Know-how

A Stellar Combination

Optical and Digital

Making a virtue out of necessity, the organisers used optical fibres for the multi- kilometre cable links between the separate sites. The 2003 Ski World Championships were the first where all the video, audio, and intercom signals were distributed solely using fibre-optic cables. The number of channels was limited, so for more efficient operation, video, audio, and intercom signals were transmitted over the same cable. tpc used a multiplexing method with different “coloured” light signals on the same fibre for this purpose, thus improving the cable utilisation by up to 400 per cent. tpc utilised recently developed Flashlink components, capable of encoding signals with different wavelengths using the Dense Wave Length Division Multiplexing DWDM method.

Widespread

The use of fibre-optic lines brought another first for the Ski World Champs, completely digital video and sound production. However, this is nothing new for tpc: The NEXUS, usually in combination with the CANTUS, is now almost a standard component in both outside broadcasting and production studios. Therefore, selection of a signal router and an audio/intercomdistribution system for use at the Ski World Championships was simple. A large NEXUS network was the obvious choice. The concept of distributed control suggested the establishment of two technical headquarters: the Technical Operation Centre, TOC, at the finish area and the International Broadcasting Centre, IBC, at St. Moritz Bad. Both centres were locally networked using a NEXUS STAR and interconnected via MADI, to keep the networks isolated yet allow for free exchange of signals.

The TOC was the host broadcaster’s main technical area, housing not only the NEXUS STAR but also 17 widely scattered NEXUS base devices with a total of 1,436 inputs and 1,380 outputs. These were positioned, for example, in boxes along the runs where they gathered microphone signals and interfaced to the intercom system. Some of the base devices were mobile and could be operated right at the edge of the ski run whenever necessary. Others were used by Eurovision, or to integrate four studios overlooking the finishing line into the network. Other base devices connected the microphones required for short interviews with the athletes at the finish area. These signals were then routed to an O.B. van or the IBC. All base devices were connected to the STAR in star topology, so the STAR was a real distribution centre.

Constellation at 2,000 Metres

Even in summer, it is a tricky job to drive an O.B. Truck up the mountain around steep and narrow serpentine bends. In winter, when the roads are icy and enclosed by snow walls and when snow chains are a must, it is specialist work and impossible to accomplish without the support of tractors or snowploughs.
Despite the immense expenditure, in total eight O.B. Trucks were taken up the mountain and parked close to the TOC. Two of these huge vehicles owned by tpc produced the international feed for all participating TV stations. To be more accurate, the two tpc Trucks were responsible for mixing signals from the middle of the course and the finish line, while signals from the start were mixed by a studio within the TOC. Both Trucks smoothly integrated with the TOC network, since they are equipped with CANTUS and NEXUS.
Some of the visiting broadcasters made the effort to take their own O.B. vehicles to the TOC. One, Austrian broadcaster ORF for example, has a traditionally strong affinity with the Ski World Championships. An additional NEXUS base device was supplied to enable these stations’ O.B. Trucks to integrate into the network too.

Two Strong Partners

The Swiss tpc (tv productioncenter zürich ag) and the SALZBRENNER STAGETEC MEDIAGROUP have close ties. They both hold a half share in tpc international, a TV-production company based near Stuttgart. Beginning with a co-operation agreement late in 2001, the Swiss share holders participation in tpc international officially came into effect on 1 January 2003. This co-operation is based on positive experience gained during previous joint projects — tpc has been extensively working with STAGETEC products for a considerable time. tpc is a subsidiary of the SRG SSR idée suisse broadcasting service and is Switzerland’s largest TV-production company with 800 employees. The corporation produces telecasts for the DRS Swiss broadcasting service and other TV stations in the German-speaking countries. The partnership also proved itself during the Alpine Skiing World Championships 2003. While tpc sent staff and equipment to St. Moritz, tpc international provided support for some other TV productions in Switzerland. For example, O.B.s from the World Economic Forum at Davos and the "Art of Ice” show in Zurich.

