To include regional contents in a national Single Frequency Network (SFN), Rai has studied and tested in the laboratory a system configuration that benefits from the multiple Physical Layer Pipes (PLP) of DVB-T2. According to the proposed solution, in each region, the national programmes are transmitted in one PLP, while other k PLPs convey the regional contents of macro-regional SFN, formed by a region and the (k-1) surrounding ones. The DVB Single Illumination System standard (DVBSIS) can be a valid technical solution to distribute such complex signals to SFN transmitters via satellite or terrestrial contribution links in a cost-effective way.
The paper presents the rules adopted to map content into DVB-T2 PLPs and their application to the Italian case. Furthermore, it describes the end-to-end laboratory set-up and the results of tests carried out, showing that a national SFN can broadcast both national and regional contents with high flexibility and spectrum efficiency.
DVB-T2 is the candidate DVB technology to complement (or replace) the current DVB-T terrestrial transmission format in Italy after the release of the 700 MHz band in 2022, allowing us to compensate for the reduction of available spectrum resources.
Large Single Frequency Networks (SFN) are recognised by EBU and ITU studies as the best configurations for the optimal exploitation of spectrum resources, with respect to Regional SFNs or Multi-Frequency Networks (MFN). However, a national SFN would normally not allow the inclusion of regional contents, since different contents from adjacent SFN transmitters would interfere.
The paper presents a possible solution to broadcast regional programmes (21 for Italy) in a national SFN, along with national ones, while keeping a good spectrum efficiency (much higher than the trivial solution of simulcasting the 21 regional contents all over the national SFN network).