Digiturk, one of the largest digital satellite TV providers in Turkey, has upgraded its systems to add new channels and also to support new HD services. The broadcaster is based in Istanbul, Turkey, and launched in 1999 with just 25 channels. Since then, it has increased that number to 99 exclusive TV channels, reaching 1.8 million subscribers.
The original system, which is still in use today, was built by Philips with playout from tape and MediaPool video servers, and is controlled by Alamar automation. The transmissions use Philips MPEG-2 encoders and STBs.
In Turkey, football is a major sport, and the demand called for the launch of an HD version of the football channel, LigTV, as well as general entertainment in HD. Now, the broadcaster has capacity for 120 TV channels with 11 transponders on Eutelsat W3A, nine on Turksat 2A and one on EuroBird 3.
The new 36MHz HD transponder on Eutelsat will initially carry one HD and seven SD services using MPEG-4 AVC encoding and DVB-S2 modulation for more efficient use of transponder, expected to be a 30 percent decrease in bandwidth per channel. With a 50Mb/s payload, around 12MB/s can be allocated to each HD channel. Transmissions carry dual stereo soundtracks, one in the original language and one for the Turkish translation, if needed. The HD services also carry 5.1 Dolby Digital audio and use Pace MPEG-4HD PVR boxes with three tuners. One tuner is dedicated to push VOD and the EPG. A 250GB drive will be split equally between push VOD and user recording.
With the launch of HD services for its football and entertainment channels, Digiturk installed a new production chain alongside the existing system. The new system can run SD or HD with integral crossconversion to give the broadcaster operational flexibility.
It was not an option to extend the existing installation because the Philips systems are no longer manufactured, so in 2006 Digiturk issued a request for proposal to increase the number of channels, support HD projects and make provisions for the end of life of the Philips system.
For the complementary system, Digiturk chose a Harris video path and automation solution to run 10 additional channels. (The remainder of the broadcaster's output consists of pass-through channels.) Because Digiturk wanted to run the Alamar system until the end of its life, the new IT systems had to ensure that two different automation systems could run from one existing traffic system. The broadcast center's new system includes the Harris H-Class D-Series playout automation system and 10 NEXIO XS servers. Harris regional distributor Bilgi Elektronik provides ongoing support for the installation.
The D-Series automation can scale to control large numbers of channels for future development. A D-Series A7800 chassis controls ingest from a Sony Flexicart and standalone Digital Betacam, HDCAM and Panasonic DVCPRO VTRs. A D-Series DALstation with a jog/shuttle controller manages the ingest process.
The dual-redundant A7500 playout automation controls more than 30 server ports to feed the 10 HD and SD playout channels. Ten servers are split between two server domains in a main/backup configuration. High-speed network connectivity delivers 1.2Gb/s bandwidth between the digital archive and the NEXIO XS server domains, and partial mirroring provides greater redundancy for the premium channels.
The servers are configurable between HD and SD formats and include up-, down- and crossconversion, with the capability to easily adjust the aspect ratios to address the various studio requirements. Server inputs for ingest and playout outputs are routed with a Harris Platinum.
IconLogo branding modules and Screen Subtitling captioning systems complete each playout chain. The Screen Subtitling Polistream DVB system provides Turkish and English subtitles for each channel. An Inscriber G3 CG system creates graphics. Videotek TVM950 instruments provide test and measurement facilities for the video system.
Video file archive
The old Philips system had insufficient file storage. To free space, content was deleted at the end of the rights window. If the rights were reacquired at a later date, then the material had to be reingested with a further round of quality control checks.
The new system includes a Sun StorageTek L1400M tape archive for long-term storage of program files so that a videotape only needs to be ingested and checked once. The current storage capacity is 250 LTO-3 tapes (400GB), giving a maximum of 100TB, which equates to 7400 hours at 25Mb/s. Video files are encoded at 50Mb/s for the HD service and 25Mb/s for SD in the Harris native LXF format. A Front Porch Digital DIVArchive system moves files by FTP over GigE between the server gateway and the tape library.
The D-Series system interfaces with the existing traffic and scheduling system to import channel schedules and media data. It also sends as-run logs to the database. This tight interface continually updates all new ingest data on the automation database to highlight any upcoming problems for scheduled material. Nagravision Nagra-Lysis provides program management. Digiturk developed and runs its own centralized resource management (CRM) and billing for the subscription channels. Conditional access is based on the former Philips Crypto-works and later Irdeto products.
The new system consists of 10 channels but provides a springboard if the station wants to increase that number. It has an extensible architecture for the day when Digiturk replaces the aging Philips system.
The broadcaster invested about $17 million in the project. There were several drivers for the development. A large cost was monitoring and control, as automation lowers the associated manning costs. Digiturk wanted to launch an HD channel to capitalize on the Turkish love of football, and there will be future opportunities for an IPTV service.
Hatice Memigüven, CTO
Ümit Bey Dağli, head of engineering
Emre Uysal, product development and operations and head of headend
Aşkin Erdemir, general mgr.
Said Bacho, managing dir., Middle East
Mat Shell, business development mgr.
Technology at work
Front Porch Digital
DIVArchive content storage management
D-Series broadcast automation
Inscriber G3 graphics
NEXIO XS video servers
Platinum routing switcher
Videotek TVM950 test and measurement
Irdeto conditional access
Nagravision Nagra-Lysis program management
Pace MPEG-4 HD PVR boxes
Polistream subtitling system
Sun StorageTek SL1400 LTO tape library system