Broadcast Ringmain (IPTV)

IPTV long ago replaced the RF ringmain in broadcast facilities, giving staff a far wider choice of channels at every desk. The next step, IPTV anywhere, extends that ringmain beyond the building, so anyone with an internet connection can securely watch the same channels they would have in the office. The viewer never sees IPTV, but for production and engineering teams in larger broadcasters it is an essential tool.

Producing live programmes requires total awareness. In news that means seeing incoming footage and rushes, seeing when reporters are at their standup positions and hearing the teams around other programmes. In sport it means seeing all of the action, which is straightforward for a football match but far harder for athletics, gymnastics, sailing or golf where many competitors perform at once. For technical staff, being able to see any point in the chain before and after transmission is invaluable for monitoring, diagnosis and rectification.

A broadcast ringmain also has to reflect how people now work. Staff at home, in temporary offices or at a venue need the same channel list, the same quality and the same security as the gallery, while branding and advertising teams need quick access to the channels they are responsible for. Extending the ringmain rather than duplicating it keeps one source of truth for every viewer.

A broadcaster asked Techex to deliver every pre-transmission and post-transmission feed to production and engineering teams spread across many countries and stationed at event venues. Sports such as sailing, snooker, golf and athletics run many simultaneous competitions, many of which never reach a broadcast channel, yet production teams need all of the day’s events available in real time to make informed decisions.

Video over the internet is unpredictable, so reliable delivery depends on ARQ protocols such as SRT and RIST, which allow the receiver to request retransmission of missing or errored packets. Techex installed tx edge on virtual machine infrastructure in two of the broadcaster’s data centres. Each node received the multicast channel from an encoder on the broadcast network, carried out ETSI TR 101 290 measurements, then delivered it to the IPTV network on a dedicated multicast address, while also listening on a dedicated port for remote connections once the encryption key had been exchanged.

Viewing was delivered through BrightSign set top boxes, so any television in an office or on location could receive any channel, each box connecting securely to a high availability tx core cluster spanning multiple data centres. tx core provided the channel list and encryption keys, unified management and monitoring of every software and hardware decoder, channel and user, and configuration of the tx edge instances. Software multiviewers on commodity servers were commissioned in the data centres, with custom web based control written by Techex so staff could choose their own layouts, used heavily by talent in green rooms and by directors and producers during productions. For desktop and mobile, a dedicated player application covered iOS, iPadOS, Windows and macOS, automatically selecting the correct channel type in or out of the office.

The system delivered more than 300 channels into the ringmain, scaled to carry an additional 100 temporary channels for major events, and proved reliable enough for daily sports production across production centres in Europe.

A broadcast ringmain has to be dependable enough for transmission monitoring and open enough for everyday production use. tx iptv is built for both.

Techex designs the whole ringmain, from encoder ingest and monitoring through to the endpoint on the desk and supports it as a single system. Making use of existing infrastructure where possible.