T HE I MPACT OF TCP C ONGESTION W INDOW S IZE ON THE P ERFORMANCE E VALUATION OF M OBILE A D H OC (MANET) R OUTING P ROTOCOLS

International Journal of Wireless & Mobile Networks (IJWMN) Vol. 7, No. 2, April 2015
DOI : 10.5121/ijwmn.2015.7203 29
THE IMPACT OF TCP CONGESTION WINDOW SIZE
ON THE PERFORMANCE EVALUATION OF MOBILE
AD HOC (MANET) ROUTING PROTOCOLS
Nihad I. Abbas1
, Emre Ozen2
and Mustafa Ilkan3
1
Department of Computer Engineering, Eastern Mediterranean University, Famagusta,
N.Cyprus
2
School of Computing and Technology, Eastern Mediterranean University, Famagusta,
N.Cyprus
3
School of Computing and Technology, Eastern Mediterranean University,
Famagusta, N.Cyprus
ABSTRACT
A mobile ad hoc network (MANET) is a temporary collection of mobile nodes randomly moved within a
limited terrain area. The nodes are connected to form a wireless network without use any communication
infrastructure. Because of the limiting resources of MANET nodes, multiple hops scheme is proposed for
data exchange across the network. Varieties of mobile ad hoc routing protocols have been developed to
support the multi-hop scheme of ad hoc networks. A popular Transmission Control Protocol (TCP)
provides a reliable connection in a computer network environment; it sets its congestion window size in
response to the behavior of the network to achieve the best performance. This work aims to investigate and
compare the MANET protocol performance, such as DSDV, AODV and DSR in terms of network
throughput, average routing load, the packet delivery ratio (PDR), and average end-to-end delay by
varying the maximum congestion window size. Our simulation has been implemented using a well-known
NS-2.35 network simulator. The simulated results show that the demonstrates of the concepts of MANET
routing protocols with respect to TCP congestion window size in MANET environment.
KEYWORDS
MANET, Routing Protocols, DSR, DSDV, AODV, Window size, NS 2.
1. INTRODUCTION
Mobile ad hoc Network (MANET) has received considerable attention over the past few years’
decades. The rapid deployment of wireless mobile networks in many emergency cases, such as
disaster areas, search and rescue operations, and battlefield operations make these types of
networks more attractive, where there is a little or no time available to build a service
communication infrastructure. MANET is an infrastructure less wireless communication network
with different mobile types. The nodes in MANET can connect and interact with each other via
wireless multi-hop scheme to preserve node’s energy and prolong the network lifetime [1]. The
nodes in a mobile ad hoc network may act as a router, which forwards the data information to the
neighbors in the network. Unfortunately, route failures in MANET are frequently occurring in

