Selective Repeat Protocol [Matlab]

clc;

clear all;

n=input('Enter the number of frames: ');

w=input('Window Size: ');

pt=w+1;

flag=0;

ext=0;

flag1=0;

flag2=0;

a=1:n;

for i=1:w

fprintf('Frame %d Transferred\n',a(i));

end

while flag==0

s=randint(1,1,10);

if s>3

fprintf('PAK of frame %d received\n',a(pt-w));

else

fprintf('NAK of frame %d received\n',a(pt-w));

ext=ext+1;

for i=n+ext:-1:pt+1

a(i)=a(i-1);

end

a(pt)=a(pt-w);

end

fprintf('Frame %d Transferred\n',a(pt));

if a(pt)==n

flag=1;

end

pt=pt+1;

end

k=pt-w;

while flag2==0

test=randint(1,1,[1 7]);

if flag1==1

fprintf('Frame %d Transmitted\n',a(k));

flag1=0;

end

if test>3

fprintf('PAK of frame %d received\n',a(k));

k=k+1;

else

fprintf('NAK of frame %d received\n',a(k));

flag1=1;

end

if k==n+ext+1

flag2=1;

end

end