VoIP using WISMOs


Did anyone try to transmit voice data over GPRS?

The thing is that WISMO already has all needed codecs aboard. And they are able to make a good phone speech quality. Is there some possibility of using those codecs with Open AT, ADL or somehow? I guess there is.
Does anybody now how to get the codec’s streams?


Well, they’ll be the codecs for GSM Voice, won’t they? I think you’d probably need different codecs for VoIP?

I’m not even sure that GPRS is suitable for VoIP - last time I looked, Skype didn’t support it…


GPRS is MUCH too slow for VoIP. I read an article that even with UMTS in th real world there are gaps and delay and stuff all the time.

By the way a codec is hardware and a codec is software. You both are not talking abou the same.


You may be interested to know that the latest versions of the firmware for the ARM946 based Fastrack Supreme, Q26 Series and WMP100 support a very cool new feature called OAP (Open Audio Path - not Old Aged Pensioner!). Here’s a brief description:

Open Audio Path:Although M2M applications usually use data channels, having full control over the audio chain can be very useful. Therefore, Wavecom has opened the Audio Path to let you do whatever is requested for your solution - from Audio sniffing, playing and recording to equalizing.

That means you can tap in to the DSP audio flow with new Open AT APIs to listen, record, playback, and even inject your own audio streams into the GSM audio channel.


I saw that as adl_audioService in OS V-4.20, however the adl_audioStreamPlay() function is there declared as “Reserved for Future use”.

As I intent to play with audio functionality in the near future, is there any info about new OS version, which implements both listen and play functions?


It’s part of the new software product release in March 2008 (beta releases earlier) which allows the same OS to run accross multiple Wireless CPU devices with unified APIs (and backwards compatibility wrapper for legacy support). That is coming in Open AT Software Suite 2.0 and recalling that a suite consists of an IDE, OS, Applications, Plug-Ins and Firmware, this release will included: OS6.0 & FW7.0 supporting the following major enhancements:

  • Multitasking RTOS
  • IDS Step1: RDMS*
  • Audio Chain Control
  • Audio Player
  • Audio Recorder
  • ADC register Access
  • IDS (Intelligent Device Services) is a service based model, which in the first step will provide server based difference engine over-the-air downloads of the OS, FW and Open AT Application (with Plug-Ins).