Algorithm 2 Re-encoding strategy

1: Intermediate node $\mathit{T}$ receives a packet $\mathit{pkg}\mathit{2}$ from $\mathit{S}$.

2: $\mathit{T}$ extracts frame number $\mathit{N}$ from $\mathit{pkg}\mathit{2}$. 3: If $\mathit{N}\mathbf{=}\mathbf{=}\mathit{RFlag}$ 4:  $\mathit{T}$ discards $\mathit{pkg}\mathit{2}$. 5: Else 6:  $\mathit{T}$ extracts row vector ${\mathit{P}}_i$ and encoded data slice ${\mathit{Y}}_i$ from $\mathit{pkg}\mathit{2}$. 7:  If $\mathit{N}\mathbf{=}\mathbf{=}\mathit{Flag}$

8:    $\mathit{r}\mathit{1}\mathbf{=}\mathit{rank}\mathbf{\left(}\mathit{G}\mathbf{\right)}$ 9:    ${\mathit{r}\mathit{2}\mathbf{=}\mathit{rank}\mathbf{(}\mathit{P}}_i\cup \mathit{G}\mathbf{)}$ 10:    If $\mathit{r}\mathit{2}\mathbf{>}\mathit{r}\mathit{1}$ do 11:      Add ${\mathit{P}}_{\mathit{i}}$ into matrix $\mathit{G}$.

12:      Add ${\mathit{P}}_{\mathit{i}}$ into existing encoded data $\mathit{H}$.

13:      $\mathit{Count}\mathbf{+}\mathbf{+}$;

14:      If $\mathit{Count}\mathbf{=}\mathbf{=}\mathit{K}$

15:        Re-encode $\mathit{G}$, $\mathit{H}$ and compose new data packets $\mathit{pkg}$. 16:        $\mathit{T}$ sends $\mathit{pkg}$ back to the network. 17:        $\mathit{RFlag}\mathbf{=}\mathit{N}$

18:      Endif

19:    Endif 20:  Else

21:    $\mathit{Flag}\mathbf{=}\mathit{N}$

22:     Get $\mathit{K}$ from $\mathit{pkg}\mathit{2}$ and save the data in it

23:    Clear matrix $\mathit{G}$ and encoded data $\mathit{H}$

24:    $\mathit{Count}\mathbf{=}\mathit{0}$

25:  Endif

26: Endif