The Pronto 2 ISDN Audio Codec & The Pronto 3 ISDN Codec

Pronto2-ISDN is designed for those users who demand higher quality in their ISDN connections. It includes the two ISO MPEG Layer II compression modes most widely-used in broadcasting: MONO 64 Kbps (10.5 Khz) and Joint Stereo 128 Kbps (20Khz). The last one with the J52 standard for transmission via two independent 64 Kbps channels. It also includes a

digital audio I/0 AES/EBU signal and a connector for transmitting and receiving auxiliary data simultaneously with the MPEG audio. It is also possible to replace the ISDN communications interface with two X21 ports. This expands the possibilities for connecting the equipment to other digital communication networks (dedicated networks, satellite communications etc.)

In G711 mode, the Pronto2 ISDN provides an alternative to normal telephone hybrids, by allowing standard voice communications on the ISDN network as well as on analogue telephone networks. A conventional analogue telephone connected to the front panel, allows to make, receive and transfer calls or put them on hold or on air in the same way as conventional telephone hybrids.

When G722 mode is selected, the unit permits high quality voice communications via the ISDN network, with the advantage over other audio encoding systems of having a low coding delay.

Its most important features are:

• ISDN universal terminal adapter (S0 ) and X21 interface.

• Analog or digital audio (AES/EBU). The AES/EBU interface provides input for external clock.

• Dual operation (two fully independent communications) in G711, G722 and MPEG ayer II MONO 64 Kbps.

• Independent operating encoding and decoding modes.

• Automatic detection of the encoding mode used by the remote unit.

• Compatibility in all modes (G722 and MPEG Layer II) with CCS and TELOS.

• Auxiliary data in MPEG Layer II modes.

• Electrical echo canceller and multiplex (conferencing) in G711

EXTERNAL TELEPHONE: The Prontos also features de ability, accessed through a simple front panel menu, to remote control the unit with a standard analogue telephone (connected to the RJ11 socket on the front panel) using the DTMF (multifrequency) tones generated by the dial pad. The same telephone can also replace an audio I/O channel in G711/G722 modes to act, for example, as a talkback system.