For more than 25 years, Troll Systems has been a major part of the commercial broadcast industry manufacturing air-to-ground HD video, ground receive systems and studio master controllers. Troll equipment is used in almost every commercial broadcast facility in the United States and is essential to the real-time delivery of national and local news programming throughout North America. In 2008, Troll introduced the XNG – Next Generation News Gathering an IP based diversity antenna system that included a high-gain directional tracking antenna and swappable 360° diversity antenna panels. With the addition of diversity antenna panels, XNG antennas could now receive reflected signals from spatially diverse antennas. These reflected signals could be combined to create cohesive video streams. Other benefits include the ability to receive multiple frequencies simultaneously and tracking airborne vehicles to the horizon.
As diversity ground receive sites became more commonplace, Troll introduced multi-channel diversity receivers that makes it possible to provide power to and control of DVB-T signal levels from up to eight remote antennas simultaneously. In operation, ASI encoded video is transported from the receiver over Ethernet to a control center. At the control center, Troll’s Video Network Server (VNS4000), decrypts the ASI and provides transcoding into multiple video formats for monitoring and display. In the most advanced systems, multiple diversity receivers can be daisy chained together to enable numerous transmission sources to access each diversity antenna site over a wide area.
In these systems, the digital data streams from each location can be monitored and combined at a “packet level” to support transmissions from a variety of aircraft, land or sea vehicles simultaneously on the same frequency and without interruption. An optional six or eight channel spectrum viewer makes it easy to identify interference and isolate it before it can cause an interruption in service.