1. An Energy Efficient Routing Protocol for Cluster-Based Wireless Sensor Networks Using Ant Colony Optimization Ali-Asghar Salehpour, Babak Mirmobin, Ali Afzali-Kusha, Siamak Mohammadi 1

2. Outline Introduction Introduction Clustering Algorithms Clustering Algorithms ACO-Based Routing in WSN ACO-Based Routing in WSN Proposed Algorithm Proposed Algorithm Results and Discussion Results and Discussion Conclusion Conclusion 2

3. Introduction Intra-cluster, cluster members send data directly to their cluster head. Intra-cluster, cluster members send data directly to their cluster head. Inter-cluster, the cluster heads use ant colony optimization (ACO) algorithm to find a route to the base station. Inter-cluster, the cluster heads use ant colony optimization (ACO) algorithm to find a route to the base station. 3

4. Introduction Each cluster is managed by a chosen Cluster- Head (CH). Each cluster is managed by a chosen Cluster- Head (CH). Cluster members send data packets to the cluster heads which communicate with each other and send the aggregated packet to the Base Station (BS). Cluster members send data packets to the cluster heads which communicate with each other and send the aggregated packet to the Base Station (BS). 4

5. Introduction The clustering techniques can considerably reduce the energy consumption. The clustering techniques can considerably reduce the energy consumption. Use the ant colony optimization (ACO) to find the optimal route from the cluster heads to the base station. Use the ant colony optimization (ACO) to find the optimal route from the cluster heads to the base station. 5

6. Clustering Algorithms In a routing algorithm called LEACH (Low- Energy Adaptive Clustering Hierarchy). In a routing algorithm called LEACH (Low- Energy Adaptive Clustering Hierarchy). The operation of LEACH is separated into rounds. The operation of LEACH is separated into rounds. Each round consists of two phases of clustering and message transmission. Each round consists of two phases of clustering and message transmission. 6

7. Clustering Algorithms Each non cluster head node sends and receives data only during its allocated transmission slot. Each non cluster head node sends and receives data only during its allocated transmission slot. The cluster head sends the aggregated and compressed data to the base station. The cluster head sends the aggregated and compressed data to the base station. 7

8. Clustering Algorithms In HEED (Hybrid Energy-Efficient Distributed Clustering), the clustering process requires a number of iterations. In HEED (Hybrid Energy-Efficient Distributed Clustering), the clustering process requires a number of iterations. A node becomes a cluster head with a certain probability which considers a mixture of energy and communication cost. A node becomes a cluster head with a certain probability which considers a mixture of energy and communication cost. 8

9. Clustering Algorithms All other nodes, which are not cluster head, select the cluster head which has the lowest intra-cluster communication cost and directly communicate with it. All other nodes, which are not cluster head, select the cluster head which has the lowest intra-cluster communication cost and directly communicate with it. 9

10. ACO-Based Routing in WSNS The most recognized ACO-based routing algorithm, AntNet, uses backward and forward agents or “ants” that explore routing possibilities throughout the network. The most recognized ACO-based routing algorithm, AntNet, uses backward and forward agents or “ants” that explore routing possibilities throughout the network. 10

11. ACO-Based Routing in WSNS At every intermediate node i, an ant chooses its next hop j toward its destination if it has not previously visited the next hop. At every intermediate node i, an ant chooses its next hop j toward its destination if it has not previously visited the next hop. The next hop is selected based on a probabilistic decision rule as The next hop is selected based on a probabilistic decision rule as 11

12. ACO-Based Routing in WSNS This enables an ant to make a decision based on the energy level of the neighbor nodes. This enables an ant to make a decision based on the energy level of the neighbor nodes. When the forward agent arrives at its destination node, a backward ant (agent) is created and the memory of the forward ant is transferred to the backward ant. When the forward agent arrives at its destination node, a backward ant (agent) is created and the memory of the forward ant is transferred to the backward ant. 12

13. ACO-Based Routing in WSNS The backward ant deposits a quantity of pheromone on each node given by The backward ant deposits a quantity of pheromone on each node given by These pheromone values are saved in the node memory to be used in future decision making for the next hop by this node. These pheromone values are saved in the node memory to be used in future decision making for the next hop by this node. 13

14. ACO-Based Routing in WSNS The operation of pheromone evaporation is used to avoid unlimited accumulation of the pheromone trails and enables the algorithm to “forget” previously done bad decisions. The operation of pheromone evaporation is used to avoid unlimited accumulation of the pheromone trails and enables the algorithm to “forget” previously done bad decisions. The operation is performed in similar intervals using The operation is performed in similar intervals using 14

15. Proposed Algorithm At intervals of definite time (round), first clustering is done using LEACH and then each cluster member sends its data to its own CH directly. At intervals of definite time (round), first clustering is done using LEACH and then each cluster member sends its data to its own CH directly. After gathering the data of the members, the CH sends the gathered data to the BS through neighbor nodes using ACO. After gathering the data of the members, the CH sends the gathered data to the BS through neighbor nodes using ACO. 15

16. Proposed Algorithm The proposed approach has three following steps: The proposed approach has three following steps: 1. Selection of CH’s and the members of each cluster. 2. TDMA scheduling where each CH decides when each node is to send its data, using TDMA. 3. Route setup where each node finds the optimal route to base through CH’s. 16

17. Proposed Algorithm After gathering the data of its own members, each CH adds some parameters to the data for making a frame (forward ant). After gathering the data of its own members, each CH adds some parameters to the data for making a frame (forward ant). 17

18. Proposed Algorithm 18

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21. Proposed Algorithm After receiving the data by BS, it should update the pheromone value of the path nodes. After receiving the data by BS, it should update the pheromone value of the path nodes. This is performed by the acknowledge frame transmitted via the backward ants. This is performed by the acknowledge frame transmitted via the backward ants. If the source node does not receive the acknowledge frame, after finishing the time- out, the transferred data is sent through another path. If the source node does not receive the acknowledge frame, after finishing the time- out, the transferred data is sent through another path. 21

22. Result and Discussion The reference network used in our simulations had 500 nodes with a diameter of 1000 meters. The reference network used in our simulations had 500 nodes with a diameter of 1000 meters. Each node had 2 joules of initial energy. Each node had 2 joules of initial energy. The packet size was 2000 bits and five percent of the nodes were selected as cluster heads. The packet size was 2000 bits and five percent of the nodes were selected as cluster heads. The base station was chosen randomly in the network. The base station was chosen randomly in the network. 22

23. Result and Discussion We assume that the energy loss due to the channel transmission is proportional to the distance to the power of two. We assume that the energy loss due to the channel transmission is proportional to the distance to the power of two. To transmit a k-bit message to a distance of d, the dissipated energy is obtained To transmit a k-bit message to a distance of d, the dissipated energy is obtained 23

24. Result and Discussion Similarly, the dissipated energy to receive a k- bit message is given by Similarly, the dissipated energy to receive a k- bit message is given by 24

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26. Conclusion We proposed a routing algorithm for the cluster-based large scale wireless sensor networks using the ant colony optimization. We proposed a routing algorithm for the cluster-based large scale wireless sensor networks using the ant colony optimization. The simulation results showed a higher system lifetime and load balancing for the proposed routing algorithm compared to these routing algorithms. The simulation results showed a higher system lifetime and load balancing for the proposed routing algorithm compared to these routing algorithms. 26

27. Thank you for your listening 27