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many cases due to the node’s mobility, free movement of nodes in any speed and direction within
the network. For that reason, therefore, an efficient routing protocol is needed to reconnect the
broken routes. A number of protocols have been proposed for MANET networks such as: DSDV
(Destination-Sequenced Distance Vector), DSR (Dynamic Source Routing), and AODV (Ad-Hoc
On Demand Distance Vector).
Transport Control Protocol (TCP) is the most predominant protocol utilized in the Transport
Layer of wired and wireless network environments. It is widely used to achieve a reliable
transmission over the internet world. There have been several attempts to improve TCP
performance since its introducing in 1981. Congestion control and avoidance techniques are the
two important concepts proposed by Jacobson. In order to control the amount of packets sends by
a sender, the sender changes its TCP congestion window size according to the network
environments. TCP congestion window size (cwnd) increases exponentially up to the receiver’s
maximum window size. The TCP window size of the sender’s node remains at a constant size and
equals the maximum size unless the receiver’s advertised window, reaches to a constant size
during the transmission period [2]. In this study, we simulate and observe the effect of the
maximum window size changes in the popular wireless routing protocol performance.
Comparing the evaluation results to estimate the optimum value of maximum window size that
could be used for specific environment for each protocol simulated in this study. The organized of
the rest of this paper would be as follows: Section 2, explain the overview of MANET Routing
Protocols. Section 3, provides the transport control protocol (TCP). Section 4, summarize the
related research works. The simulation environment, the simulation results and the conclusions
drawn from this work are presented in sections 5, 6 and 7 respectively.
2.OVERVIEW OF MANET ROUTING PROTOCOLS
The routing protocol consists of the procedural steps that need to be obeyed by the MANET
nodes to successfully transfer source information packets to the destination node. The routing
protocol should be able to automatically establish the route with a limited period of time and
without any intervention. The nodes in MANET are self-organizing in distributed form behavior.
The route establishment is essential to perform the routing process properly. MANET routing
protocols can be categorized into [3, 4]:
• Table driven routing protocols (proactive protocols).
• On-demand routing protocols (Reactive protocols).
• Hybrid routing protocols.
Some of popular routing protocols adopted by MANET networks are described below:
2.1. Destination - Sequenced Distance Vector (DSDV) Protocol
The DSDV routing protocol is one of a proactive protocols based on the Routing Information
Protocol (RIP). The MANET nodes store a table of the number of hops to each destination and all
routes valid to the destinations in the network. DSDV uses bi-directional links and provides just
one route for source-destination pairs; it also updates periodically the broadcast routing table.
Each node keeps a listing of route table indicating the next hop to a pre-determined destination.
DSDV protocol generates a unique sequence number tag with each route in the MANET and uses

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the most favorable one with the lowest metric. All nodes in the network, advertise, monotonically
incrementing their sequence number. When an established route between nodes (S) to node (D) in
the network has broken anytime, it advertises an infinite metric to the route to (D) by increasing
the sequence number by one. So that if the node (A) forwarded data through node (B)
incorporates an infinite-metric route into its routing table until the node (A) recovers a route to
node (D) with a higher sequence number. Each table entry in DSDV protocol has a sequence
number that is incremented upon each updated packet sending. In addition, the routing tables in
DSDV are periodically updated each time the network topology is changed. The updated tables
are broadcast throughout the network to retain consistent updated information. MANET nodes
keep one routing table for forwarding the data packet, and another table for advertising
incremental routing packets. The information of routing sent periodically includes: destination
address, new sequence number, hop count to destination, and the destination sequence number.
Any node in network that detects network topology changes will send an updated packet to all
neighboring nodes [5].
2.2.Ad-hoc On Demand Distance Vector (AODV) Protocol
AODV is one of the most popular reactive MANET routing protocols in the research
environment. The AODV routing protocol supports multicast besides a unicast routing. It uses an
on-demand scheme to discover the best route valid to the destination. Moreover, the protocol uses
a sequence number to recognize the most updated path to guarantee the freshness routes to the
destination. Also, AODV is one of the reactive protocols that exploits minimum control traffic
overhead signals in detecting new routes. It periodically broadcasts a (HELLO) packet to inform
the neighbors in the network that the link is still active. Whenever a source node in MANET
wishes to transmit data to another node, the source broadcasts a Route Request (RREQ) packet
throughout the network. The source node waits a predefined period of time for an acknowledged
a reply to its route requested packet. If a Route Reply (RREP) packet does not received, then the
source retransmits a new RREQ. After a neighbor node receives a (RREQ) packet, it generates a
(RREP) packet to notify the source node that the node is the destination or it has a route to the
destination else it rebroadcasts the (RREQ) packet. The route validity is approved by comparing
the sequence number of the intermediate node with the destination sequence number of the Route
Request packet. Once the source receives a (RREP) packet, it stores the information on this route
and starts sending data information to the destination. However, if the source receives multiple
(RREP) packets, the shortest hop count route will be selected. In cases of network link failure
occurs any time, a packet of Route Error (RERR) is created and returned back to the originator
node that will initiate a route discovery process again if more data available to send and the route
is still needed [6].
2.3. Dynamic Source Routing (DSR) Protocol
DSR uses a source routing algorithm. In this algorithm, all header packets routed in the network
carry the complete list of nodes addresses through which the packets must pass. The intermediate
nodes in the network do not need to retain updated routing information to forward data packets,
because the packets themselves previously include all information of routing decisions to the
destinations. For that reason, the DSR protocol avoids the needing of a repeating route
advertisement. DSR protocol applies two operation phases in its routing process scheme:

32
1- Route Discovery phase
2- Route Maintenance phase.
The initiation of a Route Discovery process phase is occurring when the source node has a data
packet to send, then it will try to send its packets to a destination node in the network. At the
beginning, the source node broadcasts a ROUTE REQUEST (RREQ) packet through the
network, and then it waits the reply that will be either by the destination node or by the
intermediate node which has a route to the destination. In order to minimize the Route Discovery
cost, each node in the network keeps a cache table of source routes it has collected previously and
it uses to limit the number of RREQs packet propagation repeatedly. The Route Maintenance
process starts when the source node detects any changes occurring or which have occurred in the
MANET network topology. When a route breakage is discovered by the source node, and which
is informed by a ROUTE ERROR packet. The source will attempt to use any already exist route
stored in its cache or it explore a new route by recalling the Route Discovery process again to find
a new route [7].
3.TRANSPORT CONTROL PROTOCOL (TCP)
TCP [8, 9], is the traditional internet transport protocol, uses a congestion window size (cwnd) for
controlling the data packets flow according to the network congestion. Congestion window size
can be defined as the maximum number of packets that the source can transmit without receipt of
any acknowledgment (ACK) from the destination node. In TCP protocol, congestion control
mechanism is achieved by the receiver to prevent the sender to send more data packets through
the network. The sender in TCP protocol regulates its window size (cwnd) according to the
window size of the receiver advertised in order to avoid extra packets transmitted and as a result,
minimizing the probability of network congestion occurring. The TCP sender utilizes slow start
mechanisms by setting its window size (cwnd) to one segment. As the first ACK packet receipts
by the sender, its congestion window size incremented by one. Thus, in the first round trip time
(RTT), there is one data packet is transmitted by the sender. In second RTT, there is two data
packets are sent, in third RTT, there is four data packets are sent, and so on. This incrementing of
data packet transmission will continue as an exponential function behavior. The slow start
mechanism sometimes called as an exponential growth phase. The slow start process increments
cwnd by the number of packets acknowledgments received and the process will stop in one of the
following conditions: 1) the receiver’s window size equal to the sender’s cwnd. 2) An
acknowledgment lost for some transmitted packets. 3) Reaching to the slow start threshold value
[10]. The cwnd size increases by the value calculated by the formula [(segment size x segment
size) / (congestion window)] each time an ACK is received. In MANETs, because of the network
topology frequent changes during the TCP connection lifetime, the relation becomes too loose
between tolerable data rate and the cwnd. In [11], the authors explain the reasons of degrading the
TCP performance when the cwnd value is incremented larger than an upper bound value. Also,
the authors in [12] determined the optimal cwnd size for specific flow pattern and network
topology that TCP shows the best throughput. Usually, TCP operates at a mean value of window
size which is larger than the calculated cwnd; this, unfortunately, leads to increasing of packet
loss due to the wireless channel contention.

