SlideShare uma empresa Scribd logo
1 de 33
Baixar para ler offline
MOBILE AD HOC NETWORKS
Seminar Report
Submitted in partial fulfilment of the requirements
for the award of the degree of
Bachelor of Technology
in
Computer Science Engineering
of
Cochin University Of Science And Technology
by

PRAVEEN KUMAR P
(12080059)

DIVISION OF COMPUTER SCIENCE
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
KOCHI-682022
OCTOBER 2010
DIVISION OF COMPUTER SCIENCE
SCHOOL OF ENGINEERING
COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY
KOCHI-682022

Certificate
Certified that this is a bonafide record of the seminar entitled
“MOBILE AD HOC NETWORKS”
Presented by the following student
“PRAVEEN KUMAR P”
th
of the VII semester, Computer Science and Engineering in the year 2010
in partial fulfillment of the requirements in the award of Degree of
Bachelor of Technology in Computer Science and Engineering of Cochin
University of Science and Technology.

Mr. SUDHEEP ELAYIDOM
Seminar guide

Dr. DAVID PETER
Head Of Division
ACKNOWLEDGEMENT

I thank GOD almighty for guiding me throughout the seminar. I would like to thank all those
who have contributed to the completion of the seminar and helped me with valuable
suggestions for improvement.

I am extremely grateful to Dr. David Peter, Head Of Division, Division of Computer
Science, for providing me with best facilities and atmosphere for the creative work guidance
and encouragement. I am profoundly indebted to my seminar guide, Mr. Sudheep Elayidom,
sr.Lecturer, Division of Computer Science, for innumerable acts of timely advice,
encouragement and I sincerely express my gratitude to him. I thank all Staff members of my

college and friends for extending their cooperation during my seminar.

Above all I would like to thank my parents without whose blessings; I would not have been
able to accomplish my goal.

PRAVEEN KUMAR P
TABLE OF CONTENTS
CHAPTER NO

TITLE

PAGE NO.

LIST OF FIGURES

ii

LIST OF TABLES

iii

1.

INTRODUCTION

1

2.

BASICS OF MANET

2

2.1 WIRELESS AD HOC NETWORKS

2

2.2 CHARACTERISTICS OF MANET

4

AD HOC ROUTING PROTOCOLS

5

3.1 WHY ROUTING PROTOCOLS

5

3.2 AD HOC ROUTING PROTOCOLS

5

3.3 TABLE DRIVEN ROUTING PROTOCOLS

7

3.

3.3.1 DESTINATIONSEQUENCED
DISTANCE VECTOR ROUTING ALGORITHM 7
3.3.2 CLUSTERHEAD GATEWAY SWITCH
ROUTING (CGSR)
3.4 SOURCE INITIATED ON DEMAND ROUTING

10
11

3.4.1 AD HOC ON DEMAND DISTANCE VECTOR
ROUTING (AODV)

11

3.4.2 DYNAMIC SOURCE ROUTING PROTOCOL
(DSR)

14

3.5 HYBRID SCHEME

16

3.5.1 ZONE ROUTING PROTOCOLS (ZRP)

16

3.6 COMPARISON

19
i
4.

VEHICULAR AD HOC NETWORK (VANET)

20

4.1 ARCHITECTURE OF VANET

21

4.2 APPLICATIONS OF VANET

22

5.

APPLICATIONS OF MANET

25

6.

CONCLUSION

26

7.

REFERENCE

27

LIST OF FIGURES

FIGURE NO

TITLE

PAGE NO.

2.1

WIRELESS AD HOC NETWORK

3.1

CATEGORIZATION OF AD HOC ROUTING
PROTOCOLS

3.2

2

6

AD HOC NETWORK HAVING ROUTING
TABLES

9, 10

3.3

CGSR ROUTING

11

3.4

AODV ROUTING PROTOCOL

13

3.5

DSR ROUTING PROTOCOL

15

3.6

ZONE ROUTING PROTOCOLS

17

4.1

TYPICAL VEHICULAR AD HOC NETWORK

20

4.2

LAYERED ARCHITECTURE

22

ii
4.3

UNLAYERED ARCHITECTURE

22

LIST OF TABLES
TABLE NO.
3.1

TITLE

PAGENO.

COMPARISON BETWEEN TABLE DRIVEN
AND ON DEMAND ROUTING PROTOCOLS

iii

19
1

Mobile ad hoc networks

Chapter 1
INTRODUCTION
Communication is the primary factor which influenced the development of
mankind. One of the primary goal of communication is exchanging information between two
persons. Today we have advanced technologies for communication. Communication can be
between human beings or between machines. For the purpose of communication between
machines we provided networks, generally connected by physical channels. Then to avoid the
difficulties with wired networks there come wireless networks. Then need for more advanced
technology arise and we thought about mobility. Mobile networks established due to this
demand and the communication become more flexible. MANET is a type of wireless mobile
network.
A mobile ad hoc network (MANET), sometimes called a mobile mesh network, is a
self-configuring network of mobile devices connected by wireless links. Each device in a
MANET is free to move independently in any direction, and will therefore change its links to
other devices frequently. Each must forward traffic unrelated to its own use, and therefore be
a router. The primary challenge in building a MANET is equipping each device to
continuously maintain the information required to properly route traffic. Such networks may
operate by themselves or may be connected to the larger Internet.
MANETs are a kind of wireless ad hoc networks that usually has a routable networking
environment on top of a Link Layer ad hoc network. They are also a type of mesh network,
but many mesh networks are not mobile or not wireless.
The growth of laptops and 802.11/Wi-Fi wireless networking have made MANETs a
popular research topic since the mid- to late 1990s. Different protocols are used for the
communication between the mobile nodes. There is no particular access points in this
networks, instead the nodes itself transfer data between the communication nodes. Like any
other networks there is also some algorithms used for the routing of information between
nodes.

Division Of Computer Science Engineering, SOE, CUSAT
2

Mobile ad hoc networks

Chapter 2
BASICS OF MANET
MANET (Mobile Ad hoc Network) is a wireless ad hoc network, which uses mobile
devices like laptops, PDAs, mobile phones etc. as nodes which communicate each other for the
purpose of information transfer between nodes. MANET does not have any particular infrastructure
due to the absence of access points and due to the presence of mobile nodes. To know about
MANET first we need to know about a wireless ad hoc network.
2.1WIRELESS AD HOC NETWORKS
A wireless ad hoc network is a decentralized network. The network is ad hoc because it
does not rely on a pre existing infrastructure, such as routers in wired network or access points in
wireless networks. Instead each node participate in routing by forwarding data for other nodes, and
so the determination of which nodes forward the data is done dynamically, based on the network
connectivity.

Fig 2.1 Wireless ad hoc network
Above figure shows a typical wireless ad hoc network in which the communication is happening in
between mobile nodes. There is also a single base station which is not connected to each and every
node in the network, instead there are two nodes which directly communicate with the base station.
These nodes will have the complete responsibility of information exchange between the base

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

3

station and any node in the network. Such a node must know protocols for communicating with the
nodes in the network as well as protocols required for the communication with base station
An ad hoc network is made up of multiple ―nodes‖ connected by ―links‖. Links are influenced
by the node's resources (e.g. available energy supply, transmitter power, computing power and
memory) and by behavioural properties (reliability, and trustworthiness), as well as by link
properties (e.g. line-of-sight interference, length-of-link and signal loss, interference and noise).
Since new and old links can be connected or disconnected at any time, a functioning network must
be able to cope with this dynamic restructuring, preferably in a way that is timely, efficient,
reliable, robust and scalable.
The network must allow any two nodes to communicate, often via other nodes that relay
the information. A ―path‖ is a series of links that connects two nodes. Often there are multiple
paths between any two nodes. Nodes are often limited by transmitter power (transmission
range) and available energy resources. Transmitter power often consumes the most energy in
the node. According to the inverse square law, it is more energy efficient to relay information
across a network via multiple nodes
The decentralized nature of wireless ad hoc networks makes them suitable for a variety of
applications where central nodes can't be relied on, and may improve the scalability of
wireless ad hoc networks compared to wireless managed networks, though theoretical and
practical limits to the overall capacity of such networks have been identified.
Minimal configuration and quick deployment make ad hoc networks suitable for
emergency situations like natural disasters or military conflicts. The presence of a dynamic
and adaptive routing protocol will enable ad hoc networks to be formed quickly. Wireless ad
hoc networks can be further classified according to their applications
-

Mobile ad hoc networks (MANET): It is a wireless ad hoc network in which mobile
nodes are mobile devices like laptops, PDAs, mobile phones etc. In this type of
networks each node will act as routers hence no need of access points. One or more
nodes can be connected to an external router, which is connected to the internet, so
that each node in the network, if need can connect to internet and can transfer
information bi directionally.

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

-

4

Wireless mesh networks (WMN): It is a communication network made up of radio
nodes organised in a mesh topology. Wireless mesh networks often consist of mesh
clients, mesh routers and gateways. The mesh clients are often laptops, cell phones
and other wireless devices while the mesh routers forward traffic to and from the
gateways which may but need not connect to the Internet.

-

Wireless sensor networks (WSN): This type of networks consist of spatially
distributed autonomous sensors to cooperatively monitor physical or environmental
conditions, such as temperature, sound, vibration, pressure, motion or pollutants. The
development of wireless sensor networks was motivated by military applications such
as battlefield surveillance and are now used in many industrial and civilian application
areas, including industrial process monitoring and control, machine health monitoring,
environment and habitat monitoring, healthcare applications, home automation, and
traffic control

2.2 Characteristics of MANET
-

-

-

-

Dynamic Topologies: Since nodes are free to move arbitrarily, the network topology
may change randomly and rapidly at unpredictable times. The links may be
unidirectional bidirectional.
Bandwidth constrained, variable capacity links: Wireless links have significantly
lower capacity than their hardwired counterparts. Also, due to multiple access, fading,
noise, and interference conditions etc. the wireless links have low throughput.
Energy constrained operation: Some or all of the nodes in a MANET may rely on
batteries. In this scenario, the most important system design criteria for optimization
may be energy conservation.
Limited physical security: Mobile wireless networks are generally more prone to
physical security threats than are fixed- cable nets. The increased possibility of
eavesdropping, spoofing, and denial-of-service attacks should be carefully considered.
Existing link security techniques are often applied within wireless networks to reduce
security threats. As a benefit, the decentralized nature of network control in MANET
provides additional robustness against the single points of failure of more centralized
approaches.

Division Of Computer Science Engineering, SOE, CUSAT
5

Mobile ad hoc networks

Chapter 3
AD HOC ROUTING PROTOCOLS
3.1 Why Routing Protocols
Routing support for mobile hosts is presently being formulated as mobile IP technology.
When the mobile agent moves from its home network to a foreign (visited) network, the
mobile agent tells a home agent on the home network to which foreign agent their packets
should be forwarded. In addition, the mobile agent registers itself with that foreign agent on
the foreign network. Thus, the home agent forwards all packets intended for the mobile agent
to the foreign agent, which sends them to the mobile agent on the foreign network. When the
mobile agent returns to its original network, it informs both agents (home and foreign) that
the original configuration has been restored. No one on the outside networks need to know
that the mobile agent moved.
But in Ad Hoc networks there is no concept of home agent as it itself may be moving.
Supporting Mobile IP form of host mobility requires address management, protocol inter
operability enhancements and the like, but core network functions such as hop by hop routing
still presently rely upon pre existing routing protocols operating within the fixed network. In
contrast, the goal of mobile ad hoc networking is to extend mobility into the realm of
autonomous, mobile, wireless domains, where a set of nodes, which may be combined routers
and hosts, themselves to form the network routing infrastructure in an ad hoc fashion. Hence,
there is need to study special routing algorithms to support this dynamic topology
environment. Routing protocols for mobile ad-hoc networks have to face the challenge of
frequently changing topology, low transmission power and asymmetric links.

3.2 Ad Hoc Routing Protocols:
A number of routing protocols have been suggested for ad-hoc networks. These protocols can
be classified into two main categories:

Table driven routing protocols

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

6

Source initiated on demand routing protocols

Table Driven Routing Protocols:
Table-driven routing protocols attempt to maintain consistent, up-to-date routing
information from each node to every other node in the network. These protocols require each
node to maintain one or more tables to store routing information, and they respond to changes
in network topology by propagating updates throughout the network in order to maintain a
consistent network view. The areas in which they differ are the number of necessary routingrelated tables and the methods by which changes in network structure are broadcast.
Source Initiated On Demand Routing:
A different approach from table-driven routing is source-initiated on demand routing.
This type of routing creates routes only when desired by the source node. When a node
requires a route to a destination, it initiates a route discovery process within the network. This
process is completed once a route is found or all possible route permutations have been
examined. Once a route has been established, it is maintained by a route maintenance
procedure until either the destination becomes inaccessible along every path from the source
or until the route is no longer desired.

Fig 3.1: Categorization of ad hoc routing protocols .

