1. AntNet: A nature inspired routing algorithm
Lecturer: Nona Helmi
Student:

2. Presentation Content Introduction Routing Basics MAS- ACO
AntNet Algorithm
Conclusion
Reference list

3. Introduction Rapid growth of networks
Increase of network communication
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

4. What Is Routing?
Routing is the act of moving information across a network from a source to a destination.
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

5. Tasks of Routing The tasks of a routing protocol are
determine the optimal paths
route information
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

6. Design Goals Optimality Simplicity and low overhead Rapid convergence
Robustness and stability
Flexibility
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

7. Agent & multi-agent system
Agent is a software that have some specification:
Autonomy
Reactivity
Pro-activeness
Social ability
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

8. Mobile Agent
A mobile agent is a software agent that can move between locations (mobility).
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

9. Nature inspired algorithms
PSO
ABC GA
ACO
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

10. ACO
introduced by Marco Dorigo (MILAN,ITALY) in his doctoral thesis in 1992
M. Dorigo, Optimization, Learning and Natural Algorithms, PhD thesis, Politecnico di Milano, Italie,1992
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

11. ACO (cont.) Based on ants method of finding food. Using to solve
traveling salesman
routing in networks
load balancing
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

12. Swarm intelligence introduction Routing basics MAS-ACO
AntNet Algorithm
Conclusion
References
End

13. Stigmergy A mechanism of indirect coordination between agents .
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

14. The process that ants search the shortest path
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

15. Ants & routing
Ants dropping different pheromones used to compute “shortest” path from source to destination(s);
Advantages:
more flexible adaptation to failures and network congestion;
use only local knowledge for routing and avoid costly communication of state to all network nodes.
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

16. AntNet AntNet: A Mobile agents Approach to Adaptive Routing.
Introduced by GIANNI DI CARO and MARCO DORIGO.
G.D Caro and M.Dorigo,“ AntNet: distributed stigmergetic control for communications networks.” Journal of Artificial Intelligence Research 9 (1998),
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

17. AntNet:Description Two kinds of Agents (Ant Packets) Forward Ant.
explores the network and collects information.
when reaches the destination, changes into backward ant.
Backward Ant.
goes back in the same path as forward ant.
update routing tables for all the
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

18. AntNet:Description (cont.)
Two data structures stored in each network node:
Routing table (P)
An array
mean
the best trip time from i to j.
variance
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

19. AntNet:Description (cont.)
Outgoing
Links
Routing table
Local
traffic
statistics
Network Node(i)
P11
P12
P1N
P2N
PmN,
P21
Pm1
Pm2
Network Nodes
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

20. AntNet algorithm
At regular interval δt,a forward agent is launched from source toward the destination.
At each node,the agent keeps the memory of the path and the traffic condition.
At each node, the next hop is selected from among all those neighboring nodes which have not yet been visited.
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

21. AntNet algorithm (cont.)
If a cycle is detected, the ant memory is popped out of stack.
When reaches destination, it generates a backward ant, transfers its stack to it and dies.
Backward ant takes the same path back using the ant stack transferred by the forward ant.
When a backward ant reaches a node k, Mk and Routing table for destination d is updated.
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

22. AntNet algorithm (cont.)
Pfd = Pfd r(1- Pfd )
Pnd = Pnd r Pnd , n  Nk, n  f
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

23. AntNet: Overview 1 3 4 2 5 6 Forward Ant (13) Backward Ant (13)
At Node 2, Update Routing Information for 3
At Node 1, Update Routing Information for 3 and
Update routing information for 2
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

24. Conclusion
The main characteristics of AntNet algorithm
Nature inspired,
Adaptivity
Inherent parallelism
Sclalablity
the Ant Colony Optimization can be applied to many other hard problems.
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

25. References
1. B.Baran ,R.Sosa, AntNet routing algorithm for data networks based on mobile agents” Inteligencia Artificial’ (2001),75-84.
2. Dorigo M., Di Caro G.A., Gambardella L.M., "Ant Algorithms for Discrete Optimization" , Artificial Life, Vol. 5, N. 2, 1999
3. Dorigo M., Stuetzle T., Ant Colony Optimization, scholarpedia, 2010
4. Di Caro G. A. "Ant Colony Optimization and its application to adaptive routing in telecommunication networks" PhD thesis in Applied Sciences, Polytechnic School, Université Libre de Bruxelles, Brussels, Belgium, 2004
introduction
Routing basics
MAS-ACO
AntNet Algorithm
Conclusion
References
End

26. Questions, Comments? Thank You  introduction Routing basics MAS-ACO
AntNet Algorithm
Conclusion
References
End