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4. LITERATURE REVIEW
Mobile Ad Hoc (MANET) routing protocol’s performance has been an important research field.
The focus of these routing studies concerns the investigation of the effects of changing routing
protocol parameters on their performances in different environments. The performance metrics
determine which protocol is suitable for a specific application for each environment case. Also,
different simulators are used for this purpose. Rusdi et al [13] proposed a new approach to
enhance the TCP performance over mobile ad hoc network environments by using a dynamic
path for TCP congestion estimation. They are succeeded in decreasing the amount of the packet
loss. Their simulation results show that the TCP performance improved over different scenarios
of mobile ad hoc network. S. j. Kohakade and S. A Jain in [14] explains the effects of congestion
window size on the improving of TCP performance and also discusses the problems of the
medium channel contention on the MANET networks. They propose a dynamic adjustment of the
congestion window size to improve the TCP performance by reducing the overshooting problems
of congestion window. A. Deshpande [15] discusses the reasons of TCP performance degrading
due to mobile ad hoc network environment. In his work, the author suggests different
optimization techniques to enhance TCP performance by using contemporary WAN optimization
techniques to avoid the challenges of TCP performance degradation. Nilesh et al [16] examine
AODV and DSR routing protocols using an NS2 simulator. In their simulation study, a 50 node
density is simulated with varying MANET sizes in an ad hoc environment. A channel access
control using IEEE 802.11 performance study is summarized by Zhenghua et al in [17] they
investigate the existence of an optimal size of the congesting window at which TCP protocol
performs best throughput by maximum spatial reuse of multihop wireless shared channels.
Dimitrios et al [18] tested a TCP performance of 32 nodes deployed in a realistic environment
mesh network. In their studies, they recommended the use of a maximum window size in order to
gain maximum throughput in the some simulated cases when disabling the RTS/CTS control
signals. Ankur Patel. et. al [3] modelled Proactive and Reactive routing protocols with different
mobility patterns. In their simulation research focuses on the performance evaluation of the same
numbers of node groups using an NS2 simulator. B. Nithya et al [19] proved from the simulated
results that the degradation in TCP performance of an ad-hoc wireless network was due to an
incorrect reaction to the congestion window size which affects the overall mobile ad hoc network
performance. The shorter delay in packet transferring through the network is achieved by
adjusting and modifying the TCP congestion window size compared to traditional TCP protocol.
Jekishan et al in [20] investigates the behavior of the AODV routing protocol using two different
simulators: NS2 and OMNET++. The analysis of the performance results shows the effects of the
simulator architecture on the results obtained. Abdul Hadi et al [5] studied the performance
behavior of ad-hoc on-demand protocols using the NS2 simulator. In their work, different
scenarios of MANET networks with various numbers of nodes and different pause times were
tested.

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5. SIMULATION ENVIRONMENT
5.1. Simulation Model
Performance evaluations of wireless ad-hoc routing protocol have been done using a discrete
event simulator NS2 version NS-2.35 [21]. The NS2 simulator supports simulations of various
wired and wireless routing protocols such as TORA, AODV, DSDV, and DSR. The core
programming language used in writing NS2 simulation package is C++ and the interactive user
interface language is Tool Command Language (TCL). TCL makes the network simulation
environment parameters change easily without the need to recompile NS2 software each time
modifying the network attributes parameters.
5.2. Simulation Parameters
Our simulation study considers a network area size of 500 m x 500 m with 50 wireless mobile
nodes randomly distributed across the simulated area with a maximum speed of 20m/s and
constant pause time. The parameter values of the performance simulation are listed in table 1.
Table 1. Parameter values of simulation scenario
Parameters Values
Network Simulator NS-2.35
Routing protocols AODV, DSR and DSDV
Wireless Mac Layer protocol IEEE 802.11
Number of nodes 50
Simulation area 500m x 500m
Wireless transmission range 250m
Mobility model Random waypoint model
Pause time 5 Sec
Simulation time 100 Sec
Mobility maximum speed 20 m/Sec
Interface queue size 50
Packet size 512 bytes/packet
Application Layer FTP
5.3. Performance Metrics
Routing protocols of MANET’s performance can be evaluated using many quantitative
metrics. We have used a popular performance evaluation metrics in our wireless ad- hoc
routing protocol simulation.
5.3.1. Average Network Throughput:
It is defined as the number of data packets successfully received per unit of
simulation time.

