Wireless Adhoc Network - On Demand Routing Protocols

1. Experimental Analysis Of On
Demand Routing Protocol

2. OUTLINE
 INTRODUCTION
 Terminologies
 LITERATURE REVIEW
 PROBLEM STATEMENT
 CONCLUSION
 REFERENCES
2

3. INTRODUCTION
(Terminologies)
3
Multi-Hop: The mobile nodes are cooperating to forward data on behalf of one another to reach distant
stations that would otherwise have been out of range of sending node.[3]
Protocol: Set of rules that governs data communication. Protocol defines what is communicated, how it
is communicated, when it is communicated. Key elements of protocol: syntax, semantics & timing.[5]
Router: Device that forwards data packets along networks; Connected to at least two networks,
commonly LANs or WANs or a LAN and its ISP's network.; Located at gateways, the places where two
or more networks connect.[4]
Hub: It is a multiport repeater to enhance signals within the same LAN.[6]
Switch: It is mostly like hub but it is more intelligent. It gives better performance.[6]
Unicasting: One to one communication.[6]
Multicasting: One to many communication.[6]
Broadcasting: One to all communication occurs.[6]
Network Topology: Refers to the way computers and its peripheral environment is configured:-[6]
Bus topology: All computers are synchronize by a single line of cable.
Star topology: Multiple computers are linked to a main computer, which is called a host
Ring topology: Each computer is connected to two computers with entire network; It Forms a circle.

4. LITERATURE-REVIEW
4

5. LITERATURE-REVIEW(1/2)
5
• Title: “ENERGY OPTIMIZATION IN MANETS
USING ON DEMAND ROUTING PROTOCOL”[1]
Author: K.Sumathia, A.Priyadharshinib
Year of Publication: 2015
• Aim: To implement Adaptive HELLO messaging scheme to determine
the local link connectivity along with the incorporation of Dynamic On
Demand Routing Protocol to reduce the energy consumption of mobile
nodes.
• Keywords: Mobile ad hoc networks; Routing; Hello message; DYMO;
Energy management; On demand routing.

6. LITERATURE-REVIEW(1/2 Cont..)
6
• Introduction Mobile Ad hoc Network (MANET) :
– MANET is a self configuring and infrastructure- less network.
– Each device or node is free to move independently, and will therefore change its
links with other devices frequently in any direction.
– The primary challenge in creating a MANET environment is to continuously
maintain the information required to route the traffic properly.
– Such networks can operate by themselves or by connecting itself to the larger
Internet.
– May contain one or more transceivers. This results in a highly dynamic and
autonomous topology.
– Different protocols are simulated for measuring the packet drop rate, the overhead
introduced by the routing protocol, end-to-end delay of packet, network
throughput, etc.

7. • ADVANTAGE OF GOING TO
MANET:
‾ Business application,
‾ Military application,
‾ Emergency operations,
‾ Home, office, and educational
applications,
‾ VANET,
‾ Wireless sensor networks, mesh
networks, etc
LITERATURE-REVIEW(1/2 Cont..)
Fig. 1: Simple MANET Scenario[1]

8. • ROUTING PROTOCOL IN MANET:
1. PROACTIVE ROUTING PROTOCOL:
• Each node maintains its route to all other network nodes.
• The route creation and maintenance are performed by both periodic and event-driven
messages.
• E.g.: Destination Sequenced Distance Vector (DSDV), Optimized Link State Routing
(OLSR).
2. REACTIVE ROUTING PROTOCOL:
• The route between two node is discovered only when it is demanded.
• Thus message overhead is reduced.
• E.g.: Ad hoc On-Demand Distance Vector (AODV), Dynamic Source Routing (DSR),
Dynamic MANET On-Demand (DYMO).
– HYBRID ROUTING PROTOCOL:
• Combines both proactive and reactive approach.
• E.g. Zone-Based Hierarchical Link-State Routing Protocol (ZRP).
• If the destination node’s position is within the zone of source then it uses proactive
routing else it uses reactive routing protocol.
LITERATURE-REVIEW(1/2 Cont..)

