APPLICATION OF ANT COLONY OPTIMIZATION TO
DEVELOP ENERGY EFFICIENT PROTOCOL IN
MOBILE AD-HOC NETWORKS
Sanjay K. Dhurandher
1
, Mohammad S. Obaidat
2
and Mayank Gupta
3
1
CAITFS, Division of Information Technology, Netaji Subhas Institute of Technology, University of Delhi, New Delhi, India
2
Department of Computer Science & Software Engineering, Monmouth University, New Jersey, U.S.A.
3
Division of Computer Engineering, Netaji Subhas Institute of Technology, University of Delhi, New Delhi, India
Keywords: Mobile ad hoc networks, Any colony schemes, Optimization, Energy-aware protocols.
Abstract: Foraging Behavior in Ant Swarms can be very helpful when applied to the protocols in Mobile Ad hoc
NETworks (MANETs). When the Ant Colony Optimization Scheme (ACO) is applied to a protocol, larger
number of paths are generated from the source to destination which helps in improving the packet delivery
ratio because an alternate back up path is always available in case a path gets broken due to the mobile
nodes. In this paper, we apply the ACO scheme on an already existing Energy efficient protocol Conditional
Max-Min Battery Capacity Routing (CMMBCR) (C.-K. Toh, 2001). The CMMBCR not only takes care of
the total transmission energy in the network but also the residual battery capacity of the nodes. Hence
applying ACO scheme on CMMBCR makes it more efficient in terms of energy, packet delivery ratio etc.
The efficiency of our proposed protocol A-CMMBCR is then established by comparing it with some of the
other existing Energy aware protocols such as Energy-Aware Routing protocol (EAAR) (Dhurandher et al.,
2009), Minimum Transmission Power Routing (MTPR) (Scott and Bambos, 1996) and CMMBCR. The
results are captured in the form of a graphical format.
1 INTRODUCTION
In the next generation of wireless communication
systems, there will be need of networks that can
establish themselves without any requirement of
preexisting infrastructure. Mobile Ad-Hoc Networks
(MANETS) basically refers to such type of networks.
As the name suggests Mobile implies that the
interconnecting nodes are not succumbed to be
remain at one place, rather they can move from one
place to the other. Ad-Hoc implies that the network
does not depend on any preexisting infrastructure
such as routers. Some of the main applications of
MANETS are dynamic communication for
emergency/rescue operations, disaster relief efforts
and military networks.
One of the most important performance
parameter in ad- hoc networks is minimizing the total
transmission energy in the path and extending the
battery life of the nodes. Conventional Routing
algorithms such as AODV (Perkins et al., 2001),
DSR (Johnson et al., 2001) and TORA (Park and
Corson, 2001) ignore the residual battery of the
participating nodes.
These protocols generally focus on finding the
shortest path available from source node to the
destination node. MTPR protocol tries to minimize
the total transmission power consumption of nodes
participating in an acquired route but it suffers from
the drawback that it does not consider the residual
battery of the nodes.
MMBCR (Singh et al., 1998) is another protocol
that finds the path which has longest battery life
amongst all other paths. CMMBCR is a combination
of MMBCR and MTPR. In this scheme, a parameter
gamma with some value assigned to it is used. Then
all paths from source node to destination node are
generated and the Minimum residual battery energy
(MBR) for each path is compared with the parameter
gamma. The paths which have MBR greater than
gamma are finally selected and MTPR scheme is
applied on this set of selected paths. In case no path
has MBR>gamma, the MMBCR scheme is followed.
Hence CMMBCR takes care of both
the residual
12
K. Dhurandher S., S. Obaidat M. and Gupta M..
APPLICATION OF ANT COLONY OPTIMIZATION TO DEVELOP ENERGY EFFICIENT PROTOCOL IN MOBILE AD-HOC NETWORKS.
DOI: 10.5220/0003677200120017
In Proceedings of the International Conference on Wireless Information Networks and Systems (WINSYS-2011), pages 12-17
ISBN: 978-989-8425-73-7
Copyright
c
2011 SCITEPRESS (Science and Technology Publications, Lda.)
battery of the nodes as well as minimizing the total
transmission energy.
It has been seen from [8, 9, 10] that the Ant
Colony Optimization (ACO) scheme when applied to
ad-hoc networks greatly enhances the packet delivery
ratio. Some of the popular ACO based routing
schemes are AntNet (Dorigo et al., 1991), AntHocNet
(Di Caro et al., 2005) and ARA (Guenes et al., 2002).
The earlier ACO – based routing schemes such as
AntHocNet (Di Caro et al., 2005) and ARA (Guenes
et al., 2002), devised for ad-hoc networks, were not
targeted towards energy conservation.
