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AMSS 25.12.2007

Deutschlandradio Kultur 990 kHz 18.50 UTC

AMSS 17.12.2007

BBC World Service 5875 kHz, 21.00 UTC


AMSS 18.02.2007

234 kHz


AMSS - результаты приема 2 и 3 декабря 2005 года, декодер Dream 1.5cvs

648 kHz

9410 kHz




What is AMSS?
AMSS allows some data to be transmitted on "conventional" AM transmissions. For instance the station label (i.e. BBC WorldService) & alternate frequency information of other AM, DRM, DAB transmissions with the same audio service is sent.

What are the main advantages?
Added feature for DRM receivers: ability to receive the station label on AM transmissions
Seamless changeover by receiver between AM & DRM transmissions
Ability for receiver tuned to AM to find better AM or DRM frequencies automatically
Ability for receiver to track transmitter frequency changes

How does it work?
Some phase modulation is applied to the AM carrier. This carries the data at 47bps. The phase modulation is not enough to cause audible problems. Its not a new idea, but what is different this time is that DRM receivers easily have the processing power to decode this information.

What is the point of this post?
This week (May 20, 2005), a prototype AMSS modulator was tested in the UK. Next week longterm tests into Europe (from Cyprus; HF) will start. AMSS decoding should be implemented into DRM receivers including the DReaM software. Would anyone be prepared to take on this task? The system specification is available on the ETSI website: ETSI TS 102 386 V1.1.1 (2005-03) or from me, james dot briggs at vtplc.com