5th etsi speech Quality Test Event Anonymous Test Report

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3.9G.729

The listening speech quality scores measured for the three IP phones using the G.729 speech coder are given in table 6.3 respectively figure 6.3. It should be noted that the measurements in receiving direction are again influenced by the acoustic performance of the handset (see table 6.1 respectively figure 6.1).

The results can be summarized as follows:

The listening speech quality in sending direction is nearly identical for two devices but differs slightly for one implementation. The same ranking was measured for the G.711 speech coder. The highest scores are comparable to the G.729 reference results.
The TMOS results in receiving direction basically represent the quality differences between the implementations as already measured for the G.711 coder (see table 6.1, figure 6.1).

The delay differences are approximately 30 ms in receiving direction.

G.729 – TMOS (TOSQA2001), VAD off, 20 ms, 8 N (except where otherwise stated)
	Delay [ms] / PL / jitter [ms]	TMOS			Av. one way delay (ms)
	Delay [ms] / PL / jitter [ms]	min	av.	Max	min	av.	Max
Sending	0 / 0% / 0	3.4	3.5	3.6	88.6	96.2	102.3
2 N	100 / 0% / 0	2.2	2.6	3.3	67.3	80.6	106.1
8 N	100 / 0% / 0	2.5	2.8	3.4	65.3	77.5	98.0
13 N	100 / 0% / 0	2.6	3.0	3.4	67.6	80.7	100.4
	G.729 ref.	---	3.6	---	---	---	---

Table 6.3: TMOS (TOSQA2001) results, G.729 speech coder, 20 ms packet length (PL)

Fig. 6.3: TMOS results calculated using TOSQA2001; G.711, 20 ms PL

The same conclusions can be drawn for the G.729 speech coder measured under the influence of packet loss and jitter. The results are given in table 6.4 and figure 6.4. The ranking between the phones is comparable to figure 6.3 because both tests are carried out in receiving direction and packet loss is integral part of the G.729 speech coder.

G.729 – TMOS (TOSQA2001), VAD off, 20 ms, 8 N
	Delay [ms] / PL / jitter [ms]	TMOS			Av. one way delay (ms)
	Delay [ms] / PL / jitter [ms]	min	av.	Max	min	av.	max
1c – VAD off	100 / 0% / 0	2.5	2.8	3.4	65.3	81.2	104.8
3c	100 / 1% / 0	2.3	2.6	3.3	30.3	62.9	83.7
5c	100 / 3% / 0	2.2	2.6	3.2	66.7	74.0	82.0
4c	100 / 0% / 20	2.1	2.6	3.3	112.7	124.5	134.2
2c	100 / 1% / 20	2.0	2.4	3.2	99.5	112.3	133.2

Table 6.4: TMOS (TOSQA2001) results under the influence of IP network impairments, G.729 speech coder, 20 ms packet length (PL)

Fig. 6.4: TMOS results under the influence of IP network impairments, G.729, 20 ms PL

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