slotted_ALHOA.rar_Contention Window_Slotted-Aloha_slotted_slotte

N=input('please input the number of nodes:') M=input('please input the Transmission window size:') D=input('please input the maximum number of slot a node will wait after a collision:') L=0; %L is the average CW size for k=1:1:100000 %for 10 thousand loops T=ones(1,N); %for simplicity,we assume at one moment, all the nodes get collision,assume all the nodes get collision,we set them in one position,that is '1' as a matrix %for k=1:100000 for i=1:1:N rand_slot=randint(1,D,[1,D]);%generate a waiting-slot sequence which max number is S,which is randomly distribute T(i)=T(i)+rand_slot(D); %after a random waiting slot(D),some users may transmit,some user may get collision end S=sort(T); if S(1)~=S(2) %try to find the number which only show once.it means this user has transmit success and no collision with others S(1)=0; %and put this success nodes '0' end if S(N)~=S(N-1) S(N)=0; end for i=2:1:(N-1) if (S(i)~=S(i+1))&&(S(i)~=S(i-1)) S(i)=0; end end %%%%%%%%%%%%%%%%%%%%%%%%%% while S(N-1)~=0 %in the end,all the nodes will finish the transmit.the last number in matrix S will be one contention window S=sort(S); for i=1:1:N rand_slot=randint(1,D,[1,D]); if S(i)~=0 S(i)=S(i)+rand_slot(D); end end S=sort(S); j=1; while S(j)==0 j=j+1; end if S(j)~=S(j+1) S(j)=0; end for j=(j+1):1:(N-1) if (S(j)~=S(j+1))&&(S(j)~=S(j-1)) S(j)=0; end end %if S(N)~=S(N-1) % S(N)=0; end L=S(N)+L; end L=L/1000; L %the output will be the matrix S,which the last number will be the size of contention window %However I did not know how to make 100000 trails for loop, I will keep %thinking the way to implement it. I will sent the revised one as soon as I make this improvent. %this is a .m file:double click the MATLAB 7.5 and click File,Open this %file(maybe it require to add this file to the path), and click Run %Thank you very much and I am will to explain my code by myself %copyright@Yuan Song