The 15-kHz ISDN Telephone can be used for telephony and for the transmission of 7-kHz and CD transparent audio signals over the ISDN network. One remarkable feature of the 15-kHz ISDN Telephone is its extremely easy operation.
The 15-kHz ISDN Telephone is built around a multi-function ISDN Telephone with a base unit incorporating a speech codec operating to ITU-T G.722 and an audio codec operating to ISO/MPEG Layer 3, to provide the improved bandwidth. During call set-up, the unit automatically determines whether or not the called party can operate in 7-kHz or ISO/MPEG Layer 3 mode. If this is possible, the 7-kHz or the ISO/MPEG Layer 3 (15-kHz) mode is set on both units via the ITU-T J.52, inband signalling; otherwise the telephone automatically operates in the conventional 3.1-kHz mode. To guarantee compatibility with other manufacturerers audio codecs, it is possible to switch off the J.52 signalling. To input external audio signals, an analogue audio interface is provided.
Follow-up model
The follow-up model for the 15-kHz ISDN Telephone is the MAGIC AC1 XIP Audio Codec. The Audio Codecs offer the same functions as the 15-kHz ISDN Telephone and provide further useful features. With the “Create 15-kHz Telephone Mixer Presets“ functionality, you can create Mixer Presets for the MAGIC Audio Codecs which provide a similar navigation as the 15-kHz ISDN Telephone. In this way, the systems allow a simple switching between the telephone handset and the Audio interface by pressing only a single key. First, you can talk to the partner via the telephone handset and then start an external Audio transmission by pressing the telephone receiver key.
