By,
Name:
Roll:
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Branch:
Suraj Padhy
S/07/73
0701204232
CSE
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). 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.
• One of the most important performance parameter in adhoc networks is minimizing the total transmission energy
in the path and extending the battery life of the nodes.
Introduction cont…
• Conventional Routing algorithms were developed for that
such as AODV [1], DSR[2] and TORA[3] .
• These protocols generally focus on finding the shortest
path available from source node to the destination node.
• There exists a protocol Minimum Transmission Power
Routing (MTPR) [4] which tries to minimize the total
transmission power And the whole concept of ANT
COLONY OPTIMIZATION is to minimize the path and
power consumption.
General Tendency Of Ants
 Can explore vast areas without global view of the
ground.
 Can find the food and bring it back to the nest.
 Will converge to the shortest path.
Ant Moves
 Four types:
 From home to food


Goal has never been reached:
Goal reached:
moveStraightAwayFromAway();
moveTowardAway();
 Back to home


Goal has never been reached:
Goal reached:
moveFromFoodToHome();
moveFromHomeToFood();
 Idea: generates several random moves and see which one is
the best among them.
Applications
 Traveling Salesman Problem
 Quadratic Assignment Problem
 Network Model Problem
 Vehicle routing
 Scheduling
 Telecommunication Network
 Graph Coloring
 Water Distribution Network
etc . . .
Traveling Salesman Problem
TSP PROBLEM : Given N cities, and a distance function d between cities,
find a tour that:
1. Goes through every city once and only once
2. Minimizes the total distance.
•
•
Problem is NP-hard
Classical combinatorial
optimization problem to
test.
ACO for Traveling Salesman Problem
The TSP is a very important problem in the context of
Ant Colony Optimization because it is the problem to
which the original AS was first applied, and it has later
often been used as a benchmark to test a new idea and
algorithmic variants.
The TSP was chosen for many reasons:
• It is a problem to which the ant colony metaphor
• It is one of the most studied NP-hard problems in the combinatorial optimization
• it is very easily to explain. So that the algorithm behavior is not obscured
too many technicalities.
by
Algorithm for TSP
Initialize
Place each ant in a randomly chosen city
For Each Ant
Choose NextCity(For Each Ant)
yes
more cities
to visit
No
Return to the initial cities
Update pheromone level using the tour cost for each ant
No
Stopping
criteria
yes
Print Best tour
Iteration 1
[B]
[A]
1
2
A
B
[C]
3
C
[E]
[D]
4
D
5
E
Iteration 2
[E,A]
5
[C,B]
3
A
B
[B,C]
2
C
[A,D]
[D,E]
1
D
4
E
Iteration 3
[D,E,A]
4
[E,A,B]
5
A
B
[A,D,C]
1
C
[B,C,D]
[C,B,E]
2
D
3
E
Iteration 4
[B,C,D,A]
2
[D,E,A,B]
4
A
B
[E,A,B,C]
5
C
[C,B,E,D]
D
[A,DCE]
3
1
E
Iteration 5
[A,D,C,E,B]
[C,B,E,D,A]
1
3
A
B
[D,E,A,B,C]
4
C
[E,A,B,C,D]
[B,C,D,A,E]
D
5
E
2
ACO Algorithms : An Overview
Problem name
Authors
Algorithm name
Year
Traveling salesman
Dorigo, Maniezzo & Colorni
AS
1991
Gamberdella & Dorigo
Ant-Q
1995
Dorigo & Gamberdella
ACS &ACS 3 opt
1996
Stutzle & Hoos
MMAS
1997
Bullnheimer, Hartl & Strauss
ASrank
1997
Cordon, et al.
BWAS
2000
Maniezzo, Colorni & Dorigo
AS-QAP
1994
Gamberdella, Taillard & Dorigo
HAS-QAP
1997
Stutzle & Hoos
MMAS-QAP
1998
Maniezzo
ANTS-QAP
1999
Maniezzo & Colorni
AS-QAP
1994
Colorni, Dorigo & Maniezzo
AS-JSP
1997
Stutzle
AS-SMTTP
1999
Barker et al
ACS-SMTTP
1999
den Besten, Stutzle & Dorigo
ACS-SMTWTP
2000
Merkle, Middenderf & Schmeck
ACO-RCPS
1997
Bullnheimer, Hartl & Strauss
AS-VRP
1999
Gamberdella, Taillard & Agazzi
HAS-VRP
1999
Quadratic assignment
Scheduling problems
Vehicle routing
ACO Algorithms : An Overview cont…
Problem name
Authors
Algorithm name
Year
Connection-oriented
Schoonderwood et al.
ABC
1996
network routing
White, Pagurek & Oppacher
ASGA
1998
Di Caro & Dorigo
AntNet-FS
1998
Bonabeau et al.
ABC-smart ants
1998
Connection-less
Di Caro & Dorigo
AntNet & AntNet-FA
1997
network routing
Subramanian, Druschel & Chen
Regular ants
1997
Heusse et al.
CAF
1998
van der Put & Rethkrantz
ABC-backward
1998
Sequential ordering
Gamberdella& Dorigo
HAS-SOP
1997
Graph coloring
Costa & Hertz
ANTCOL
1997
Shortest common supersequence
Michel & Middendorf
AS_SCS
1998
Frequency assignment
Maniezzo & Carbonaro
ANTS-FAP
1998
Generalized assignment
Ramalhinho Lourenco & Serra
MMAS-GAP
1998
Multiple knapsack
Leguizamon & Michalewicz
AS-MKP
1999
Optical networks routing
Navarro Varela & Sinclair
ACO-VWP
1999
Redundancy allocation
Liang & Smith
ACO-RAP
1999
Constraint satisfaction
Solnon
Ant-P-solver
2000
Advantages
 Positive Feedback accounts for rapid discovery of good
solutions
 Distributed computation avoids premature convergence
 The greedy heuristic helps find acceptable solution in the
early solution in the early stages of the search process.
 The collective interaction of a population of agents.
Disadvantages
 Slower convergence than other Heuristics
 Performed poorly for TSP problems larger than 75
cities.
 No centralized processor to guide the AS towards good
solutions
Conclusion
 ACO is a recently proposed metaheuristic approach for




solving hard combinatorial optimization problems.
Artificial ants implement a randomized construction
heuristic which makes probabilistic decisions.
The a cumulated search experience is taken into account by
the adaptation of the pheromone trail.
ACO Shows great performance with the “ill-structured”
problems like network routing.
In ACO Local search is extremely important to obtain good
results.