Nt1330 Exercise 1.1
1.6.1.1 Basic principles of trail laying
Ants may lay pheromone trails when travelling from the nest to food, or from food to the nest, or when travelling in either direction depending on the species. They also follow these trails with a allegiance which is a function of the trail strength, among other variables. Ants drop pheromones as they walk by stopping briefly and touching their gaster, which carries the pheromone secreting gland, on the ground. The strength of the trail they lay is a function of the rate at which they make deposits, and the amount per deposit. Since pheromones evaporate and diffuse away, the strength of the trail when it is encountered by another ant is a function of the original strength, and the time since the trail …show more content…
Every node has a pheromone table for every possible destination in the network, and each table has an entry for every neighbor. For example, a node with four neighbors in a 30-node network has 29 pheromone tables with four entries each. One could say that an n-node network uses n different kinds of pheromones. The entries in the tables are the probabilities which influence the ants’ selection of the next node on the way to their destination node. Figure 4 shows a possible network configuration and a pheromone table. For example, ants travelling from node 1 to node 3 have a 0.49 probability of choosing node 2 as their next node, and 0.51 of choosing node …show more content…
Newly arriving calls influence the load on nodes, which will influence the ants by means of the delay mechanism. Ants influence the routes represented by the pheromone tables, which in their turn determine the routing of new calls. These relationships are illustrated in Figure 5. One needs to realize that the pheromone table by which an individual ant is influenced, is a different table than the pheromone table that will be updated by this ant. The load on the network at any given time influences which calls can subsequently be placed on the network and which calls will fail; which of course determines the load at a later
Ants may lay pheromone trails when travelling from the nest to food, or from food to the nest, or when travelling in either direction depending on the species. They also follow these trails with a allegiance which is a function of the trail strength, among other variables. Ants drop pheromones as they walk by stopping briefly and touching their gaster, which carries the pheromone secreting gland, on the ground. The strength of the trail they lay is a function of the rate at which they make deposits, and the amount per deposit. Since pheromones evaporate and diffuse away, the strength of the trail when it is encountered by another ant is a function of the original strength, and the time since the trail …show more content…
Every node has a pheromone table for every possible destination in the network, and each table has an entry for every neighbor. For example, a node with four neighbors in a 30-node network has 29 pheromone tables with four entries each. One could say that an n-node network uses n different kinds of pheromones. The entries in the tables are the probabilities which influence the ants’ selection of the next node on the way to their destination node. Figure 4 shows a possible network configuration and a pheromone table. For example, ants travelling from node 1 to node 3 have a 0.49 probability of choosing node 2 as their next node, and 0.51 of choosing node …show more content…
Newly arriving calls influence the load on nodes, which will influence the ants by means of the delay mechanism. Ants influence the routes represented by the pheromone tables, which in their turn determine the routing of new calls. These relationships are illustrated in Figure 5. One needs to realize that the pheromone table by which an individual ant is influenced, is a different table than the pheromone table that will be updated by this ant. The load on the network at any given time influences which calls can subsequently be placed on the network and which calls will fail; which of course determines the load at a later