node is used to
relay or forward the packet from the source toward
the destination.
• Since an ad hoc wireless network does not rely on any
fixed network entities, the network itself is essentially
infrastructure-less. There is no need for any fixed
radio base stations, no wires or fixed routers.
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• An ad hoc wireless network is self-organizing and
adaptive.
• This means that a formed network can be de-formed
on-the- fly without the need for any system
administration.
• The term "ad hoc" tends to imply "can take different
forms"
and "can be mobile, standalone, or networked.“
• Ad hoc nodes or devices should be able to detect the
presence of other such devices and to perform the
necessary handshaking to allow communications and
the sharing of information and services.
What Is an Ad Hoc
Network?
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Wireless Ad-hoc
Network
• A wireless adhoc network is a decentralized type of
wireless network.
• The network is adhoc because it does not rely on a pre-
existing infrastructure, such as routers in wired networks
or access points in managed (infrastructure) wireless
networks.
• Each node participates in routing by forwarding data for
other nodes, and so the determination of which nodes
forward data is made dynamically based on the network
connectivity.
• In addition to the classic routing, adhoc networks can use
flooding for forwarding the data
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Mobile Ad Hoc Networks
(MANET)
• Selfconfiguring network of mobile
routers (and associated hosts)
connected by wireless links
• This union forms a random topology
• Routers move randomly free
• Topology changes rapidly and unpredictably
• Standalone fashion or connected to the larger Internet
• While MANETs are selfcontained, they can also be tied to
an IP-based global or local network–Hybrid MANETs
• Suitable for emergency situations like natural or human-
induced disasters, military conflicts, emergency medical
situations, etc.
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Issues in Ad-
Hoc
• Ad hoc wireless devices can take different forms (for
example, palmtop, laptop, Internet mobile phone,
etc.),the computation, storage, and communications
capabilities and interoperability of such devices will vary
tremendously.
• Ad hoc devices should not only detect the presence of
connectivity with neighbouring devices/nodes, but also
identify what type the devices are and their
corresponding attributes.
• Due to the presence of mobility, routing information will
have to change to reflect changes in link connectivity.
• The diversity of ad hoc mobile devices also implies that
the battery capacity of such devices will also vary. Since
ad hoc networks rely on forwarding data packets sent by
other nodes, power consumption becomes a critical
issue.
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INTRODUCTION TO WSN
• A wireless sensor network is one form of an ad hoc
wireless network.
• A sensor network is a collection of a large number of
sensor nodes that are deployed in a particular region.
• Sensors are wirelessly connected and they, at
appropriate times, relay information back to some
selected nodes.
• These selected nodes then perform some computation
based on the collected data to derive an ultimate statistic
to allow critical decisions to be made.
• There are a variety of sensors, including acoustic(sound
related) , seismic (Subject to an earthquake or earth
vibration), image, heat, direction, smoke, and
temperature sensors.
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Basic features of sensor
networks
• A large number of low-cost, low-power,multifunctional,
and small sensor nodes
• Sensor node consists of sensing, data processing, and
communicating components
• A sensor network is composed of a large number of
sensor nodes, which are densely deployed either
inside the phenomenon or very close to it.
• The position of sensor nodes need not be
engineered or pre- determined.
• sensor network protocols and algorithms must possess
self- organizing capabilities.
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• Self-organizing capabilities
• Short-range broadcast communication and multihop
routing
• Dense deployment and cooperative effort of sensor
nodes
• Frequently changing topology due to fading and node
failures
• Limitations in energy, transmit power, memory,
and computing power
Basic features of sensor
networks
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Factors influencing sensor
network design
• Fault tolerance;
• Scalability;
• Production costs;
• Operating environment;
• Sensor network
topology;
• Hardware constraints;
• Transmission media;
• Power consumption.
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Sensor Networks Architecture
• Sensor node
• Made up of four basic components
• Sensing unit, Processing unit, Transceiver unit, and
Power unit
• Additional application-dependent components
• Location finding system, power generator, and mobilizer
• Scattered in a sensor field
• Collect data and route data back to the sink to Sink
• Communicate with the task manager node (user) via
Internet or satellite
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Components of Sensor
Node
• A sensor node is made up of four basic
components sensing unit
• usually composed of two subunits: sensors and analog
to digital converters (ADCs).
