Fleksibilni Internet servisi na bazi kontrole kašnjenja i
Fleksibilni Internet servisi na bazi kontrole kašnjenja i
Fleksibilni Internet servisi na bazi kontrole kašnjenja i
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NTS<br />
1<br />
where DTS<br />
= t − ∑ t<br />
N k = 1<br />
TS<br />
k<br />
NTS<br />
1<br />
and QTS<br />
= ∑ q<br />
N k = 1<br />
Similarly, expected average delay of delay-sensitive packets is:<br />
N DS 1<br />
where DDS<br />
= t − ∑ t<br />
N k = 1<br />
DS<br />
k<br />
d<br />
DS<br />
TS<br />
N DS 1<br />
and QDS<br />
= ∑ q<br />
N k = 1<br />
k<br />
35<br />
.<br />
1<br />
= DDS<br />
+ QDS<br />
, (21)<br />
r<br />
DS<br />
Fig. 10. The heuristic approximation of BPR+ uses timestamps to calculate the average experienced<br />
delay of backlogged packets.<br />
dTS<br />
On each packet departure, service rates rTS and rDS that satisfy = δ and rTS + rDS<br />
= C<br />
d<br />
are calculated from:<br />
r<br />
2 TS DS<br />
TS<br />
TS +<br />
⎜<br />
TS<br />
DTS<br />
D ⎟<br />
0<br />
−δ<br />
DS DTS<br />
−δ<br />
DDS<br />
r<br />
DS<br />
⎛ Q + δ Q<br />
⎜<br />
⎝<br />
= C − r<br />
TS<br />
⎞<br />
− C ⎟r<br />
⎠<br />
k<br />
DS<br />
.<br />
−<br />
Q<br />
C<br />
=<br />
DS<br />
. (22)<br />
Packets are scheduled based on virtual service functions VTS(t) and VDS(t). These<br />
functions approximate the difference between an amount of traffic that would have been<br />
transmitted from TS and DS queues during the current busy period if these queues were<br />
serviced by rates rTS and rDS, respectively and an amount of traffic that has been actually<br />
transmitted from these queues. The virtual service functions are updated upon every
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