Scalable Video Streaming for Single-Hop Wireless Networks Using a Contention-Based Access MAC Protocol

Algorithm 2

Compute $p_i$'s given all $R_i^{\prime }$'s.

$[p_1\mathrm{,}{p}_2,\dots ,p_N\mathrm{,}\text{success}]=\text{Compute}\_p(R_1^{\prime }\mathrm{,}{R}_2^{\prime },\dots ,R_N^{\prime }\mathrm{,}N)$

$ϵ=0.01$

$I^{\prime }=1$

$\{I^{\prime }$ is the percentage of idle slots$\}$

$\text{search\_step}=0.01$

$\text{success}=0$

for $i=1$ to $N$ do

 $S_i=\frac{R_i^{\prime }}{\text{TXOP}\times (1-{\sum }_{i=1}^N{R}_i^{\prime })}$

end for

while $I^{\prime }<1$ do

 for $i=1$ to $N$ do

  $p_i=\frac{S_i}{I^{\prime }+S_i}$

 end for

 $\{$run Algorithm 1 to compute collision probability $C\}$

 $C=\text{Compute}\_C(p_1\mathrm{,}{p}_2,\dots ,p_N\mathrm{,}N)$

 $\text{total}=I^{\prime }+C(\text{RTS}+\text{DIFS})+{\sum }_{i=1}^N{S}_i(\text{RTS})$

 $\{$check for boundary condition smaller $ϵ$ results in higher accuracy$\}$

 if $(\text{abs}(\text{total}-1)<ϵ)$ then

  $\text{success}=1$

  $\text{return}[p_1\mathrm{,}{p}_2,\dots ,p_N\mathrm{,}\text{success}]$

 end if

 $I^{\prime }=I^{\prime }-\text{search\_step}$

$endwhile\{$fail to find $p$, $\text{success}=0\}$

$\text{return}[\mathrm{0,0,}\dots \mathrm{,0,}\text{success}]$