• processing unit,
• Manages the procedures that make the sensor node
collaborate with the other nodes to carry out the
assigned sensing tasks.
• Transceiver unit
• Connects the node to the network.
• Power units (the most important unit)
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APPLICATIONS OF
WSN
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Challenges in Ad Hoc
Networks
• Limited wireless transmission range
• Broadcast nature of the wireless medium
• Packet losses due to transmission errors
• Mobility-induced route changes
• Mobility-induced packet losses
• Battery constraints
• Potentially frequent network partitions
• Ease of snooping on wireless transmissions (security
hazard)
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Issues in Ad Hoc Networks
1.Spectrum Allocation and Purchase
2.Medium access scheme
3.Routing
4.Multicasting
5.Transport layer protocol
Performance
6.Pricing scheme
7.QoS
provisioning
8.Security
9.Energy management
10.Addressing and service
discovery 11.Scalability
12.Deployment considerations
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Spectrum Allocation and
Purchase
• FCCcontrol the regulations regarding the use of
radio spectrum.
• Who regulates the use of radio spectrum in INDIA??
• T
o prevent interference, ad hoc networks operate
over some form of allowed or specified spectrum
range.
• Most microwave ovens operate in the 2.4GHz band,
which can therefore interfere with wireless LAN
systems.
• Frequencyspectrum is not only tightly controlled
and allocated, but it also needs to be
purchased.
• With ad hoc networks capable of forming and
deforming on-the-fly, it is not clear who should pay for
this spectrum.
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Medium Access Scheme
• Distributed operation
• Synchronization
• Hidden terminal problem
• Exposed terminal problem
• Throughput
• Access delay
• Fairness: especially for relaying
nodes
• Real-time traffic support
• Resource reservation
• Ability to measure resource
availability
• Capability for power control
• Adaptive rate control
• Use of directional antennas
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Routing
• Challenges
• Mobility
• results in path breaks, packet collisions, transient loops,
stale routing information, and difficulty in resource
reservation
• BW constraints
• Error-prone and shred channel
• Bit error rate BER:10-5~ 10-3wireless vs. 10-12~ 10-9
wired
• Location-dependent contention
• Distribute load uniformly
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• The presence of mobility implies that links make and break
often and in an indeterministic fashion.
• Classical distributed Bellman-Ford routing algorithm is
used to maintain and update routing information in a
packet radio network.
• Yet distance-vector-based routing not designed for
wireless networks, still applicable to packet radio
networks since the rate of mobility is not high.
• Mobile devices are now small, portable, and highly integrated.
• Ad hoc mobile networks are different from packet radio
networks since nodes can move more freely, resulting in a
dynamically changing topology.
• Existing distance-vector and link-state-based routing
protocols are unable to catch up with such frequent link
changes in ad hoc wireless networks, resulting in poor
route convergence and very low communication
throughput. Hence, new routing protocols are needed
Routing
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Multicasting
• Multiparty communications are enabled through the
presence of multicast routing protocols.
• The
multicas
t
(MBone) comprises
an
interconnection of
backbone
multicast routers that are capable of
tunnelling multicast packets through non-multicast
routers.
• Some multicast protocols use a broadcast-and-prune
approach to build a multicast tree rooted at the source .
Others use core nodes where the multicast tree
originates.
• All such methods rely on the fact that routers are static,
and once the multicast tree is formed, tree nodes will not
move. However, this is not the case in ad hoc wireless
networks.
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Energy Efficiency
devices
toda
y
• Mobile
Batter
y
are mostly operated by
batteries. technology isstill lagging
behind microprocessor
technology.
• The lifetime of an Li-ion battery today is only 2-3 hours.
Such a limitation in the operating hours of a device
implies the need for power conservation.
• For ad hoc mobile networks, mobile devices must
perform both the role of an end system (where the user
interacts and where user applications are executed) and
that of an intermediate system (packet forwarding).
