% 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;
