delay_fixed.m

L. Dong and A. P. Petropulu, 揗ultichannel ALLIANCES: A Cross-layer Cooperative Scheme for Wireless

% delay for fixed subchannel selection scheme (figure 7(a))
% adpative subchannel allocation according to traffic load

clear all
close all
G=4; % number of subchannel
M=10000;  % number of simulation slots   
J=32;   % number of users
simurange=20; % number of points to plot
WorkLoad=[0:simurange-1]/simurange+0.01;
BufSize = M;  % buffer size
num_trial=20;    % number of Monto-Carlo experiments
avg_delay=zeros(simurange,1);   % fix subchannel allocation (each traffic type only uses its own subchannels)
avg_delay1=zeros(simurange,1);  % type I with adaptive subchannel allocation
avg_delay2=zeros(simurange,1);  % type II with adaptive subchannel allocation
avg_delay3=zeros(simurange,1);  % type III with adaptive subchannel allocation

for ss=1:num_trial
    ss
    
    % generate the Poisson traffic
    [Traffic,WorkLoad] = gen_traffic(M, J, simurange);
    
    for ii = 1:simurange % for each traffic
        sm_traffic = Traffic(:,:,ii); % Generate new traffic
        
        %%%%%%%% initialization %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        
        % new traffic load
        Loads=zeros(1,J);
        Loads1 = zeros(1,J);    
        Loads2 = zeros(1,J);  
        Loads3 = zeros(1,J);
        
        % to indicate which packet each user is transmiting
        flag=zeros(1,J);
        flag1=zeros(1,J);
        flag2=zeros(1,J);
        flag3=zeros(1,J);
        
        % used to store the time slots at which packets are resolved 
        time_table=zeros(J,M+J);
        time_table1=zeros(J,M+J);
        time_table2=zeros(J,M+J);
        time_table3=zeros(J,M+J);
        
        % record time slots at which packets are generated (put in the first
        % coule of columns of the matrix pos_pack)
        pos_pack=zeros(J,M+J);
        for nn=1:J
            temp=find(Traffic(nn,:,ii)==1); % find packets
            pos_pack(nn,1:length(temp))=temp;
        end 
        
        % count number of packets
        count_pack=0;
        count_pack1=0;
        count_pack2=0;
        count_pack3=0;
        
        % indicate whether a CTE is over
        flag_CTE=0;
        flag_CTE1=0;
        flag_CTE11=0;
        flat_CET13=0;
        flag_CTE2=0;
        flag_CTE3=0;
        
        %%%%%%%%%%% start the simulation  %%%%%%%%%%%%%%%%%%%%%%%%%%%%%
        
        for t1 = 1:M % for each slot
            newLoads = sm_traffic(:,t1)';   % generate new traffic
            Loads1 = Loads1 + newLoads; % Add new traffic of type I to buffer
            Loads2 = Loads2 + newLoads; % Add type II to buffer
            Loads3 = Loads3 + newLoads; % Add type III to buffer
            Loads = Loads + newLoads; %  Add to buffer
            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
            % fixed subchannel allocation (each traffic type uses its own
            % subchannels for collsion resolution)
            
            flag_CTE=max(0,flag_CTE-1);
            
            Trans = Loads >0;   % check whether buffer is not empty
            num_active=sum(Trans); % number of active users
            if num_active>0 & flag_CTE==0
                
                active = find(Trans)'; % active users
                flag_CTE=num_active;    % CTE length + collision slot
                
                ret_array = zeros(1,J);
                ret_array(active)=1;
                
                Loads = Loads - ret_array; % update the buffer 
                count_pack=count_pack+num_active; % count received packets
                
                for kk=1:num_active
                    flag(active(kk))=flag(active(kk))+1; % update flag
                    t_gen=pos_pack(active(kk),flag(active(kk)));  % which time slot the packet is generated
                    time_table(active(kk),flag(active(kk)))=num_active+t1-t_gen; % record the duration for this packet's transmission
                end
            end
            
            
            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
            % traffic I packet
            
            flag_CTE1=max(0,flag_CTE1-1);
            flag_CTE11=max(0,flag_CTE11-1);
            
            if flag_CTE11==0
                flag_CTE13=0;
            end
            
            if flag_CTE1==0
                
                Trans1 = Loads1 >0;
                num_active1=sum(Trans1);
                active1 = find(Trans1)';
                
                if num_active1>0
                    
                    time1=num_active1-1; % uses its own 2 subchannels
                    
                    if WorkLoad(ii) > 0.7
                        for kk=1:num_active1
                            t_gen=pos_pack(active1(kk),flag1(active1(kk))+1);
                            temptime(kk)=num_active1+t1-t_gen;
                        end 
                        if  min(temptime) > 5
                            time1=(2*num_active1-2)/3;  % uses its own subchannel as well as Type III (totally 3)
                            flag_CTE13=1;
                        end
                    end
                    
                    flag_CTE1=1+ceil(time1);
                    flag_CTE11=1+fix(time1);
                    ret_array = zeros(1,J);
                    ret_array(active1)=1;
                    