• Hence, forwarding packets on the behalf of others will
consume power, and this can be quite significant for
nodes in an ad hoc wireless network.
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TCP Performance
• TCP is an end-to-end protocol designed to provide flow
and congestion control in a network. TCP is a
connection-oriented protocol ; hence, there is a
connection establishment phase prior to data
transmission. The connection is removed when data
transmission is completed.
• TCP(Transmission Control Protocol) assumes that nodes
in the route are static, and only performs flow and
congestion activities at the SRC and DEST nodes.
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Service Location, Provision, and
Access
• Ad hoc networks
comprise
heterogeneousdevices
and
machines and not every one is capable of being a
server.
• The concept of a client initiating task requests to a
server for execution and awaiting results to be returned
may not be attractive due to limitations in bandwidth
and power.
• Concept of remote programming as used in mobile
agents is more applicable since this can reduce the
interactions exchanged between the client and server
over the wireless media.
• Also, how can a mobile device access a remote
service in an ad hoc network? How can a device that is
well-equipped advertise its desire to provide services
to the rest of the members in the network? All these
issues demand research.
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Security & Privacy
• Ad hoc networks are intranets and remain as intranets
unless connected to Internet.
• Such confined communications have already isolated
attackers who are not local in the area.
• Through neighbor identity authenication, a user can
know if neighboring users are friendly or hostile.
• Information sent in an ad hoc route can be protected in
some way but since multiple nodes are involved, the
relaying of packets has to be authenicated by
recognizing the originator of the packet and the flow ID
or label
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Deployment Consideration
• Adv. in ad hoc net
• Low cont of deployment
• Incremental deployment
• Short deployment time
• Reconfigurablity
• Scenario of deployment
• Military deployment: data-centric or user-centric
• Emergency operation deployment: hand-held,
voice/data, < 100 nodes
• Commercial wide-area deployment: e.g. WMN
• Home network deployment
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ISSUES IN DESIGNING A ROUTING
PROTOCOL
• Mobility
• Bandwidth constraint
• Error prone shared broadcast radio
channel
• hidden and exposed terminal problems
• Resource Constraints
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DSDV
• DSDV: Destination-Sequenced Distance-Vector
• Adds two things to distance-vector routing
• Sequence number; avoid loops
• Damping; hold advertisements for changes of short
duration.
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DSDV routing updates
• Each node periodically transmits updates
• Includes its own sequences number, routing table
updates
• Nodes also send routing table updates for
important link changes
• When two routes to a destination received from two
different
 neighbors
• Choose the one with greatest destination
sequence number
• If equal, choose the smaller metric (hop count)
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DSDV full dump
• Full Dumps
• Carry all routing table information
• Transmitted relatively infrequently
• Incremental updates
• Carry only information changed since last
full
dump
• Fits within one network protocol data unit
• If can’t, send full dump
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DSDV link addition
When A joins network
–Node A transmits routing table: <A, 101, 0>
–Node B receives transmission, inserts <A, 101, A,
1>
–Node B propagates new route to neighbors <A, 101,
1>
–Neighbors update their routing tables: <A, 101, B,
2> and continue propagation of information
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DSDV link breaks
Link between B and D breaks
– Node B notices break
• Update hop count for D and E to be
infinity
• Increments sequence number for D and E
– Node B sends updates with new route
information
• <D, 203, infinite>
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• Each node periodically transmits updates
• Includes its own sequences number, routing table
updates
• Nodes also send routing table updates for
important link changes
• When two routes to a destination received from two
different
 neighbors
• Choose the one with greatest destination
sequence number
• If equal, choose the smaller metric (hop count)
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• Routes maintained through periodic and event
triggered routing table exchanges
• Incremental dumps and settling time used to reduce
control overhead
• Lower route request latency, but higher overhead
• Perform best in network with low to moderate mobility,
few nodes and many data sessions
Problems:
• Not efficient for large ad-hoc networks
• Nodes need to maintain a complete list of routes.