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

7

3.3 TABLE DRIVEN ROUTING PROTOCOLS
3.3.1 Destination Sequenced Distance Vector Routing Algorithm:
The Destination Sequenced Distance Vector (DSDV) Routing Algorithm is based on the idea
of the Distributed Bellman Ford (DBF) Routing Algorithm with certain improvements. The
primary concern with using a Distributed Bellman Ford algorithm in Ad Hoc environment is
its susceptibility towards forming routing loops and counting to infinity problem. DSDV
guarantees loop free paths at all instants.
Each node maintains a routing table, which contains entries for all the nodes in the
network. Each entry consists of:


the destination's address



the number of hops required reaching the destination (hop count)



the sequence number as stamped by the destination.

Whenever a node B comes up, it broadcasts a beacon message ("I am alive message")
stamping it with a locally maintained sequence number. The nodes in its neighbourhood
listen to this message and update the information for this node. If the nodes do not have any
previous entry for this node B, they simply enter B's address in their routing table, together
with hop count and the sequence number as broadcasted by B. If the nodes had previous entry
for B, then sequence number of broadcasted information is compared to the sequence number
stored in the node for destination B. If the message received has a higher sequence number,
then this means that the node B has propagated a new information about its location so the
entry must be updated in accordance with the new information received. The information
with a newer sequence number is definitely new as the node B itself stamps sequence
number.
The new information that a node receives is scheduled for broadcasting to its neighbours
so that they can know about the changes in topology. The neighbouring nodes also follow the
same rule i.e. updating the information when information about a node with a newer sequence
number is received. The metrics for routes chosen from the newly received broadcast
information are each incremented by one hop. So, the new information is updated gradually
at all nodes and they now know the next hop node in order to correctly route the packet to
destination B. B also generates the new information with a newer sequence number when it
sees that it is moving. By moving, it is meant that B observes that there is a change in
topology because it's neighbours are changing, may be due to it's motion or other nodes

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

8

(neighbours) motion. And it comes to know that the neighbours are changing since it receives
new beacon messages or does not receive beacon messages from its current neighbours.
The information is broadcasted periodically to neighbours. It could be advertised when
specifically asked for or when there is a significant change in topology. Thus, it is both 'event
driven' and 'time driven'.
The routing table updates can be sent in two ways. The first is known as a full dump. This
type of packet carries all available routing information and can require multiple network
protocol data units (NPDUs). During periods of occasional movement, these packets are
transmitted infrequently. Smaller incremental packets are used to relay only that information
which has changed since the last full dump. Each of these broadcasts should fit into a
standard-size NPDU, thereby decreasing the amount of traffic generated. The mobile nodes
maintain an additional table where they store the data sent in the incremental routing
information packets.
Routes that show an improved metric are scheduled for an advertisement at a time which
depends on the average settling time for routes to the particular destination under
consideration.
To avoid a burst of new advertisements in case of rapidly changing routes, the Mobile
host delays the advertisement of such routes, when it can determine that a route with a better
metric is likely to show up soon. For this, the Mobile Host has to keep a history of weighted
average time that routes to a particular destination fluctuate until the route with the best
metric is received.
Though it delays advertising the new route, it uses it for routing. Thus, it maintains two
tables one for forwarding packets and another to be advertised. In order to bias the damping
mechanism
in favour of recent events, the most recent measurement of the settling time of a particular
route must be counted with a higher weighting factor than are less recent measurements. A
parameter must be selected which indicates how long a route has to remain stable before it is
counted as truly stable.
When no broadcasts are received from a neighbour within a particular time interval, the
link is supposed to be broken. Now, any route through that next hop is immediately assigned

Division Of Computer Science Engineering, SOE, CUSAT
9

Mobile ad hoc networks

an infinite metric (i.e. any number greater than the maximum allowed metric) and assigned an
updated sequence number. Note that this sequence number is assigned by the Mobile host
other that the destination Mobile Host. Sequence numbers defined by the originating Mobile
host are defined to be even numbers and sequence numbers generated to indicate infinite
metrics are odd numbers. This information is broadcasted to the neighbouring nodes. If the
neighbouring nodes have chosen this node as a next hop neighbour for any destination then
they also set the route to destination as infinity. If the neighbouring nodes, do have a path to
destination through some other neighbour and they ignore this information though it has a
higher sequence number, which is odd. Thus, it is just like any distance vector algorithm with
the added novelty of sequence numbers, which is used to distinguish stale routes from new
routes. The concept of sequence numbers also ensures loop free routes.

Destination
A
B
C
D
E
F

Next
Hop
A
B
C
D
D
D

Distance
0
1
1
1
2
2

Sequence
Number
S205_A
S334_B
S198_C
S567_D
S767_E
S45_F

A‘s routing table before change

Division Of Computer Science Engineering, SOE, CUSAT
10

Mobile ad hoc networks

Destination
A
B
C
D
E
F

Next
Hop
A
D
C
D
D
D

Distance

Sequence Number

0
3
1
1
2
2

S304_A
S424_B
S297_C
S687_D
S868_E
S164_F

A‘s routing table after change
Fig 3.2 ad hoc network having routing tables
3.3.2 Clusterhead Gateway Switch Routing (CGSR):
The Clusterhead Gateway Switch Routing (CGSR) protocol differs from the previous
protocol in the type of addressing and network organization scheme employed. Instead of a
flat network, CGSR is a clustered multi hop mobile wireless network with several heuristic
routing schemes. In that by having a cluster head controlling a group of ad hoc nodes, a
framework for code separation (among clusters), channel access, routing, and bandwidth
allocation can be achieved. A cluster head selection algorithm is utilized to elect a node as the
cluster head using a distributed algorithm within the cluster. The disadvantage of having a
cluster head scheme is that frequent cluster head changes can adversely affect routing
protocol performance since nodes are busy in cluster head selection rather than packet
relaying.
Hence, instead of invoking cluster head reselection every time the cluster membership
changes, a Least Cluster Change (LCC) clustering algorithm is introduced. Using LCC,
cluster heads only change when two cluster heads come into contact, or when a node moves
out of contact of all other cluster heads.
CGSR uses DSDV as the underlying routing scheme, and hence has much of the same
overhead as DSDV. However, it modifies DSDV by using a hierarchical cluster-head-togateway routing approach to route traffic from source to destination. Gateway nodes are
nodes that are within communication range of two or more cluster heads. A packet sent by a
node is first routed to its cluster head, and then the packet is routed from the cluster head to a
gateway to another cluster head, and so on until the cluster head of the destination node is
reached. The packet is then transmitted to the destination. Figure illustrates an example of

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

11

this routing scheme. Using this method, each node must keep a cluster member table where it
stores the destination cluster head for each mobile node in the network. Each node
periodically using the DSDV algorithm broadcasts these cluster member tables. Nodes update
their cluster member tables on reception of such a table from a neighbor. In addition to the
cluster member table, each node must also maintain a routing table, which is used to
determine the next hop in order to reach the destination. On receiving a packet, a node will
consult its cluster member table and routing table to determine the nearest cluster head along
the route to the destination. Next, the node will check its routing table to determine the next
hop used to reach the selected cluster head. It then transmits the packet to this node.

Fig 3.3 CGSR routing from node 1 to node 8

3.4 SOURCE INITIATED ON DEMAND ROUTING
3.4.1 Ad Hoc On-Demand Distance Vector Routing (AODV):
The Ad Hoc On Demand Distance Vector (AODV) routing protocol builds on the DSDV
algorithm previously described. AODV is an improvement on DSDV because it typically
minimizes the number of required broadcasts by creating routes on a demand basis, as
opposed to maintaining a complete list of routes as in the DSDV algorithm. AODV classify
as a pure on-demand route acquisition system, since nodes that are not on a selected path do
not maintain routing information or participate in routing table exchanges .
When a source node desires to send a message to some destination node and does not
already have a valid route to that destination, it initiates a path discovery process to locate the

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

12

other node. It broadcasts a route request (RREQ) packet to its neighbors, which then forward
the request to their neighbors, and so on, until either the destination or an intermediate node
with a fresh enough routes to the destination is located. Figure 3.4(a) illustrates the
propagation of the broadcast RREQs across the network. AODV utilizes destination sequence
numbers to ensure all routes are loop free and contain the most recent route information. Each
node maintains its own sequence number, as well as a broadcast ID. The broadcast ID is
incremented for every RREQ the node initiates, and together with the node‘s IP address,
uniquely identifies an RREQ. Along with its own sequence number and the broadcast ID, the
source node includes in the RREQ the most recent sequence number it has for the destination.
Intermediate nodes can reply to the RREQ only if they have a route to the destination whose
corresponding destination sequence number is greater than or equal to that contained in the
RREQ.
During the process of forwarding the RREQ, intermediate nodes record in their route
tables the address of the neighbor from which the first copy of the broadcast packet is
received, thereby establishing a reverse path. If additional copies of the same RREQ are later
received, these packets are discarded.
Once the RREQ reaches the destination or an intermediate node with a fresh enough
route, the destination intermediate node responds by unicasting a route reply (RREP) packet
back to the neighbor from which it first received the RREQ(Fig3.4(b)). As the RREP is
routed back along the reverse path, nodes along this path set up forward route entries in their
route tables which point to the node from which the RREP came. These forward route entries
indicate the active forward route. Associated with each route entry is a route timer that will
cause the deletion of the entry if it is not used within the specified lifetime. Because the
RREP is forwarded along the path established by the RREQ, AODV only supports the use of
symmetric links. Routes are maintained as follows. If a source node moves, it is able to
reinitiate the route discovery protocol to find a new route to the destination. If a node along
the route moves, its upstream neighbor notices the move and propagates a link failure
notification message (an RREP with infinite metric) to each of its active upstream neighbors
to inform them of the erasure of that part of the route. These nodes in turn propagate the link
failure notification to their upstream neighbors, and so on until the source node is reached.
The source node may then choose to reinitiate route discovery for that destination if a route is
still desired.

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

13

An additional aspect of the protocol is the use of hello messages, periodic local
broadcasts by a node to inform each mobile node of other nodes in its neighborhood. Hello
messages can be used to maintain the local connectivity of a node. However, the use of hello
messages is not required. Nodes listen for retransmission of data packets to ensure that the
next hop is still within reach. If such a retransmission is not heard, the node may use any one
of a number of techniques, including the reception of hello messages, to determine whether
the next hop is within communication range. The hello messages may list the other nodes
from which a mobile has heard, thereby yielding greater knowledge of network connectivity.

Fig 3.4 AODV routing protocol

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

14

3.4.2 Dynamic Source Routing Protocol (DSR):
The Dynamic Source Routing (DSR) protocol presented in is an on-demand routing protocol
that is based on the concept of source routing. Mobile nodes are required to maintain route
caches that contain the source routes of which the mobile is aware. Entries in the route cache
are continually updated as new routes are learned.
The protocol consists of two major phases: route discovery and route maintenance. When
a mobile node has a packet to send to some destination, it first consults its route cache to
determine whether it already has a route to the destination. If it has an unexpired route to the
destination, it will use this route to send the packet. On the other hand, if the node does not
have such a route, it initiates route discovery by broadcasting a route request packet. This
route request contains the address of the destination, along with the source node‘s address
and a unique identification number. Each node receiving the packet checks whether it knows
of a route to the destination. If it does not, it adds its own address to the route record of the
packet and then forwards the packet along its outgoing links. To limit the number of route
requests propagated on the outgoing links of a node, a mobile only forwards the route request
if the mobile has not yet seen the request and if the mobile‘s address does not already appear
in the route record.
A route reply is generated when the route request reaches either the destination itself, or
an intermediate node, which contains in its route cache an unexpired route to the destination.
By the time the packet reaches either the destination or such an intermediate node, it contains
a route record yielding the sequence of hops taken. Figure 3.5 (a) illustrates the formation of
the route record as the route request propagates through the network. If the node generating
the route reply is the destination, it places the route record contained in the route request into
the route reply. If the responding node is an intermediate node, it will append its cached route
to the route record and then generate the route reply. To return the route reply, the responding
node must have a route to the initiator. If it has a route to the initiator in its route cache, it
may use that route. Otherwise, if symmetric links are supported, the node may reverse the
route in the route record. If symmetric links are not supported, the node may initiate its own
route discovery and piggyback the route reply on the new route request. Figure 3.5 (b) shows
the transmission of the route reply with its associated route record back to the source node.

Division Of Computer Science Engineering, SOE, CUSAT
15

Mobile ad hoc networks

Route maintenance is accomplished through the use of route error packets and
acknowledgments. Route error packets are generated at a node when the data link layer
encounters a fatal transmission problem. When a route error packet is received, the hop in
error is removed from the node‘s route cache and all routes containing the hop are truncated
at that point. In addition to route error messages, acknowledgments are used to verify the
correct

operation

of

the

route

links.

Such

acknowledgments

include

passive

acknowledgments, where a mobile is able to hear the next hop forwarding the packet along
the route.

Fig 3.5 DSR routing protocol

One trade off between source routing and distance vector routing is the handling of partitioned
networks. Under dynamic source routing, if a host wishes to communicate with an unreachable host,
then though the rate at which route request are made will be reduced by a back off mechanism but
Division Of Computer Science Engineering, SOE, CUSAT
16

Mobile ad hoc networks

the protocol continues to make periodic efforts to find a route to the unreachable host, consuming
some network resources. Under distance vector routing, with the assumption that routes have had
time to converge once the host become unreachable, no network resources are used trying to send
packets to unreachable host, as none of the host in the sender's partition of the network has a
routing table entry for the destination.