9. • WORKING OF ROUTING PROTOCOL:
1. Route Discovery:
‾ The node begins the route discovery by broadcasting a route request (RREQ)
message containing the IP address of the destination.
‾ The intermediate node rebroadcasts the RREQ or if it has recent information about a
route to the destination, route reply (RREP) message is generated.
‾ This RREP is unicast back to the source using the reverse route.
‾ When a RREP reaches the source, it begins to send data packets to the destination
along the discovered path.
‾ If more than one RREP is received by the source, the route with the lowest hop count
is selected.
2. Route Maintenance:
‾ When a link breaks along an active path, the node upstream detects the
break and creates a route error (RERR) message.
‾ Each intermediate hop deletes any broken routes and forwards the RERR
packet towards the source.
‾ When the source receives this, it determines whether the packet still needs
to be forwarded. If so, it begins the route discovery process for forwarding.
LITERATURE-REVIEW(1/2 Cont..)

10. LITERATURE-REVIEW(1/2 Cont..)
Fig.2 Propagation of RREQ, RREP[1]

11. LITERATURE-REVIEW(1/2 Cont..)
• ENERGY EFFICIENT ROUTING PROTOCOL:
Energy is said to be a limiting factor in case of ad hoc networks.
Routing characteristics in ad-hoc network:
‾ Energy of node is crucial and it depends upon battery which has limited power
supply.
‾ Nodes can move in an uncontrolled manner, so frequent route failures are possible.
‾ Wireless channels have lower and more variable bandwidth compared to wired
network.
Here the efficiency not only refers to the successful delivery of packets with less
consumption of power, but also refers to the increase in duration of maintaining the link
between the nodes to ensure increase in performance.
This can be achieved by using AODV & DYMO routing protocol.

12. LR1-BACKGROUND
• SYSTEM DESIGN AND IMPLEMENTATION:
– In the proposed system, the behavior of packet switching network is simulated
using opnet modeler 14.5.
– This network may consist of four peripheral nodes to generate traffic while a
central hub node that relays the traffic to the appropriate destination.
– The performance of the network is measured by the end-to-end packet delay
experienced by traffic on the network.
– This proposed system consists of following modules:
Creation of nodes,
Defining the packet model, and link model,
Creating the hub model,
Creation of peripheral node model,
Propagation of HELLO packets.

13. • SYSTEM REQUIREMENTS:
– Processor : INTEL PENTIUM III, 4 or compatible (500 MHZ or Better)
– RAM : 256 MB, 512 MB
– Disk space : 400 MB
– Display : 1024×768 or higher resolution, 256or more colors
– Platform : Windows 2000,xp,vista
– Application Development : Opnet modeler 14.5
– OPNET stood for Optimized Network Engineering Tool.
– OPNET Modeler is a software tool for computer network modeling and simulation.
– It offers the fastest discreet event simulation engine when compared with other
networking solutions in the industry.
– It has an open interface for easy integration of libraries, external object files and
other network simulators.
LITERATURE-REVIEW(1/2 Cont..)

14. LITERATURE-REVIEW(1/2 Cont..)
PERFORMANCE EVALUATION:
To examine the effect of the packet generation rate for measuring the performance of the
network, two simulation runs with different packet inter arrival times are to be
considered:
– End to end delay and link utilization is measured.
– Here the source node creates packets of a constant size.
– If the packet inter arrival time is varied, the end-to-end delay will be varied and
will be affected.
– End to end delay is calculated, when packets are transmitted and received.

15. LITERATURE-REVIEW(2/2)
15
• Title: “Optimum Experimental Results of AODV, DSDV &
DSR Routing Protocol in Grid Environment”[2]
Authors: Bal Krishna Saraswat, Manish Bhardwaj, Analp Pathak
Year of Publication: 2015
• Aim: This paper presents the simulation results in order to choose the
highest performing routing protocol. This simulation gives the results for
three ad-hoc routing protocols named DSDV, DSR and AODV.
• Keywords: Mobile grid, DSDV, DSR, AODV, NS-2

16. 16
• INTRODUCTION:
‾ Mobile Grid, in relevance to both Grid and Mobile Computing, has the
additional feature of supporting mobile users and resources in a seamless,
transparent, secure and efficient way.
‾ It has the ability to deploy underlying ad-hoc networks;
‾ Forming arbitrary and unpredictable Mobile Grid enables both the mobility
of the users: requesting access to a fixed Grid and the resources that are
themselves part of the Grid.
LITERATURE-REVIEW(2/2 Cont..)

