I've created a 600X600m WSN with 200 nodes. Each node having 60m transmission range. Now I've placed 5 Sinks randomly in same WSN. Now I want to use PSO for Sink placement for increasing lifetime of WSN by optimizing its Energy and Cost with the help of PSO. It is assumed that sensors have already been deployed and their positions are known and positions of sinks are required to be determined. How to use PSO for this problem? Also how to provide location of Sink and nodes to the PSO? To reach the global best solution, it uses its personal and global best to update the velocity Vi,d and position X i,d using the following equations-
Vi,d(t+1) = w*Vi,d(t) +c1*r1(Pi,d(t)-Xi,d(t)) + c2*r2(G(t)-Xi,d))
Xi,d (t+1) = Xi,d(t)+ Vi,d(t+1)
where 0 < ω < 1 is the inertia weight, c1, c2, 0 ≤ c1, c2 ≤ 2 are the acceleration coefficients and, r1,r2, 0 < r1,r2 < 1 are the randomly generated values. This updation of velocity and position is updated in all iterations till maximum iterations reaches. After getting new updated position, the particle evaluates the fitness function and updates Pbesti as well as Gbest.
Fitness Function can be calculated as follows-
1. Euclidian distance: Sensor consumes some energy to send data to the sinks. To maximize the lifetime of the network, we need to reduce the distance between sensors and sinks.
2. Hop Count: During the communication between sensor and sink, sensor use multihop routes to send the data. To decrease the delay we need to minimize the number of hop count.
Minimize fitness = α * F1 + β * F2