In the protocol proposed in this paper, we have
applied this ACO scheme in CMMBCR. The
proposed protocol is inspired from the EAAR. In
EAAR, ACO scheme is applied on the already
existing MMBCR and thus significantly improving
the packet delivery ratio. In the proposed work we
have applied ACO scheme to develop a more
efficient energy aware protocol that not only takes
care of minimizing total energy consumed in the path
but also gives special attention to the residual battery
of nodes.
EAAR only talks about residual battery of nodes,
but doesn’t bother about the total transmission
energy. Our protocol is better than CMMBCR
because we have applied ACO scheme which ensures
that there is always a back up path available in case a
route breaks due to the mobile nodes. This greatly
enhances the packet delivery ratio. Moreover, it also
takes care of the fact that if a route gets overloaded
due to traffic, an alternate route is selected for
routing which ultimately takes care of the residual
battery of nodes.
2 PROPOSED SCHEME
Initially, when a Source node 'S' wishes to
communicate with a Destination node 'D' and it does
not have the routing information for ‘D’ available, it
broadcasts a route request packet (RREQ). Each
neighbour of ‘S thus receives the RREQ packet. At
each node this Request packet is used to find the
destination node and the corresponding node checks
whether there is an entry in its routing table for this
destination node. If an entry for the destination node
D’ is found the node sends a route reply packet back
to the source node along the same path from which it
received the RREQ. If it does not have any entry for
D’ available in its routing table, it further broadcasts
the RREQ packet. Furthermore, to apply the ACO
scheme, we need to calculate the pheromone for each
path. A-CMMBCR considers a combination of two
routing schemes, hence, we need to calculate two
pheromones – pheromone(mt) for MTPR and
pheromone(mm) for MMBCR.As the route request
packet traverses through the path it keeps on storing
the path so that the route request packet will have to
traverse back along the same path in the opposite
direction.
Meanwhile, all the route request packets received
get converted to route reply packets as soon as they
arrive to the destination and they travel back to the
source retracing the path. If this is not possible
because of the absence of the next hop due to node
movements, the route reply packet is discarded. At
the source node when RREP packet is received
corresponding values of pheromone(mt) and
pheromone(mm) are also received. Moreover the
MBR of that route is also received.
Each node has a routing table associated with it.
The routing table contains the addresses of
destination nodes along with the neighbor node to
which the source node should forward the packet in
order to make it reach the destination. Moreover it
contains the values of various pheromones associated
with a route.
If a source node 'S' wants to send data to a
destination node 'D' then following steps must take
place:
Step 1: The node S checks its routing table to find
whether a path to D exists or not. If a path exists, it
sends the data to the next Hop; else Step 2 is
performed.
Step 2: The node S broadcasts route request packet
(RREQ). Then Step 3 is performed.
Step 3: If any neighbor node’s routing table has a
path to D exists it replies back to node S through
Route Reply packet (RREP) else it broadcasts the
RREQ. Step3 is followed for each intermediate node
thus receiving the RREQ. If
no path for D is
available, the intermediate node relays the RREQ
packet.
Step 4: As the RREQ packet is broadcast in the
network, it can eventually reach the destination node
D. At the destination node, Route Reply packet
(RREP) is generated and reply is sent back to S.
RREP is passed to node S through the intermediate
nodes along the path from which RREQ was
received. Now as each node receives the RREP
packet, it updates its routing table and inserts an
entry for the destination node.
Calculations: Since we have to apply ACO we need
to know the Pheromone for each route generated and
our scheme requires calculation of TWO
pheromones: one for MTPR and the other for
APPLICATION OF ANT COLONY OPTIMIZATION TO DEVELOP ENERGY EFFICIENT PROTOCOL IN MOBILE
AD-HOC NETWORKS
13
MMBCR, which are calculated as follows:
Pheromone(mt])=1/(Total Transmission energy of
path * Number of Hops)
Pheromone(mm)= MBR/(Number of Hops)
where, MBR=Minimum battery of a node in the path.
Total transmission power is the sum of
transmission power to send data to next hop for each
node in the path.
We calculate MBR and Total Transmission
energy of path during the RREQ packet and
Pheromone(mt)and Pheromone(mm) during the
generation of RREP packet.
At the source node when RREP packet is received
corresponding values of pheromone(mt) and
pheromone(mm) are also received. Moreover the
MBR of that route is also received.
For all the routes obtained corresponding to a
particular destination we check:
if (MBR> γ)
{Select this route for MTPR}
else
{Select this route for MMBCR}.
For all those routes obtained for MTPR category the
route with highest Pheromone(mt) is selected for data
transmission. If no such route exists the Route with
highest Pheromone(mm) from MMBCR category is
selected for data transmission.
Assuming that the battery of any node has
maximum value of 100 units and applying ACO in
CMMBCR we get:
CMMBCR= ACO + MTPR if MBR>γ,
ACO + MMBCR otherwise
We can take value of gamma depending upon our
own choice.
