Pope Francis concluding ma in the Philippines powered by Village Islands live broadcasting system

Pope Francis concluding mass in the Philippines powered by Village Islands live broadcasting system 21 January 2015

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Pope Francis visited the Philippines from 15th to 19th according through a tied schedule with the a climax event being the concluding mass at Quirino Grandstand on 18th afternoon.

Through a wide area of more than 36 hectares covering Manila s Rizal Park and surroundings, fourteen twelve square meter large Led wall displays were placed in addition to the ones at main stage of Quirino Grandstand to permit the six million people attending the event to receive in live High-Definition video and audio feed through terrestrial digital broadcast (ISDB-T) transmission.

It was necessary to reach display distant by 1.5 km and the topology of the terrain was quite complex due the numerous presence of obstacles, large trees, monuments, and indesirable interferences. Also a one seg (QPSK modulation) would have been easy to cope with the situation, it would have only allowed mobile-type low resolution video resolution and not the High-Definition required for this project, therefore it was decided to configure the DekTec DTA-2111 output modulator with 13segment of robust reception parameters such as Guard Interval of 1/4, 16QAM modulation and Code Rate of 3/4, giving apprimately 10.9Mbps.

With such modulation parameters, 25dBWhat of MER was required for quality reception, but on T.M. Kalaw street Led Display Wall, it was impossible to get that good reception level due to the fact there was no direct line of sight. After consultation with the government authorities, it was decided to autorise the installation of an RF reception antenna on the top of the National Library nearby wired with a 200 m coax cable.

The 3U VillageFlow system aquired by Stagecraft (who was the event main contractor and stage coordinator) empowered the live broadcasting by offering combined function of HD H.264 encoding at 8Mbps from an HD-SDI input, ISDB-T remultiplexing with custom Table and Service definition and Insertion and OFDM RF modulation thanks to the embedded DTA-2111 DekTec OFDM modulator output board. On the top of Quirino Grandstand was placed a DX Antenna RF amplifier and transmitting ISDB-T system and each Led display was equipped with terrestrial reception antenna. Each LED display was equipped with powerful speakers receiving video and audio through HDMI from EWD terrestrial STBs.

Through the whole day, various show and performances happened on the stage, involving classical orchestra performance with more than 500 musician and singers. Because of the high expectations in term of audio quality, audio was compressed at high bit-rate of 384Kbps in AAC LC .

The audio delays over the whole area had to be carefully considered due to several parameters. First, the OFDM Terrestrial video and audio broadcast system has a general delay of 1.5 sec but propagating at light speed. Second, the sound from the main stage propagate and sound speed of approximately 300 m per sec. This implied that displays that were very close to the stage at to receive their sound and video directly wired from the stage system (signals before been broadcasted), that some display a little further and still receiving a fair volume of sound from the stage were showing video only but no audio from the STB to prevent "echo"-like weird effect for the audiance nearby. Display farder than 450 meter were all receiving and playing video and audio with a fixed delay and limited volume to address their nearby area.

To prevent any issue, a VillageFlow back-up system was builded on a laptop with DekTec DTU-351 HD-SDI USB input, and a DTU-215 Terrestrial USB modulator output. The DTU-215

Such light and powerful set-up is possible thanks to the VillageFlow TS processing platform. Although it is always recommended to use PCIe card than USB device that can be unplugged easily by pulling the cable, the back-up system showed satisfactory result with quality reception on all displays.

In conclusion, this was the first time that ISDB-T Terrestrial Digital transmission was used for such large scale live event. The VillageFlow emplowers highly-reliable, high-quality and flexible solution for encoding and transmission through complex topology area. Although the broadcast transmission overall delay can be an issue for short distance live transmission, it is appropriate for large area coverage and can be addressed properly thanks to synchronization betwen video and audio experts.

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