17. ‾ On-demand routing protocols build and maintain only needed routes to reduce
routing overheads.
‾ E.g.: AODV, DSR, and Temporally Ordered Routing Algorithm (TORA).
‾ Each node in on demand routing does not need periodic route table update
exchange and does not have a full topological view of the network.
‾ Each intermediary computer performs routing by passing along the message to the
next computer;
‾ Part of this process involves analyzing a routing table to determine the best path.
LITERATURE-REVIEW(2/2 Cont..)

18. LITERATURE-REVIEW(2/2 Cont..)
• Ad-hoc On Demand Distance Vector (AODV):
‾ AODV is capable of both unicast and multicast routing.
‾ Forms trees which connect multicast group members.
‾ It is loop-free, self-starting;
‾ Builds routes using a route request / route reply query cycle.
‾ In addition to the source node's IP address, current sequence number, and
broadcast ID, the RREQ also contains the most recent sequence number for the
destination of which the source node is aware.
‾ A node receiving the RREQ may send a RREP if it is either the destination or if it
has a route to the destination with corresponding sequence number greater than or
equal to that contained in the RREQ.
‾ If this is the case, it unicasts a RREP back to the source.
‾ Otherwise, it Re-broadcasts the RREQ.
‾ If nodes receive a RREQ which they have already processed, they discard the
RREQ and do not forward it.
‾ Once the source receives the RREP, it begins to forward packets to the destination.

19. LITERATURE-REVIEW(2/2 Cont..)
• AODV(Cont..):
‾ Consider a set of entities which interact with each other; divided into two classes:
Fig.3: RREQ flooding[2] Fig4: RREP propagation[2]
‾ If a link break occurs while the route is active, the node upstream inform it of the now
unreachable destination(s).
‾ After receiving the RERR, if the source node still desires the route, it can re-initiate
route discovery.

20. • Dynamic Source Routing (DSR):
‾ DSR is a routing protocol for wireless mesh networks.
‾ It is similar to AODV in that it forms a route on-demand when a transmitting
computer requests one.
‾ However, it uses source routing instead of relying on the routing table at each
intermediate device.
‾ The accumulated path information is cached by nodes processing the route discovery
packets.
‾ To accomplish source routing, the routed packets contain the address of each device
the packet will traverse.
‾ Which results in in high overhead for long paths.
‾ To avoid using source routing, DSR optionally defines a Flow-ID that allows packets
to be forwarded on a hop-by hop basis.
‾ It is truly based on source routing whereby all the routing information is maintained
(continually updated) at mobile nodes.
LITERATURE-REVIEW(2/2 Cont..)

21. • DSR(Cont..)
‾ It has only 2 major phases which are Route Discovery and Route Maintenance.
‾ Route Reply would only be generated if the message has reached the intended
destination node.
‾ To return the Route Reply, the destination node must have a route to the source.
‾ If the route is in the Destination Node's route cache, the route would be used.
‾ Otherwise, the node will reverse the route based on the route record in the Route
Reply message header (symmetric links).
‾ In the event of fatal transmission, the Route Maintenance Phase is initiated
whereby the Route Error packets are generated.
‾ The erroneous hop will be removed from the node's route cache, all routes
containing the hop are truncated at that point.
‾ Again, the Route Discovery Phase is initiated to determine the most viable route.
LITERATURE-REVIEW(2/2 Cont..)

22. LITERATURE-REVIEW(2/2 Cont..)
• Destination-Sequenced Distance-Vector Routing (DSDV):
– DSDV is a table-driven routing scheme for ad-hoc mobile networks based on
the Bellman-Ford algorithm.
– It was developed by C. Perkins and P Bhagwat in 1994.
– The main contribution of the algorithm was to solve the Routing Loop
problem.
– Each entry in the routing table contains a sequence number, the sequence
numbers are generally Even if a link is present; else, an Odd number is used.
– Which is generated by the destination.
– Routing information is distributed between nodes by sending full dumps
infrequently and smaller incremental updates more frequently.
– Suitable for creating ad-hoc networks with small number of nodes.
– Whenever the topology of the network changes, a new sequence number is
necessary before the network re-converges;
– Thus, DSDV is not suitable for highly dynamic networks.

