A Novel Model on Curve Fitting and Particle Swarm Optimization for Vertical Handover in Heterogeneous Wireless Networks

Pseudocode 1

Network selection by MOPSO pseudo-code.

%% MOPSO Parameters

MaxIt=200;      % Maximum Number of Iterations

nPop=50;       % Population Size

nRep=50;       % Repository Size

w=0.5;        % Inertia Weight

wdamp=0.99;       % Inertia Weight Damping Rate

c1=1;           % Personal Learning Coefficient

c2=2;           % Global Learning Coefficient

nGrid=5;            % Number of Grids per Dimension

alpha=0.1;       % Inflation Rate

beta=2;         % Leader Selection Pressure

gamma=2;       % Deletion Selection Pressure

mu=0.1;          % Mutation Rate

%% Initialization

pop=repmat(empty_particle,nPop,1);

 for i=1:nPop

  pop(i).Position=unifrnd(VarMin,VarMax,VarSize);

  pop(i).Velocity=zeros(VarSize);

  pop(i).Cost=CostFunction(pop(i).Position);

% Update Personal Best

  pop(i).Best.Position=pop(i).Position;

  pop(i).Best.Cost=pop(i).Cost;

  end

% Determine Domination

pop=DetermineDomination(pop);

rep=pop(~[pop.IsDominated]);

Grid=CreateGrid(rep,nGrid,alpha);

for i=1:numel(rep)

  rep(i)=FindGridIndex(rep(i),Grid);

end

 %% MOPSO Main Loop

for it=1:MaxIt

  for i=1:nPop

  leader=SelectLeader(rep,beta);

  pop(i).Velocity = w*pop(i).Velocity …

  +c1*rand(VarSize).*(pop(i).Best.Position-pop(i).Position) …

  +c2*rand(VarSize).*(leader.Position-pop(i).Position);

  pop(i).Position = pop(i).Position + pop(i).Velocity;

  pop(i).Cost = CostFunction(pop(i).Position);

% Apply Mutation

  pm=(1-(it-1)/(MaxIt-1))^∧(1/mu);

  NewSol.Position=Mutate(pop(i).Position,pm,VarMin,VarMax);

  NewSol.Cost=CostFunction(NewSol.Position);

  rep=[rep; pop(~[pop.IsDominated])]; % Add Non-Dominated Particles to REPOSITORY

  rep=DetermineDomination(rep); % Determine Domination of New Resository Members

  rep=rep(~[rep.IsDominated]); % Keep only Non-Dminated Memebrs in the Repository

  Grid=CreateGrid(rep,nGrid,alpha); % Update Grid

  for i=1:numel(rep) % Update Grid Indices

  rep(i)=FindGridIndex(rep(i),Grid);

  end

  if numel(rep)>nRep    % Check if Repository is Full

  Extra=numel(rep)-nRep;

  for e=1:Extra

  rep=DeleteOneRepMemebr(rep,gamma);

  end

 end