This document analyzes the performance of different routing protocols in a mobile ad hoc network (MANET) under hybrid traffic conditions. It simulates a MANET with 50 nodes moving at speeds up to 20 m/s using the AODV, DSDV, and DSR routing protocols. Traffic included both constant bit rate and variable bit rate sources. Results found that AODV had lower average end-to-end delay and higher packet delivery ratios than DSDV and DSR as the percentage of variable bit rate traffic increased. AODV also performed comparably under both low and high node mobility scenarios with hybrid traffic.

1. International Journal of Computer Engineering (IJCET), ISSN 0976 – 6367(Print),
International Journal of Computer Engineering and Technology
ISSN 0976 – 6375(Online) Volume 1, Number 2, Sep - Oct (2010), © IAEME
and Technology (IJCET), ISSN 0976 – 6367(Print) IJCET
ISSN 0976 – 6375(Online) Volume 1
Number 2, Sep - Oct (2010), pp. 160-165 ©IAEME
© IAEME, http://www.iaeme.com/ijcet.html
PERFORMANCE ANALYSIS OF MANET ROUTING
PROTOCOL IN PRESENCE OF HYBRID TRAFFIC
Archana Chougule
Sr.Lecturer
Army Institute of Technology Pune
E-Mail: archanachougule2004@gmail.com
Dr.Vijay Wadhai
Professor & Dean of Research
MITSOT, MAE Pune
ABSTRACT:
In this study we tested the average end to end delay and packet loss performance
of Mobile Adhoc network (MANET) under hybrid traffic. Hybrid traffic is tested here
which represent multimedia application. As data and voice are constant bit rate traffic
(CBR) and video is variable bit rate traffic. So traffic used here is combination of variable
bit rate (VBR) and CBR. Performance is compared by increasing vbr traffic sources. So
average end to end delay is less when aodv routing protocol is used under hybrid traffic
case. Also routing protocol aodv shows slightly large packet delivery ratio than other.
Comparison of the protocols is done under different mobility condition with hybrid
traffic.
Keyword: Hybrid traffic, MANET, CBR, VBR
1. INTRODUCTION:
As nodes are mobile in a MANET, links are created and destroyed in an
unpredictable way, which makes quite challenging determination of routes between a pair
of nodes that wants to communicate with each other. In this context large number of
routing protocols have been proposed [2] [8][9].Such routing protocols are classified as
proactive and reactive routing protocols.
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2. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 – 6367(Print),
ISSN 0976 – 6375(Online) Volume 1, Number 2, Sep - Oct (2010), © IAEME
In proactive protocols routing table is updated periodically and reactive protocols
are on demand when source wants to send data to destination then it finds the route.
DSDV is proactive protocol and AODV, DSR are reactive protocol [2][8][7].
In this paper comparison of three routing protocols in MANET in the context of
hybrid traffic is shown. Hybrid traffic represents multimedia application which contains
CBR and also VBR data. As CBR class is commonly used for voice and data services and
VBR used for video. Here VBR video is artificially generated using on-off sources [4].
These sources transmit at fixed rate during on periods and are silent during off period.
The rest of paper is organized as follows:
In section 2 parameters to implement network are explained. Section 3 presents
simulation results and analysis. Where as section 4 gives concluding remarks.
2. PARAMETERS FOR THE NETWORK IMPLEMENTATION
Network considered for simulation consist of 50 nodes that move over an area
500 * 500 m2. The MAC layer protocol considered is 802.11b.The propagation model
used at the physical layer is Two-ray ground propagation. Request to send signal is kept
on at MAC layer. Two important variable parameters are considered in network model
formation, one is node mobility and traffic type.