Case 1: γ = 0
All routes will be selected for MTPR. Hence our
protocol performs similar to ACO+ MTPR
Case 2: γ =100
No route will be selected for MTPR and all routes
will be selected for MMBCR. Hence our algorithm
behaves as MMBCR+ACO.
Case 3: Taking any Random Value of γ between 0
and 100.
The proposed scheme will be followed
.
3 TEST CASES
Figure 1: An Illustrative example.
Note in Figure 1 the nodes are represented by circles
containing data in the form a:b , where a is node
address and b is the node battery level left. The data
on edges represents the power required to send data
between nodes forming the edge.
For convenience, the node battery level is taken
from 0 to 100 only.
From Figure 1 it is seen that there are 4 routes
from the source node ‘S’ to the destination node ‘D’.
These paths are listed below:
1. S -> 1 -> 2 -> 3 -> D
2. S -> 1 -> 2 -> 6 -> D
3. S -> 4 -> 5 -> 6 -> D
4. S -> 4 -> 5 -> 7 -> 8 -> D
For all these routes MBR, Pheromone(mm) and
Pheromone(mt) are calculated.
This data is shown for each of above 4 routes
below:
1. MBR=10, Pheromone(mm) =10/3,
Pheromone(mt) =
1/ (26*3).
2. MBR = 50, Pheromone(mm) =50/3,
Pheromone(mt) =
1/ (17*3).
3. MBR = 30, Pheromone(mm) =30/3,
Pheromone(mt) =
1/ (39*3).
4. MBR = 30, Pheromone(mm)=30/4,
WINSYS 2011 - International Conference on Wireless Information Networks and Systems
14
Pheromone(mt) =
1/ (47*4).
Now depending on the value of γ different routes can
be selected for data transmission using MTPR or
MMBCR.
In this test case:
If γ<= 49, route 2 will be selected for transmission
using Pheromone(mt).
Else route 2 will be selected for transmission using
Pheromone(mm).
The other routes can also be used for data
transmission by comparing their MBR with the value
of γ and deciding whether to use MMBCR or MTPR.
4 SIMULATION ANALYSIS AND
RESULTS
In this section, we report the results generated by
conducting the simulation experiments and
comparing our protocol with some standard and
selected benchmark protocols. Simulation was done
using Glomosim tool.
The following parameters were considered for the
simulations performed:
1) Simulation time: 500 seconds
2) Terrain dimensions: (2000,2000) meters square
3) Number of Nodes:30
4) Mac Protocol: 802.11
5) Initial energy of Nodes: All Nodes were initiated
with equal energy.
The traffic considered n this work is the Constant Bit
Rate (CBR) traffic with the following scenarios:
1) CBR 17 100 1536 1S 0S 250S
2) CBR 12 19 100 1536 1S 250S 400S
3) CBR 14 27 100 1536 1S 400S 500S
The benchmark protocols used to compare with our
protocol are CMMBCR, EAAR, and MTPR.
Since our protocol is an improvement over
CMMBCR hence we decided to take this protocol in
our consideration. EAAR is an improvement our
MMBCR in that it implements the ACO scheme.
MTPR tries to optimize the energy used in the
network. Hence the choice of benchmark protocols is
justified.
We conducted the simulation experiments under
the following six situations:
1) Data size =100 times Control Packet Size;
Mobility :NONE
2) Data size =125 times Control Packet Size;
Mobility :NONE
3) Data size =150 times Control Packet Size.
Mobility :NONE
4) Data size =100 times Control Packet Size;
Mobility speed: 10m/s, random way point model.
5) Data size =125 times Control Packet Size;
Mobility speed: 10m/s, random way point model.
6) Data size =150 times Control Packet Size;
Mobility speed: 10m/s, random way point model.
Parameters that we considered for comparison with
other protocols are: (1) Total Energy consumed, (2)
Number of dead nodes, (3) Number of packets
delivered, (4) Energy per packet delivered, and (4)
Number of packets
dropped.
Figure 2: Energy consumed per packet.
Figure 2 shows that the energy consumed per
packet in the network is the least for A-CMMBCR.
A-CMMBCR performs better than CMMBCR
because the ACO scheme generates multiple paths
from one node to the other. When the traffic on one
path increases its pheromone decreases. This is done
so that the packets that would be transmitted later on
would go through some different path rather than
overloading this path. This helps in increasing the
number of packets delivered and hence lesser energy
is consumed per packet.
A-CMMBCR performs better than EAAR here
because the energy consumed in the network is lesser
as the path having the highest pheromone consumes
lower energy than the normal path selected by ACO
scheme in EAAR.
APPLICATION OF ANT COLONY OPTIMIZATION TO DEVELOP ENERGY EFFICIENT PROTOCOL IN MOBILE
AD-HOC NETWORKS
15
Figure 3: Number of Packets Delivered.
