COPMUTER NETWORKS

Group Members: Asadullah Ilyas – 396 Zain Ul Islam – 407 Fazeel Ashraf – 398 Ali Haider – 392

AODV AND OLSR ROUTING PROTOCOLS

Key Terms

Ad hoc Network: Infra Structure less networks

AODV: Ad hoc On Demand Distance Vector

OLSR: Optimized Link State Routing

Wireless Ad hoc is Dynamically forming a

temporary network

1: COMPARING AODV AND OLSR ROUTING PROTOCOLS

By: Aleksandr Huhtonen (Helsinki University of Technology)

Abstract

Mobile networks creates underlying architecture

for communication without the help of fixed

routers

Hosts have limited transmission range

No fixed router

Each host act as a router

PROBLEM

Challenge for mobile protocols is that they

also have to deal with mobility of hosts.

Hosts can appear and disappear in various

locations.

AD HOC NETWORK ROUTING PROTOCOLS

Ad hoc network routing protocols

Table Driven (Pro-Active): OLSR and  Better

Approach To Mobile Ad hoc Networking

(B.A.T.M.A.N)

On Demand (Reactive): AODV, Admission

Control Enabled On Demand Routing (ACOR),

Dynamic Source Routing and Dynamic Man-NET

on Demand Routing

QUALITIES TO BE EFFECTIVE

Distributed Operation

Loop freedom

Demand based operation

Proactive operation

Security

Sleep period operation

AD HOC ON DEMAND PROTOCOL (AODV)

AODV is a Reactive protocol n Routes are created when needed

Routing table stores information about next hop 2 destination

Route Discovery RREQ message with destination IP and Seq. # is

broadcasted Sequence number prevent looping RREP from desired destination is unicasted RREP-ACK optional RERR in case of route breakage Route repairing

ROUTE REQUEST (RREQ) MESSAGE

ROUTE REPLY (RREP) MESSAGE

AODV ROUTING TABLE

Destination address

Destination sequence number

Hop count

Next hop

Route state (valid, in valid)

Precursor list

ADVANTAGES

Doesn’t need any central administrative system to handle the routing system

Reduce the control traffic messages The AODV has great advantage in overhead

over simple protocols. Using the RRER message AODV reacts

relatively quickly to the topological changes in the network and updating affected host

AODV is a loop free protocol

OPTIMIZED LINK STATE ROUTING (OLSR)

OLSR is a proactive protocol, Routes are always available

Information of the network Topological change causes flooding Control Messages

Hello Messages (one hop count) Topology Control Messages (TC) topology info.

Multipoint Relays (MPR) Neighbor Sensing by Hello Messages MPR Selector Set MPR can only transmit topology information

MPR (MULTI-POINT RELAYS)

The core optimization in OLSR is that of MPR. It’s used to reduce the message exchange

overhead by reducing the number of hosts that broadcast messages in a network.

For efficiency MPR is kept low n only MPR can send throughout messages.

ROUTING TABLE CALCULATION The host maintains the routing table The routing table entries have following

information: i. destination addressii. next address,iii. number of hops to the destination iv. local interface address. The routing table is recalculated if any change

occurs in these sets. For the routes for routing table entry the

shortest path algorithm is used.

ADVANTAGES OLSR doesn’t need any infrastructure The proactive protocol provides that the

protocol has all the information to all the participated hosts.

Flooding is minimized by the MPRs having the drawback of maximum usage of bandwidth

OLSR is best for the networks using larger number of nodes.

AODV AND OLSR ROUTING PROTOCOLS FOR WIRELESS AD-HOC AND MESH NETWORKSANALYSIS & RESULTS

For 50 nodesFor 100 nodes

End to end delay

NETWORK LOAD

THROUGHPUT

For 50 nodes 100 nodes

IMPLEMENTATION AND PERFORMANCES OF AODV AND OLSR

Writers A. Saika M.M.Himmi

Abstract Comparing a reactive and proactive protocol Network Simulator 2 was used Concluded that it depends on several constraints

EXPERIMENT AND RESULTS

There were 4 nodes, two fixed and two mobile.

Measuring area was set to 500 x 500 m2

Time of simulation was 150 seconds Protocols used were:

AODV (for reactive) OLSR (for proactive)

The result of network was a .tr file, used for creating graphs and charts

EXPERIMENT AND RESULTS

EXPERIMENT AND RESULTS

A COMPARATIVE STUDY OF AODV AND OLSR ON THE ORBIT TEST BED ORBIT stands for Open Access Research Test

bed It is an indoor grid based wireless network

emulator consisting of 400 radio nodes. It is a test bed to conduct network based

experiments under conditions that are similar to real life conditions.

EXPERIMENTAL SETUP

Orbit Traffic Generator(OTG) and Orbit Traffic Receiver(OTR) was used to generate TCP and UDP traffic.

20 nodes were created in the experiment. The input load was gradually increased and conducted the experiment for 100 s at each setting to obtain steady.

For each channel rate offered load was increased until saturation.

RESULTS AND CONCLUSION

After saturation OLSR lost stability and showed large variation in throughput.

At high loads the nodes started competing for bandwidth ,causing collisions

AODV performed better in terms of stability. AODV doesn’t allow throughput to increase

beyond saturation.

TCP UDP BASED ANALYSIS OF AODV AND OLSR

Experimental Setup Network simulations are implemented using NS-2

simulator. Each node is then assigned a particular

trajectory . The number of nodes which we take in this is of

about 30. In each simulation scenario, the nodes are

initially located at the center of the simulation.

EXPERIMENTAL SETUP

Data rate of 512 Mbps in UDP and of 1024 Mbps in TCP is used

The nodes start moving after the first 20 seconds.

Constant Bit Rate (CBR) traffic and Internet Protocol (IP) is used as Network layer protocol.

the number of traffic sources was fixed at 20 maximum speed of the nodes was set to

100m /s the pause time was varied as 20, 40 ,60, 80

and 100 seconds.

RESULTS AND CONCLUSION

The AODV protocol will perform better in the networks with static traffic.

It uses fewer resources than OLSR. The AODV protocol can be used in resource

critical environments. The OLSR protocol is more efficient in

networks with high density and highly sporadic traffic.

COMPARISON AND CONCLUSION

AODV performs efficiently in case of low bandwidth

OLSR requires more band width to send TC messages in case of topology change

AODV performs better in case of low mobility In case of high mobility AODV per packet

delay is increased but is more effective in case of throughput as compared to OLSR.

Scalability is limited in case of large network, AODV suffers flooding and OLSR table grows

Remarkable to consider to combine both and have maximum benefit