3.5 HYBRID SCHEME
3.5.1 Zone Routing Protocol (ZRP)
Proactive routing uses excess bandwidth to maintain routing information, while reactive
routing involves long route request delays. Reactive routing also inefficiently floods the
entire network for route determination. The Zone Routing Protocol (ZRP)

aims to address

the problems by combining the best properties of both approaches. ZRP can be classed as a
hybrid reactive/proactive routing protocol.
In an ad-hoc network, it can be assumed that the largest part of the traffic is directed to
nearby nodes. Therefore, ZRP reduces the proactive scope to a zone centered on each node.
In a limited zone, the maintenance of routing information is easier. Further, the amount of
routing information that is never used is minimized. Still, nodes farther away can be reached
with reactive routing. Since all nodes proactively store local routing information, route
requests can be more efficiently performed without querying all the network nodes.
Despite the use of zones, ZRP has a flat view over the network. Nodes belonging to
different subnets must send their communication to a subnet that is common to both nodes.
This may congest parts of the network. ZRP can be categorized as a flat protocol because the
zones overlap. Hence, optimal routes can be detected and network congestion can be reduced.
Further, the behavior of ZRP is adaptive. The behavior depends on the current configuration
of the network and the behavior of the users.
Architecture:
The Zone Routing Protocol, as its name implies, is based on the concept of zones. A
routing zone is defined for each node separately, and the zones of neighbouring nodes
overlap. The routing zone has a r-radius expressed in hops. The zone thus includes the nodes,
whose distance from the node in question is at most r-hops.

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

17

An example routing zone is shown in Fig 3.6, where the routing zone of S includes the nodes
A–I, but not K. In the illustrations, the radius is marked as a circle around the node in
question. It should however be noted that the zone is defined in hops, not as a physical
distance. The nodes of a zone are divided into peripheral nodes and interior nodes. Peripheral
nodes are nodes whose minimum distance to the central node is exactly equal to the zone
radius r. The nodes whose minimum distance is less than rare interior nodes, in figure, the
nodes A–F are interior nodes, the nodes G–J are peripheral nodes and the node K is outside
the routing zone. Note that node H can be reached by two paths, one with length 2 and one
with length 3 hops. The node is however within the zone, since the shortest path is less than
or equal to the zone radius.

Fig 3.6 Zone routing protocol with radius = 2.

ZRP refers to the locally proactive routing component as the Intra-zone Routing Protocol
(IARP). The globally reactive routing component is named Inter-zone Routing Protocol
(IERP). IARP maintains routing information for nodes that are within the routing zone of the
node. IERP offer enhanced route discovery and route maintenance services based on local
connectivity monitored by IARP. The fact that the topology of the local zone of each node is
known can be used to reduce traffic when global route discovery is needed. Instead of
broadcasting packets, ZRP uses a concept called border casting. Border casting utilizes the
topology information provided by IARP to direct query request to the border of the zone. The
Border cast Resolution Protocol (BRP) provides the border cast packet delivery service. In
order to detect new neighbor nodes and link failures, the ZRP relies on a Neighbor Discovery

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

18

Protocol (NDP) provided by the Media Access Control (MAC) layer. NDP transmits
―HELLO‖ beacons at regular intervals. Upon receiving a beacon, the neighbor table is
updated. Neighbors, for which no beacon has been received within a specified time, are
removed from the table
Route updates are triggered by NDP, which notifies IARP when the neighbor table is
updated. IERP uses the routing table of IARP to respond to route queries. IERP forwards
queries with BRP. BRP uses the routing table of IARP to guide route queries away from the
query source.
A node that has a packet to send first checks whether the destination is within its local zone
using information provided by IARP. In that case, the packet can be routed proactively.
Reactive routing is used if the destination is outside the zone.
The reactive routing process is divided into two phases: the route request phase and the route
reply phase. In the route request, the source sends a route request packet to its peripheral
nodes using BRP. If the receiver of a route request packet knows the destination, it responds
by sending a route reply back to the source. Otherwise, it continues the process by border
casting the packet. In this way, the route request spreads throughout the network. If a node
receives several copies of the same route request, these are considered as redundant and are
discarded. The reply is sent by any node that can provide a route to the destination. To be
able to send the reply back to the source node, routing information must be accumulated
when the request is sent through the network. The information is recorded either in the route
request packet, or as next-hop addresses in the nodes along the path. In the first case, the
nodes forwarding a route request packet append their address and relevant node/link metrics
to the packet. When the packet reaches the destination, the sequence of addresses is reversed
and copied to the route reply packet. The sequence is used to forward the reply back to the
source. In the second case, the forwarding nodes records routing information as next-hop
addresses, which are used when the reply is sent to the source. This approach can save
transmission resources, as the request and reply packets are smaller.
The source can receive the complete source route to the destination. Alternatively, the nodes
along the path to the destination record the next-hop address in their routing table. In the
border casting process, the border casting node sends a route request packet to each of its
peripheral nodes. This type of one-to-many transmission can be implemented as multicast to
reduce resource usage. One approach is to let the source compute the multicast tree and attach
Division Of Computer Science Engineering, SOE, CUSAT
19

Mobile ad hoc networks

routing instructions to the packet. This is called Root-Directed Border casting (RDB). The
zone radius is an important property for the performance of ZRP. If a zone radius of one hop
is used, routing is purely reactive and border casting degenerates into flood searching. If the
radius approaches infinity, routing is reactive. The selection of radius is a tradeoff between
the routing efficiency of proactive routing and the increasing traffic for maintaining the view
of the zone.

Route maintenance
In ZRP, the knowledge of the local topology can be used for route maintenance. Link failures
and sub-optimal route segments within one zone can be bypassed. Incoming packets can be
directed around the broken link through an active multi-hop path. Similarly, the topology can
be used to shorten routes, for example, when two nodes have moved within each other‘s radio
coverage. For source-routed packets, a relaying node can determine the closest route to the
destination that is also a neighbor. Sometimes, a multi-hop segment can be replaced by a
single hop. If next-hop forwarding is used, the nodes can make locally optimal decisions by
selecting a shorter path.

3.6 COMPARISON

Parameters

TABLE DRIVEN

ON DEMAND

Availability of routing
information

Available when needed

Always available regardless
of the need

Routing philosophy

Flat

Mostly flat except CGSR

Periodic route updates

Not required

Required

Coping with mobility

Use localized route
recovery
Grows with increasing

Inform other nodes to
achieve a consistent routing
Greater than that of on

Signaling traffic generated

Tab 3.1 Comparison between table driven and on demand routing protocols

Division Of Computer Science Engineering, SOE, CUSAT
20

Mobile ad hoc networks

Chapter 4
VEHICULAR AD HOC NETWORK (VANET)
A Vehicular Ad-Hoc Network, or VANET, is a technology that uses moving cars as nodes in a
network to create a mobile network. VANET turns every participating car into a wireless router or
node, allowing cars approximately 100 to 300 metres of each other to connect and, in turn, create a
network with a wide range. As cars fall out of the signal range and drop out of the network, other
cars can join in, connecting vehicles to one another so that a mobile Internet is created. It is
estimated that the first systems that will integrate this technology are police and fire vehicles to
communicate with each other for safety purposes.

Fig 4.1 Typical vehicular ad hoc network (VANET)

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

21

4.1 ARCHITECTURE OF VANET
In general, protocol architecture achieves for communication among network nodes and
provides the framework for implementation. When designing the communication suit for VANETs
two approaches can be taken: First, following the traditional approach, the overall functionality
could be de-composed and organized in layers such that at the protocols fulfill small, well-defined
tasks and form a protocol stack as in TCP/IP and OSI. Second, one could try to build a customized
solution that meets the requirements of VANETs. With such non-layered .

The first approach—called layered approach and depicted in Fig. 1 attempts to retain the order
of functions and protocol layers with well-defined interfaces between them. It adapts system
functionalities to the needs of a VANET communication system resulting, e.g., in protocol layers
for single-hop and multi-hop communication. The limitations and inflexibility of traditional
network stacks when used in ad hoc networks are well known. E.g., each layer is implemented as
an independent module with interfaces (SAPs) only to the above and below layers. Consequently,
protocols cannot easily access state or metadata of a protocol on a different layer what makes data
aggregation difficult. Moreover, some of VANET-specific functions do not fit into the traditional
layered OSI model, such as those for network stability and control, and cannot be uniquely
assigned to a certain layer. It is also worth noting that every layer accesses external information
separately with no common interface which might lead to problems when this information
influences protocol flow.
The second un-layered approach would be the result of tailoring a whole new system
to the needs of VANETs‘ main focus, i.e., safety applications. Having accurate specifications of
these applications and willing to use the ‗probabilistic‘ channel in the most efficient manner leads
to have a highly coupled set of protocols. Therefore, all application and communication protocols
are placed in one single logical block right over the physical interface and connected to the external
sensors (Fig. 2). Inside this block, all protocol elements are modularized such that there are no
restrictions for interaction, state information is arbitrary accessible. Note though, that this
‗architecture‘ inherits a high design complexity due to arbitrary and complex interactions of their
modules. This makes protocol specification a complicated work and so, once designed becomes an
extremely inflexible system for other types of application. Also it would be tough to systematically

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

22

avoid control loop, what is rather easy in the layered approach with its clean top-down or bottomup packet traversal. While both approaches would certainly be feasible.

Fig 4.2 Layered architecture

Fig 4.3 Un-layered architecture
4.2 APPLICATIONS OF VANET
There are many applications for vehicular networks. Just name a few important ones: Collision
Avoidance – About 21,000 of the 43,000 deaths that occur each year on U.S. highways result from

Division Of Computer Science Engineering, SOE, CUSAT
Mobile ad hoc networks

23

vehicles leaving the road or travelling unsafely through intersections. Data transmitted from a
roadside base station to a vehicle could warn a driver that it‘s not safe to enter an intersection.
Communication between vehicles and between vehicles and the roadsides can save many lives and
prevent injuries. Some of the worst traffic accidents involve many vehicles rear-ending each other
after a single accident at the front of the line suddenly halts traffic. In this application, if a vehicle
reduces its speed significantly, it will broadcast its location to its neighbor vehicles. And other
receivers will try to relay the message further. And the vehicles behind the vehicle in question will
emit some kind of alarm to its drivers and other drivers behind. In this way, more drivers far behind
will get an alarm signal before they see the accident. Cooperative Driving – Like violation warning,
turn conflict warning, curve warning, lane merging warning etc. These services may greatly reduce
the life-endangering accidents. In fact, many of the accidents come from the lack of cooperation
between drivers. Given more information about the possible conflicts, we can prevent many
accidents.

Traffic Optimization – Traffic delays continue to increase, wasting more than a 40-hour
workweek for peak time travelers. A significant reduction in these numbers could be achieved
through vehicular networks.
Vehicles could serve as data collectors and transmit the traffic condition information for the
vehicular network. And transportation agencies could utilize this information to actively relieve
traffic congestion. To be more specifically, in this application, vehicles could detect if the number
of neighboring vehicles is too many and their speed is too slow, and then relay this information to
vehicles approaching the location.
To make it work better, the information can be relayed by vehicles travelling in the other
direction so that it may be propagated faster to the vehicles toward the congestion location. In this
way, the vehicles approaching the congestion location will have enough time to choose alternate
routes. Vehicles can also collect the data about weather, road surface, construction zones, highway
rail intersection, emergency vehicle signal preemption and relay them to other vehicles.
Payment Services – Like toll collection. It‘s very convenient and desirable to pass a toll
collection without having to decelerate your car, waiting in line, looking for some coins and
something like that.

Division Of Computer Science Engineering, SOE, CUSAT
24

Mobile ad hoc networks

Location-based Services – Like finding the closest fuel station, restaurant, lodge etc. In fact,
these kinds of services are not specific to the vehicular networks. Many GPS systems have such
kinds of services already.
Intelligent vehicular ad hoc networks (InVANETs) use Wi-Fi IEEE 802.11p(WAVE
standard)and Wi-MAX IEEE 802.16 for easy and effective communication between vehicles with
dynamic mobility. Effective measures such as media communication between vehicles can be
enabled as well methods to track automotive vehicles. InVANET is not foreseen to replace current
mobile (cellular phone) communication standards. Automotive vehicular information can be
viewed on electronic maps using the Internet or specialized software. The advantage of Wi-Fi
based navigation system function is that it can effectively locate a vehicle which is inside big
campuses like universities, airports, and tunnels. InVANET can be used as part of automotive
electronics, which has to identify an optimally minimal path for navigation with minimal traffic
intensity. The system can also be used as a city guide to locate and identify landmarks in a new
city. Communication capabilities in vehicles are the basis of an envisioned InVANET or intelligent
transportation systems (ITS). Vehicles are enabled to communicate among themselves (vehicle-tovehicle, V2V) and via roadside access points (vehicle-to-roadside, V2R). Vehicular communication
is expected to contribute to safer and more efficient roads by providing timely information to
drivers, and also to make travel more convenient. The integration of V2V and V2R communication
is beneficial because V2R provides better service sparse networks and long distance
communication, whereas V2V enables direct communication for small to medium distances/areas
and at locations where roadside access points are not available. Providing vehicle-to-vehicle and
vehicle-to-roadside communication can considerably improve traffic safety and comfort of driving
and travelling. For communication in vehicular ad hoc networks, position-based routing has
emerged as a promising candidate. For Internet access, Mobile IPv6 is a widely accepted solution
to provide session continuity and reachability to the Internet for mobile nodes. While integrated
solutions for usage of Mobile IPv6 in (non-vehicular) mobile ad hoc networks exist, a solution has
been proposed that, built upon on a Mobile IPv6 proxy-based architecture, selects the optimal
communication

mode

(direct

in-vehicle,

vehicle-to-vehicle,

and

vehicle-to-roadside

communication) and provides dynamic switching between vehicle-to-vehicle and vehicle-toroadside communication mode during a communication session in case that more than one
communication mode is simultaneously available.

