Abstract- Delay Tolerant Network (DTN) in routing concerns itself with the ability to route data from source to destination which is the fundamental ability all communication network must have. During the transmission of packets it has the fixed landmark so that only one path can be chosen. It cannot choose the alternative path, that path is considered to be as the best path. To solve this problem, an optimized inter – landmark data routing algorithm, namely DTN – FLOW which chooses the alternative path that is considered to be as the shortest and best path. The DTN – FLOW algorithm not only transmit packet with the use of landmark and inter – landmark. The information message will be performed in all the nodes so the performance of each and every node decreases by means of traffic. In order to increase the high throughput, node to node communication can be done effectively in DTN network.

1. Optimized Inter – Landmark by DTN – FLOW
Algorithm
Abstract- Delay Tolerant Network (DTN) in routing concerns itself with the ability to route data from source to destination
which is the fundamental ability all communication network must have. During the transmission of packets it has the fixed
landmark so that only one path can be chosen. It cannot choose the alternative path, that path is considered to be as the best path.
To solve this problem, an optimized inter – landmark data routing algorithm, namely DTN – FLOW which chooses the
alternative path that is considered to be as the shortest and best path. The DTN – FLOW algorithm not only transmit packet
with the use of landmark and inter – landmark. The information message will be performed in all the nodes so the performance
of each and every node decreases by means of traffic. In order to increase the high throughput, node to node communication can
be done effectively in DTN network.
Index Terms – Delay Tolerant Network (DTN), robustness, intermittent, throughput, Ad hoc On – Demand Distance Vector (AODV).
—————————  ——————————
1 INTRODUCTION
elay-tolerant network (DTN) is an approach to computer
network architecture that seeks to address the technical
issues in heterogeneous networks that may lack continuous
network connectivity. DTN support interoperability of regional
networks by accommodating long delays between and within
regional networks and by translating between regional network
communications characteristics. In providing these functions,
DTNs accommodate the mobility and limited power of evolving
wireless communication devices. DTN has the great potential to
connecting devices and regions of the world that are presented
under served by current networks. Challenge for DTN is to
determine the router through the network without having an end
to end or knowing which routers can be connected at any instance
of time.
DTN is a set of protocols that act together to enable a
standardized method of performing store – carry – and – forward
communications featured by intermittent connection and frequent
network partition [9]. Thus, DTN routing is usually realized in a
carry-store-forward manner. In those areas they exchange data
among or collect data from different areas because DTNs usually
exist in areas without infrastructure networks and thereby are
good mediums to realize data communication among these areas.
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State – of - art DTN routing algorithm exploit either past
encounter records, social network properties or past moving paths
to deduce a nodes probability of reaching a certain node or area,
and forward packets to nodes with higher probability than the
current packet holder [8]. The number of nodes with high
probability of visiting the destination usually is limited, by only
relying on such nodes, previous routing algorithms fail to fully
utilize all node movements leading to degraded overall
throughput.
An inter-landmark data flow routing algorithm, called DTN-
FLOW, which fully utilizes all node movements in DTN by
assuming that there is a popular place in each of the nine
subareas. DTN-FLOW then determines landmarks from these
popular places and adopts the same subarea division. Each
subarea is represented by one landmark. Each landmark is
configured with a central station, which is an additional
infrastructure with high processing and storage capacity. Then,
node movement can be regarded as transits from one landmark to
another landmark. The most sophisticated trackers currently
commercially – available use Global Positioning Systems (GPS)
to track position and use satellite uploads to transfer data to a
base station [10]. DTN- FLOW utilizes such transits to forward
packets from one landmark to other landmark to reach their
destination areas. Nodes transiting between landmarks relay
packets, even though they rarely visit the destination of the
relayed packets.
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G. Shoba1
R. Maheswari2
Senior Assistant Professor, CSE, Final Year M.Tech, CSE,
Christ College of Engg. & Tech,
Puducherry.
Christ College of Engg. & Tech,
Puducherry.
