Hello,
our local supplier told us that the Airprime MC7304/7354 modem modules, which have a PCM audio port, support voice calls using AMR-WB (HD-Voice) encoding, although the datasheet and AT command specs that I could find do not mention any supported codecs at all.
So, do these modems really support HD-Voice?
And if so, is there a way to find out, what codec is currently active?
If tehy do not, what does the modem send over the air when being fed with PCM audio?
Thanks very much for your support.
topic moved to correct section…
Hello,
since nobody replied, here’s a what I found out myself.
I tested the MC7304, which is the Euopean version of the module, in a telecom lab and the modem communicated to the network that it would support AMR-WB, AMR and AMR2 (also FR, EFR, HR). We were not able to actually verify this with a call, but if the mobile reports these capabilities, I think think it’s safe to assume that it actually supports them.
So, the modem supports HD-voice. It’s a wonderfully capable machine. If only it did not need this SDK under Linux for packet data transfers that can only be run once on a single computer. We need to drive multiple units from the same Linux machine and would really appreciate Direct IP control, as we use for the 7710. 
DirectIP is not supported on the new MC73xx series, but the new Linux SDK can support multiple modules in a system. You can access this SDK through the sharepoint service, if you do not have access to this, please contact your local distributor.