AMBE voice compression framing
 

I am investigating using a DSVD modem for remote control.
I have been told that conventional DSVD's have rather poor
audio quality. The new AMBE chips promise higher fidelity
voice compression. Does anyone know of a DSVD that uses
these chips? How hard would it be to interface an AMBE chip
to a conventional (non-DSVD) modem? Apparently, the chip
requires an external circuit to do framing, so it is not serial
port ready. Anyone have info on how to do framing?

BTW, I only have a 28.8k dial up connection to work with.
I would like to avoid getting a second phone line.

Rick Karlquist N6RK

"Rick Karlquist N6RK" wrote
I am investigating using a DSVD modem for remote control.
I have been told that conventional DSVD's have rather poor
audio quality.

At 8 kbps I'd say it was much more than "poor" quality, and should
be sufficient for any voice communications.

The new AMBE chips promise higher fidelity
voice compression. Does anyone know of a DSVD that uses
these chips?

None. DSVD standard is written to use G.729 standard.

How hard would it be to interface an AMBE chip
to a conventional (non-DSVD) modem?

Hard, and expensive.

Apparently, the chip
requires an external circuit to do framing, so it is not serial
port ready. Anyone have info on how to do framing?

It requires an external A/D and D/A converter, but it does all the
framing (variable speeds plus FEC).

BTW, I only have a 28.8k dial up connection to work with.
I would like to avoid getting a second phone line.

Rick Karlquist N6RK

Get a couple of MultiTech DSVD modems.

"Rick Karlquist N6RK" wrote
I am investigating using a DSVD modem for remote control.
I have been told that conventional DSVD's have rather poor
audio quality.

At 8 kbps I'd say it was much more than "poor" quality, and should
be sufficient for any voice communications.

The new AMBE chips promise higher fidelity
voice compression. Does anyone know of a DSVD that uses
these chips?

None. DSVD standard is written to use G.729 standard.

How hard would it be to interface an AMBE chip
to a conventional (non-DSVD) modem?

Hard, and expensive.

Apparently, the chip
requires an external circuit to do framing, so it is not serial
port ready. Anyone have info on how to do framing?

It requires an external A/D and D/A converter, but it does all the
framing (variable speeds plus FEC).

BTW, I only have a 28.8k dial up connection to work with.
I would like to avoid getting a second phone line.

Rick Karlquist N6RK

Get a couple of MultiTech DSVD modems.