FAQs from Rohde & Schwarz

DTMF analysis on CMW500 and CMW290


How can DTMF signaling tested with CMW500 and CMW290 with the RF Test (Callbox) application?


CMW500 has no DTMF coding/decoding function inside the RF Test (Callbox) user interface, even not in VoLTE.
DTMF tones are not transmitted in the speech channel, it is signalling and the receiving UE has to generate the tone by itself.
The CMW500 will not convert received signalling message into a audio tone, so it is not posible to hear the DTMF tones via the AF audio ports.
The only posibility to check trasmission of DTMF tone is the analysis of a msglog file with MARS or MARSviewer, to see the signalling message (2G and 3G)
In case of VoLTE the Signaling for DTMF can be seen in a DAU pcap trace.

Example DTMF signaling (2G/3G) in MARS tool:

DTMF analysis on CMW500 and CMW290

DTMF in VoLTE (MT UE generate Tone):

DTMF analysis on CMW500 and CMW290