| | Redundancy allocation algorithm | | Input: | | L = number of layers | | D(j) = quality increment of layer j | | K(j) = number of packets of layer j | | Ploss = Packet loss probability | | Rtot = total number of redundancy packets | | Output: | | Ropt(j) = redundancy packets assigned layer | | Q(j,h) = overall quality provided by layers j to L when | | protected by a total redundancy of h | | | function redund (L,D,K,Ploss,Rtot) | | Variable initialization | | r(j,h) = redundancy assigned to layer j given that | | layers j to L have a total budget of hredundancy | | blocks | | r = 0; Q=0; | | for h=0 : Rtot, | | r(L,h) = h; | | Q(L,h) = binocdf(K(L)+h,h,Ploss)(L); | | endfor | | Recursion | | for j=L-1:-1:1, | | for h=0:Rtot, | | for g=0:h; | | p_jh=binocdf(K(j)+g,g,Ploss); | | Qtmp = p_jh(D(j)+Q(j+1,h-g)); | | if Qtmp Q(j,h) | | Q(j,h) =Qtmp; | | r(j,h) = g; | | endif | | endfor | | endfor | | endfor | | Search for the overall best allocation of the total | | redundancy Rtot | | Rres = Rtot; | | for j=1:L, | | Qopt = 0; | | for h=0:Rres, | | if Q(j,h)Qopt, | | Qopt = Q(j,h) | | Ropt(j) = r(j,h); | | endif | | Rres = Rres-Ropt(j); | | endfor | | return Q | | return Ropt | | Binomial CDF | | function binocdf(n,m,p) | | f= n!/(m!(n-m)!)pm(1-p)(n-m) | | return f |
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