This Hong Kong test indicates that W-CDMA is unable to syncronize voice and vidio. In Vidio Conferencing, voice consistantly lags data by as much as 1 to 2 seconds.
JohnG
telecomasia.net
Voice will lag video on 3G, Hong
Kong trial finds
A W-CDMA trial in Hong Kong by competitive
carrier, New T&T, concluded that voice will lag
behind moving images during video-conferences
over 3G systems by as much as 2 seconds.
The trial successfully demonstrated circuit
switched voice and packet oriented multi-media
services running over the 3G air-interface.
Samples of mobile radio interface signaling layer 3
messages and RF parameters were also
measured for reference.
The test, conducted in Hong Kong, tested 2-way
video conferences with the network speed set at
384kbps, 128 kbps and 64kbps. The test used
Meeting Point version 3.01 for the trial.
New T&T said in a submission to the Hong Kong
regulator, OFTA, that all applications ran smoothly
on all three different network settings, but that
"voice lags behind video by 1 to 2 seconds
regardless of speed of transmission."
The report also found that most applications,
including video conferencing, video streaming, and
Web browsing worked over the lowest speed
setting of 64kbps although quality was
compromised.
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