International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 309 ISSN 2278‐7763 PERFORMANCE COMPARISON OF
AOMDV AND EGMP FOR VIDEO
TRANSMISSION IN MOBILE ADHOC
NETWORK
Leelavathy Loganathan , E.D Kanmani Ruby and N.Kasthuri
E-mail: leels.ece@gmail.com, bewin_santhukumar@yahoo.co.in
Department Of Electronics and Communication Engineering
Kongu Engineering College
Perundurai, Erode, Tamil Nadu,India
Abstract: Mobile Ad-hoc networks are
demonstrate that EGMP has high
formed by an autonomous system of
throughput, high packet delivery ratio
mobile nodes that are connected via
and low flow blocking compared to
wireless
AOMDV and is scalable to both group
links
and
there
is
no
centralized administration. Employing
efficient
and
scalable
multicast
multipath transmission technique in
Mobile Ad hoc Networks (MANET) is
an challenging task. In this paper,
comparative
study
size and network size.
of
multipath
Ad-hoc
Routing
protocols;
Multipath; Simulation;
Keywords:
networks;
Multicast;
INTRODUCTION
multicast protocol is done and packet
In wireless networks computers
level analysis of video streaming is
are connected and communicate with
analyzed. To analyze video streaming
each other not by a visible medium, but
traffic, the packet level performance of
by emissions of electromagnetic energy
multipath
is
in the air. As the importance of computer
taken into account, which sends video
in daily life increases it also sets new
traffic bursts over multiple available
demands for connectivity. Wired solution
channels by means of comparative
have been for a long time but there is
analysis of AOMDV and EGMP.
increasing demand on working wireless
Packet level performance in-terms of
solution for connecting to internet,
throughput, packet delivery ratio, and
sending E-mail etc. One of the solution to
flow blocking probability is evaluated
these need is Adhoc network.
transmission
scheme
using multipath multicast transmission
scheme.
Our
simulation
Copyright © 2013 SciResPub. results
A mobile ad-hoc network or
MANET is a collection of mobile nodes
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 310 ISSN 2278‐7763 sharing a wireless channel without any
destination are likely to be lost if the route
centralized
established
to the destination changes [1]. To reduce
communication backbone. They have no
the topology maintenance over-head in
fixed routers with all nodes capable
multicasting, an option is to make use
of movement and arbitrarily dynamic.
of the position information. But there
These nodes can act as both end systems
are many challenges to implement an
and routers at the same time. When acting
efficient and scalable geographic multicast
as routers, they discover and maintain
scheme in MANET. For example, in
routes to other nodes in the network.
unicast geographic routing, destination’s
With a one-to-many or many-to-many
position is carried in the packet header
transmission pattern, multicast is an
to guide packet forwarding. But in
efficient method to realize group
multicast routing, the destination is a
communications.
or
group of members. Putting all the
reactive routing protocols, the routes are
members’ addresses and positions into the
created on requirement basis. To find a
packet header is a direct and easy way, but
path from source to destination, it invokes
this is only applicable for the small group
the route discovery mechanisms. Only
case [2] [3] [4]. Besides scalable packet
the routes that are currently in use are
forwarding,
maintained
routing
multicast protocol also needs to efficiently
inherent
manage the membership of a possible
protocols
control
a.
or
In
on-demand
Reactive
have
some
scalable
large
maintained while in use, it is usually
positions and forward packets to the
required to perform a route discovery
members distributed in a possible large
before
exchanged
network terrain. These are ignored in
between communication peers. This
the above protocols. We propose an
leads to a delay for the first packet to
efficient geographic multicast protocol
be transmitted.
(EGMP). EGMP can scale to large
route
can
be
Second, even though
maintenance
for
reactive
efficiently
currently in use, it may still generate an
delivery.
the topology of the network changes
frequently.
Finally,
packets
Copyright © 2013 SciResPub. to
the
the
members’
group size and network size and can
algorithms is restricted to the routes
important amount of network traffic when
obtain
geographic
limitations. First, since routes are only
packets
group,
a
implement
multicasting
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 311 ISSN 2278‐7763 discovery process by flooding a RREQ
ROUTING PROTOCOL
A routing protocol is a protocol
that specifies the way in which routers
communicate
with
each
other,
disseminating information that enables
them to select routers between any two
nodes or a computer network, the choice
of route being done by routing algorithm.
Each router has a prior knowledge of
network attached directly to it. A routing
protocol shares information first among
immediate and
then throughout the
network.
for destination throughout the network.
