EDACS Provoice

Digital communications is also available for EDACS systems and exists in two different formats, AEGIS and ProVoice. AEGIS was the first format introduced and ProVoice was the last and current format. Neither one is APCO-25 Common Air Interface compliant unlike Motorola's ASTRO, which is. Also, neither AEGIS nor ProVoice can communicate with each other.

There are three different types of EDACS control channels. The most common is the wideband EDACS control channel, which operates at 9600 baud. Listen to it here. There is also a narrowband EDACS control channel which operates at 4800 baud and primarly is used for EDACS systems in the 900 MHz band. Listen to the narrowband control channel here. Finally, there is the wideband EDACS "encrypted" control channel which is basically a variation on the standard 9600 baud wideband control channel. M/A-COM's trademark name for this feature is ESK (EDACS Security Key).

ProVoice is MA/Com's (formerly Ericsson) implementation of IMBE digital modulation. It is not APCO-25 compliant, but does use the same IMBE vocoder developed by DVSI Inc. The technical difference between ProVoice and the APCO Project-25 standard is how error correction and modulation is provided to transmit the data.

El Pase and San Antonio, Texas, the State of Florida, and St Tammany Parish, Louisiana, are using ProVoice EDACS or are in the process of building ProVoice systems.

EDACS ProVoice systems use the MA/Com EDACS control channel.

There is no scanner available today that can monitor EDACS ProVoice Digital voice.