%function?[?output_args?]?=?aloha（?input_args?）
%ALOHA?Summary?of?this?function?goes?here
%???Detailed?explanation?goes?here
%SIMULATION?PARAMETERS
%simulation?for?pure?Aloha?protocol
%total?simulation?time?in?seconds
runtime=0.2;
%total?number?of?stations
nstation=10;
%transmission?throughput?of?the?media?in?bits?per?second
netthrou=10e6;
%frame?size?in?bits
fsize=8000;
%avarage?frame?arrival?rate?per?second?for?each?station
%frate=10;
for?frate=1:5:150
%average?frame?arrival?rate?per?simulation?iteration
trh=frate/10000;
%random?wait?window?in?number?of?simulation?iterations
wwind=100;
%EVENTS?VARIABLES
%transmit?active
tr=zeros（1nstation）;
%transmit?queue
tq=zeros（1nstation）;
%transmit?progress?counter
tcnt=zeros（1nstation）;
%collision?keeper
colis=zeros（110000*runtime）;
%collision?station?index
colin=zeros（1nstation）;
%random?wait?after?collision
rwait=zeros（1nstation）;
%transmit?keeper
trkeep=zeros（nstation10000*runtime）;
%packet?arrival?keeper
pakeep=0;
for?i=1:10000*runtime
for?j=1:nstation
????%check?if?the?transmitter?is?active
????if?tr（j）==1
????????trkeep（ji）=1;
????end
????%check?if?the?packet?has?been?sent
?????if?tcnt（j）>0
????????tcnt（j）=tcnt（j）-1;
????????if?tcnt（j）==0
????????????tr（j）=0;
????????????%check?if?the?transmission?is?collision?free
????????????if?colin（j）==1
????????????????rwait（j）=ceil（wwind*rand（11））;
????????????????tq（j）=tq（j）+1;
????????????????colin（j）=0;
????????????end
????????end
????else
????????if?tq（j）>0?&?rwait（j）==0
????????????tr（j）=1;
????????????tcnt（j）=ceil（fsize/netthrou*10000）;
????????????tq（j）=tq（j）-1;
????????end
????end
????%check?if?a?new?packet?has?arrived
????pa=rand（11）;
????if?pa????????pakeep=pakeep+1;
????????%if?the?transmit?is?ready
????????if?tr（j）==0?&?rwait（j）==0
???????????tr（j）=1;
???????????tcnt（j）=ceil（fsize/netthrou*10000）;
????????else
???????????tq（j）=tq（j）+1;
????????end
????end
????%decrease?random?waiting?count
????if?rwait（j）>0
????????rwait（j）=rwait（j）-1;
????end
end
%check?for?collision
if?sum（tr）>1
????????colis（i）=1;
????????for?k=1:nstation
????????????if?tr（k）==1
????????????????colin（k）=1;
????????????end
????????end
end
end
px1（frate）=（pakeep-sum（tq））;
py1（frate）=pakeep;
end
g1=[0:0.01:1.2];
s1=g1.*exp（-2*g1）;
figure（1）
plot（px1*8000/runtimepy1*8000/runtime‘x‘s1*1e7g1*1e7‘-‘）
grid
xlabel（‘Throughput?（bps）‘）
ylabel（‘Arrival?Rate?（bps）‘）

?屬性????????????大小?????日期????時(shí)間???名稱(chēng)
-----------?---------??----------?-----??----
?????文件????????2383??2009-11-10?00:24??aloha.m