International Journal of Research In Science & Engineering
Volume: 1 Issue: 1
e-ISSN: 2394-8299
p-ISSN: 2394-8280
Enhanced AODV Protocol for Reliable Routing in Wireless Sensor Networks
Chetan B S1, Roopa Banakar2, Dr. Prashanth C M3
1
Post Graduate Student, Dept of CS&E, SCE Bangalore, India.Email-id:chetanbs90@gmail.com
2
Asst. Prof , Dept of CS&E , SCE Bangalore, India. Email-id:roopabanakar @sapthagiri.edu.in
3
Prof & HOD, Dept of CS&E, SCE Bangalore, India. Email-id: hodcse@sapthagiri.edu.in
ABSTRACT
Improving reliability and energy efficiency is an important consideration in the wireless sensor network. In this
work, we present the Enhanced AODV protocol to increase the resilience to link dynamics for WSNs. This
protocol is designed to enhance existing reactive routing protocols to provide reliable and energy-efficient packet
delivery against the unreliable wireless links by utilizing the local path diversity. The main aim of this protocol is
to introduce a biased backoff scheme during the route-discovery phase to find a robust guide path, which can
provide more cooperative forwarding opportunities. Along this guide path, data packets are greedily progressed
toward the destination through nodes cooperation without utilizing the location information. In the enhanced
AODV even if the node has shorter delay and path is longer then it will give the priority to longer path itself there
Enhanced AODV fails. To overcome this problem introduced a Quadrant Based Approach. In this paper By
enhancing AODV protocol mainly demonstrated its effectiveness and feasibility and also to achieve reliability,
packet delivery ratio, while maintaining high energy efficiency and low delivery latency.
Keywords: Wireless Sensor Networks (WSNs), Cooperative Forwarding, reliable forwarding, unreliable
wireless links, Adhoc Ondemand Distance Vector(AODV).
----------------------------------------------------------------------------------------------------------------------------1. INTRODUCTION
Adhoc On demand Distance Vector Routing (AODV) is the most prominently reactive routing protocol
in wireless sensor networks. This protocol has the ability to detect only the link failure condition in the network.
Link failure conditions are detected by the absence of HELLO messages between the neighbour nodes in the
network [1]. Thus in case of link failure condition in the network the source node again reinitiates the route
discovery phase by flooding the network with Route request packet. Improving reliability and energy efficiency is
an important consideration in the wireless sensor networks (WSNs). This is because, in reality, the link conditions in
wireless networks can be highly unreliable due to many factors such as interference, attenuation, and channel fading.
Due to the limited energy and communication ability of sensor nodes, it seems especially important to design a
routing protocol for WSNs so that sensing data can be transmitted to the receiver effectively.
The sensed data should be reliably and timely transmitted to the sink node, and the programming or
retasking data for sensor node operation, command, and query should be reliably delivered to the target nodes. It is
also required that these networks can operate for years without replacing the device batteries. Therefore, the
reliability, timeliness, and energy efficiency of data forwarding are crucial to ensure proper functioning of an WSN.
Since the varying wireless channel conditions and sensor node failures may cause network topology
and connectivity changes over time, to forward a packet reliably at each hop, it may need multiple retransmissions.
This results in undesirable delay as well as additional energy consumption. Cooperative Forwarding has been
proposed as an effective cross-layering technique to combat fading channels, thus improving the robustness and
energy efficiency in wireless networks. The idea of cooperative forwarding is to take advantage of the broadcast
nature of wireless communication, involving multiple neighbors of the sender into local forwarding. Since the
wireless medium is shared, each node can overhear data packets sent by its neighbors.
IJRISE| www.ijrise.org|editor@ijrise.org
International Journal of Research In Science & Engineering
Volume: 1 Issue: 1
e-ISSN: 2394-8299
p-ISSN: 2394-8280
When the intended receiver fails to receive the packet correctly,those neighbors could deliver
the packet to the downstream node (possibly the intended receiver or the node closer to the destination). The path
with higher spatial diversity (more potential helper nodes) may possibly provide more reliable and efficient packet
delivery against the unreliable links. With this observation, the aim is to find such a reliable virtual path to guide the
packets to be progressed toward the destination. Such a virtual path is called guide path, in which the nodes are
named as guide nodes. In this way, cooperative forwarding improves the transmission reliability, at the same time
avoids the undesirable additional retransmissions[5].The Focus in this project, mainly proposing a Enhanced
AODV protocol which is highly Reliable and Reactive to increase the resilience to link dynamics for WSNs. The
design inherits the advantages of cooperative forwarding, thus achieving shorter end-to-end delivery delay, higher
energy efficiency, and reliability.
