Consecutive Lost Packets (CLP)

As shown in Figure 7.2 and Figure 7.1(a), 7.1(c) and 7.1(e) the effect of increasing CLP is benefic to speech quality when keeping the other parameters constant. An absolute improvement of 0.5, 0.7, and 0.5 when CLP increases from 1 to 5 in the Figures is shown on the left-hand side in Figure 7.2, where LR=5 %. While, we can see an improvement of 0.8, 0.7, 0.6 when LR=10 %. However, as we can see from Figure 7.2, there is no improvement on the quality when PI is high (about 60ms). Thus, the improvement becomes more important for smaller values of PI. The explanation of this phenomena is as follows. When fixing all the other parameters (including the LR) and increasing CLP, the number of loss occurrences decreases. Therefore, the number of distorted words in the speech decreases when increasing CLP.