                    Loads1 = Loads1 - ret_array;
                    count_pack1=count_pack1+num_active1;
                    for kk=1:num_active1
                        flag1(active1(kk))=flag1(active1(kk))+1;
                        t_gen=pos_pack(active1(kk),flag1(active1(kk)));
                        time_table1(active1(kk),flag1(active1(kk)))=1+ceil(time1)+t1-t_gen;
                    end  
                end
            end

            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
            % traffic II packet
            flag_CTE2=max(0,flag_CTE2-1);
            
            if flag_CTE2==0
                Trans2 = Loads2 >0;
                num_active2=sum(Trans2);
                active2 = find(Trans2)';
                
                if num_active2>0                    
                    time2=num_active2-1;
                    flag_CTE2=num_active2;
                    for kk=1:num_active2
                        flag2(active2(kk))=flag2(active2(kk))+1;
                        t_gen=pos_pack(active2(kk),flag2(active2(kk)));
                        time_table2(active2(kk),flag2(active2(kk)))=num_active2+t1-t_gen;
                    end  
                    
                    ret_array = zeros(1,J);
                    ret_array(active2)=1;                
                    
                    Loads2 = Loads2 - ret_array;
                    count_pack2=count_pack2+num_active2;  
                    
                end
            end
            
            %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
            % traffic III packet
            
            flag_CTE3=max(0,flag_CTE3-1);                        
            
           if flag_CTE3==0
                Trans3 = Loads3 >0;
                num_active3=sum(Trans3);
                active3 = find(Trans3)';
                if num_active3>0
                    
                    if WorkLoad(ii)<=0.7 | (WorkLoad(ii)>=0.7 & flag_CTE13==0) 
                        flag_CTE3=num_active3;
                        ret_array = zeros(1,J);
                        ret_array(active3)=1;                      
                        Loads3 = Loads3 - ret_array;
                        count_pack3=count_pack3+num_active3;
                        num_active3_save=num_active3;
                        active3_save=active3;
                        
                        for kk=1:num_active3
                            flag3(active3(kk))=flag3(active3(kk))+1;
                            t_gen=pos_pack(active3(kk),flag3(active3(kk)));
                            time_table3(active3(kk),flag3(active3(kk)))=num_active3+t1-t_gen;
                        end   
                    else
                        if num_active1>0 | flag_CTE11==0                   
                            
                            flag_CTE3=fix(time1)+num_active3;
                            ret_array = zeros(1,J);
                            ret_array(active3)=1;                      
                            Loads3 = Loads3 - ret_array;
                            count_pack3=count_pack3+num_active3;
                            num_active3_save=num_active3;
                            active3_save=active3;

                            for kk=1:num_active3
                                flag3(active3(kk))=flag3(active3(kk))+1;
                                t_gen=pos_pack(active3(kk),flag3(active3(kk)));
                                time_table3(active3(kk),flag3(active3(kk)))=fix(time1)+num_active3+t1-t_gen;
                            end                     
                        end
                    end
                    
                end
            end
            
            if WorkLoad(ii)>0.7 & flag_CTE13==1 & flag_CTE3>0 & num_active3_save>0 & num_active1>0 &  flag_CTE1 ==1+ceil(time1);
                additional=fix(time1);
                for kk=1:num_active3_save
                    time_table3(active3_save(kk),flag3(active3_save(kk)))=time_table3(active3_save(kk),flag3(active3_save(kk)))+additional;
                end
            end
            
            num_active1=0; 
            num_active2=0; 
            num_active3=0;
            time1=0;
            time2=0;
            time3=0;
        end % for t1 = 1:M
        
        if count_pack>0
            avg_delay(ii)=avg_delay(ii)+sum(sum(time_table))/count_pack;
            avg_delay1(ii)=avg_delay1(ii)+sum(sum(time_table1))/count_pack1;
            avg_delay2(ii)=avg_delay2(ii)+sum(sum(time_table2))/count_pack2;
            avg_delay3(ii)=avg_delay3(ii)+sum(sum(time_table3))/count_pack3;
        end
        
        
        
    end
end
figure
plot(WorkLoad,avg_delay/num_trial,'b','linewidth',2)
hold on
plot(WorkLoad,avg_delay1/num_trial,'k-','linewidth',2)  % traffic I
plot(WorkLoad,avg_delay2/num_trial,'k-.','linewidth',2) % traffic II
plot(WorkLoad,avg_delay3/num_trial,'k--','linewidth',2) % traffic III