1.1 Gaps Identified
All the above routing approaches achieves undesirable delay, not reliable as well as additional energy
consumption and also in WSN’s transmission failures can also result in missing or delaying of process.
1.2 proposed system
An Enhanced AODV protocol is designed to increase the resilience to link dynamics for WSNs. The
proposed design inherits the advantages of cooperative forwarding, thus achieving shorter end-to-end delivery
delay, higher energy efficiency, and reliability.
2. LITERATURE SURVEY
Routing protocols can be classified according to various approaches which are as follows:
A. Proactive Routing
Proactive protocols continuously evaluates the routes within the network so that when we are required to
forward the packet route is already known and immediately ready for use.
B. Reactive routing
The main idea behind this type of routing is to find a route between a source and destination whenever that
route is needed whereas in proactive protocols we were maintaining all routes without regarding its state of use.
C. Hybrid Routing
In hybrid routing a combination of proactive and reactive routing methods are used which are better than
the both used in isolation. It includes the advantages of both protocols.
Perkins and Bhagvat “Destination Sequenced Distance Vector routing (DSDV)” [1] proposed first
protocol for wireless networks. This protocol maintain the global topology information in form of tables at every
node. These tables are updated frequently in order to maintain consistent and accurate network state information. In
this protocol each node maintain a table that contains the shortest distance and the first node on the shortest path to
every other node in the network.It incorporates the table updates with increasing sequence number tags to prevent
loops to counter the count to infinity problem and for faster convergence. As it is table driven routing protocol
routes to destination are readily available at every node at all times.
Perkins and Royer “Ad-hoc on-demand distance vector routing(AODV)”[2] proposed that a route is
established only when it is required by a source node for transmitting data packets. In AODV, the source node and
intermediate nodes store the next-hop information corresponding to each flow for data packet transmission. The
major difference between AODV and other on-demand routing protocol is that it uses a destination sequence
number ( DestSeqNum) to determine an up-to-date path to the destination.A node updates its path information only
if the DestSeqNum of the current packet received is greater than the last DestSeqNum stored at the node. AODV
utilizes routing tables to store routing information. If a node wants to send a packet to some destination. At first, it
checks its routing table to determine whether it has a current route to the destination or not. If yes, it forwards the
packet to next hop node of the route. If no, it initiates a route discovery process. It begins with the creation of a
RouteRequest (RREQ) packet.
IJRISE| www.ijrise.org|editor@ijrise.org
International Journal of Research In Science & Engineering
Volume: 1 Issue: 1
e-ISSN: 2394-8299
p-ISSN: 2394-8280
D. B. Johnson and D. A. Maltz, “Dynamic source Routing protocol (DSR)”[3] designed to restrict the
bandwidth consumed by control packets in ad hoc wireless networks by eliminating the periodic table-update
messages required in the table-driven approach. The major difference between DSR and other on demand routing
protocols is beaconless and hence does not require periodic hello packet(beacon) transmission,which are used by a
node to inform its neighbours of its presence. The basic approach of this protocol during the route construction
phase is to establish a route by flooding Route Request packets in the network. The destination node on receiving a
Route Request packet,responds by sending a Route Reply packet back to source which carries the route traversed by
the Route Request packet received.
X. Mao, S. Tang, X. Xu, Li X.-Y, and H. Ma, “Zone Routing Protocol (ZRP)”[4] proposed hybrid
routing protocol which effectively combines the best features of both proactive and reactive routing protocols. The
key concept employed in ZRP is to use a proactive routing scheme within a limited zone in the γ-hop neighborhood
of every node, and use a reactive routing scheme for nodes beyond this zone. An Intra-zone routing protocol(IARP)
is used in the zone where a particular node employs proactive routing. The reactive routing protocol used beyond
this zone is referred to as interzone routing protocol(IERP). The routing zone of a given node is a subset of the
network within which all nodes are reachable within less than or equal to zone radius hops
3. METHODOLOGY
The Reliable routing can be achieved from the following three main modules namely,
1.Reliable Route discovery
2.Potential Forwarder selection and prioritization
3.Forwarding decision module
3.1 Architecture
Figure 1 shows the system architecture for Reliable Routing in Wireless Sensor Networks.
1. Reliable Route Discovery Module:
This module is responsible for finding and maintaining the route information for each node. During
the route discovery phase, each node involved in the cooperative forwarding process stores the downstream
neighborhood information, that is to say, when a node serves as a forwarder, it already knows the next-hop
forwarding candidates along the discovered path.