shoba@christcet.edu.in mahi.it04@gmail.com
D

2. 2 ROUTING PROTOCOLS IN DELAY TOLERANT
NETWORK
Routing in Delay Tolerant Network (DTN) concerns itself with the
ability to transport or route data from a source to destination which is
the fundamental ability communication networks must have. DTN
are characterized by their lack of connectivity, resulting in a lack of
instantaneous end – to – end paths. Whenever a packet is to be
transmitted from source to a destination via number of other nodes,
routing protocol is required which is responsible for finding routes to
a particular destination and delivering packets to it. These routing
protocols are broadly divided into three main categories:
2.1 Epidemic Routing
If a route to a node is unavailable then the node performs a
controlled local broadcast to its immediate neighbors. In the relaying
mode, the MRP first checks with the routing protocols to see if a
route of less than d hops exists to forwarding packet [1]. If so, it
forwards the packet and the packet is delivered. If no valid route
exists for the packets, it enters the storage phase, until it has a route
to the destination. To limit the amount of broadcasting to all its
neighbors, the spraying protocol restricts forwarding to a ray in the
vicinity of the destination last known location. A sprayed packet is
first unicast to a node close to the destination, and then multicast to
multiple nodes around the destination. The magnitude of the
spraying depends on the mobility and larger vicinity. When the
message arrives at an intermediate node, the node floods the message
to all its neighbors. Epidemic routing represents a node that receives
packet for the first time
2.2 Deterministic Routing
A tree is built from the source host by adding children nodes and the
time associated with nodes. Each node records all the previous nodes
the messages has to travel and the earliest time to reach it. A final
path can be selected from the tree by choosing the earliest time to
reach the desired destination. Deterministic routing assumes that
characteristic profiles are initially unknown to hosts. Hosts gain this
information through learning the future by letting neighbor hosts
exchange the characteristic profiles available between them.
2.3 Geographic Routing
In geographic routing, next hop for a packet is decided according to
the location of destination and topology near the current packet
holder. The local knowledge finds the optimal behavior for current
holder. An obvious tradeoff exists between transportation cost and
packet delivery delay
2.4 Dynamic Source Routing
When source node wants to send a packet to destination node but
does not know a route to destination, source node initiates a route
discovery [3]. The source node floods the route request. Each node
appends own identifier when forwarding route request. Destination
on receiving the first route request sends a route reply.
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Route reply is sent on a route obtained by reversing the route
appended to receive route request. Route reply includes the route
from source to destination on which route request was received by
destination node. The source node on receiving the route reply,
caches the route included in the route reply. When source node sends
a data packet to destination, the entire route is included in the packet
header. Intermediate nodes use the source route included in a packet
to determine to whom a packed should be forwarded. Route caching
reduces the cost of route discovery. A single route discovery may
yield many routes to the destination, due to intermediate nodes may
reply route request from local caches.
3 AD HOC ON – DEMAND DISTANCE VECTOR
(AODV) ROUTING PROTOCOL
The AODV protocol is only used when two endpoints do not have a
valid active route to each other. Nodes contain the IP address for
each of its neighbors that are likely to use it for a next hop in their
routing table. Route table information must be kept for all routes
even short – lived routes. AODV enables dynamic, self – starting,
multi – hop routing between mobile nodes wishing to establish and
maintain an ad hoc network [5]. AODV allows for the construction
of routes to specific destinations and does not require that nodes
keep these routes when they are not in active communication.
AODV protocol is designed for mobile ad hoc networks of ten to
thousands of nodes. The protocol was also designed to work in a
network where all the nodes trust each other.
AODV belongs to the class of Distance Vector Routing Protocols
(DV). In a DV every node knows its neighbors and the costs to reach
them. Every node checks if there is a useful route to another node
using this neighbor as next hop. When a link breaks a count – to –
infinity could happen. AODV is the routing protocol with small
delay which means that the routes are only established when needed
to reduce traffic overhead. The count - to – infinity and loop problem
is solved using sequence number and the registration of the costs.
The routes age quickly transmit in order to accommodate the
movement of the mobile nodes. Links breakage can locally be
repaired very efficiently. To characterize the AODV with the criteria
used by AODV is distributed based on hop – by – hop. AODV uses
IP in a special way that treats an IP address just as a unique
identifier. Only one router is responsible to operate the AODV for
the whole subnet as a default gateway by maintaining a sequence
number for the whole subnet and to forward every package. In
AODV the routing table is expanded by a sequence number to every
destination and by time to live for every entry.
AODV generates the route using the two types of protocol namely
proactive and reactive protocol.
3.1 Proactive Protocol
Proactive routing is a traditional distributed shortest – path protocol
which is based on periodic updates and high routing overhead.
AODV is like all reactive protocols in which the topology
information is only transmitted by nodes on – demand. When a node
transmits traffic to a host to which it has no route by generating a
route request message that will be flooded in a limited way to other
nodes.
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3. This causes control traffic overhead to be dynamic by resulting in an
initial delay when initiating such communication. When the route
becomes invalid, AODV again sends a request.
3.2 Reactive Protocol
Reduction in routing overhead is useful when number of traffic
sessions is much lower than the number of nodes. No routing
structure is creased based on a priori. The two key methods for route
discovery are source routing and backward learning. Reactive
routing eliminates the periodic updates which are adaptive to
network dynamics. The mobility and distributed traffic are based on
the high flood – search overhead and high route acquisition latency.
