Thread: "HD Voice" rolling out on Orange UK
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lma is offline lma
2010-09-04 , 05:08
Posts: 2,802 | Thanked: 4,491 times | Joined on Nov 2007
#9
Originally Posted by Milhouse View Post
I guess they have to start somewhere and to be fair they have been pretty upfront about it only working between HD-enabled handsets.
Sure, that was a general comment on HD audio rather than this particular offering.


Although I'm still not sure why it won't work between an HD-enabled handset and a POTS landline - presumably this is a cellular network limitation when interfacing with POTS?
Potentially that too, but more fundamentally it's a limitation of the POTS side (wires, handsets etc) which is only specced to handle "narrowband", and that is more often than not enforced by digitising the audio to ISDN (ie G.711) as soon as it leaves the "last mile".

BTW, it seems even the N8x0s came with some AMR-WB support:

Code:
Nokia-N810-43-7:/lib/dsp/modules# ls -l amrw*
-rw-r--r--    1 root     root          751 Aug 22  2008 amrwb.cmd
-rw-r--r--    1 root     root        13089 Aug 22  2008 amrwb.o
though they're not used in SIP either (disabled in /etc/farsight/gstcodecs.conf, and there are no corresponding gstreamer modules as far as I can see).