BlåtAnt-R

BlåtAnt-R is an improved version of the BlåtAnt algorithm that introduces fault tolerance, recovery mechanisms, and balanced link distribution. It retains the fully distributed nature of the original algorithm, with the use of adaptive methods inspired by Ant colonies.

Test on LAN-1281, different scenarios are considered:

• S-R: Static reliable, no changes are made during the simulation
• DP-R: Dynamic reliable with proper disconnection, nodes are added and properly removed from iteration 100 to 5000 with a frequency of 1 add/remove every 20 iterations
• DI-R: Dynamic reliable with improper disconnection, nodes are added and removed from iteration 100 to 5000 with a frequency of 1 add/remove every 20 iterations
• S-U: Static unreliable, no changes are made during the simulation. Network delays packet delivery for one iteration with a probability of 10%, and looses packets with a probability of 1% each iteration.
• DP-U: Dynamic unreliable with proper disconnection, nodes are added and properly removed from iteration 100 to 5000 with a frequency of 1 add/remove every 20 iterations. Network delays packet delivery for one iteration with a probability of 10%, and looses packets with a probability of 1% each iteration.
• DI-U: Dynamic unreliable with improper disconnection, nodes are added and removed from iteration 100 to 5000 with a frequency of 1 add/remove every 20 iterations. Network delays packet delivery for one iteration with a probability of 10%, and looses packets with a probability of 1% each iteration.

In the following graphs, vertical dotted lines indicate the 100th, repectively the 5000th iteration. Additional parameters are:

• D = 5, target diameter
• alpha_maxsize = 28, maximum alpha table size
• m = 8, maximum connections per node
• mo = 6, maximum optimization connections per node
• iota = 25, discovery ant lifespan
• mu = 0.05, discovery ant birth probability
• lv = 15, discovery ant vector length 15
• delta_fill = 1, pheromone update
• psi = 0.9, pheromone decay
• gamma_min = 0.25, minimum gamma pheromone concentration
• beta_min = 0.005, minimum beta pheromone concentration
• omega = 1, pheromone evaporation interval
• c = 1, evaluation interval
• clant_ttl = 100, construction link ants lifespan

Diameter

Average Path Length

Edges Count

Largest Connected Component

Traffic

Visual demo of a 25 nodes (initial) topology, D=5

The pseudo code of the algorithm can be found in (draft 10-11-2008).