function sensor_node_simulation()

node_number = 1000;

time_frames = 10000;

lambda = 0.12;

rand(‘twister’, sum(100*clock));

x_lim = [-100 100];

y_lim = [-100 100];

r_lim = [0 100];

phi_lim = [0 360];

node_distribution = ‘xy’;

switch node_distribution

case ‘xy’

x = rand(1,node_number).*(x_lim(2)-x_lim(1)) + x_lim(1);

y = rand(1,node_number).*(y_lim(2)-y_lim(1)) + y_lim(1);

case ‘rphi’

r = rand(1,node_number).*(r_lim(2)-r_lim(1)) + r_lim(1);

phi = rand(1,node_number).*(phi_lim(2)-phi_lim(1)) + phi_lim(1);

[x,y] = pol2cart(phi,r);

end

for i = 1:node_number

node_field(i) = struct(‘x’,x(i),’y’,y(i),’state’,’idle’,’contest_wait’,1,’brxss’,-90,’txpower’,0,’rxs’,-70,’event_chance’,0.001,’sleep_chance’,0,’wakeup_chance’,0,’received’,0,’backoff’,0,’packet_data’,[],’prev_backoff_level’,0,’batcap’,10000,’battery’,10000);

end

for i = 1:node_number

linkage = {};

link_num = 0;

for j = 1:node_number

if i ~=j

dist = ((node_field(i).x – node_field(j).x).^2 + (node_field(i).y – node_field(j).y).^2).^0.5;

pathloss = 20.*log10((lambda./4./pi./dist));

if -pathloss < (node_field(i).txpower – node_field(j).rxs)

link_num = link_num + 1;

linkage{link_num}= {j, pathloss};

end

end

end

node_field(i).link_num = link_num;

node_field(i).links = linkage;

end

node_display_r = [0 0;

0.25 0.25;

0.5 0.5;

0.75 0.75;

1 1;

1 1;

1 1;

1 1;

1 1;

0.75 0.75];

node_display_g = [1 1;

1 1;

1 1;

1 1;

1 1;

1 1;

0.75 0.75;

0.5 0.5;

0.25 0.25;

0 0];

node_display_b = zeros(10,2);

node_display = cat(3,node_display_r,node_display_g,node_display_b);

cf = figure(‘Units’,’pixels’,’Position’,[200 50 625 625]);

ca = axes(‘Parent’,cf,’Position’,[0 0 1 1]);

link_map = ones(625);

display_map(node_number,node_field,x_lim,y_lim,node_display,link_map,cf,ca);

drawnow;

scaling_factor = 3;

for time_slot = 1:time_frames

[node_field,link_map] = node_event_check_full(node_field,node_number,x_lim,y_lim,scaling_factor,link_map);

if rem(time_slot,25) == 1

display_map(node_number,node_field,x_lim,y_lim,node_display,link_map,cf,ca);

drawnow;

end

end