TDF and Rai today launched the first LTE-A+ broadcast trials from high-power TV transmitters in Paris and Aosta. This joint project, based on the original "Tower Overlay" concept developed and implemented by Technische Universität Braunschweig (Germany) in 2013, also involves GatesAir (USA) and is supported by IRT (Germany) and Expway (France).
The aim of these tests
The aim of these trials is to demonstrate the real possibility of true convergence between the LTE ecosystem and conventional broadcast infrastructure.
They come at a key time, when the mobile telecoms sector is showing increasing interest in eMBMS, the broadcast technology integrated into the LTE standard, to meet the growing consumption of video/TV content on mobiles. Adapting LTE broadcast to traditional broadcast towers means that cellular and broadcast networks can cooperate, ultimately reducing network load, energy consumption and network costs.
Conversely, the use of high towers by LTE-inspired technology enables all mobile terminals to be reached, without the need to add a specific receiver for broadcasting in the terminals, which has proved a difficult evolution to achieve in the past.
In these tests, two data streams share the same UHF time-division channel: one stream broadcasts conventional digital TV programs for home DVB-T2 TV sets, while another embedded stream broadcasts a specific content stream for 4G LTE smartphones, laptops and tablets.
Trials in Paris and Aosta
The Paris trial is based on the Eiffel Tower transmitter, which operates on a UHF frequency (channel 54, temporarily authorized by the CSA). The stream for mobile devices is made up of a wide variety 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 end-user decides when to view it.
The trial in Aosta is based on two adjacent transmitters, located in the Aosta Valley in northern Italy, operating on the same frequency (Single Frequency Network or SFN, on UHF channel 53 at 730 MHz) and will be extended to two further transmitters in the coming months. The transmitted data stream is split between 4 HDTV programs using the DVB-T2 standard and 4 high-quality mobile video broadcast streams using the LTE-A+ protocol. HEVC video encoding is used in both broadcast streams.
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In addition, verbatim comments from partners
Professor Ulrich Reimers, "father" of the Tower Overlay concept, commented: " I'm proud to see that our original concept is becoming a reality, thanks to the joint work of my team, who set up the prototypes used in these tests, and our partners Rai, TDF and GatesAir. I'm delighted that the project is also supported by Expway and IRT.
Vincent Grivet, TDF's Director of Broadcast Development, adds: " In 2013, we demonstrated the concept of broadcasting popular content of all types to a tablet as part of the B2M project, also from the Eiffel Tower, and thus proved that broadcasting could also serve "on-demand" consumption, and not just live broadcasting. Today, the completion of these trials with a technology close to LTE, used instead of DVB-T, opens up a whole new perspective of convergence between the audiovisual and telecom environments, the two markets in which TDF is present, which is particularly exciting and promising ".
Alberto Morello, Director of Rai's research center in Turin, also commented on the tests: " I'm convinced that high-power TV transmitters, thanks to their vast coverage areas, can be a good way of meeting the growing need for live video broadcasting to mobile terminals. The solution currently being tested enables capacity to be flexibly allocated to either conventional TV or mobile multimedia, depending on requirements ".
Joseph Seccia, Head of Strategy for GatesAir's TV transmission business added: " Our aim is to offer our customers the best solution for content delivery. Delivering high-quality content to mobile devices is a challenge that needs to be met, and LTE broadcast via high towers could well be one such solution ".
Thierry Sergent, CEO of Expway said, " As one of the leading providers of application software for LTE broadcast to mobile operators and handset manufacturers worldwide, we are very interested in exploring how LTE A+ can enhance the customer experience and bring more content to more consumers. We strongly believe in the convergence of broadcast and telecoms, and LTE-A+ could be a key technology for the next 5G standard."
Klaus Illgner-Fehns, Managing Director of IRT, the Munich-based R&D institute of the broadcasting companies ARD, ZDF, DRadio, ORF and SRG/SSR, commented: " The high-tower LTE-A+ broadcast trials carried out in Paris and Aosta will be very useful for us in evaluating more precisely the most suitable models for broadcasting TV content to mobile devices, and they complement our own research work on eMBMS, such as the IMB5 project ".