Wednesday, July 19, 2006

Monitoring the Pro Voice Digital Protocol - Not!

I have noticed some people using Google searching for information on how to monitor a radio trunk system that uses the ProVoice digital protocal.

In short, "you won't, and there will not be a scanner that will include that mode." M/A-COM has made it clear that they will NOT allow the scanner manufacturers a license to include that proprietary codec in a scanner. The IMBE vocoder is used in ProVoice, but ProVoice is not compatible with Project 25, so a Project 25 scanner will not automatically be able to follow ProVoice systems.

Oh yes, same thing applies for:

Open Skies, which is used by the Pennsylvania statewide public safety system uses the popular Internet Protocol (IP) and is rather unique in that all radio traffic is digital from one end of the system to the other. OpenSky uses a different DVSI vocoder known as AMBE (Advanced Multi-Band Excitation), and is not compatible with Project 25.

Aegis was originally developed by Ericsson (now M/A-COM) that uses yet another type of vocoder, and it is not compatible with Project 25.

Motorola VSELP is an older Motorola ASTRO digital protocol that uses a different vocoder referred to as VSELP, which stands for Vector Sum Excited Linear Prediction. As with any non-IMBE vocoder, VSELP is not compatible with Project 25.

And those are the facts folks.