Computer networks comparison of aodv and olsr in ad hoc networks
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Transcript of Computer networks comparison of aodv and olsr in ad hoc networks
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