Division Of Computer Science Engineering, SOE, CUSAT
25

Mobile ad hoc networks

Chapter 5
APPLICATIONS OF MANET
The field of wireless networking emerges from the integration of personal computing,
cellular technology, and the Internet. This is due to the increasing interactions between
communication and computing, which is changing information access from "anytime
anywhere" into "all the time, everywhere."
1. Tactical networks: military communications and operation, automated battle fields
2. Emergency services: search and rescue operations, disaster recovery, replacement of
fixed infrastructure in case of environmental disaster, policing and fire fighting,
supporting doctors and nurses in hospitals
3. Commercial and civilian environments: E-commerce, dynamic database access,
mobile offices, road or accident guidance, transmission of road and weather
conditions, taxi cab network, inter-vehicle networks, sports stadiums, trade fairs,
shopping malls, networks of visitors at airports
4. Home and enterprise networking: home/office wireless networking, conferences,
meeting rooms, personal area networks, networks at construction sites
5. Education: universities and campus settings, virtual class rooms
6. Entertainment: multiuser games, wirelessP2P networking, outdoor internet access,
robotic pets, theme parks
7. Sensor networks: smart sensors and actuators embedded in household electronic
devices, body area networks, data tracking of environmental conditions, animal
movements, chemical or biological detection
8. Context-aware services: call forwarding, mobile workspace, location-specific
services, time dependent services, infotainment touristic information
9. Coverage extension: extending cellular network access, linking up with the internets
intranets etc.

Division Of Computer Science Engineering, SOE, CUSAT
26

Mobile ad hoc networks

Chapter 6
CONCLUSION
In conclusion, mobile ad-hoc networks allow the construction of flexible and adaptive
networks with no fixed infrastructure. These networks are expected to play an important role
in the future wireless generation. Future wireless technology will require highly-adaptive
mobile networking technology to effectively manage multi-hop ad-hoc network clusters,
which will not only operate autonomously but also will be able to attach at some point to the
fixed networks.

Division Of Computer Science Engineering, SOE, CUSAT
27

Mobile ad hoc networks

Chapter 7
REFERENCE
1. Ad-hoc networks: Fundamental properties and network topologies by Ramin Hekmat
2. Ad hoc networks technologies and protocols by Prasant Mohapatra and Srikanth V.
Krishnamurthy
3. Elizabeth M. Royer, Chai-Keong Toh, A Review of Current Routing Protocols for Ad
Hoc Mobile Wireless Networks , Proc. IEEE,1999.
4. http://en.wikipedia.org/wiki/Mobile_ad_hoc_network

Division Of Computer Science Engineering, SOE, CUSAT

Mais conteúdo relacionado

Mais procurados

Black-Hole and Wormhole Attack in Routing Protocol AODV in MANET
Black-Hole and Wormhole Attack in Routing Protocol AODV in MANETBlack-Hole and Wormhole Attack in Routing Protocol AODV in MANET
Black-Hole and Wormhole Attack in Routing Protocol AODV in MANETIJCSEA Journal
 
AODV information
AODV informationAODV information
AODV informationanilds02
 
Secure communications over wireless broadcast networks
Secure communications over wireless broadcast networksSecure communications over wireless broadcast networks
Secure communications over wireless broadcast networkspraveen369
 
Window based smart antenna design
Window based smart antenna designWindow based smart antenna design
Window based smart antenna designijwmn
 
A Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc Networks
A Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc NetworksA Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc Networks
A Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc Networkscscpconf
 
IRJET- An Introduction to Wireless Sensor Networks, its Challenges and Security
IRJET- An Introduction to Wireless Sensor Networks, its Challenges and SecurityIRJET- An Introduction to Wireless Sensor Networks, its Challenges and Security
IRJET- An Introduction to Wireless Sensor Networks, its Challenges and SecurityIRJET Journal
 
A Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor Networks
A Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor NetworksA Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor Networks
A Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor NetworksIJERA Editor
 
Energy Minimization in Wireless Sensor Networks Using Multi Hop Transmission
Energy Minimization in Wireless Sensor Networks Using Multi  Hop TransmissionEnergy Minimization in Wireless Sensor Networks Using Multi  Hop Transmission
Energy Minimization in Wireless Sensor Networks Using Multi Hop TransmissionIOSR Journals
 
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...IOSR Journals
 
207088 633815660985047486
207088 633815660985047486207088 633815660985047486
207088 633815660985047486Sathish Pilla
 
Wireless Mesh Networks
Wireless Mesh NetworksWireless Mesh Networks
Wireless Mesh Networkschris zlatis
 
Routing security in ad hoc wireless network
Routing security in ad hoc wireless networkRouting security in ad hoc wireless network
Routing security in ad hoc wireless networkElanthendral Mariappan
 
Performance Analysis of Wireless Sensor Network in Smart Grid Environment
Performance Analysis of Wireless Sensor Network in Smart Grid EnvironmentPerformance Analysis of Wireless Sensor Network in Smart Grid Environment
Performance Analysis of Wireless Sensor Network in Smart Grid Environmentijtsrd
 
MobiMESH: Introduction to Wireless MESH Networks
MobiMESH: Introduction to Wireless MESH NetworksMobiMESH: Introduction to Wireless MESH Networks
MobiMESH: Introduction to Wireless MESH Networksacapone
 
PERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEME
PERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEMEPERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEME
PERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEMEijasuc
 

Mais procurados (19)

Black-Hole and Wormhole Attack in Routing Protocol AODV in MANET
Black-Hole and Wormhole Attack in Routing Protocol AODV in MANETBlack-Hole and Wormhole Attack in Routing Protocol AODV in MANET
Black-Hole and Wormhole Attack in Routing Protocol AODV in MANET
 
AODV information
AODV informationAODV information
AODV information
 
H010524049
H010524049H010524049
H010524049
 
Secure communications over wireless broadcast networks
Secure communications over wireless broadcast networksSecure communications over wireless broadcast networks
Secure communications over wireless broadcast networks
 
Window based smart antenna design
Window based smart antenna designWindow based smart antenna design
Window based smart antenna design
 
A Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc Networks
A Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc NetworksA Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc Networks
A Review on - Comparative Study of Issues in Cellular, Sensor and Adhoc Networks
 
IRJET- An Introduction to Wireless Sensor Networks, its Challenges and Security
IRJET- An Introduction to Wireless Sensor Networks, its Challenges and SecurityIRJET- An Introduction to Wireless Sensor Networks, its Challenges and Security
IRJET- An Introduction to Wireless Sensor Networks, its Challenges and Security
 
A Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor Networks
A Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor NetworksA Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor Networks
A Comparative Analysis for Hybrid Routing Protocol for Wireless Sensor Networks
 
Energy Minimization in Wireless Sensor Networks Using Multi Hop Transmission
Energy Minimization in Wireless Sensor Networks Using Multi  Hop TransmissionEnergy Minimization in Wireless Sensor Networks Using Multi  Hop Transmission
Energy Minimization in Wireless Sensor Networks Using Multi Hop Transmission
 
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...
An Overview of Mobile Ad hoc Network: Application, Challenges and Comparison ...
 
207088 633815660985047486
207088 633815660985047486207088 633815660985047486
207088 633815660985047486
 
Wireless Mesh Networks
Wireless Mesh NetworksWireless Mesh Networks
Wireless Mesh Networks
 
L046027479
L046027479L046027479
L046027479
 
Manet ns2
Manet ns2Manet ns2
Manet ns2
 
Routing security in ad hoc wireless network
Routing security in ad hoc wireless networkRouting security in ad hoc wireless network
Routing security in ad hoc wireless network
 
Performance Analysis of Wireless Sensor Network in Smart Grid Environment
Performance Analysis of Wireless Sensor Network in Smart Grid EnvironmentPerformance Analysis of Wireless Sensor Network in Smart Grid Environment
Performance Analysis of Wireless Sensor Network in Smart Grid Environment
 
MobiMESH: Introduction to Wireless MESH Networks
MobiMESH: Introduction to Wireless MESH NetworksMobiMESH: Introduction to Wireless MESH Networks
MobiMESH: Introduction to Wireless MESH Networks
 
PERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEME
PERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEMEPERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEME
PERFORMANCE COMPARISON OF QOS METRICS FOR A DISTRIBUTED PRICING SCHEME
 
Manet
ManetManet
Manet
 

Destaque

Glog Presentation
Glog PresentationGlog Presentation
Glog PresentationAndrew Kohl
 
Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...
Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...
Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...Rachabodin Suwannakanthi
 
Basics of JSON (JavaScript Object Notation) with examples
Basics of JSON (JavaScript Object Notation) with examplesBasics of JSON (JavaScript Object Notation) with examples
Basics of JSON (JavaScript Object Notation) with examplesSanjeev Kumar Jaiswal
 
Urban Leadership Slides
Urban Leadership SlidesUrban Leadership Slides
Urban Leadership SlidesNathan Smith
 
Themes from Ascent of a Leader
Themes from Ascent of a LeaderThemes from Ascent of a Leader
Themes from Ascent of a LeaderNathan Smith
 
Social Psych And Ethics
Social Psych And EthicsSocial Psych And Ethics
Social Psych And EthicsSteve Kashdan
 
White paper on Spool space in teradata
White paper on Spool space in teradataWhite paper on Spool space in teradata
White paper on Spool space in teradataSanjeev Kumar Jaiswal
 
Postcards from the future texas state fbla
Postcards from the future   texas state fblaPostcards from the future   texas state fbla
Postcards from the future texas state fblaBill M Wooten, PhD
 
eCMO 2010 Digital lifestyles and media consumption habits of four generations...
eCMO 2010 Digital lifestyles and media consumption habits of four generations...eCMO 2010 Digital lifestyles and media consumption habits of four generations...
eCMO 2010 Digital lifestyles and media consumption habits of four generations...HKAIM
 
Hong Kong Mobile Marketing Survey 2009 by HKAIM
Hong Kong Mobile Marketing Survey 2009 by HKAIMHong Kong Mobile Marketing Survey 2009 by HKAIM
Hong Kong Mobile Marketing Survey 2009 by HKAIMHKAIM
 
Coinlove helping children sweeden
Coinlove helping children sweedenCoinlove helping children sweeden
Coinlove helping children sweedenmariogomezprieto
 
VietnamRealEstate_E-Directory_VN_Q1_2009
VietnamRealEstate_E-Directory_VN_Q1_2009VietnamRealEstate_E-Directory_VN_Q1_2009
VietnamRealEstate_E-Directory_VN_Q1_2009internationalvr
 

Destaque (20)

Glog Presentation
Glog PresentationGlog Presentation
Glog Presentation
 
Beekman5 std ppt_01
Beekman5 std ppt_01Beekman5 std ppt_01
Beekman5 std ppt_01
 
Coo look
Coo lookCoo look
Coo look
 
Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...
Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...
Basic Creating Virtual Reality with HDR Panoramic Photography Technique - Day...
 
Basics of JSON (JavaScript Object Notation) with examples
Basics of JSON (JavaScript Object Notation) with examplesBasics of JSON (JavaScript Object Notation) with examples
Basics of JSON (JavaScript Object Notation) with examples
 
Meet Clumsy
Meet ClumsyMeet Clumsy
Meet Clumsy
 
Moral Psychology
Moral PsychologyMoral Psychology
Moral Psychology
 
Urban Leadership Slides
Urban Leadership SlidesUrban Leadership Slides
Urban Leadership Slides
 
Blagoslov
BlagoslovBlagoslov
Blagoslov
 
Themes from Ascent of a Leader
Themes from Ascent of a LeaderThemes from Ascent of a Leader
Themes from Ascent of a Leader
 
Social Psych And Ethics
Social Psych And EthicsSocial Psych And Ethics
Social Psych And Ethics
 
Pantone fcr-sp2010f
Pantone fcr-sp2010fPantone fcr-sp2010f
Pantone fcr-sp2010f
 
White paper on Spool space in teradata
White paper on Spool space in teradataWhite paper on Spool space in teradata
White paper on Spool space in teradata
 
Postcards from the future texas state fbla
Postcards from the future   texas state fblaPostcards from the future   texas state fbla
Postcards from the future texas state fbla
 
eCMO 2010 Digital lifestyles and media consumption habits of four generations...
eCMO 2010 Digital lifestyles and media consumption habits of four generations...eCMO 2010 Digital lifestyles and media consumption habits of four generations...
eCMO 2010 Digital lifestyles and media consumption habits of four generations...
 