35
ܶℎ‫݃ݑ݋ݎ‬ℎ‫ݐݑ݌‬ =
∑ ܲܽܿ݇݁‫.ܴܿ݁ ݐ‬௡
ଵ
ܵ݅݉‫݁݉݅ݐ ݊݋݅ݐ݈ܽݑ‬
5.3.2. Packet Delivery Ratio (PDR):
It can be defined as the ratio of the packets successfully receipted by the destination
nodes to the packets sent by the source nodes.
ܲܽܿ݇݁‫ ݋݅ݐܴܽ ݕݎ݁ݒ݈݅݁ܦ ݐ‬ሺܲ‫ܴܦ‬ሻ% =
∑ ௉௔௖௞௘௧ ோ௘௖.೙
భ
∑ ௉௔௖௞௘௧ ௦௘௡௧೙
భ
× 100
5.3.3. Average Routing Overhead Load:
It can be defined as the total number of all routing control overhead packets sent by
all nodes in the network over simulation time.
‫݀ܽ݋ܮ ݃݊݅ݐݑ݋ܴ ݁݃ܽݎ݁ݒܣ‬ =
∑ ܴܴܶ ܲܽܿ݇݁‫ݐ‬௡
ଵ
ܵ݅݉‫݁݉݅ݐ ݊݋݅ݐ݈ܽݑ‬
5.3.4. Average End to End Delay:
It can be defined as the average time has elapsed by data packets for transferring from
source nodes to destination nodes with considering all delays caused by queuing,
buffering, and propagation delays.
‫.݃ݒܣ‬ ‫ݕ݈ܽ݁ܦ ݀݊ܧ ݋ݐ ݀݊ܧ‬ =
∑ ሺܲܽܿ݇݁‫.ܴܿ݁ ݐ‬௧௜௠௘− ܲܽܿ݇݁‫ݐ݊݁ܵ ݐ‬௧௜௠௘ሻ௡
ଵ
∑ ܲܽܿ݇݁‫.ܴܿ݁ ݐ‬௡
ଵ

6. SIMULATION RESULTS
Simulations have been done with varying maximum congestion window size to examine the
protocols in different performance metrics. Comparisons have been evaluated on a proactive
protocol (DSDV) and two reactive protocols: DSR and AODV. The results obtained are discussed
below.
The main task of a routing algorithm is to set a route to connect a source node to destination one
in MANET. Thus, one metric of routing protocol success is the throughput of data packets
received successfully by destinations over a specific period of time.

(a) AODV throughput with different window size
(b)
(c) DSDV Throughput with different window size
Figure 1. Throughput for AODV, DSR and DSDV with different window size
Figure 1 presents the throughput of
congestion window size. It is observed that DSR has insensitive behaviors
variation compared to AODV and DSDV protocols. Throughput values of AODV and DSR
protocols are slightly larger than the throughput of DSDV. When we increase the congestion
window size in MANET network, more data packets are lost due to
AODV throughput with different window size
DSR Throughput with different window size
DSDV Throughput with different window size
Throughput for AODV, DSR and DSDV with different window size
throughput of AODV, DSR and DSDV protocols with increasing
congestion window size. It is observed that DSR has insensitive behaviors to the window size
network, more data packets are lost due to collision.
36
Throughput for AODV, DSR and DSDV with different window size
with increasing of
to the window size

(a) AODV Packet Delivery Ratio with different window size
(b) DSR Packet Delivery Ratio with different window size
(c) DSDV Packet Delivery Ratio with different window size
Figure 2. Packet Delivery Ratio
Figure 2 shows that the two reactive routing protocols
equivalent and deliver the same amount of packets
notice the effects of packets’ buffering in the reactive protocols, in case
the performance of the packet delivery ratio
DSDV protocol. In addition, it noticed that the window size variations have no significan
on the packet delivery ratio metric of these routing protocols in general.
AODV Packet Delivery Ratio with different window size
DSR Packet Delivery Ratio with different window size
) DSDV Packet Delivery Ratio with different window size
Figure 2. Packet Delivery Ratio of AODV, DSR and DSDV with different window size
Figure 2 shows that the two reactive routing protocols DSR and AODV perform roughly
equivalent and deliver the same amount of packets at the simulation time in the network. We
buffering in the reactive protocols, in case of a route is not availabl
packet delivery ratio of DSR and AODV is slightly higher than that of
. In addition, it noticed that the window size variations have no significan
on the packet delivery ratio metric of these routing protocols in general.
37
AODV, DSR and DSDV with different window size
perform roughly
the network. We
a route is not available,
is slightly higher than that of
. In addition, it noticed that the window size variations have no significant effect

