From SD to 3DTV-Ready

Guangxi TV (GXTV) is the largest shareholder in Guangxi Radio and Television Information Network Co., Ltd. After deciding to upgrade from SD to HD, GXTV decided to futureproof its system by deploying a 3DTV-ready infrastructure. Initially, we were looking to upgrade our existing playout system for eight SD channels, as well as launch our first HD satellite channel. We started researching the market’s latest HD broadcast technology in 2009, including master control, routing, and infrastructure solutions.

It made sense for us to build our three new channels to be SD/HD compatible in preparation for the projected increasing HD demands over the next two to five years. We also decided to modify three existing SD channels to make ready for HD/SD simulcasting.

During our investigations into potential infrastructure vendors, it soon became obvious that Miranda’s modular Densité Series offered more flexibility and functionality than competing solutions. It would allow us to significantly reduce the complexity of a traditional processing chain.

At this point, we observed that the majority of the Densité HD processing modules were already equipped with 3Gbps functionality. We also realized that we could readily integrate our existing transmission router with two new 3Gbps NV8280 routers – with control from the existing control panels – to achieve a highly capable 3Gbps infrastructure.

This inspired us to go ahead, and build the first 3Gps ready system in mainland China. Our new system was completed in September, 2010.

With this new system, we only need to perform minimal upgrades on the existing HD system to support 3DTV playout in the future, with minimal additional cost and disruption to operations. For instance, with the Densité LGK-3901 channel branding processor, it is as simple as ordering and keying in a new 3Gps license.

So far we have installed 240+ Densité cards. These are housed in 30 3RU Densité frames for processing across our entire transmission chain, from ingest to post-production to playout.

This system includes ten Densité integrated receiver/decoders and 100+ 3Gbps/HD/SD SDI video DAs, which are installed upstream of two NVISION 8144 routers; an existing NVISION 5128 router, and six NV5100MC master control switchers. Other elements in the signal processing infrastructure include eight XVP-1801 up/down/cross converters with ARC.

We also have three LGK-3901 channel branding graphics processors sitting downstream of the routers and master control, which can insert up to five layers of graphics.

We were impressed with the simplicity of the Densité range and its control systems, as well as its capabilities. Not only does it address all our signal processing requirements, but it can be expanded to manage a wide mix of functions; even including multiviewers and video playout.

Another advantage to Miranda’s approach to signal processing is that the cards are extremely multi-functional, and this saves space and power. For instance, a single signal processor module will perform the same functions that previously required five separate cards.

This fact simplified system integration and made expansion much easier, while also reducing capital costs. What’s more, we can add more complex features to individual cards as required.

Currently, we use the XVP-1801 signal processor for handling HD and SD signals in fixed aspect ratio conversion mode. We plan to use the module’s AFD function in the future to provide better management of the aspect ratio issues during playout.

The IRD-3811 integrated receiver/decoders are fed by RF and ASI sources, and provide HD/SD-SDI outputs for our core NVISION 5128 transmission router. These HD/SD-SDI signals are then routed to our playout or production systems.

It’s very important for GXTV to maintain stable and reliable signal transmission across our services, so we have used Densité fibre connectivity for long distance links between facilities.

Additional Miranda equipment in the facility includes the Densité HCO-1821 change-over, which provides emergency switching between the main and backup playout channels.

We also use three Miranda Kaleido-X16 multiviewers for signal monitoring. These feed six 50-inch plasma screens across the playout and transmission areas.

For the three SD/HD compatible channels and one full HD channel, Miranda’s NV5100MC master control switchers are used as the main playout links. The NV5100MC combines routing and master control capabilities in a single frame, and this simplifies control and saves space.

With our new system, we have resolved many of the issues associated with traditional HD/SD playout. We can also look ahead to 3DTV broadcasting, without worrying about having to swap out core equipment.

We’re confident that our tightly integrated solution provides the best in signal processing with regards to quality and efficiency.

Yuan Fang is Chief Manager of Transmission and Playout at GXTV.

Miranda Technologies
+ 852 2539 6987

- from TV Technology Asia/Pacific