Hong Kong Mobile Marketing Survey 2009 by HKAIM
Hong Kong Mobile Marketing Survey 2009 by HKAIMHong Kong Mobile Marketing Survey 2009 by HKAIM
Hong Kong Mobile Marketing Survey 2009 by HKAIM
 
Beekman5 std ppt_02
Beekman5 std ppt_02Beekman5 std ppt_02
Beekman5 std ppt_02
 
Coinlove helping children sweeden
Coinlove helping children sweedenCoinlove helping children sweeden
Coinlove helping children sweeden
 
VietnamRealEstate_E-Directory_VN_Q1_2009
VietnamRealEstate_E-Directory_VN_Q1_2009VietnamRealEstate_E-Directory_VN_Q1_2009
VietnamRealEstate_E-Directory_VN_Q1_2009
 
Chpt1
Chpt1Chpt1
Chpt1
 

Semelhante a Introduction to Mobile adhoc-network

Blackhole attack in Manet
Blackhole attack in ManetBlackhole attack in Manet
Blackhole attack in ManetProf Ansari
 
Correlation Associativity b/w Sensor Information Network Architecture & Softw...
Correlation Associativity b/w Sensor Information Network Architecture & Softw...Correlation Associativity b/w Sensor Information Network Architecture & Softw...
Correlation Associativity b/w Sensor Information Network Architecture & Softw...Iqra khalil
 
Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...
Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...
Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...IJERA Editor
 
Project report a dhoc wireless network
Project report a dhoc wireless networkProject report a dhoc wireless network
Project report a dhoc wireless networkShiza Kokab
 
Mobile Adhoc Network (MANET) Routing Protocols Analytical Study
Mobile Adhoc Network (MANET) Routing Protocols Analytical StudyMobile Adhoc Network (MANET) Routing Protocols Analytical Study
Mobile Adhoc Network (MANET) Routing Protocols Analytical StudyIOSR Journals
 
Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...
Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...
Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...Editor IJMTER
 
A Background Study Of MANET
A Background Study Of MANETA Background Study Of MANET
A Background Study Of MANETAngela Shin
 
A simulation and analysis of secured aodv protocol in mobile ad hoc networks
A simulation and analysis of secured aodv protocol in mobile ad hoc networksA simulation and analysis of secured aodv protocol in mobile ad hoc networks
A simulation and analysis of secured aodv protocol in mobile ad hoc networkseSAT Journals
 
ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...
ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...
ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...ijwmn
 
A RELATIVE STUDY ON CELLULAR, WSN AND MANETS
A RELATIVE STUDY ON CELLULAR, WSN AND MANETSA RELATIVE STUDY ON CELLULAR, WSN AND MANETS
A RELATIVE STUDY ON CELLULAR, WSN AND MANETSIAEME Publication
 
A simulation and analysis of secured aodv protocol in
A simulation and analysis of secured aodv protocol inA simulation and analysis of secured aodv protocol in
A simulation and analysis of secured aodv protocol ineSAT Publishing House
 
Paper id 28201444
Paper id 28201444Paper id 28201444
Paper id 28201444IJRAT
 
Vikash file full_final
Vikash file full_finalVikash file full_final
Vikash file full_finalRahul Ranjan
 

Semelhante a Introduction to Mobile adhoc-network (20)

Blackhole attack in Manet
Blackhole attack in ManetBlackhole attack in Manet
Blackhole attack in Manet
 
Correlation Associativity b/w Sensor Information Network Architecture & Softw...
Correlation Associativity b/w Sensor Information Network Architecture & Softw...Correlation Associativity b/w Sensor Information Network Architecture & Softw...
Correlation Associativity b/w Sensor Information Network Architecture & Softw...
 
Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...
Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...
Performance Evaluation of DSDV and MDSDV Routing Protocol with Varying Node D...
 
Project report a dhoc wireless network
Project report a dhoc wireless networkProject report a dhoc wireless network
Project report a dhoc wireless network
 
Mobile adhoc networks
Mobile adhoc networksMobile adhoc networks
Mobile adhoc networks
 
eaodv
eaodveaodv
eaodv
 
Mobile Adhoc Network (MANET) Routing Protocols Analytical Study
Mobile Adhoc Network (MANET) Routing Protocols Analytical StudyMobile Adhoc Network (MANET) Routing Protocols Analytical Study
Mobile Adhoc Network (MANET) Routing Protocols Analytical Study
 
Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...
Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...
Comparison of Various Unicast-Multicast Routing Protocols for Mobile Ad-Hoc N...
 
40120140503011
4012014050301140120140503011
40120140503011
 
A Background Study Of MANET
A Background Study Of MANETA Background Study Of MANET
A Background Study Of MANET
 
CHAPTER-1234
CHAPTER-1234CHAPTER-1234
CHAPTER-1234
 
A simulation and analysis of secured aodv protocol in mobile ad hoc networks
A simulation and analysis of secured aodv protocol in mobile ad hoc networksA simulation and analysis of secured aodv protocol in mobile ad hoc networks
A simulation and analysis of secured aodv protocol in mobile ad hoc networks
 
ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...
ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...
ANALYZING THE IMPACT OF EAVES ON ENERGY CONSUMPTION OF AODV ROUTING PROTOCOL ...
 
A RELATIVE STUDY ON CELLULAR, WSN AND MANETS
A RELATIVE STUDY ON CELLULAR, WSN AND MANETSA RELATIVE STUDY ON CELLULAR, WSN AND MANETS
A RELATIVE STUDY ON CELLULAR, WSN AND MANETS
 
A simulation and analysis of secured aodv protocol in
A simulation and analysis of secured aodv protocol inA simulation and analysis of secured aodv protocol in
A simulation and analysis of secured aodv protocol in
 
Paper id 28201444
Paper id 28201444Paper id 28201444
Paper id 28201444
 
A0110104
A0110104A0110104
A0110104
 
Vikash file full_final
Vikash file full_finalVikash file full_final
Vikash file full_final
 
Do black holes exist
Do black holes existDo black holes exist
Do black holes exist
 
[IJET-V1I6P19] Authors : Kirti
[IJET-V1I6P19] Authors : Kirti[IJET-V1I6P19] Authors : Kirti
[IJET-V1I6P19] Authors : Kirti
 

Último

Designing A Time bound resource download URL
Designing A Time bound resource download URLDesigning A Time bound resource download URL
Designing A Time bound resource download URLRuncy Oommen
 
Linked Data in Production: Moving Beyond Ontologies
Linked Data in Production: Moving Beyond OntologiesLinked Data in Production: Moving Beyond Ontologies
Linked Data in Production: Moving Beyond OntologiesDavid Newbury
 
Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Brian Pichman
 
UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...
UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...
UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...UbiTrack UK
 
UiPath Community: AI for UiPath Automation Developers
UiPath Community: AI for UiPath Automation DevelopersUiPath Community: AI for UiPath Automation Developers
UiPath Community: AI for UiPath Automation DevelopersUiPathCommunity
 
AI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity WebinarAI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity WebinarPrecisely
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6DianaGray10
 
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfIaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfDaniel Santiago Silva Capera
 
How Accurate are Carbon Emissions Projections?
How Accurate are Carbon Emissions Projections?How Accurate are Carbon Emissions Projections?
How Accurate are Carbon Emissions Projections?IES VE
 
Computer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and HazardsComputer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and HazardsSeth Reyes
 
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDEADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDELiveplex
 
Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024D Cloud Solutions
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintMahmoud Rabie
 
Building AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxBuilding AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxUdaiappa Ramachandran
 
UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8DianaGray10
 
VoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBXVoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBXTarek Kalaji
 
COMPUTER 10: Lesson 7 - File Storage and Online Collaboration
COMPUTER 10: Lesson 7 - File Storage and Online CollaborationCOMPUTER 10: Lesson 7 - File Storage and Online Collaboration
COMPUTER 10: Lesson 7 - File Storage and Online Collaborationbruanjhuli
 
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...Will Schroeder
 

Último (20)

Designing A Time bound resource download URL
Designing A Time bound resource download URLDesigning A Time bound resource download URL
Designing A Time bound resource download URL
 
Linked Data in Production: Moving Beyond Ontologies
Linked Data in Production: Moving Beyond OntologiesLinked Data in Production: Moving Beyond Ontologies
Linked Data in Production: Moving Beyond Ontologies
 
Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )Building Your Own AI Instance (TBLC AI )
Building Your Own AI Instance (TBLC AI )
 
UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...
UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...
UWB Technology for Enhanced Indoor and Outdoor Positioning in Physiological M...
 
UiPath Community: AI for UiPath Automation Developers
UiPath Community: AI for UiPath Automation DevelopersUiPath Community: AI for UiPath Automation Developers
UiPath Community: AI for UiPath Automation Developers
 
AI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity WebinarAI You Can Trust - Ensuring Success with Data Integrity Webinar
AI You Can Trust - Ensuring Success with Data Integrity Webinar
 
UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6UiPath Studio Web workshop series - Day 6
UiPath Studio Web workshop series - Day 6
 
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdfIaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
IaC & GitOps in a Nutshell - a FridayInANuthshell Episode.pdf
 
How Accurate are Carbon Emissions Projections?
How Accurate are Carbon Emissions Projections?How Accurate are Carbon Emissions Projections?
How Accurate are Carbon Emissions Projections?
 
Computer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and HazardsComputer 10: Lesson 10 - Online Crimes and Hazards
Computer 10: Lesson 10 - Online Crimes and Hazards
 
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDEADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
ADOPTING WEB 3 FOR YOUR BUSINESS: A STEP-BY-STEP GUIDE
 
Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024Artificial Intelligence & SEO Trends for 2024
Artificial Intelligence & SEO Trends for 2024
 
Empowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership BlueprintEmpowering Africa's Next Generation: The AI Leadership Blueprint
Empowering Africa's Next Generation: The AI Leadership Blueprint
 
Building AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptxBuilding AI-Driven Apps Using Semantic Kernel.pptx
Building AI-Driven Apps Using Semantic Kernel.pptx
 
UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8UiPath Studio Web workshop series - Day 8
UiPath Studio Web workshop series - Day 8
 
20150722 - AGV
20150722 - AGV20150722 - AGV
20150722 - AGV
 
VoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBXVoIP Service and Marketing using Odoo and Asterisk PBX
VoIP Service and Marketing using Odoo and Asterisk PBX
 
COMPUTER 10: Lesson 7 - File Storage and Online Collaboration
COMPUTER 10: Lesson 7 - File Storage and Online CollaborationCOMPUTER 10: Lesson 7 - File Storage and Online Collaboration
COMPUTER 10: Lesson 7 - File Storage and Online Collaboration
 
20230104 - machine vision
20230104 - machine vision20230104 - machine vision
20230104 - machine vision
 
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
Apres-Cyber - The Data Dilemma: Bridging Offensive Operations and Machine Lea...
 