RREQs should be uniquely identified by
a sequence number so that duplicates can
be recognized and discarded. Upon
receiving a non-duplicate RREQ, an
intermediate node records previous hop
and checks whether there is a valid and
fresh route entry to the destination in
routing table. If such is the case, the node
sends back a RREP to the source; if not it
rebroadcasts the RREQ. A node updates
its routing information and propagates
upon receiving further RREPs only if a
Ad-hoc On-demand Multipath Distance
Vector Routing (AOMDV)
The AOMDV uses the basic
RREP contains either a larger destination
sequence number (fresher) or a shorter
route found. AOMDV has numerous
features. AOMDV discovers routes on
demand using route discovery method.
AODV route construction process. In this
The most important variation is the
case, however, some extensions are made
amount of routes found in each route
to create multiple loop-free, link-disjoint
discovery.
paths.The main idea in AOMDV is to
transmission from source to the target
compute multiple paths during route
establishes multiple reverse paths both at
discovery. It consists of two components:
intermediate node in addition to the
1) A route update rule to establish and
destination. Multiple reverse paths at
maintain multiple loop-free paths at each
intermediate nodes in addition to the
node. 2) A distributed protocol to find
destination. Multiple RREP’s navigate
link-disjoint paths.
this reverse route back to form multiple
Before describing AOMDV, we
first discuss AODV, from which it is
In
AOMDV,
RREQ
routes to target at the source and
intermediate nodes.
derived. In AODV, when a source needs
The basis of AOMDV protocol
a route to a destination, it initiates a route
lies in guaranteeing that multiple route
Copyright © 2013 SciResPub. International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 312 ISSN 2278‐7763 revealed are loop-free and disjoint, and in
RREQs need to arrive via different
competently discovering such paths by
neighbors of the source. This is verified
means of a flood based route discovery.
with the first hop field in the RREQ
In AOMDV each RREQ, respectively
packet and the first hop list for the RREQ
RREP arriving at a node potentially
packets at the node. At the destination a
defines an alternate path to the source or
slightly different approach is used, the
destination. Just accepting all such copies
paths determined there are link-disjoint,
will lead to the formation of routing
not node-disjoint. In order to do this, the
loops.
destination replies up to k copies of the
In
order
to
eliminate
any
possibility of loops, the “advertised hop-
RREQ, regardless of the first hops.
count” is introduced. The advertised hop-
Algorithm
count of a node i for a destination d
Step1: Send request from source to the
represents the maximum hop-count of the
selected destinations.
multiple paths for d available at i. The
Step2: Shortest multipath selection is
protocol only accepts alternate routes
done and transmission takes place.
with hop-count lower than the advertised
Step3:
hop-count, alternate routes with higher or
consisting hop count of route.
the same hop-count is discarded. The
Step4: Multipath route selection is done
advertised
and is updated in the routing table.
hop-count
mechanism
Destination
will
send
reply
establishes multiple loop-free paths at
Step5: Divide the traffic on available
every node. These paths still need to be
routes as less hop count routes will assign
disjoint. For this we use the following
more traffic.
notion: When a node S floods a RREQ
Step6: Now transmit data according to
the above division ratio through
discovered routes.
packet in the network, each RREQ
arriving at node l via a different neighbor
of S, or S itself, defines a node-disjoint
path from l to S.
In AOMDV this is used at the
Efficient
Protocol
intermediate nodes. Duplicate copies of a
Geographic
EGMP
supports
Multicast
scalable
RREQ are not immediately discarded.
and
Each packet is examined to see if it
management
provides a node-disjoint path to the
forwarding through a two-tier
source.
virtual-zone-based structure. At
For
node-disjoint
Copyright © 2013 SciResPub. paths
all
reliable
membership
and
multicast
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 313 ISSN 2278‐7763 the lower layer, in reference to a
will flow along the multicast tree
predetermined virtual origin, the
both upstream to the root zone and
nodes in the network self-organize
downstream to the leaf zones of the
themselves into a set of zones as
tree. At the lower layer, when an
shown in Fig. 1, and a leader is
on-tree zone leader receives the
elected in a zone to manage the
packets, it will send them to the
local group membership. At the
group members in its local zone.
upper layer, the leader serves as
a representative for its zone to join
i) Moving between Different Zones
or leave a multicast group as
When a member node moves to a
required. As a result, a network
new zone, it must rejoin the
wide zone-based multi-cast tree is
multicast tree through the new
built. Each zone is given a zone id.