4 HYBRID ROUTING ALGORITHMS IN DTN – FLOW
4.1 DTN – FLOW Algorithm
In DTN – FLOW algorithm during the transmission each and every
landmark finds the new inter – landmark for a individual path. In
order to increase the throughput each and every landmark has a
individual path so traffic cannot be reduced by forcing the landmark.
For each and every transmission there is some fixed path. If the
destination node is moving from one location to another location
requires a new path. There are more number of landmarks for a
single path so the communication cost is high. In DTN – FLOW
algorithm, Ad hoc On – Demand Distance Vector (AODV) routing
technique is used to enhance the node to node communication for
effective throughput.
4.2 PROPHET Algorithm
In PROPHET algorithm if the intermediate node is busy it goes to
the previous node and finds the next landmark which is considered
as the inter – landmark and reaches the destination [2]. In this
technique, all the node mobility can be better utilized to realize
efficient data forwarding among different areas in DTN. In order to
produce the optimized inter – landmark all the nodes can be used in
all mobility nodes. The overall performance can be increased by
increasing the N number of dynamic paths so the number of
landmarks and the cost is limited.
Delivery ratio transfers messages that the encounter doesn’t have the
very high message overhead. Limits the number of message copies
L: max # of message copies. Probabilistic routing protocol uses
delivery predictability.
Overhead ratio controls the # of message relays with the region and
node information. A source creates the limit of # message relays for
known regions.
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All the nodes are having the handover acknowledgement. Only half
of the acknowledgement is contacted to intra region node for current
region id. The acknowledgement for other region is contacted to the
first node which goes for that region where it creates the
acknowledgement for newly found region.
5 SYSTEM DESIGN
This System mechanism explains that all senders such as base
station, landmark, receiver and information are connected by the
interface session. The interface session is the communication layer
those are Transport Control Protocol layers (TCP). Throughput
analysis is the block where the implementation of node to node
communication of each and every node forms a complete analyzing
report. In view report session can modify can parameter in analyzing
session such as creating a new path, deleting the intermediate nodes
and giving dynamic path to base station. In the database session
finally say the analyzed data into base station or network database
used is SQL 2008 as a virtual database.
Fig. 1 System Architecture
6 METHODOLOGIES
6.1 Network Formation
If you are the new user going to access the network then they have
to register first by providing necessary details. After successful
completion of sign up process, the user has to login into the
application by providing username and exact password. The user
has to provide exact username and password which was provided
at the time of registration, if login success means it will take up to
main page else it will remain in the login page itself.
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messages)createdallof(#
n)destinatiothetomessagesdeliveredof(#
ratioDelivery 
messages)createdallof(#
messages)deliveredof(#-messages)relayedof(#
ratioOverhead 

4. 6.2 Base Station
If you are authenticated successfully, get the permission to access
into the DTN network to form as a new client. During the
transmission of messages the sender authenticator checks all the
node movements to find the path and performance. The path and
performance of the node movements are calculated by the
intermediate and receiver. The base station appoints a receive node
along with the landmark and inter-landmark and selects the file to
send. In the view report the acknowledgment is been checked
whether the file has been reached.
6.3 Landmark and inter – landmark approval
Intermediator has to wait for receive file and store the file into the
database. The database checks the receiver’s performances and
forwards the particular file when file status is pending. Each and
every landmark receives the file and forwards the file to next
landmark by storing their status of the bandwidth and throughput
level. The database verifies the best landmark and inter-landmark
for forwarding the packets to next landmark.
6.4 Message Recall
The receiver authentication receivers the message from the base
station and sends back the status of the complete path by analyzing.
The receiver can wait for intermediate request and the receiver can
receive the file. Store the file to his location. Any receiver node
can receive the message and send the acknowledgement of
bandwidth and throughput on its own part.
6.5 Analyzing Path
Analyzing path is just used to study in detail of transmission nodes
like landmark and inter-landmark. The destination node with the
mean of Dartmouth Campus Trace (DART) and Diesel AP Trace
(DNET) traces finalize the best path by estimating the bandwidth and
throughput. Sender has to view the report when file has sent. Report
viewer has bandwidth, sender details and throughput analysis for
further file to send.
7 CONCLUSION
In this paper, we proposed the DTN- FLOW algorithm to transfer
data among landmarks with high throughput in DTN with the Ad hoc
On Demand Distance Vector (AODV) technique. AODV technique
makes the better shortest path with high reliability inter – landmark
by maximizing the throughput in DTN. DTN frames the data packet
with high robustness. In the future, by studying the node to node
communication we can make strong and better DTN network.
IJTET©2015
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