Introduction to Mobile adhoc-network

  • 1. MOBILE AD HOC NETWORKS Seminar Report Submitted in partial fulfilment of the requirements for the award of the degree of Bachelor of Technology in Computer Science Engineering of Cochin University Of Science And Technology by PRAVEEN KUMAR P (12080059) DIVISION OF COMPUTER SCIENCE SCHOOL OF ENGINEERING COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY KOCHI-682022 OCTOBER 2010
  • 2. DIVISION OF COMPUTER SCIENCE SCHOOL OF ENGINEERING COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY KOCHI-682022 Certificate Certified that this is a bonafide record of the seminar entitled “MOBILE AD HOC NETWORKS” Presented by the following student “PRAVEEN KUMAR P” th of the VII semester, Computer Science and Engineering in the year 2010 in partial fulfillment of the requirements in the award of Degree of Bachelor of Technology in Computer Science and Engineering of Cochin University of Science and Technology. Mr. SUDHEEP ELAYIDOM Seminar guide Dr. DAVID PETER Head Of Division
  • 3. ACKNOWLEDGEMENT I thank GOD almighty for guiding me throughout the seminar. I would like to thank all those who have contributed to the completion of the seminar and helped me with valuable suggestions for improvement. I am extremely grateful to Dr. David Peter, Head Of Division, Division of Computer Science, for providing me with best facilities and atmosphere for the creative work guidance and encouragement. I am profoundly indebted to my seminar guide, Mr. Sudheep Elayidom, sr.Lecturer, Division of Computer Science, for innumerable acts of timely advice, encouragement and I sincerely express my gratitude to him. I thank all Staff members of my college and friends for extending their cooperation during my seminar. Above all I would like to thank my parents without whose blessings; I would not have been able to accomplish my goal. PRAVEEN KUMAR P
  • 4. TABLE OF CONTENTS CHAPTER NO TITLE PAGE NO. LIST OF FIGURES ii LIST OF TABLES iii 1. INTRODUCTION 1 2. BASICS OF MANET 2 2.1 WIRELESS AD HOC NETWORKS 2 2.2 CHARACTERISTICS OF MANET 4 AD HOC ROUTING PROTOCOLS 5 3.1 WHY ROUTING PROTOCOLS 5 3.2 AD HOC ROUTING PROTOCOLS 5 3.3 TABLE DRIVEN ROUTING PROTOCOLS 7 3. 3.3.1 DESTINATIONSEQUENCED DISTANCE VECTOR ROUTING ALGORITHM 7 3.3.2 CLUSTERHEAD GATEWAY SWITCH ROUTING (CGSR) 3.4 SOURCE INITIATED ON DEMAND ROUTING 10 11 3.4.1 AD HOC ON DEMAND DISTANCE VECTOR ROUTING (AODV) 11 3.4.2 DYNAMIC SOURCE ROUTING PROTOCOL (DSR) 14 3.5 HYBRID SCHEME 16 3.5.1 ZONE ROUTING PROTOCOLS (ZRP) 16 3.6 COMPARISON 19 i
  • 5. 4. VEHICULAR AD HOC NETWORK (VANET) 20 4.1 ARCHITECTURE OF VANET 21 4.2 APPLICATIONS OF VANET 22 5. APPLICATIONS OF MANET 25 6. CONCLUSION 26 7. REFERENCE 27 LIST OF FIGURES FIGURE NO TITLE PAGE NO. 2.1 WIRELESS AD HOC NETWORK 3.1 CATEGORIZATION OF AD HOC ROUTING PROTOCOLS 3.2 2 6 AD HOC NETWORK HAVING ROUTING TABLES 9, 10 3.3 CGSR ROUTING 11 3.4 AODV ROUTING PROTOCOL 13 3.5 DSR ROUTING PROTOCOL 15 3.6 ZONE ROUTING PROTOCOLS 17 4.1 TYPICAL VEHICULAR AD HOC NETWORK 20 4.2 LAYERED ARCHITECTURE 22 ii
  • 6. 4.3 UNLAYERED ARCHITECTURE 22 LIST OF TABLES TABLE NO. 3.1 TITLE PAGENO. COMPARISON BETWEEN TABLE DRIVEN AND ON DEMAND ROUTING PROTOCOLS iii 19
  • 7. 1 Mobile ad hoc networks Chapter 1 INTRODUCTION Communication is the primary factor which influenced the development of mankind. One of the primary goal of communication is exchanging information between two persons. Today we have advanced technologies for communication. Communication can be between human beings or between machines. For the purpose of communication between machines we provided networks, generally connected by physical channels. Then to avoid the difficulties with wired networks there come wireless networks. Then need for more advanced technology arise and we thought about mobility. Mobile networks established due to this demand and the communication become more flexible. MANET is a type of wireless mobile network. A mobile ad hoc network (MANET), sometimes called a mobile mesh network, is a self-configuring network of mobile devices connected by wireless links. Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Such networks may operate by themselves or may be connected to the larger Internet. MANETs are a kind of wireless ad hoc networks that usually has a routable networking environment on top of a Link Layer ad hoc network. They are also a type of mesh network, but many mesh networks are not mobile or not wireless. The growth of laptops and 802.11/Wi-Fi wireless networking have made MANETs a popular research topic since the mid- to late 1990s. Different protocols are used for the communication between the mobile nodes. There is no particular access points in this networks, instead the nodes itself transfer data between the communication nodes. Like any other networks there is also some algorithms used for the routing of information between nodes. Division Of Computer Science Engineering, SOE, CUSAT
  • 8. 2 Mobile ad hoc networks Chapter 2 BASICS OF MANET MANET (Mobile Ad hoc Network) is a wireless ad hoc network, which uses mobile devices like laptops, PDAs, mobile phones etc. as nodes which communicate each other for the purpose of information transfer between nodes. MANET does not have any particular infrastructure due to the absence of access points and due to the presence of mobile nodes. To know about MANET first we need to know about a wireless ad hoc network. 2.1WIRELESS AD HOC NETWORKS A wireless ad hoc network is a decentralized network. The network is ad hoc because it does not rely on a pre existing infrastructure, such as routers in wired network or access points in wireless networks. Instead each node participate in routing by forwarding data for other nodes, and so the determination of which nodes forward the data is done dynamically, based on the network connectivity. Fig 2.1 Wireless ad hoc network Above figure shows a typical wireless ad hoc network in which the communication is happening in between mobile nodes. There is also a single base station which is not connected to each and every node in the network, instead there are two nodes which directly communicate with the base station. These nodes will have the complete responsibility of information exchange between the base Division Of Computer Science Engineering, SOE, CUSAT
  • 9. Mobile ad hoc networks 3 station and any node in the network. Such a node must know protocols for communicating with the nodes in the network as well as protocols required for the communication with base station An ad hoc network is made up of multiple ―nodes‖ connected by ―links‖. Links are influenced by the node's resources (e.g. available energy supply, transmitter power, computing power and memory) and by behavioural properties (reliability, and trustworthiness), as well as by link properties (e.g. line-of-sight interference, length-of-link and signal loss, interference and noise). Since new and old links can be connected or disconnected at any time, a functioning network must be able to cope with this dynamic restructuring, preferably in a way that is timely, efficient, reliable, robust and scalable. The network must allow any two nodes to communicate, often via other nodes that relay the information. A ―path‖ is a series of links that connects two nodes. Often there are multiple paths between any two nodes. Nodes are often limited by transmitter power (transmission range) and available energy resources. Transmitter power often consumes the most energy in the node. According to the inverse square law, it is more energy efficient to relay information across a network via multiple nodes The decentralized nature of wireless ad hoc networks makes them suitable for a variety of applications where central nodes can't be relied on, and may improve the scalability of wireless ad hoc networks compared to wireless managed networks, though theoretical and practical limits to the overall capacity of such networks have been identified. Minimal configuration and quick deployment make ad hoc networks suitable for emergency situations like natural disasters or military conflicts. The presence of a dynamic and adaptive routing protocol will enable ad hoc networks to be formed quickly. Wireless ad hoc networks can be further classified according to their applications - Mobile ad hoc networks (MANET): It is a wireless ad hoc network in which mobile nodes are mobile devices like laptops, PDAs, mobile phones etc. In this type of networks each node will act as routers hence no need of access points. One or more nodes can be connected to an external router, which is connected to the internet, so that each node in the network, if need can connect to internet and can transfer information bi directionally. Division Of Computer Science Engineering, SOE, CUSAT
  • 10. Mobile ad hoc networks - 4 Wireless mesh networks (WMN): It is a communication network made up of radio nodes organised in a mesh topology. Wireless mesh networks often consist of mesh clients, mesh routers and gateways. The mesh clients are often laptops, cell phones and other wireless devices while the mesh routers forward traffic to and from the gateways which may but need not connect to the Internet. - Wireless sensor networks (WSN): This type of networks consist of spatially distributed autonomous sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants. The development of wireless sensor networks was motivated by military applications such as battlefield surveillance and are now used in many industrial and civilian application areas, including industrial process monitoring and control, machine health monitoring, environment and habitat monitoring, healthcare applications, home automation, and traffic control 2.2 Characteristics of MANET - - - - Dynamic Topologies: Since nodes are free to move arbitrarily, the network topology may change randomly and rapidly at unpredictable times. The links may be unidirectional bidirectional. Bandwidth constrained, variable capacity links: Wireless links have significantly lower capacity than their hardwired counterparts. Also, due to multiple access, fading, noise, and interference conditions etc. the wireless links have low throughput. Energy constrained operation: Some or all of the nodes in a MANET may rely on batteries. In this scenario, the most important system design criteria for optimization may be energy conservation. Limited physical security: Mobile wireless networks are generally more prone to physical security threats than are fixed- cable nets. The increased possibility of eavesdropping, spoofing, and denial-of-service attacks should be carefully considered. Existing link security techniques are often applied within wireless networks to reduce security threats. As a benefit, the decentralized nature of network control in MANET provides additional robustness against the single points of failure of more centralized approaches. Division Of Computer Science Engineering, SOE, CUSAT
  • 11. 5 Mobile ad hoc networks Chapter 3 AD HOC ROUTING PROTOCOLS 3.1 Why Routing Protocols Routing support for mobile hosts is presently being formulated as mobile IP technology. When the mobile agent moves from its home network to a foreign (visited) network, the mobile agent tells a home agent on the home network to which foreign agent their packets should be forwarded. In addition, the mobile agent registers itself with that foreign agent on the foreign network. Thus, the home agent forwards all packets intended for the mobile agent to the foreign agent, which sends them to the mobile agent on the foreign network. When the mobile agent returns to its original network, it informs both agents (home and foreign) that the original configuration has been restored. No one on the outside networks need to know that the mobile agent moved. But in Ad Hoc networks there is no concept of home agent as it itself may be moving. Supporting Mobile IP form of host mobility requires address management, protocol inter operability enhancements and the like, but core network functions such as hop by hop routing still presently rely upon pre existing routing protocols operating within the fixed network. In contrast, the goal of mobile ad hoc networking is to extend mobility into the realm of autonomous, mobile, wireless domains, where a set of nodes, which may be combined routers and hosts, themselves to form the network routing infrastructure in an ad hoc fashion. Hence, there is need to study special routing algorithms to support this dynamic topology environment. Routing protocols for mobile ad-hoc networks have to face the challenge of frequently changing topology, low transmission power and asymmetric links. 3.2 Ad Hoc Routing Protocols: A number of routing protocols have been suggested for ad-hoc networks. These protocols can be classified into two main categories: Table driven routing protocols Division Of Computer Science Engineering, SOE, CUSAT
  • 12. Mobile ad hoc networks 6 Source initiated on demand routing protocols Table Driven Routing Protocols: Table-driven routing protocols attempt to maintain consistent, up-to-date routing information from each node to every other node in the network. These protocols require each node to maintain one or more tables to store routing information, and they respond to changes in network topology by propagating updates throughout the network in order to maintain a consistent network view. The areas in which they differ are the number of necessary routingrelated tables and the methods by which changes in network structure are broadcast. Source Initiated On Demand Routing: A different approach from table-driven routing is source-initiated on demand routing. This type of routing creates routes only when desired by the source node. When a node requires a route to a destination, it initiates a route discovery process within the network. This process is completed once a route is found or all possible route permutations have been examined. Once a route has been established, it is maintained by a route maintenance procedure until either the destination becomes inaccessible along every path from the source or until the route is no longer desired. Fig 3.1: Categorization of ad hoc routing protocols . Division Of Computer Science Engineering, SOE, CUSAT
  • 13. Mobile ad hoc networks 7 3.3 TABLE DRIVEN ROUTING PROTOCOLS 3.3.1 Destination Sequenced Distance Vector Routing Algorithm: The Destination Sequenced Distance Vector (DSDV) Routing Algorithm is based on the idea of the Distributed Bellman Ford (DBF) Routing Algorithm with certain improvements. The primary concern with using a Distributed Bellman Ford algorithm in Ad Hoc environment is its susceptibility towards forming routing loops and counting to infinity problem. DSDV guarantees loop free paths at all instants. Each node maintains a routing table, which contains entries for all the nodes in the network. Each entry consists of:  the destination's address  the number of hops required reaching the destination (hop count)  the sequence number as stamped by the destination. Whenever a node B comes up, it broadcasts a beacon message ("I am alive message") stamping it with a locally maintained sequence number. The nodes in its neighbourhood listen to this message and update the information for this node. If the nodes do not have any previous entry for this node B, they simply enter B's address in their routing table, together with hop count and the sequence number as broadcasted by B. If the nodes had previous entry for B, then sequence number of broadcasted information is compared to the sequence number stored in the node for destination B. If the message received has a higher sequence number, then this means that the node B has propagated a new information about its location so the entry must be updated in accordance with the new information received. The information with a newer sequence number is definitely new as the node B itself stamps sequence number. The new information that a node receives is scheduled for broadcasting to its neighbours so that they can know about the changes in topology. The neighbouring nodes also follow the same rule i.e. updating the information when information about a node with a newer sequence number is received. The metrics for routes chosen from the newly received broadcast information are each incremented by one hop. So, the new information is updated gradually at all nodes and they now know the next hop node in order to correctly route the packet to destination B. B also generates the new information with a newer sequence number when it sees that it is moving. By moving, it is meant that B observes that there is a change in topology because it's neighbours are changing, may be due to it's motion or other nodes Division Of Computer Science Engineering, SOE, CUSAT