In the first scenario mobility is set to zero. Hence,
the nodes do not move, which implies that once a
path between two nodes has been established it
would remain intact. Number of packets delivered
using ACO scheme are higher than the normal on
demand scheme as shown in figure 3.
Figure 4: Number of Packets Dropped.
Figure 4 shows the number of packets dropped by
each protocol for various scenarios. It can be seen
that the protocol based on ACO scheme has lesser
number of packets dropped; reason being that there is
always an alternative path available in case the
current path gets broken or is overloaded with traffic.
This guarantees that most of the packets would reach
the destination more often than not.
Figure 5 shows that CMMBCR and A-CMMBCR
has lesser number of dead nodes than other protocols.
This is due to the use of a combination of MTPR and
EAAR, which ensures that the least energy would be
used in the network along with taking care of weak
nodes. Hence the probability of choosing a path that
has weak node is very low.
From the above results, it has been seen that A-
CMMBCR performs better than other three protocols
because it is based on ACO scheme. Moreover, ACO
scheme does guarantee the availability of multiple
paths for data transfer, which ensures a higher packet
delivery ratio.
Figure 5: Number of Dead Nodes.
Figure 6: Total Energy Consumed in the Network.
5 CONCLUSIONS AND FUTURE
WORK
This paper has presented an ACO based A-
CMMBCR energy efficient routing technique to
conserve energy in the process of routing of data
from one node to another. Furthermore, from the
graphical results it can be concluded that the
proposed A-CMMBCR performs better than the
CMMBCR protocol as the overall energy consumed
in the network is reduced and also the number of
packets dropped is decreased due to the ACO scheme
applied on the CMMBCR. The results also point
towards the better performance of the A-CMMBCR
in terms of energy over the other energy efficient
protocols, namely, EAAR and the MTPR of which
EAAR is the most recently designed/proposed and is
also based on the ACO technique.
One of the limitations of the proposed A-
CMMBCR is that it lacks the fault tolerance aspect.
So, our next work would be to ensure that the
network selects only those paths in which the nodes
are not prone to any fault and if there exists no such
WINSYS 2011 - International Conference on Wireless Information Networks and Systems
16
path then select those paths which are least prone to
faults. The new protocol would make sure that the
selected path has highest fault tolerance amongst the
other paths.
REFERENCES
C.-K. Toh, “Maximum Battery Life Routing to Support
Ubiquitous Mobile Computing in Wireless Ad Hoc
Networks”, IEEE Communications Magazine, Vol. 39,
No. 6, June 2001, pp. 138-147.
Sanjay K. Dhurandher , Sudip Mishra and Mohammad S.
Obaidat , “ An Energy-Aware Routing Protocol for Ad-
Hoc Networks Based on Foraging Behavior in Ant
Swarms,” IEEE ICC 2009, pp. 1-5.
K. Scott and N. Bambos, “Routing and Channel
Assignment for Low Power Transmission in PCS”,
Proc. Intl. Conf. Universal Personal Communications
(ICUPC’96), Cambridge, MA, 1996, pp. 498-502.
C. E. Perkins, E. M. Belding-Royer, and S. Das,Ad Hoc
On-demand Distance Vector (AODV) Routing”, IETF
Internet Draft, 2001.
B. Johnson, D. A. Maltz, Y.-C. Hu and J. G. Jetcheva,
“The Dynamic Source Routing for Mobile
AdHocWirelessNetworks”,http://www.ietf.org/internet
-drafts/draft-ietfmanet-dsr-06.txt,IETF Internet Draft,
Nov. 2001.
V. Park and S. Corson, “Temporally-Ordered Routing
Algorithm (TORA) Version 1”, IETF Internet Draft,
July 2001.
S. Singh, M. Woo, and C. S. Raghavendra, “Power-Aware
Routing in Mobile Ad Hoc Networks”, Proc. 4th
Annual ACM/IEEE Intl. Conf. Mobile Computing and
Networking, 1998, Dallas, TX, pp. 181-190.
M. Dorigo, V. Maniezzo and A. Colorni, The Ant System:
An Autocatalytic Optimizing Process, TR91-016,
Politecnico di Milano, 1991.
G. Di Caro, F. Ducatelle and L. M. Gambardella,
“AntHocNet: An Adaptive Nature-Inspired Algorithm
for Routing in Mobile Ad Hoc Networks”,
Telecommunications (ETT), Vol. 16, No. 2, 2005.
M. Guenes, U. Sorges and I. Bouazizi, "ARA: The Ant-
Colony Based Routing Algorithm for MANETs", Proc.
of ICPPW'02, 2002, pp. 79- 85.
APPLICATION OF ANT COLONY OPTIMIZATION TO DEVELOP ENERGY EFFICIENT PROTOCOL IN MOBILE
AD-HOC NETWORKS
17