R&S^®DM001 DAB Multiplexer

R&S^®DM001 DAB Multiplexer is part of the Rohde&Schwarz product line for DAB transmission links. It is fully compatible with DAB standard ETS300401 and based on the multiplexer which has proven itself in the DAB pilot projects of Deutsche Telekom and Fraunhofer Institut für Integrierte Schaltungen. The multiplexer is a central element in a DAB network.It combines the incoming audio and data channels to form the ensemble transport interface (ETI), which drives the subsequent COFDM modulators and thus the complete transmitter network.

The 19" multiplexer of three height units comprises up to three input modules with max. 12 physical inputs and a DSP board. Two output modul es are used to generate the ensemble ETI and the back channel (STI-C). The fast information channel (FIC) can be generated from internal or external information. For example, fast information groups (FIG) can be fed externally which have been generated by a PC.

R&S^®DM001 DAB Multiplexer supports time-synchronized, dynamic reconfigurations. To this end, it is locked to a reference time and clock.

Multiplex signal

The output of R&S^®DM001 DAB Multiplexer is the ensemble transport interface (ETI) with a data rate of 2.048 Mbit/s. This interface is organized in 2 layers:ET(NI) and ET (NA).

ETI(NI)

The network-independent layer ETI(NI) has a 24 ms frame structure. It is used for transmission via satellite or microwave links.

ETI(NA)

The network-adapted layer ETI(NA) is used for transmission via telecommunication networks. It has a frame structure in line with G.704 and features Reed-Solomon coding. To enable dynamic delay compensation, additional time information is inserted into the frame structure. To this end,a time reference signal (eg GPS) is applied to the multiplexer.