  • 14. Mobile ad hoc networks 8 (neighbours) motion. And it comes to know that the neighbours are changing since it receives new beacon messages or does not receive beacon messages from its current neighbours. The information is broadcasted periodically to neighbours. It could be advertised when specifically asked for or when there is a significant change in topology. Thus, it is both 'event driven' and 'time driven'. The routing table updates can be sent in two ways. The first is known as a full dump. This type of packet carries all available routing information and can require multiple network protocol data units (NPDUs). During periods of occasional movement, these packets are transmitted infrequently. Smaller incremental packets are used to relay only that information which has changed since the last full dump. Each of these broadcasts should fit into a standard-size NPDU, thereby decreasing the amount of traffic generated. The mobile nodes maintain an additional table where they store the data sent in the incremental routing information packets. Routes that show an improved metric are scheduled for an advertisement at a time which depends on the average settling time for routes to the particular destination under consideration. To avoid a burst of new advertisements in case of rapidly changing routes, the Mobile host delays the advertisement of such routes, when it can determine that a route with a better metric is likely to show up soon. For this, the Mobile Host has to keep a history of weighted average time that routes to a particular destination fluctuate until the route with the best metric is received. Though it delays advertising the new route, it uses it for routing. Thus, it maintains two tables one for forwarding packets and another to be advertised. In order to bias the damping mechanism in favour of recent events, the most recent measurement of the settling time of a particular route must be counted with a higher weighting factor than are less recent measurements. A parameter must be selected which indicates how long a route has to remain stable before it is counted as truly stable. When no broadcasts are received from a neighbour within a particular time interval, the link is supposed to be broken. Now, any route through that next hop is immediately assigned Division Of Computer Science Engineering, SOE, CUSAT
  • 15. 9 Mobile ad hoc networks an infinite metric (i.e. any number greater than the maximum allowed metric) and assigned an updated sequence number. Note that this sequence number is assigned by the Mobile host other that the destination Mobile Host. Sequence numbers defined by the originating Mobile host are defined to be even numbers and sequence numbers generated to indicate infinite metrics are odd numbers. This information is broadcasted to the neighbouring nodes. If the neighbouring nodes have chosen this node as a next hop neighbour for any destination then they also set the route to destination as infinity. If the neighbouring nodes, do have a path to destination through some other neighbour and they ignore this information though it has a higher sequence number, which is odd. Thus, it is just like any distance vector algorithm with the added novelty of sequence numbers, which is used to distinguish stale routes from new routes. The concept of sequence numbers also ensures loop free routes. Destination A B C D E F Next Hop A B C D D D Distance 0 1 1 1 2 2 Sequence Number S205_A S334_B S198_C S567_D S767_E S45_F A‘s routing table before change Division Of Computer Science Engineering, SOE, CUSAT
  • 16. 10 Mobile ad hoc networks Destination A B C D E F Next Hop A D C D D D Distance Sequence Number 0 3 1 1 2 2 S304_A S424_B S297_C S687_D S868_E S164_F A‘s routing table after change Fig 3.2 ad hoc network having routing tables 3.3.2 Clusterhead Gateway Switch Routing (CGSR): The Clusterhead Gateway Switch Routing (CGSR) protocol differs from the previous protocol in the type of addressing and network organization scheme employed. Instead of a flat network, CGSR is a clustered multi hop mobile wireless network with several heuristic routing schemes. In that by having a cluster head controlling a group of ad hoc nodes, a framework for code separation (among clusters), channel access, routing, and bandwidth allocation can be achieved. A cluster head selection algorithm is utilized to elect a node as the cluster head using a distributed algorithm within the cluster. The disadvantage of having a cluster head scheme is that frequent cluster head changes can adversely affect routing protocol performance since nodes are busy in cluster head selection rather than packet relaying. Hence, instead of invoking cluster head reselection every time the cluster membership changes, a Least Cluster Change (LCC) clustering algorithm is introduced. Using LCC, cluster heads only change when two cluster heads come into contact, or when a node moves out of contact of all other cluster heads. CGSR uses DSDV as the underlying routing scheme, and hence has much of the same overhead as DSDV. However, it modifies DSDV by using a hierarchical cluster-head-togateway routing approach to route traffic from source to destination. Gateway nodes are nodes that are within communication range of two or more cluster heads. A packet sent by a node is first routed to its cluster head, and then the packet is routed from the cluster head to a gateway to another cluster head, and so on until the cluster head of the destination node is reached. The packet is then transmitted to the destination. Figure illustrates an example of Division Of Computer Science Engineering, SOE, CUSAT
  • 17. Mobile ad hoc networks 11 this routing scheme. Using this method, each node must keep a cluster member table where it stores the destination cluster head for each mobile node in the network. Each node periodically using the DSDV algorithm broadcasts these cluster member tables. Nodes update their cluster member tables on reception of such a table from a neighbor. In addition to the cluster member table, each node must also maintain a routing table, which is used to determine the next hop in order to reach the destination. On receiving a packet, a node will consult its cluster member table and routing table to determine the nearest cluster head along the route to the destination. Next, the node will check its routing table to determine the next hop used to reach the selected cluster head. It then transmits the packet to this node. Fig 3.3 CGSR routing from node 1 to node 8 3.4 SOURCE INITIATED ON DEMAND ROUTING 3.4.1 Ad Hoc On-Demand Distance Vector Routing (AODV): The Ad Hoc On Demand Distance Vector (AODV) routing protocol builds on the DSDV algorithm previously described. AODV is an improvement on DSDV because it typically minimizes the number of required broadcasts by creating routes on a demand basis, as opposed to maintaining a complete list of routes as in the DSDV algorithm. AODV classify as a pure on-demand route acquisition system, since nodes that are not on a selected path do not maintain routing information or participate in routing table exchanges . When a source node desires to send a message to some destination node and does not already have a valid route to that destination, it initiates a path discovery process to locate the Division Of Computer Science Engineering, SOE, CUSAT
  • 18. Mobile ad hoc networks 12 other node. It broadcasts a route request (RREQ) packet to its neighbors, which then forward the request to their neighbors, and so on, until either the destination or an intermediate node with a fresh enough routes to the destination is located. Figure 3.4(a) illustrates the propagation of the broadcast RREQs across the network. AODV utilizes destination sequence numbers to ensure all routes are loop free and contain the most recent route information. Each node maintains its own sequence number, as well as a broadcast ID. The broadcast ID is incremented for every RREQ the node initiates, and together with the node‘s IP address, uniquely identifies an RREQ. Along with its own sequence number and the broadcast ID, the source node includes in the RREQ the most recent sequence number it has for the destination. Intermediate nodes can reply to the RREQ only if they have a route to the destination whose corresponding destination sequence number is greater than or equal to that contained in the RREQ. During the process of forwarding the RREQ, intermediate nodes record in their route tables the address of the neighbor from which the first copy of the broadcast packet is received, thereby establishing a reverse path. If additional copies of the same RREQ are later received, these packets are discarded. Once the RREQ reaches the destination or an intermediate node with a fresh enough route, the destination intermediate node responds by unicasting a route reply (RREP) packet back to the neighbor from which it first received the RREQ(Fig3.4(b)). As the RREP is routed back along the reverse path, nodes along this path set up forward route entries in their route tables which point to the node from which the RREP came. These forward route entries indicate the active forward route. Associated with each route entry is a route timer that will cause the deletion of the entry if it is not used within the specified lifetime. Because the RREP is forwarded along the path established by the RREQ, AODV only supports the use of symmetric links. Routes are maintained as follows. If a source node moves, it is able to reinitiate the route discovery protocol to find a new route to the destination. If a node along the route moves, its upstream neighbor notices the move and propagates a link failure notification message (an RREP with infinite metric) to each of its active upstream neighbors to inform them of the erasure of that part of the route. These nodes in turn propagate the link failure notification to their upstream neighbors, and so on until the source node is reached. The source node may then choose to reinitiate route discovery for that destination if a route is still desired. Division Of Computer Science Engineering, SOE, CUSAT
  • 19. Mobile ad hoc networks 13 An additional aspect of the protocol is the use of hello messages, periodic local broadcasts by a node to inform each mobile node of other nodes in its neighborhood. Hello messages can be used to maintain the local connectivity of a node. However, the use of hello messages is not required. Nodes listen for retransmission of data packets to ensure that the next hop is still within reach. If such a retransmission is not heard, the node may use any one of a number of techniques, including the reception of hello messages, to determine whether the next hop is within communication range. The hello messages may list the other nodes from which a mobile has heard, thereby yielding greater knowledge of network connectivity. Fig 3.4 AODV routing protocol Division Of Computer Science Engineering, SOE, CUSAT
  • 20. Mobile ad hoc networks 14 3.4.2 Dynamic Source Routing Protocol (DSR): The Dynamic Source Routing (DSR) protocol presented in is an on-demand routing protocol that is based on the concept of source routing. Mobile nodes are required to maintain route caches that contain the source routes of which the mobile is aware. Entries in the route cache are continually updated as new routes are learned. The protocol consists of two major phases: route discovery and route maintenance. When a mobile node has a packet to send to some destination, it first consults its route cache to determine whether it already has a route to the destination. If it has an unexpired route to the destination, it will use this route to send the packet. On the other hand, if the node does not have such a route, it initiates route discovery by broadcasting a route request packet. This route request contains the address of the destination, along with the source node‘s address and a unique identification number. Each node receiving the packet checks whether it knows of a route to the destination. If it does not, it adds its own address to the route record of the packet and then forwards the packet along its outgoing links. To limit the number of route requests propagated on the outgoing links of a node, a mobile only forwards the route request if the mobile has not yet seen the request and if the mobile‘s address does not already appear in the route record. A route reply is generated when the route request reaches either the destination itself, or an intermediate node, which contains in its route cache an unexpired route to the destination. By the time the packet reaches either the destination or such an intermediate node, it contains a route record yielding the sequence of hops taken. Figure 3.5 (a) illustrates the formation of the route record as the route request propagates through the network. If the node generating the route reply is the destination, it places the route record contained in the route request into the route reply. If the responding node is an intermediate node, it will append its cached route to the route record and then generate the route reply. To return the route reply, the responding node must have a route to the initiator. If it has a route to the initiator in its route cache, it may use that route. Otherwise, if symmetric links are supported, the node may reverse the route in the route record. If symmetric links are not supported, the node may initiate its own route discovery and piggyback the route reply on the new route request. Figure 3.5 (b) shows the transmission of the route reply with its associated route record back to the source node. Division Of Computer Science Engineering, SOE, CUSAT
  • 21. 15 Mobile ad hoc networks Route maintenance is accomplished through the use of route error packets and acknowledgments. Route error packets are generated at a node when the data link layer encounters a fatal transmission problem. When a route error packet is received, the hop in error is removed from the node‘s route cache and all routes containing the hop are truncated at that point. In addition to route error messages, acknowledgments are used to verify the correct operation of the route links. Such acknowledgments include passive acknowledgments, where a mobile is able to hear the next hop forwarding the packet along the route. Fig 3.5 DSR routing protocol One trade off between source routing and distance vector routing is the handling of partitioned networks. Under dynamic source routing, if a host wishes to communicate with an unreachable host, then though the rate at which route request are made will be reduced by a back off mechanism but Division Of Computer Science Engineering, SOE, CUSAT
  • 22. 16 Mobile ad hoc networks the protocol continues to make periodic efforts to find a route to the unreachable host, consuming some network resources. Under distance vector routing, with the assumption that routes have had time to converge once the host become unreachable, no network resources are used trying to send packets to unreachable host, as none of the host in the sender's partition of the network has a routing table entry for the destination. 3.5 HYBRID SCHEME 3.5.1 Zone Routing Protocol (ZRP) Proactive routing uses excess bandwidth to maintain routing information, while reactive routing involves long route request delays. Reactive routing also inefficiently floods the entire network for route determination. The Zone Routing Protocol (ZRP) aims to address the problems by combining the best properties of both approaches. ZRP can be classed as a hybrid reactive/proactive routing protocol. In an ad-hoc network, it can be assumed that the largest part of the traffic is directed to nearby nodes. Therefore, ZRP reduces the proactive scope to a zone centered on each node. In a limited zone, the maintenance of routing information is easier. Further, the amount of routing information that is never used is minimized. Still, nodes farther away can be reached with reactive routing. Since all nodes proactively store local routing information, route requests can be more efficiently performed without querying all the network nodes. Despite the use of zones, ZRP has a flat view over the network. Nodes belonging to different subnets must send their communication to a subnet that is common to both nodes. This may congest parts of the network. ZRP can be categorized as a flat protocol because the zones overlap. Hence, optimal routes can be detected and network congestion can be reduced. Further, the behavior of ZRP is adaptive. The behavior depends on the current configuration of the network and the behavior of the users. Architecture: The Zone Routing Protocol, as its name implies, is based on the concept of zones. A routing zone is defined for each node separately, and the zones of neighbouring nodes overlap. The routing zone has a r-radius expressed in hops. The zone thus includes the nodes, whose distance from the node in question is at most r-hops. Division Of Computer Science Engineering, SOE, CUSAT
  • 23. Mobile ad hoc networks 17 An example routing zone is shown in Fig 3.6, where the routing zone of S includes the nodes A–I, but not K. In the illustrations, the radius is marked as a circle around the node in question. It should however be noted that the zone is defined in hops, not as a physical distance. The nodes of a zone are divided into peripheral nodes and interior nodes. Peripheral nodes are nodes whose minimum distance to the central node is exactly equal to the zone radius r. The nodes whose minimum distance is less than rare interior nodes, in figure, the nodes A–F are interior nodes, the nodes G–J are peripheral nodes and the node K is outside the routing zone. Note that node H can be reached by two paths, one with length 2 and one with length 3 hops. The node is however within the zone, since the shortest path is less than or equal to the zone radius. Fig 3.6 Zone routing protocol with radius = 2. ZRP refers to the locally proactive routing component as the Intra-zone Routing Protocol (IARP). The globally reactive routing component is named Inter-zone Routing Protocol (IERP). IARP maintains routing information for nodes that are within the routing zone of the node. IERP offer enhanced route discovery and route maintenance services based on local connectivity monitored by IARP. The fact that the topology of the local zone of each node is known can be used to reduce traffic when global route discovery is needed. Instead of broadcasting packets, ZRP uses a concept called border casting. Border casting utilizes the topology information provided by IARP to direct query request to the border of the zone. The Border cast Resolution Protocol (BRP) provides the border cast packet delivery service. In order to detect new neighbor nodes and link failures, the ZRP relies on a Neighbor Discovery Division Of Computer Science Engineering, SOE, CUSAT