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AODV(ADHOC ON DEMAND
DISTANCE VECTOR
ROUTING)
• DSR includes source routes in packet headers
• Resulting large headers can degrade performance
• When data content is small
•AODV improves on DSR by maintaining routing tables
(reverse paths) at nodes, instead of in
• data packets.
•AODV retains the desirable feature of DSR that routes
are only maintained between
• communicating nodes.
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• The Ad-hoc On-Demand Distance Vector
• Algorithm
• Descendant of DSDV
• Reactive
• Route discovery cycle used for route finding
• Maintenance of active routing
• Sequence number used for loop prevention and
route freshness criteria
• Provides unicast and multicast communication
AODV(ADHOC ON DEMAND
DISTANCE VECTOR
ROUTING)
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Goal of AODV
• Quick adaptation under dynamic link
• conditions
• Lower transmission latency
• Consume less network bandwidth (less
broadcast)
• Loop-free property
• Scalable to large network
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AODV – unicast route
discovery
• RREQ (route request) is broadcast
• Sequence Number:
• Source SN: freshness on reverse route to source
• Destination SN: freshness on route to destination RREQ
message
•<bcast_id, dest_ip, dest_seqno, src_seqno, hop_count>
RREP (route reply) is unicast back
• From destination if necessary
• From intermediate node if that node has a recent route
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AODV multicast route discovery
• Message types
• RREQ, with new flags:
• Join and Repair
• RREP
• MACT (Multicast activation message)
• Multicast routes have destination
• sequence number and multiple next
hops
•Multicast group leader extension for
RREQ and RREP
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AODV route discovery
Node S needs a route to D
2. Create a route request (RREQ)
–Enters D’s IP address, sequence number,
S’s IP address, sequence number
– Broadcasts RREQ to neighbors
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Node A receives RREQ
Makes reverse route entry for S
• Dest = S, nexthop = S, hopcount = 1
It has no route to D, so it broadcasts RREQ
4. Node C receives RREQ
Makes reverse route entry
for S
• Dest = S, nexthop = A, hopcount = 2
It has route to D && seq# for route D > seq# in
RREQ
• Creates a route reply (RREP)
Enters D’s IP address, sequence number, S’s IP
address, hopcount
• Unicasts RREP to A
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Node A receives RREP
– Unicasts RREP to S
– Makes forward route entry to D
• Dest = D, nexthop = C hopcount
= 2
6. Node S receives RREP
– Makes forward route entry to D
• Dest = D, nexthop = A hopcount
= 3
– Sends data packets on route to
D
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Link between C and D breaks
– Node C invalidates route to D in routing
table
– Node C creates route error (RERR)
message
• Lists all destinations with are now
unreachable
• Sends to upstream neighbors
– Node A receives RERR
• Checks whether C is its next hop on route
to D
• Deletes route to D, and forwards RERR to
AODV --- route maintenance
(1)
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AODV --- route maintenance
(2)
Node S receives RERR
• Checks whether A is its next
hop
on route to D
• Deletes route to D
• Rediscovers route if still
needed
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AODV --- Optimizations
• Expanding ring search
• Prevents flooding of network during route discovery
• Control Time to Live of RREQ
• Local repair
• Repair breaks in active routes locally instead of
notifying
source
•Use small TTL because destination probably has
not moved far
• If first repair attempt is unsuccessful, send RERR to
source
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• Reactive / On-demand
•Sequence numbers used for route freshness and loop
prevention
• Route discovery cycle
• Maintains only active routes
•Optimization can be used to reduce overhead and
increase scalability
AODV --- Optimizations
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Summary
• Discussed about the basic concepts of adhoc
networks
• Had a thorough knowledge on the routing protocols
and its classification
• Learned about the various protocols
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1.The mobile nodes add or leave a mobile adhoc network , changing the of this
network over time.
a.Infrastructure
b.Topology
c. Transmission range
d.Transmission speed
2. Mobile adhoc networks are less secure because
a.The nodes are autonomous
b.The MANET is a centralized network
c. The MANET uses multihop transmission
3. Providers of certain types of services on a network are called ?
a.Routing
b.database
c.Corba
d.Server
4. Here are the types of adhoc network except
a.WARNET
b.WANET
c.MANET
d.VANET
5.Can adhoc network be used by multiple devices?
