Background Traffic-Based Retransmission Algorithm for Multimedia Streaming Transfer over Concurrent Multipaths

Algorithm 1

RTX_CSI Algorithm.

Definition:

𝑑_𝑖: the  𝑖_th  path in the destination list of core node

𝑑_list: the active destination list of core node

𝑑_𝑖^{𝑐𝑤𝑛𝑑}: the 𝑐𝑤𝑛𝑑 value of the 𝑖_th path

𝑑_𝑖^{𝑠𝑠𝑡ℎ}: the 𝑠𝑠𝑡ℎ𝑟𝑒𝑠ℎ value of the 𝑖_th path

𝑑^tor_𝑖: total timeouts on 𝑑_𝑖 in timeslot 𝜏

𝑑^interval: the 𝑡_interval of the 𝑖_𝑡ℎ path

𝑑_{𝑟𝑡𝑥Dest}: the destination selected to retransmit loss data

Once having packet to resend

1: for each destination 𝑑_𝑖  do //scan all paths’ condition

2: if status of 𝑑_𝑖 == ACTIVE then

3:  put 𝑑_𝑖 into 𝑑_list; //ignore the inactive paths

4: end if

5: end for

6: set 𝑑_𝑠^{𝑐𝑤𝑛𝑑}=𝑑^{𝑐𝑤𝑛𝑑}_list(0),𝑑_𝑡^{𝑠𝑠𝑡ℎ}=𝑑^{𝑠𝑠𝑡ℎ}_list(0),𝑑^interval_𝑤=𝑑^interval_list(0);

7: for (𝑖=1,𝑖<=count(𝑑_list),𝑖++) do

//select the destination which has largest 𝑐𝑤𝑛𝑑 value in loop

8:  if (𝑑_𝑠^{𝑐𝑤𝑛𝑑}<𝑑^{𝑐𝑤𝑛𝑑}_list(𝑖)) then

9:    set 𝑠=𝑖; set 𝑑_𝑠^{𝑐𝑤𝑛𝑑}=𝑑^{𝑐𝑤𝑛𝑑}_list(𝑖);

10:  end if

//select the destination which has largest ssthresh value in loop

11:   if (𝑑_𝑡^{𝑠𝑠𝑡ℎ}<𝑑^{𝑠𝑠𝑡ℎ}_list(𝑖)) then

12:    set 𝑡=𝑖; set 𝑑_𝑡^{𝑠𝑠𝑡ℎ}=𝑑^{𝑠𝑠𝑡ℎ}_list(𝑖);

13:   end if

//select the destination which has lowest tor value in loop

14:  if (𝑑^tor_𝑡>𝑑^tor_list(𝑖)) then

15:    set 𝑡=𝑖; set 𝑑^tor_𝑡=𝑑^tor_list(𝑖);

16:  end if

//select the destination which has largest 𝑡_interval value in loop

17:  if (𝑑^interval_𝑤<𝑑^interval_list(𝑖)) then

18:   set 𝑤=𝑖; set 𝑑^interval_𝑤=𝑑^interval_list(𝑖);

19:  end if

20: end for

21: if !((𝑑_𝑗∈𝑑_list)&&(𝑑_𝑗^{𝑐𝑤𝑛𝑑} == 𝑑_𝑠^{𝑐𝑤𝑛𝑑})&&(j <> s)) then

//path with largest 𝑐𝑤𝑛𝑑 is set as retransmission destination

22:   set 𝑑_{𝑟𝑡𝑥Dest}=𝑑_𝑠;

23: else if !((𝑑_𝑗∈𝑑_list)&&(𝑑_𝑗^{𝑠𝑠𝑡ℎ} == 𝑑_𝑡^{𝑠𝑠𝑡ℎ})&&(j <> t)) then

//path with largest 𝑠𝑠𝑡ℎ𝑟𝑒𝑠ℎ is set as retransmission destination

24:   set 𝑑_{𝑟𝑡𝑥Dest}=𝑑_𝑡; //

25: else if !((𝑑_𝑗∈𝑑_list)&&(𝑑^tor_𝑗==𝑑^tor_𝑡)&&(j <> t)) then

//path with lowest tor is set as retransmission destination

26:   set 𝑑_{𝑟𝑡𝑥Dest}=𝑑_𝑡;

27: else if !((𝑑_𝑗∈𝑑_list)&&(𝑑^interval_𝑗==𝑑^interval_𝑤)&&(j <> w))

//path with largest 𝑡_interval is set as retransmission destination

28:   set 𝑑_{𝑟𝑡𝑥Dest}=𝑑_𝑤;

//a tie will be broken by random selection

29: else set 𝑑_{𝑟𝑡𝑥Dest} with random 𝑑_𝑖 (𝑑_𝑖∈𝑑_list);

30: end if

 let loss data be retransmitted on 𝑑_{𝑟𝑡𝑥Dest}