23. LR2-METHODOLOGY
• Three techniques for performance evaluation are: Analytical Modeling, Simulation
and Measurement.
• Computer Network Simulator Tools:
– NS-2 interprets the simulation scripts written in OTcl.
– A user has to set the different components (e.g. event scheduler objects, network
components libraries and Setup module libraries) up in the simulation environment.
• Simulation Model:
– NS-2 accepts as input a scenario file that describes the exact motion of each node and the
exact packets originated, together with the exact time at which change in packet origination
is to occur.
– The detailed trace file created by is stored to disk, and analyzed using a variety of scripts,
particularly one called file *.tr that counts the number of packets successfully delivered and
the length of the paths taken by the packets, etc..
– This data is further analyzed with AWK file and Microsoft Excel to produce the graphs.
– The simulation model run under a nominal bit rate of 2 Mbps.
– The experiments use a fixed number of packet sizes (512-bytes) with a changing of pause
times (0s, 100s, 200s , 300s, 400s, 500s, 600s, 700s, 800s, and 900s).
– The simulation used a packet rate of 4 packets per seconds.

24. LR2-METHODOLOGY
• The Simulation Assumptions:
1. For simplicity, all flows in the system are assumed to have the same type of
traffic source. Each sender has constant bit rate (CBR) traffic with the rate of
data: rate/number of stations packet /second;
2. The source node is fixed to 50 nodes with maximum connection is 40 nodes;
3. The implementation of grid and integrate between grid and routing protocols.

25. LR2-PERFORMANCE METRICS
(RESULT & DISCUSSION)
• PDF Result and Analysis:
– Figure below shown at pause time 0 seconds (high mobility) environment;
– AODV outperforms DSDV and DSR in high mobility environment, topology change
rapidly and AODV can adapt to the changes quickly since it only maintain one route that
is actively used.
– DSDV deliver less data packet compare to AODV because in rapid change topology it is
not as adaptive to route changes in updating its table.
– DSR does not have mechanism in knowing which route in the cache is stale, data packet
is forwarded to broken link.
Fig.5: Packet Delivery Fraction vs. Pause Time (simulation time)[2]

26. LR2-PERFORMANCE METRICS
(RESULT & DISCUSSION)
• Average End to End Delay Result and Analysis:
– From the graph would be able to conclude that AODV, since routes are established on
demand and destination sequence numbers are used to find the latest route to the
destination.
– The connection setup delay is less. DSDV, whenever the topology of the network
changes, a new sequence number is necessary before the network re-converges.
– DSR: data packet is forwarded to broken link.
Fig.6: Avg. End to End Delay vs. Pause Time (simulation time)[2]

27. LR2-PERFORMANCE METRICS
(RESULT & DISCUSSION)
• Packet Loss Result and Analysis:
– The graph below, show not much packet loss on AODV side.
– For DSR, show the higher packet loss because the route maintenance mechanism does
not locally repair a broken link.
Fig.7:Packet Loss vs. Pause Time (simulation time)[2]

28. PROBLEM STATEMENT
28
– A single routing protocol is hard to satisfy all requirements. i.e., one
routing protocol cannot be a solution for all energy efficient protocol.
– The On- Demand Routing Protocol - AODV performs predictably.
Delivered virtually all packets at low node mobility, and failing to
converge as node mobility increases.

29. CONCLUSION
29
‾ The proposed scheme may reduce the energy consumption to some extent
and decreases the mean delay, while achieving a good packet delivery ratio.
‾ On-Demand routing protocol AODV performance is the best considering
its ability to maintain connection by periodic exchange of information,
which is required for TCP, based traffic.
‾ DSR was very good at all mobility rates and movement speeds and DSDV
performs almost as well as DSR, but still requires the transmission of many
routing overhead packets. At higher rates of node mobility it’s actually
more expensive than DSR.

30. REFERENCES
30
1. K.Sumathia, A.Priyadharshinib “ENERGY OPTIMIZATION IN MANETS USING ON
DEMAND ROUTING PROTOCOL”, © 2015-Elsevier
2. Bal Krishna Saraswat, Manish Bhardwaj, Analp Pathak “Optimum Experimental Results of
AODV, DSDV & DSR Routing Protocol in Grid Environment”, © 2015-Elsevier
3. http://what-when-how.com/information-science-and-technology/wireless-ad-hoc-networking-
information-science/ [18-04-2016]
4. http://www.webopedia.com/TERM/R/router.html [18-04-2016]
5. http://mguys.blogspot.in/2011/07/computer-networks-interview-questions.html [18-04-2016]
6. http://blog.oureducation.in/basic-networking-questions-answers-pdf/ [18-04-2016]