a.yes,because adhoc is a WLAN network
B yes, adhoc is a WAN network
c.It cant because adhoc is one of the WLAN network
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6.Strength of signal doesn’t depend upon which of the following
factors?
a)Energy flux
b) Dwell time
c)Altitude
d) Reflection
7.Which of the following indicates the correct set of bands operated
in LISS- III
satellite?
a)Visible ray, near IR
b) Near IR, radio wave
c)Radio wave, near IR
d) Far IR, near IR
8.Energy flux may affect which of the following?
a)Lens
b) Strength of the signal
c)Aperture
d) Declination
9.Which of the following can merge the imagery of LISS-III and PAN?
a)IRS 1B
b) IRS 1A
c)IRS 1C
d) IRS multi sensor
10.Which among the following indicates the correct expansion of
WiFS?
a)Wide Field Sensor
b) Wireless Fidelity Sensor
c)Wide Fidelity Sensor
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11.IRS P3 satellite uses which of the following sensors?
a)PAN
b) LISS-III
c)MOS
d) LISS-II
12.PAN sensor uses two band operators.
a)True
b) False
13.While mapping land use and land cover, which scale is
recommended?
a) 1: 25000
b) 1: 50000
c) 1: 250000
d) 1: 25
14.The sensor used in the digital elevation model can identify
contour
heights greater than
a)5 m
b) 30 m
c)20 m
d) 10 m
15.IRS 1A and 1B satellites can carry which of the following
sensors?
a)LISS-IV
b) LISS-III
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16.Which of the following indicates the correct set of M’s used in the case
of GIS?
a)Manipulating, monitoring, mapping, modeling
b) Measuring, manipulating, mapping, modeling
c)Measuring, monitoring, marketing, modeling
d) Measuring, monitoring, mapping, modeling
17.Which of the following works involves modeling?
a)Tectonic plate movement
b) Drainage network
c)Roadway line
d) Railway line
18.Mapping involves which of the following?
a)Soil details
b) Boundary details
c)Cadastral details
d) Population details
19.In which aspect of agriculture GIS is used?
a)Soil analysis
b) Seed requirement
c)Fertilizer
d) Pesticides
20.Which of the following software can be used in case of property tax
assessment?
a)STAAD Pro
b) Revit
c)Remote sensing
d) GIS
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21.Which of the following software’s are used for developing
vehicle route?
a)Autodesk Revit
b) STAAD Pro
c)GIS
d) Remote sensing
22.Population forecast can be done by using GIS.
a)False
b) True
23.Which of the following is not a property of coordinate in GIS?
a)Line of sight
b) Origin
c)Axis
d) Units of measurement
24.Which of the following represents the correct set of coordinate
classification in GIS?
a)Spherical, projected systems
b) Geographic, projected systems
c)Geographic, spherical systems
d) Geographic, geometric systems
25.Longitudes are used to represent which of the following
directions?
a)North–East
b) South
c)North
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26.Which of the following are transport layer protocols used in
networking?
a)TCP and FTP
b) UDP and HTTP
c)TCP and UDP
d) HTTP and FTP
27.User datagram protocol is called connectionless because
a)all UDP packets are treated independently by transport layer
b) it sends data as a stream of related packets
c)it is received in the same order as sent order
d) it sends data very quickly
28.Transmission control protocol
a)is a connection-oriented protocol
b) uses a three way handshake to establish a connection
c)receives data from application as a single stream
d) all of the mentioned
29.An endpoint of an inter-process communication flow across a
computer network is called
a)socket
b) pipe
c)port
d) machine
30. Socket-style API for windows is called
a)wsock
b) winsock
c)wins
d) sockwi
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Assignmen
ts
S.No Assignment Topic K Level
1. Issues in designing a
routing protocol fro
Adhoc Wireless
Networks
K3
2. Analyze the
Commercial
applications of Adhoc
networking
K4
3. Design a wireless
network for commercial
applications
K5
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60

EC8702 – Unit 1.pptx

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EC8702 – Unit 1.pptx