CSMA_main.rar_csma

% master - nodes communication prototype with CSMA/CA algorithm; % Zach - June 11, 20115 clear all close all clc % %---------------------Input Parameters---------------------------{ % n=input('Number of nodes [5]? '); % % if length(n)==0 % % n=5; % % end % % frame_size=input('Average Transmission Time (packet size) [5]? '); % % if length(frame_size)==0 % % frame_size=zeros(n+1,1)+10; % % end % % % % simulation_time=input('Simulation Time in ms (SlotTime=2) [600]? ');%ms % % if length(simulation_time)==0 % % simulation_time=600; % % % end % % %---------------------Input Parameters---------------------------} n=5; simulation_time=100; back_off_base=4; frame_size=zeros(n+1,1)+10; max_DIFS=4; visualize=1; r=3; random_prob=0.05; movepara=5; global plot_flag; plot_flag=zeros(n+1,6); %col1:flag col2:send/ack col3:sendingx col4 sendingy col5:revx col6 revy % Simulation parameter % All the status are measured by slot % SIFS: 2 slots; % DIFS: 2 slots + SIFS; % PIFS: 1 slots + SIFS; % Frame size(each): 2 slot; % ACK: 2 slot; %State table % 0: idle(nothing to send) % 1: waiting for the media available (have something to send) % 2: Free media and wait for DIFS (have something to send) % 3: Sending Data % 4: waiting for SIFS % 5: sending ACK % 6: wait for ACK % 7: recieving Data % -1: Random back-off, not receiving ACK (Data collision) % In the simulation all the nodes only talk to master, master can talk to % each nodes; frames size are fixed % rows represent which node columes represent time status_matrix = zeros(n+1,simulation_time); %status of each node, the first row is master's status next_status_timer = zeros(n+1,simulation_time); %count the time left for current status comm_matrix = zeros(n+1,simulation_time); %which node has something to send at the time ack_matrix = zeros(n+1,simulation_time); back_off_counter=zeros(n+1,1); first_frame_flag=zeros(n+1,1); priority_matrix=zeros(n+1,1); %now we only support 2 priorities high and low their DIFS is 3 and 4 slots %comm_matrix(2,1)=1; %comm_matrix(3,1)=1; if visualize==1 masterx=0; mastery=0; figure %plot master and slave nodes x_position=zeros(1,n); y_position=zeros(1,n); for i=1:360/n:360 x_position(floor(i*n/360)+1)=r*sin(i/360*2*pi); y_position(floor(i*n/360)+1)=r*cos(i/360*2*pi); end x_position=[masterx x_position]; y_position=[mastery y_position]; h(1)=plot(x_position(1),y_position(1),'or','MarkerSize',16,'MarkerEdgeColor','k','Marker','o'); hold on; for i=2:n+1 h(i)=plot(x_position(i),y_position(i),'or','MarkerSize',10,'MarkerEdgeColor','b','Marker','o'); end axis([-5 5 -5 5]); position=[x_position;y_position]; end for clock= 2: simulation_time %random location generator if visualize==1 random = (rand(2,n+1)-0.5)/movepara; position=position+random; x_position=position(1,:); y_position=position(2,:); for i=1:n+1 set(h(i),'XData',position(1,i),'YData',position(2,i)) pause(0.015); end end % random frame generator for i=1:n+1 if(comm_matrix(i,clock-1)==0&&status_matrix(i,clock-1)~=7) if(rand(1)<random_prob) random=randi(n); if(random>=i) random=random+1; end comm_matrix(i,clock-1)=random; first_frame_flag(i)=1; end end end %comm_table is not 0 means have something to send; %first fill the current status matrix with sending status; [status,timer,flag] = working_node(status_matrix(:,clock-1),next_status_timer(:,clock-1),frame_size,first_frame_flag); status_matrix(:,clock) = status; next_status_timer(:,clock) = timer; first_frame_flag = flag; %now update current status and timer based on previous status and timer %update comm_matrix also; [status,timer,comm,counter,flag,ack] = state_machine(status_matrix(:,clock-1:clock),next_status_timer(:,clock-1),comm_matrix(:,clock-1)... ,frame_size,back_off_counter,first_frame_flag,priority_matrix,max_DIFS,x_position,y_position,ack_matrix(:,clock-1)); status_matrix(:,clock) = status; next_status_timer(:,clock) = timer; comm_matrix(:,clock) = comm; back_off_counter = counter; first_frame_flag = flag; ack_matrix(:,clock)=ack; %plot the sending/Ack signal if visualize==1 if(sum(plot_flag(:,1))>=1) plot_line; end end ss=1; end status_matrix next_status_timer figure %Visualize states Matrix imagesc(status_matrix); %# Create a colored plot of the matrix values %colormap(flipud(gray)); %# Change the colormap to gray (so higher values are %# black and lower values are white) textStrings = num2str(status_matrix(:),'%i'); %# Create strings from the matrix values textStrings = strtrim(cellstr(textStrings)); %# Remove any space padding [x,y] = meshgrid(1:size(status_matrix,2),1:size(status_matrix,1)); %# Create x and y coordinates for the strings hStrings = text(x(:),y(:),textStrings(:)... %# Plot the strings ); set(gca,'YTick',1:n+1,... %# Change the axes tick marks 'YTickLabel',{'Master','Slave1','Slave2','Slave3','Slave4','Slave5'},... 'TickLength',[0 0]); title('CSMA/CA Simulation result') sss=1;