leader. When a leader is moving
For
reliable
away from its current zone, it
transmissions,
must handover its multicast table
efficient
management
location
and
and
information
be
to the new leader in the zone, so
integrated with the design and
that all the downstream zones and
used
zone
nodes will remain connected to the
construction, group membership
multicast tree. Whenever a node M
management,
tree
moves into a new zone, it will rejoin
construction and maintenance, and
a multicast group G by sending a
packet forwarding. The zone-based
JOIN_REQ message to its new
tree is shared for all the multicast
leader. During this joining process,
sources of a group. To further
to reduce the packet loss, whenever
reduce the forwarding overhead
the node broadcasts a BEACON
and delay, EGMP supports bi-
message to update its information
directional
forwarding
to the nodes in the new zone, it
along the tree structure. That is,
also unicast a copy of the message
instead of sending the packets to
to the leader of its previous zone to
the root of the tree first, a source
update its position. Since it has not
forwards the multicast packets
sent the LEAVE message to the
directly along the tree. At the
old leader, the old leader will
upper layer, the multicast packets
forward the multicast packets to M.
to
guide
will
the
multicast
packet
Copyright © 2013 SciResPub. International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 314 ISSN 2278‐7763 This
forwarding
helps
become empty, it will use the
and
method introduced in the next
packet
section to deliver its multicast
zone
table. In the case that the leader
rejoining
dies suddenly before handing over
process finishes, M will send a
its multicast table, the down-
LEAVE message to its old leader.
stream
reduce
the
packet
facilitates
loss
seamless
transmissions
crossing.
process
during
When
the
To handle leader mobility
zones
and
nodes
will
reconnect to the multicast tree
problem, if a leader finds its
through the maintenance process.
distance to the zone border is less
If the to be empty zone is the root
than a threshold or it is already in
zone, since the root zone has no
a new zone, it assumes it is moving
upstream zone, the leader will
away from the zone where it was
check its neighbouring zones and
the leader, and it starts the
choose the one closest to the
handover process. To look for the
root zone as the new root zone.
new
The
leader,
it
compares
the
leader
then
forwards
its
positions of the nodes in the zone it
multicast table to the new root
is leaving from and selects the one
zone, and floods a NEW_ROOT
closest to the zone center as the
message to announce the change.
new leader. It then sends its
EGMP handles the zone
multicast table to the new leader,
partitioning problem as follows: If
which
its
there are multiple clusters in a zone,
immediately
because these clusters are not aware
through a BEACON message. It
of the existence of each other, each
will
cluster will elect a leader. When an
will
leadership
also
announce
role
send
a
JOIN_REQ
message to its upstream zone.
upstream
During the transition, the old
JOIN_REQ messages from multiple
leader
receive
leaders of the same zone and the
multicast packets. It will forward
new message is not sent as a
all these packets to the new leader
result
when the handover process is
which case the old leader’s address
completed. If there is no other node
needs to be carried), it detects that
in the zone and the zone will
the
may
still
Copyright © 2013 SciResPub. zone
leader
receives
of leader handover (in
downstream
zone
has
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 315 ISSN 2278‐7763 partitioned into multiple clusters. It
messages from multiple leaders of
identifies a cluster by its zone id and
the same zone, the upstream leader
the
When
can detect zone partitioning. It
sending a packet to the cluster, it
will resend the previous message
uses the leader’s position instead of
to the target cluster with the
the zone center (in which case the
position of the zone leader as the
zone
destination.
leader’s
ID
address.
is
carried
as
the
destination) as the transmission
When
the
leader
of
a
reference. Even though the leader
cluster changes, if the cluster is on-
may move, its position carried in
tree, the new leader sends a
JOIN_REQ message can still be
JOIN_REQ
used as a reference to forward
upstream zone immediately which
packets
also
receiving
to
a
its
cluster.
packet
with
When
message
to
its
carries the old leader’s
the
address. With multiple clusters in
position of the leader as the
its upstream zone, the JOIN_REQ
reference, a cluster leader can learn
message from a zone leader will
that multiple clusters exist within
generally be intercepted by one of
its zone. In case that not all the
the
clusters of a partitioned zone send
responsible for
JOIN_REQ
the
packets to the zone. Some clusters
upstream zone leader may not be
may merge later into a larger
aware of the partitioning of the
cluster, and through the leader
downstream zone. When a cluster
election procedure, only one of
leader receives a packet destined to
the leaders will win as the new
its zone but does not match its
cluster’s leader. The new leader will
status, it will send an update
send a JOIN_REQ message to the
message to its upstream zone. For
upstream zone to refresh the
example, when a cluster leader
cluster’s information.
receives a JOIN_REPLY message
Algorithm
or a multicast packet but did not
Step 1: Network is divided into square
send JOIN_REQ message, it will
zone and in each zone a leader is elected.
