Station to Station

Abit-Quantel interface developed to WDR requirements

A Phoenix is rising

Since Autumn 2000, Phoenix, the information, event and documentary broadcaster for ARD and ZDF, has been transmitting from the ex-ZDF Bonn Capital City studios, with Quantel's Clipbox Power forming the centrepiece for editing and playout. Phoenix first went on air in 1997 via Astra 1 C. Every household with a satellite system can receive Phoenix, and Deutsche Textfeld:  Telekom is upgrading its cable network to include it; however, Phoenix is not available via terrestrial. Reinhard Wagner looks at the technical concept behind the set-up and the network's special requirements, such as parallel recording, editing and time-shifted transmission.

 The Phoenix production and transmission infrastructure was first put in place in 1997 at WDR in Cologne. The difficulty and challenge of the original operational concept was the integration of a central server for the recording, editing and transmission into a broadcast chain. Once the decision had been made to use a Quantel Clipbox with Newsbox editing systems, the next difficulty arose -- how to integrate the digital equipment into the existing analogue environment via D/A- and A/D converters and MUX/DeMUX.

As Phoenix broadcast from the 'old' WDR-transmission control SK11, all the equipment was exclusively operated by WDR employees until the move to Bonn. However, ARD and ZDF employees were already involved jointly in the editorial programming.

Viewers embraced Phoenix quickly, and before it went on air the decision was made to move the channel to the ZDF studios in Bonn because of the government's decision to resite the capital of Germany in Berlin. Before the move from SK11 in Cologne to the modified studio in Bonn, Quantel supplied a new Clipbox with Editbox Seats for WDR to test in operation for the first time. In the meantime, WDR purchased a 50% share in the ZDF Bonn studio.

The plan was to move to Bonn during the Parliamentary summer break, as Phoenix mostly broadcast documentaries and did not generally put out live reports during that four-week period, thus putting less demand on transmission. For a short period, the complete Phoenix broadcast transmission had to be moved into another WDR studio while the equipment from SK11 was transferred to the Bonn studios. For those four weeks Phoenix was transmitted from WDR Studio B. A large number of personnel were required, as it was operating without its server, NLE and transmission automation. WDR's production, video engineering and technical planning departments worked together to complete the move ready for transmission from its new home on 7 August 2000.


All the experience gained during the early years of transmission from Cologne was intregrated into the new transmission operations of Phoenix in Bonn. While the move was being carried out, 13 ZDF employees were also integrated into the production operation. The two shifts required during transmission are covered by 26 ZDF and WDR employees. The third shift, 00.00 to 08.00, is covered by automatic transmission. The ZDF and WDR engineers were trained on the new equipment -- Clipbox, Editbox Seats, Philips DD35 vision mixer, Lawo mc2 audio mixer, etc -- during the last phase of the changeover in parallel with the transmission from Cologne.

Once the installation of the central equipment had taken place (i.e. routers from Metawave and Sandar, video distribution amplifiers from Ross and GVG, Tektronix sync generators and switcher units, time code generators, etc) and the commissioning of the Lawo mc2 audio mixer and Philips DD35 video mixer was complete, Clipbox Power and the three Editbox Seats came into operation in August 2000.

The new studio layout, the choice of equipment and the staff training were designed for maximum performance with minimum effort. The three cameras in the Phoenix studio can all be operated remotely via Radamec camera control from the production gallery. Every employee has been trained to take on several functions-for example, the systems administrator should also be able to take over the switching room duties. Control of the Clipbox and Cart devices have been integrated with a General User Interface for the four areas of the Phoenix engineering set-up. (It is also planned that another control unit will be installed in the journalist area to monitor the Transmission Plan sequence.) All the new technical equipment was installed in the studio's set storage area and customised for the Phoenix transmission plan. The open plan architecture of the area -- with the vision/sound gallery, transmission control, system administration and online areas all within sight of each other -- means decisions can be made quickly and easily.


Clipbox Power was installed with a view to extending production requirements while simultaneously guaranteeing the transmission operation. These requirements included the ability to edit four live events in parallel, allowing time-shifted replay of one event and simultaneous editing work. Further requirements from the journalists, such as more storage, a third edit suite and improvements to the audio processing, could also be met with the new generation of Quantel equipment in place.

Another saving was made by combining Clipbox Power with the Abit automation system. The Abit-Quantel interface was developed to specifications supplied by WDR. The Abit run-list is able to record live events or copy them across directly to the Clipbox or onto one of the Cart machines. Crash recording is also possible either on the Clipbox or a Cart machine at any time. Clipbox Power is sometimes used as a cache for trailers - trailers are copied across from the Cart machines via Abit onto the Clipbox from where they will be transmitted.

A Sandar SDI router is also controlled directly by Abit, switching the individual VTR machines and server channels according to the transmission sequence and allowing bypassing of the vision mixer during fully automated nighttime broadcasts. In addition, because of the increased editing requirements at Phoenix, both existing Newsboxes were upgraded to Editbox Seats, with a third Editbox Seat added on.

Phoenix opted for the DVCPRO50 format because the Bonn studios operate in a Digibeta environment. This was for two reasons: quality and storage capacity (it gives journalists up to 50 hours storage). Quantel also offers additional storage units, so storage capacity can be taken up to 200 hours with Clipbox Power.


The advantages when processing audio with the Editbox/Clipbox are that no mixdown has to take place when an edit is made (hard cut, wipe or dissolve) -- it can be played out directly. Audio mixdown via the Editbox internal mixing desk is also possible. A separate sound-mixing desk was installed for playout to tape or recording in from external signal sources. Lawo mc2 is available for extensive audio processing and sound mixing during studio productions: this could be replaced by a Yamaha 02R as a backup. Although these devices are not compatible, the backup solution is a cheap one, thus eliminating Textfeld:  the need for a redundant mc2 ATM switch. The emergency operation can be maintained at all times, albeit with a limited number of signal paths and mixing possibilities.

Quantel's Dylan disk arrays also cut down on maintenance costs as defragmentation is unnecessary. Only newly rendered frames are saved to disk when processing clips. And again, once the raw material is deleted, only the original frames required by the edited 'daughter' clips will be retained in the server. All these measures guarantee the most efficient use of the available storage capacity. When clips are no longer needed they are deleted, after consultation with the journalists.

Events coverage and studio productions are covered by two editorial teams from ARD (Alfred Schier) and ZDF (Alexander Kahler) in weekly rotation. "Because of the concept of the extensive events coverage, our channel is unique, not only in Germany, but also in Europe," explains Alfred Schier (ARD), editorial manager events, Phoenix.

"The time-shifted transmission, in conjunction with the capability to quickly process pictures and original sound during the parallel recording, necessitated a special processing and playout system," Schier says. "The technical concept of the system was developed as a result of cooperation between the editorial and technical teams. However, we as members of the editorial team did not have any influence on the choice of systems manufacturer. The fact that nonlinear editing on a central server represents the right way into the furture was, and will continue to be, seen by us as positive."