Hotel with Infrastructure

Redundancy

What would happen if broadcasting from such a unique and short-lived event as the Ski World Championships crashed due to technical failure? Obviously, the TV audience would not be able to see their stars. The host broadcaster would not only have to tackle massive financial problems, but cope with loss of face, not to mention 170 frustrated technicians who had been working for weeks. Nevertheless, the massively complex system is only required for a comparably short time. No matter how strong the desire for absolute certainty, it would be irrational to invest a huge amount to make it fully redundant.

So, it was decided not to mirror the overall system, but only the most vulnerable components.
In the audio and intercom network, this means the optical fibres. The NEXUS already features innate high redundancy because all fibre-optic lines can be doubled up between any base device and the STARs. In addition, the cable running from the TOC to the IBC was safeguarded with a rented fibre-optic backup line from Swisscom. An extra STAR was waiting in the wings in case of hardware failure at the IBC or the TOC; however, this device was not required thanks to the high reliability of the NEXUS.

Firm Support

This project was a big challenge for all the participants, and for STAGETEC. They provided the majority of the NEXUS equipment, the STARS and 25 base devices, plus the CANTUS and NEXUS systems of the primary international broadcast feed control room, on loan. Starting with the initial project-planning phase, STAGETEC continually supported the overall-system planning, thus directly contributing to the success of the event and the galaxy of stars.

For the first time since 1974, the sophisticated Swiss winter-sports resort of St. Moritz hosted the FIS Alpine World Ski Championships 2003. With a total of 12 kilometres of fibre-optic cable hardwired into the mountain, the City and the SRG SSR idée suisse, the association of the governmental TV and radio stations in Switzerland, as host broadcaster were well prepared for this long-desired opportunity. Last year’s World Cup Ski race was an excellent technical dress rehearsal (see STAGES Vol. 5).
However, the Championships required significantly greater effort than a World Cup race. Around 400 athletes from 59 nations, all the way from Algeria to Uzbekistan, wanted to be filmed during the twelve races and three downhill training sessions. Almost 450 hours of material were broadcast to 300 million TV spectators world-wide. For the technical staff, this meant more races needed to be broadcast in less time. Sometimes this required portable base devices and camera equipment to be physically moved to new locations when the track layout changed. The narrowest time window, just 90 minutes for technical rearrangements and operating tests, occurred when the combination downhill and slalom races took place. This was only achievable by using a helicopter.

Pure Logic: Programmable GPIs in the New Generation of NEXUS

Control of external equipment is standard with NEXUS systems. A multitude of external control functions has always been possible using general-purpose interfaces, GPIs. Although customers have been able to specify this feature when purchasing, hitherto only factory pre-sets have been available.

The latest version of NEXUS makes GPI functionality flexible. Now even com- Pure Logic: Programmable GPIs in the New Generation of NEXUS plex logical connections can be programmed and modified on the spot! This feature was heavily used at the Skiing World Championships to determine camera on-air light status for each race.

The new logic functions edit window enables every single XRI (NEXUS relay interface) input and output within the system to be defined. The output may be, for example, a TTL voltage or a switched external control voltage. Various parameters ranging from the status of NEXUS internal cross-points, other system settings or external relay signals are all legitimate input criteria.

Up to four input criteria can be combined using Boolean operators to toggle up to four outputs then stored as a function. These logic functions can be cascaded enabling complex logical sequences to be programmed for the GPIs.
Logic functions are defined using a graphic representation of the flow to keep the process comprehensible. The real challenge lies in developing the function criteria — inputting them into the NEXUS system is foolproof!

These programmable logic functions are just one of the many features provided by the new NEXUS Matrix 5 software in combination with the new CPU. Moreover, although both the software and processor were originally developed for the NEXUS STAR, they can now be used with classic NEXUS systems.