French transmitter network operator TDF and Italian public broadcaster RAI have launched the world’s first field trials of the new converged mobile broadcast system LTE-A+ Broadcast from transmitter sites in Paris and Aosta.
The joint project is based on the Tower Overlay concept developed by German university TU Braunschweig in 2013 under the leadership of Professor Ulrich Reimers. It is supported by German research institute IRT and broadcast solution providers Expway (France) and GatesAir (USA).
The trials intend to evidence the possibility of convergence between the LTE technology ecosystem on one side and traditional DVB broadcast infrastructure on the other. They come at a moment where the mobile industry is increasingly looking at eMBMS, an LTE-embedded broadcast approach to serve the growing mobile video and TV consumption.
Adapting LTE Broadcast to traditional high broadcasting towers creates the possibility of cooperation between the cellular and broadcasting networks, thus reducing network load, energy consumption and network costs, according to the trials’ initiators. All mobile devices can be reached without the need to add a specific broadcast receiver in the devices, a hurdle that proved difficult to overcome in the past.
In the trials, two data streams share the same UHF channel in time-division: one stream is conveying conventional digital HDTV channels to be viewed on domestic DVB-T2 TV sets while and a second embedded stream is conveying a specific broadcast flow intended for 4G LTE-A+ smartphones, laptops and tablets.
In the Paris trial, the Eiffel Tower transmitter site is used, operating on a UHF frequency (channel 54, temporarily authorised by CSA). The stream intended for mobile devices is aggregating a large range of digital media content (live TV, video-on-demand, catch-up TV, live radio, podcasts, magazines, newspapers, software updates). All content is received on the mobile device and stored until the consumer wants to view it at any chosen moment.
The Aosta trial consists of two adjacent transmitters located in the Aosta Valley in the northern part of Italy operating on the same frequency (single frequency network on UHF channel 53). It will be extended in the coming months by two additional transmitters. The transmitted data stream is shared by 4 HDTV channels using the DVB-T2 standard and 4 high-quality mobile video streams using LTE-A+. HEVC video coding is used in both streams.