The other two modules are responsible for the runtime forwarding phase
2. Forwarding Decision Module:
When a node successfully receives a data packet, this module checks whether it is one of the intended
receivers. If yes, this node will cache the incoming packet and start a backoff timer to return an ACK message,
where the timer value is related with its ranking in the intended receiver list (called forwarding candidate list).
3. Potential Forwarder Selection and Prioritization Module:
This module is responsible for attaching the ordered forwarder list in the data packet header for the next
hop. Finally, the outgoing packet will be submitted to the MAC layer and forwarded towards the destination.
Neibour
Selection
Module
Timer Based
Data
Forwarder
Helper Node
Routing
Manager
Data
Forwarder
Module
Reactive
Route Dection
Module
Figure 1 System Architecture
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International Journal of Research In Science & Engineering
Volume: 1 Issue: 1
e-ISSN: 2394-8299
p-ISSN: 2394-8280
3.2 Algorithm
Let Vi and Vj denote the last-hop node and current forwarding node of an RREQ, respectively.and CN(i,j)
denote the common neighbor set between Vi and Vj. Then define a helper Vk between Vi and Vj as the common
neighbor of Vi and Vj, satisfying pij where pij is the packet Reception Ratio (PRR) between Vi and Vj. Let H(i,j)
denote the set of helpers between Vi and Vj.
Before receiving the RREQ from source node it checks for two things.
Step 1:
Step 2:
Step 3:
if Non-duplicate RREQ then
if Vj is the destination node then
Send out RREP;
else
CN(i,j)=N(i) ∩ N(j)
Sort CN(i,j) decendingly ordered by pij
H(i,j)={cn1},CN(i,j)=CN(i,j)-{cn1};
while CN(i,j)≠ᴓ do
if Check Connectivity(H(i,j),cn1) then
H(i,j)=H(i,j) Ủ {cn1};
end
CN(i,j)=CN(i,j)-cn1;
end
4. RESULTS
Figure 3 shows the snapshot of selecting source and destination.
Figure 3 snapshot of selecting source and destination.
Figure 4 shows the snapshot of initating the route request from source and destination.
Figure4 snapshot of path from source to destination
IJRISE| www.ijrise.org|editor@ijrise.org
International Journal of Research In Science & Engineering
Volume: 1 Issue: 1
e-ISSN: 2394-8299
p-ISSN: 2394-8280
The comparision between AODV and Enhanced AODV for Packet Delivery ratio(PDR) and delay as shown in
below Table 1
Table 1 comparision between AODV and Enhanced AODV
Figure 7 and 8 shows the graph for comparision between AODV and Enhanced AODV for packet delivery
ratio(PDR) and delay.
Figure 7 packet delivery ratio comparision
Figure 8 End-to-End delay comparision
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International Journal of Research In Science & Engineering
Volume: 1 Issue: 1
e-ISSN: 2394-8299
p-ISSN: 2394-8280
6. CONCLUSION
It has been observed that most of the existing methods achieves undesirable delay In this project
mainly presented Enhanced AODV, which can augment most existing reactive routing protocols in WSNs to
provide reliable and energy-efficient packet delivery against the unreliable wireless links. By introducing a biased
backoff scheme in the route discovery phase to find a robust virtual path with low overhead. Without utilizing the
location information, data packets can still be greedily progressed toward the destination along the virtual path. In
the enhanced AODV even if the node has shorter delay and path is longer then it will give the priority to longer path
itself there Enhanced AODV fails. To overcome this problem introduced a Quadrant Based Approach. By enhancing
AODV mainly demonstrated its effectiveness and feasibility. Simulation results showed that, as compared with
other protocols, Enhanced AODV can effectively improve Packet Delivery Ratio(PDR), end-to-end delay and
reliability.
ACKNOWLEDGEMENT
I am thankful to Mrs. “Roopa Banakar” for her valuable advice and support extended to us without
which we could not has been able to complete our paper and I express deep thanks to Dr. Prashanth C M, Head of
Department (CS&E) for warm hospitality and affection towards me. And I thank the anonymous referees for their
reviews that significantly improved the presentation of this paper. I take this opportunity to express my sincere
thanks to all staff members of CS&E department of SCE for the valuable suggestion.
REFERENCES
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[3] D. B. Johnson and D. A. Maltz, “Dynamic source routing in ad hoc wireless networks,” Mobile Computing, pp.
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[4] X. Mao, S. Tang, X. Xu, Li X.-Y, and H. Ma, “Zone Routing Protocol (ZRP)”, Computer Commun., vol. 33, no.
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