  • 24. Mobile ad hoc networks 18 Protocol (NDP) provided by the Media Access Control (MAC) layer. NDP transmits ―HELLO‖ beacons at regular intervals. Upon receiving a beacon, the neighbor table is updated. Neighbors, for which no beacon has been received within a specified time, are removed from the table Route updates are triggered by NDP, which notifies IARP when the neighbor table is updated. IERP uses the routing table of IARP to respond to route queries. IERP forwards queries with BRP. BRP uses the routing table of IARP to guide route queries away from the query source. A node that has a packet to send first checks whether the destination is within its local zone using information provided by IARP. In that case, the packet can be routed proactively. Reactive routing is used if the destination is outside the zone. The reactive routing process is divided into two phases: the route request phase and the route reply phase. In the route request, the source sends a route request packet to its peripheral nodes using BRP. If the receiver of a route request packet knows the destination, it responds by sending a route reply back to the source. Otherwise, it continues the process by border casting the packet. In this way, the route request spreads throughout the network. If a node receives several copies of the same route request, these are considered as redundant and are discarded. The reply is sent by any node that can provide a route to the destination. To be able to send the reply back to the source node, routing information must be accumulated when the request is sent through the network. The information is recorded either in the route request packet, or as next-hop addresses in the nodes along the path. In the first case, the nodes forwarding a route request packet append their address and relevant node/link metrics to the packet. When the packet reaches the destination, the sequence of addresses is reversed and copied to the route reply packet. The sequence is used to forward the reply back to the source. In the second case, the forwarding nodes records routing information as next-hop addresses, which are used when the reply is sent to the source. This approach can save transmission resources, as the request and reply packets are smaller. The source can receive the complete source route to the destination. Alternatively, the nodes along the path to the destination record the next-hop address in their routing table. In the border casting process, the border casting node sends a route request packet to each of its peripheral nodes. This type of one-to-many transmission can be implemented as multicast to reduce resource usage. One approach is to let the source compute the multicast tree and attach Division Of Computer Science Engineering, SOE, CUSAT
  • 25. 19 Mobile ad hoc networks routing instructions to the packet. This is called Root-Directed Border casting (RDB). The zone radius is an important property for the performance of ZRP. If a zone radius of one hop is used, routing is purely reactive and border casting degenerates into flood searching. If the radius approaches infinity, routing is reactive. The selection of radius is a tradeoff between the routing efficiency of proactive routing and the increasing traffic for maintaining the view of the zone. Route maintenance In ZRP, the knowledge of the local topology can be used for route maintenance. Link failures and sub-optimal route segments within one zone can be bypassed. Incoming packets can be directed around the broken link through an active multi-hop path. Similarly, the topology can be used to shorten routes, for example, when two nodes have moved within each other‘s radio coverage. For source-routed packets, a relaying node can determine the closest route to the destination that is also a neighbor. Sometimes, a multi-hop segment can be replaced by a single hop. If next-hop forwarding is used, the nodes can make locally optimal decisions by selecting a shorter path. 3.6 COMPARISON Parameters TABLE DRIVEN ON DEMAND Availability of routing information Available when needed Always available regardless of the need Routing philosophy Flat Mostly flat except CGSR Periodic route updates Not required Required Coping with mobility Use localized route recovery Grows with increasing Inform other nodes to achieve a consistent routing Greater than that of on Signaling traffic generated Tab 3.1 Comparison between table driven and on demand routing protocols Division Of Computer Science Engineering, SOE, CUSAT
  • 26. 20 Mobile ad hoc networks Chapter 4 VEHICULAR AD HOC NETWORK (VANET) A Vehicular Ad-Hoc Network, or VANET, is a technology that uses moving cars as nodes in a network to create a mobile network. VANET turns every participating car into a wireless router or node, allowing cars approximately 100 to 300 metres of each other to connect and, in turn, create a network with a wide range. As cars fall out of the signal range and drop out of the network, other cars can join in, connecting vehicles to one another so that a mobile Internet is created. It is estimated that the first systems that will integrate this technology are police and fire vehicles to communicate with each other for safety purposes. Fig 4.1 Typical vehicular ad hoc network (VANET) Division Of Computer Science Engineering, SOE, CUSAT
  • 27. Mobile ad hoc networks 21 4.1 ARCHITECTURE OF VANET In general, protocol architecture achieves for communication among network nodes and provides the framework for implementation. When designing the communication suit for VANETs two approaches can be taken: First, following the traditional approach, the overall functionality could be de-composed and organized in layers such that at the protocols fulfill small, well-defined tasks and form a protocol stack as in TCP/IP and OSI. Second, one could try to build a customized solution that meets the requirements of VANETs. With such non-layered . The first approach—called layered approach and depicted in Fig. 1 attempts to retain the order of functions and protocol layers with well-defined interfaces between them. It adapts system functionalities to the needs of a VANET communication system resulting, e.g., in protocol layers for single-hop and multi-hop communication. The limitations and inflexibility of traditional network stacks when used in ad hoc networks are well known. E.g., each layer is implemented as an independent module with interfaces (SAPs) only to the above and below layers. Consequently, protocols cannot easily access state or metadata of a protocol on a different layer what makes data aggregation difficult. Moreover, some of VANET-specific functions do not fit into the traditional layered OSI model, such as those for network stability and control, and cannot be uniquely assigned to a certain layer. It is also worth noting that every layer accesses external information separately with no common interface which might lead to problems when this information influences protocol flow. The second un-layered approach would be the result of tailoring a whole new system to the needs of VANETs‘ main focus, i.e., safety applications. Having accurate specifications of these applications and willing to use the ‗probabilistic‘ channel in the most efficient manner leads to have a highly coupled set of protocols. Therefore, all application and communication protocols are placed in one single logical block right over the physical interface and connected to the external sensors (Fig. 2). Inside this block, all protocol elements are modularized such that there are no restrictions for interaction, state information is arbitrary accessible. Note though, that this ‗architecture‘ inherits a high design complexity due to arbitrary and complex interactions of their modules. This makes protocol specification a complicated work and so, once designed becomes an extremely inflexible system for other types of application. Also it would be tough to systematically Division Of Computer Science Engineering, SOE, CUSAT
  • 28. Mobile ad hoc networks 22 avoid control loop, what is rather easy in the layered approach with its clean top-down or bottomup packet traversal. While both approaches would certainly be feasible. Fig 4.2 Layered architecture Fig 4.3 Un-layered architecture 4.2 APPLICATIONS OF VANET There are many applications for vehicular networks. Just name a few important ones: Collision Avoidance – About 21,000 of the 43,000 deaths that occur each year on U.S. highways result from Division Of Computer Science Engineering, SOE, CUSAT
  • 29. Mobile ad hoc networks 23 vehicles leaving the road or travelling unsafely through intersections. Data transmitted from a roadside base station to a vehicle could warn a driver that it‘s not safe to enter an intersection. Communication between vehicles and between vehicles and the roadsides can save many lives and prevent injuries. Some of the worst traffic accidents involve many vehicles rear-ending each other after a single accident at the front of the line suddenly halts traffic. In this application, if a vehicle reduces its speed significantly, it will broadcast its location to its neighbor vehicles. And other receivers will try to relay the message further. And the vehicles behind the vehicle in question will emit some kind of alarm to its drivers and other drivers behind. In this way, more drivers far behind will get an alarm signal before they see the accident. Cooperative Driving – Like violation warning, turn conflict warning, curve warning, lane merging warning etc. These services may greatly reduce the life-endangering accidents. In fact, many of the accidents come from the lack of cooperation between drivers. Given more information about the possible conflicts, we can prevent many accidents. Traffic Optimization – Traffic delays continue to increase, wasting more than a 40-hour workweek for peak time travelers. A significant reduction in these numbers could be achieved through vehicular networks. Vehicles could serve as data collectors and transmit the traffic condition information for the vehicular network. And transportation agencies could utilize this information to actively relieve traffic congestion. To be more specifically, in this application, vehicles could detect if the number of neighboring vehicles is too many and their speed is too slow, and then relay this information to vehicles approaching the location. To make it work better, the information can be relayed by vehicles travelling in the other direction so that it may be propagated faster to the vehicles toward the congestion location. In this way, the vehicles approaching the congestion location will have enough time to choose alternate routes. Vehicles can also collect the data about weather, road surface, construction zones, highway rail intersection, emergency vehicle signal preemption and relay them to other vehicles. Payment Services – Like toll collection. It‘s very convenient and desirable to pass a toll collection without having to decelerate your car, waiting in line, looking for some coins and something like that. Division Of Computer Science Engineering, SOE, CUSAT
  • 30. 24 Mobile ad hoc networks Location-based Services – Like finding the closest fuel station, restaurant, lodge etc. In fact, these kinds of services are not specific to the vehicular networks. Many GPS systems have such kinds of services already. Intelligent vehicular ad hoc networks (InVANETs) use Wi-Fi IEEE 802.11p(WAVE standard)and Wi-MAX IEEE 802.16 for easy and effective communication between vehicles with dynamic mobility. Effective measures such as media communication between vehicles can be enabled as well methods to track automotive vehicles. InVANET is not foreseen to replace current mobile (cellular phone) communication standards. Automotive vehicular information can be viewed on electronic maps using the Internet or specialized software. The advantage of Wi-Fi based navigation system function is that it can effectively locate a vehicle which is inside big campuses like universities, airports, and tunnels. InVANET can be used as part of automotive electronics, which has to identify an optimally minimal path for navigation with minimal traffic intensity. The system can also be used as a city guide to locate and identify landmarks in a new city. Communication capabilities in vehicles are the basis of an envisioned InVANET or intelligent transportation systems (ITS). Vehicles are enabled to communicate among themselves (vehicle-tovehicle, V2V) and via roadside access points (vehicle-to-roadside, V2R). Vehicular communication is expected to contribute to safer and more efficient roads by providing timely information to drivers, and also to make travel more convenient. The integration of V2V and V2R communication is beneficial because V2R provides better service sparse networks and long distance communication, whereas V2V enables direct communication for small to medium distances/areas and at locations where roadside access points are not available. Providing vehicle-to-vehicle and vehicle-to-roadside communication can considerably improve traffic safety and comfort of driving and travelling. For communication in vehicular ad hoc networks, position-based routing has emerged as a promising candidate. For Internet access, Mobile IPv6 is a widely accepted solution to provide session continuity and reachability to the Internet for mobile nodes. While integrated solutions for usage of Mobile IPv6 in (non-vehicular) mobile ad hoc networks exist, a solution has been proposed that, built upon on a Mobile IPv6 proxy-based architecture, selects the optimal communication mode (direct in-vehicle, vehicle-to-vehicle, and vehicle-to-roadside communication) and provides dynamic switching between vehicle-to-vehicle and vehicle-toroadside communication mode during a communication session in case that more than one communication mode is simultaneously available. Division Of Computer Science Engineering, SOE, CUSAT
  • 31. 25 Mobile ad hoc networks Chapter 5 APPLICATIONS OF MANET The field of wireless networking emerges from the integration of personal computing, cellular technology, and the Internet. This is due to the increasing interactions between communication and computing, which is changing information access from "anytime anywhere" into "all the time, everywhere." 1. Tactical networks: military communications and operation, automated battle fields 2. Emergency services: search and rescue operations, disaster recovery, replacement of fixed infrastructure in case of environmental disaster, policing and fire fighting, supporting doctors and nurses in hospitals 3. Commercial and civilian environments: E-commerce, dynamic database access, mobile offices, road or accident guidance, transmission of road and weather conditions, taxi cab network, inter-vehicle networks, sports stadiums, trade fairs, shopping malls, networks of visitors at airports 4. Home and enterprise networking: home/office wireless networking, conferences, meeting rooms, personal area networks, networks at construction sites 5. Education: universities and campus settings, virtual class rooms 6. Entertainment: multiuser games, wirelessP2P networking, outdoor internet access, robotic pets, theme parks 7. Sensor networks: smart sensors and actuators embedded in household electronic devices, body area networks, data tracking of environmental conditions, animal movements, chemical or biological detection 8. Context-aware services: call forwarding, mobile workspace, location-specific services, time dependent services, infotainment touristic information 9. Coverage extension: extending cellular network access, linking up with the internets intranets etc. Division Of Computer Science Engineering, SOE, CUSAT
  • 32. 26 Mobile ad hoc networks Chapter 6 CONCLUSION In conclusion, mobile ad-hoc networks allow the construction of flexible and adaptive networks with no fixed infrastructure. These networks are expected to play an important role in the future wireless generation. Future wireless technology will require highly-adaptive mobile networking technology to effectively manage multi-hop ad-hoc network clusters, which will not only operate autonomously but also will be able to attach at some point to the fixed networks. Division Of Computer Science Engineering, SOE, CUSAT
  • 33. 27 Mobile ad hoc networks Chapter 7 REFERENCE 1. Ad-hoc networks: Fundamental properties and network topologies by Ramin Hekmat 2. Ad hoc networks technologies and protocols by Prasant Mohapatra and Srikanth V. Krishnamurthy 3. Elizabeth M. Royer, Chai-Keong Toh, A Review of Current Routing Protocols for Ad Hoc Mobile Wireless Networks , Proc. IEEE,1999. 4. http://en.wikipedia.org/wiki/Mobile_ad_hoc_network Division Of Computer Science Engineering, SOE, CUSAT