(a) AODV Average Routing Load with Different Window Size
(b) DSR Average Routing Load with Different Window Size
(c) DSDV Average Routing Load with Different Window Size
Figure 3. Average routing load of
Figure 3 shows average routing
under various congestion window size. It is observed that DSR exhibits excellent
minimum routing overhead control load over simulation time. There
size variations in the average routing load
overhead than AODV while DSDV generates greater overhead cont
routing protocols. Also, the DSDV proactive routing protocol shows worst performance and
almost fluctuated around a mean value
due to nature of proactive DSDV routing
AODV Average Routing Load with Different Window Size
DSR Average Routing Load with Different Window Size
DSDV Average Routing Load with Different Window Size
Average routing load of AODV, DSR and DSDV with different window size
verage routing loads of AODV, DSR and DSDV MANET routing protocols
under various congestion window size. It is observed that DSR exhibits excellent behavior with
ntrol load over simulation time. There is no influence of window
size variations in the average routing load of DSR protocol. DSR generates lower routing
overhead than AODV while DSDV generates greater overhead control packets than reactive
mean value as shown in Fig. 3 (c) for different window size
DSDV routing protocol algorithm.
38
AODV, DSR and DSDV with different window size
of AODV, DSR and DSDV MANET routing protocols
behavior with
is no influence of window
. DSR generates lower routing
rol packets than reactive
different window size and that is

(a) AODV Average
(b) DSR Average
(c) DSDV Average
Figure 4. Average end to
AODV Average end to end Delay with Different Window Size
DSR Average end to end Delay with Different Window Size
DSDV Average end to end Delay with Different Window Size
nd to end delay of AODV, DSR and DSDV with different window size
39
and DSDV with different window size

The congestion window size has considerable effects on the average packets end to end delay
performance for all studied MANET routing protocols. Generally, from
the average end to end delay values is inversely proportional to the TCP congestion window size
used for each scenario performed. However it also can observe that DSDV presents a lowe
average delay compared with the two reactive protocols. This is due to the fact that DSDV is a
proactive protocol, when a node receives a packet
predetermined next hop node. In reactive
nodes buffer if there is no valid route
delays of DSR and AODV protocol
We can display and summarize the simulation results as shown in figure 5.
he congestion window size has considerable effects on the average packets end to end delay
performance for all studied MANET routing protocols. Generally, from figure 4, we observe
values is inversely proportional to the TCP congestion window size
used for each scenario performed. However it also can observe that DSDV presents a lowe
node receives a packet, it immediately forward the packet
. In reactive protocols, the data packets are temporarily
route. This may cause a longer delay which increases
of DSR and AODV protocol performance.
We can display and summarize the simulation results as shown in figure 5.
(a)
(b)
40
he congestion window size has considerable effects on the average packets end to end delay
we observe that
values is inversely proportional to the TCP congestion window size
used for each scenario performed. However it also can observe that DSDV presents a lower
the packet to the
temporarily stored in the
increases the average