send a LEAVE message to the
Zone leader (zLdr) maintains a multicast
upstream zone. When receiving
table.
messages,
Copyright © 2013 SciResPub. clusters,
which
will
be
forwarding
the
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 316 ISSN 2278‐7763 Step 2: When a zone leader receives the
frames and bi-directionally code (B)
NEW SESSION message, it will record
frames. I frames are compressed
the group ID and the root-zone ID in its
versions of raw frames independent
multicast table.
of other frames, whereas P frames
Step 3: The leader will send JOIN REQ
only refer preceding I/P frames and
message towards root zone, on receiving
B frames can refer both preceding
it destination will sent back JOIN
and succeeding frames. A sequence
REPLY message back to source.
of video frames from I frame to
Step 4: The leader will send a JOIN REQ
next I frame comprises group of
message to the zone to refresh cluster
picture (GoP). Because P and B
information.
frames are encoded with reference
Step 5: Multipath selection is done in the
to preceding and/or succeeding I/P
cluster using Dijikstras algorithm.
frames, traffic transmission follows
Step 6: Video is split and transmitted in
the batch arrival.
the
selected
multipath
to
multiple
selected destinations.
Step 7: When a zone leader receives END
Multipath Video Multicasting
SESSION message, the node will remove
all
the
information
and
stops
the
An ad hoc network is a collection
transmission.
of wireless mobile hosts dynamically
VIDEO STREAMING TRAFFIC
A video streaming flow can
be split into multiple sub-streams
and
delivered
through
different
network simultaneously. Based on
video transmitted, each video traffic
burst
is
generated
over
fixed
intervals and consist of an I or P
frame and number of B frame.
To
remove
temporal
redundancy, intra-coded (I) frame
are interleaved with predicted (P)
Copyright © 2013 SciResPub. forming a temporary network. Quality of
Service (QoS) is a set of service
requirements that needs to be met by the
network
while
transporting
an
information stream from a source to its
destination. QoS support for Mobile Ad
hoc
Networks
(MANETs)
is
a
challenging task due to the dynamic
topology and limited resource. MANETs
should provide multiple QoS metrics for
real time applications with low delay
requirements, especially in multicast
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 317 ISSN 2278‐7763 situations. Due to the mobility of wireless
(cache) common data until needed.
nodes, the topology of ad hoc networks
Where there is a common need for the
may
same data required by a group of clients,
change
frequently.
Thus,
the
established connection routes between
multicast
transmission
senders and receivers are likely to be
significant bandwidth savings. On the
broken during video transmission. It
other hand, since all nodes in an ad-hoc
causes interruptions, freezes, or jerkiness
network can be connected dynamically in
in the received video signal. An end-to
an arbitrary manner, it is usually possible
end connection route in wireless ad hoc
to establish more than one path between a
networks generally consists of multiple
source and a destination. When this
wireless links, resulting in higher random
property of ad-hoc is used in the routing
packet loss than single hop wireless
process,
connections in wireless networks with
invoked in network
then
may
multipath
provide
routing
is
infrastructure, such as base stations.
Multicast over wireless networks is an
PERFORMANCE EVALUATION
important and challenging goal, but
Our evaluations are based on the
several issues must be addressed before
many group applications can be deployed
on a large scale. Multicasting is a more
efficient method of supporting group
communication
than
unicasting
or
broadcasting, as it allows transmission
and routing of packets to multiple
destinations
using
fewer
network
resources. The existing method deals with
100 nodes in the network with the packet
size of 2000Bytes. The video signal is
splitted into five parts and transmitted via
different paths.
The multicast mode is useful if
a group of clients require a common set
of data at the same time, or when the
clients are able to receive and store
Copyright © 2013 SciResPub. simulation of 100 wireless mobile nodes
forming an ad hoc network, moving
about over a square (1000m x 1000m)
flat space for simulated time. A square
space is chosen to allow free movement
of nodes with equal density. We choose
the traffic sources to be constant bit rate
(CBR)
source.
The
source
and
destination pairs were spread randomly
over the network. In the simulation,
node movement is due to random
waypoint model.
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 318 ISSN 2278‐7763 Fig.1 illustrates that the level of delivered
Simulation Results
information to the destination using
EGMP algorithm is 2% higher than the
We
ran
the
simulation
AOMDV. Hence, Packet loss is reduced
environments and evaluated routing
in EGMP
overhead, Packet delivery ratio and
outage probability is calculated for
ii) Throughput Throughput is the number
of useful bits per unit of time forwarded
by the network from a certain source
address to a certain destination, excluding
protocol overhead, and excluding
retransmitted data packets. Throughput is
the amount of digital data per time unit
that is delivered over a physical or logical
link, or that is passing through a certain
network node.
