scope:

The present document is one of the parts of the specification of the Digital Enhanced Cordless Telecommunications (DECT) Common Interface (CI).
This part of the DECT CI specifies the speech coding and transmission requirements.
In order to ensure satisfactory interworking of different portable and fixed units, it is necessary to specify the transmission performance of the analogue information over the digital link. This requires not only use of a common speech algorithm, but also standardization of frequency responses, reference speech levels (or loudness) at the air interface and various other parameters.
The present document applies to DECT equipment which includes all the necessary functions to provide real-time two-way speech conversation. A 3,1 kHz telephony teleservice conveyed over a DECT link (including Fixed Part (FP) and Portable Part (PP)) which is capable of being connected (directly or indirectly) to the public network access point should comply with the requirements in the present document.
Tethered fixed point local loop applications are not required to comply with the requirements of the present document.
The speech performance characteristics defined in the present document typically conform to TBR 008 (see bibliography), which specifies the overall performance between the handset acoustic interface and a 64 kbit/s A-law Pulse Code Modulated (PCM) digital network interface. The deviations from TBR 008 are mainly due to the consequences of non-PCM coding and transmission delay.
The additional features described in clause 8 are those which are not included in TBR 008, but which are likely to occur in a DECT system: analogue interface, loudspeaking and hand-free facilities, tandeming with a mobile radio network.
Headsets are not covered by the present specifications.
For the DECT systems which connect to the Public Switched Telephone Network (PSTN) via an analogue interface, the additional requirements, which are implemented in the FP, have as much as possible been aligned with TBR 038 (see bibliography).
A summary of the control and the use of the DECT echo control functions, to guide on need for options to manufacturers and installers, is found in annex A.
Information concerning test methods can be found in EN 300 176 [3]. The test methods take into account that DECT is a digital system.
The present document includes New Generation DECT, a further development of the DECT standard introducing wideband speech, improved data services, new slot types and other technical enhancements.