Figure 5. Performance
Figure 5 (a) and (b) shows that the throughput and packet delivery ratio performance metrics.
observed that DSR protocol performs better than AODV and DSDV
window size variations on the throughput and
with AODV and DSDV protocols
easily be observed that, DSDV protocol performs much worse than DSR and AODV. The high
route control packet exchanges between
updates of the routing tables of any changed occurred in network topology. Also DSR performs
much better compared to AODV in terms of average routing lo
value along with window size increasing
Figure 5 (d) demonstrates average
the effect of the window size on the ave
delay gradually increases for all protocols used. However, the values of end to end delay reaches
to approximate insignificant changes when the window size equals
(c)
(d)
Performance metrics of AODV, DSR and DSDV with different window size
Figure 5 (a) and (b) shows that the throughput and packet delivery ratio performance metrics.
protocol performs better than AODV and DSDV. There is a slight
the throughput and PDR performance of the DSR protocol
with AODV and DSDV protocols. When looking at figure 5 (c), the average routing load, it can
DSDV protocol performs much worse than DSR and AODV. The high
exchanges between MANET nodes in proactive protocol, as DSDV
to AODV in terms of average routing load and it maintains a constant
increasing.
demonstrates average end-to-end delay of DSDV, DSR, and AODV. It shows clearly
the effect of the window size on the average end to end delay performance. The rate of end to end
to approximate insignificant changes when the window size equals to or larger than
41
metrics of AODV, DSR and DSDV with different window size
Figure 5 (a) and (b) shows that the throughput and packet delivery ratio performance metrics. It is
slight effect of
the DSR protocol comparing
. When looking at figure 5 (c), the average routing load, it can
DSDV protocol performs much worse than DSR and AODV. The high
as DSDV, to track
ad and it maintains a constant
end delay of DSDV, DSR, and AODV. It shows clearly
rage end to end delay performance. The rate of end to end
or larger than the Interface

42
Queue size value (IFQ=50) used in the simulation scenarios as shown in figure 5 (d), DSDV
exhibits the lowest average end-to-end delay among the three routing protocols scenarios.
7 CONCLOSION
In this work, the routing protocols: DSR, AODV, and DSDV are simulated for the performance
metrics of throughput, average routing load, average end to end delay and packet delivery ratio
by increasing the maximum congestion window size up to 80 with steps of 10. As the window
sizes are increasing, DSR protocol performance well in terms of throughput, average route load,
and packet delivery ratio with increasing the congestion window size that is due to its reactive
characteristics in discovering fresh routes to destinations. Proactive protocol DSDV exhibit lower
end to end delay as compared with AODV and DSR. The average delay of MANET protocols
increases as the window size increased, that is due to limited node’s buffer size used in the
network. Finally, our simulation results indicate to impact of congestion window size on the
overall routing protocol performance, DSR performs well with varying window size compared
with the AODV routing protocol. While DSDV proactive protocol is attractive for minimum
packet delay applications.
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AUTHORS
Nihad I. Abbas received Bachelor of Electronic Engineering degree in Electrical
Department from University of Technology, Baghdad, Iraq. And Master degree from
University of Technology, Bagdad, Iraq. He has twenty years of teaching experience in
engineering colleges. His research interest includes image processing, Mobile ad hoc
network, and Electromagnetic computation
Assist. Prof. Emre Ozen received a PhD of Engineering degree in Computer Engineering
from Computer Engineering Department, Eastern Mediterranean University, Famagusta,
N. Cyprus. His research interest includes Mobile Ad-hoc network, artificial Intelligence
Algorithms and computer programming web Technologies.
Assoc. Prof. Mustafa Ilkan received a PhD of Engineering degree in Electrical
Engineering from Electrical Engineering Department, Eastern Mediterranean University,
Famagusta, N. Cyprus. He has around thirty years of teaching experience in engineering
colleges. His research interest includes Renewable Energy Systems-Solar Energy/Photovo,
He has more than 30 of international and local published papers on international and local journals.

T HE I MPACT OF TCP C ONGESTION W INDOW S IZE ON THE P ERFORMANCE E VALUATION OF M OBILE A D H OC (MANET) R OUTING P ROTOCOLS

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T HE I MPACT OF TCP C ONGESTION W INDOW S IZE ON THE P ERFORMANCE E VALUATION OF M OBILE A D H OC (MANET) R OUTING P ROTOCOLS