AOMDV and EGMP. The results are
summarized
below
with
their
corresponding graphs
i) PacketDeliveryRatio The ratio of the
number of delivered data packet to the
destination. This illustrates the level of
delivered data to the destination. The
greater value of packet delivery ratio
means the better performance of the
protocol.
∑ Number of packet receive / ∑ Number
of packet send
Fig.2 Comparison of AODV and
Fig.1 Comparison of AOMDV and EGMP
on basis of Packet delivery ratio
Copyright © 2013 SciResPub. AOMDV on basis of Throughput
Fig.2 shows that the EGMP
performs 20% better than the AOMDV at
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 319 ISSN 2278‐7763 different time intervals. For the lower
EGMP, blocking probability is 2% less
values of time, the throughput is low in
compared to AOMDV. The packet drop
both AOMDV and EGMP. Thus, network
is reduced in EGMP improving the
capacity is enhanced using EGMP hence
efficiency of the network.
reliability can be ensured.
CONCLUSION
iii) Flow blocking Probability If a queue is
This
paper
evaluated
the
full when a packet arrives, it will be
performances of AOMDV and EGMP
discarded,
the
using ns-2. Comparison was based on
probability that a packet is blocked is
throughput, packet delivery ratio and
exactly the same as the probability that
flow blocking probability. We conclude
the queue is full.
that
or
“blocked”.
So
EGMP is better than AOMDV.
EGMP outperforms AOMDV due its
ability to search for alternate routes
more faster when
a current link breaks
down. AOMDV incurs more throughput
while flooding the network and
packet
delivery ratio due its alternate route
discovery mechanism. It is found that
flow blocking probability is reduced,
EGMP is preferred over AOMDV.
References:
[1] H.D.Trung, W.Benjapolakul, P.M.Duc,
Fig. 3 Comparison of AODV
“Performance evaluation and comparison
of different ad hoc routing protocols”,
and AOMDV on basis of flow
Department of Electrical
blocking probability
Chulalongkorn
Engineering,
University,
Bangkok,
Thailand, May 2007
Fig..3 illustrates the Blocking
probability at different time intervals. In
Copyright © 2013 SciResPub. [2] S. Basagni, I. Chlamtac, and V. R.
Syrotiuk.
Location aware,dependable
International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 320 ISSN 2278‐7763 multicast for mobile adhoc
ComputerNetworks,
networks.
36(5-6):659-670,
Chen
and
Effective
K.
Nahrstedt.
location-guided
construction
group
Research,
of
Telecommunications
University
of
South
Australia, Australia, September 2003
August 2001
[3] K.
Institute
tree
algorithms for small
multicast
in
manet.IEEE
INFOCOM, pages 1180-1189, 2002.
[9] M.K.Marina and S.R.Das, “OnDemand
multipath
distance
vector
routing in ad hoc networks” in:
Proceedings of the 9th
IEEE
International Conference on Network
Protocols (ICNP), 2001
[4] M. Mauve, H. Fubler, J. Widmer, and
[10] C.S.R.Murthy, B.S.Manoj, Ad hoc
T. Lang. Position-based multicast routing
Wireless
for
Protocols, 6th Edition [11] The ns Manual,
mobile
ad-hoc
networks.
ACM
MOBIHOC, June 2003
multipath
distance
vector
routing in ad hoc networks” in:
Proceedings
of
IEEEInternational
the
9th
Conference
on
Network Protocols (ICNP), 2001
[6]L.B.Oliveira,
I.G.Siqueira,
A.A.F.Loureuro,”On the performance of
ad hoc routing protocols under a peer-topeer
application”, Computer
Department,
Federal
Science
University
of
Minas Gerais, Brazil, July 2005
[7] T.Fujiwara, T.Watanbe, “An ad hoc
networking scheme in hybrid networks
for
emergency
Architecture
and
formerly ns Notes and Documentation
[5] M.K.Marina and S.R.Das, “OnDemand
Networks,
communication”,
Information Technology Lab, Eugene Co.
Ltd, Hamamatsu, Shizuoka, Japan
[8] P.P.Pham, S.Perreau, “Increasing the
network performance using multi-path
routing mechanism with load balance”,
Copyright © 2013 SciResPub. International Journal of Advancements in Research & Technology, Volume 2, Issue4, April‐2013 321 ISSN 2278‐7763 Copyright © 2013 SciResPub.