The node mobility includes the nodes maximum and minimum speeds, speed
pattern and pause time. Speed pattern determines whether node moves with constant
speed or speed is constantly varying. Pause time determines the length of time each node
remains stationary between each period of movement. In this work we have set speed
between 0 to 20 m/s. Pause time takes value as 0 and 20 ms. To complete the model,
number of sources, type of traffic and data rate of traffic is specified. Here traffic is
generated by 20 sources. Traffic generated by these sources is varied as follows
i) All twenty sources generate constant bit rate traffic
ii) 50% sources generate constant bit rate traffic and 50 % sources generate variable
bit rate traffic
iii) 75% sources generate variable bit rate traffic and 25 % sources generate constant bit
rate traffic
iv) All twenty sources generate variable bit rate traffic
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3. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 – 6367(Print),
ISSN 0976 – 6375(Online) Volume 1, Number 2, Sep - Oct (2010), © IAEME
All cbr & vbr traffic has packet size 210 bytes.
3. SIMULATION RESULTS AND ANALYSIS
To evaluate the impact of mobility and traffic on performance of protocol,
simulation is carried out using ns-2.34. Performance of three protocols AODV, DSDV,
DSR is checked under hybrid traffic. Quality of service parameter used to check the
performance of these protocols is average end to end delay and packet delivery ratio.
Three set of experiments are carried out for two different pause time 0, 20 ms. In first set
routing protocol used by each node is AODV and performance parameter are measured
for following traffic:
i) 100% cbr,
ii) 50% vbr +50 % cbr
iii) 75% vbr+25% cbr
iv) 100% vbr.
In second set DSDV routing protocol is used and experiment carried out with
above four data traffic. Third set of experiment carried out in similar way with DSR
protocol.
Average end to end delay:
This parameter is measured in both cases pause time 0 & pause time 20 ms for 20
traffic sources.Figure1 shows average end to end delay for pause time 0.
Under cbr traffic delay provided by dsr protocol is less but as vbr sources increases in the
network average end to end delay due to aodv protocol is less.
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4. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 – 6367(Print),
ISSN 0976 – 6375(Online) Volume 1, Number 2, Sep - Oct (2010), © IAEME
Figure 1 Average end to end delay in pause 0 case
Figure 2 shows the result for pause time 20.Under cbr traffic delay provided by
dsr protocol is less. And as vbr sources increase within network aodv protocol transmits
data with less delay.
Figure 2 Average end to end delay in pause 20 case
With increase in vbr sources in the network, significant increase in delay is observed.
Performance of aodv under high mobility is better than low mobility.
Packet delivery ratio:
It is ratio of total data packet received successfully and total data packet
transmitted. Here how packet delivery ratio varies according to data traffic type for
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5. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 – 6367(Print),
ISSN 0976 – 6375(Online) Volume 1, Number 2, Sep - Oct (2010), © IAEME
particular routing protocol within network is observed and which protocol give better
performance is noted.
Figure 3 shows the packet delivery ratio for pause time 0. Both reactive protocols
gives better packet delivery ratio for cbr traffic but packet delivery ratio due to dsr goes
on decreasing as vbr traffic increases. Aodv gives better packet delivery ratio at high vbr
traffic.
Figure 3 Packet delivery ratio in pause 0 case
By varying the mobility of node simulation is carried out for packet delivery
parameter. Figure 4 shows the result for pause time 20 ms with low mobility.
Figure 4 Packet delivery ratio in pause 20 case
Packet delivery ratio of aodv is high compared to other two protocols in both low
and high mobility case for hybrid traffic.
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6. International Journal of Computer Engineering and Technology (IJCET), ISSN 0976 – 6367(Print),
ISSN 0976 – 6375(Online) Volume 1, Number 2, Sep - Oct (2010), © IAEME
4. CONCLUSION:
In this study we evaluated the performance of MANET using simulations with
constant bit rate traffic and variable bit rate traffic which is artificially generated video.
The result shows the performance of aodv is consistent in both cbr, vbr traffic and also it
is comparable in case of hybrid traffic. Also performance of aodv is comparable in low
and high mobility case with hybrid traffic. Still packet delivery ratio under hybrid traffic
is very less so modification is required in aodv protocol.
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