Skip to main content

Sencore Develops Customized Groomer Solution for PBS


Sencore, a provider of signal quality and video delivery solutions, has partnered with PBS to create a customized groomer solution. The Sencore Transport Data Injector (TDI 3000) provides insertion of emergency message data to support PBS's participation in the Warning, Alert, and Response Network (WARN) Act across the United States.

"With the TDI 3000, PBS fulfills its important role as the redundant backup transmission path for a critical emergency alert service, and we are able to do so without any disruptions to our member stations' broadcast streams," said Kristen Weiss, communications director for the PBS WARN Project. "Sencore's years of experience and expertise in signal transmission solutions made the company an ideal partner as we looked to support this unique and vital service."

Passed by Congress in 2006, the WARN Act establishes a system for cellular providers to transmit emergency messages such as presidential alerts, imminent threats, and Amber Alerts. The FCC's Commercial Mobile Alert System (CMAS), established in 2008, enables cell phone service providers to receive WARN emergency messages that are then formatted for 90-character text message retransmission to cell phones. In addition, the FCC requires PBS member stations to act as a backup transmission path for WARN by carrying message data in their broadcast transport streams, from which the cell provider gateways may extract the messages if the primary link to FEMA becomes unavailable.

Sencore's TDI 3000 plays a "groomer" role in the WARN system by receiving messages via satellite feed from PBS and then injecting them safely into the local broadcast stream within five minutes of their arrival, and without affecting broadcast service. Redundant TDI 3000 units are installed at most PBS member stations, operating between the production system and the ATSC modulator. An independent antenna and receiver from the PBS satellite feed brings the WARN message into the station's operation, where it is passed to the TDI 3000 via ASI or IP transport stream. The TDI 3000 uses a packet re-stamping scheme to avoid re-multiplexing the affiliate transport stream, and it does not change video or audio services or otherwise modify the primary multiplex. Null packets are used whenever possible to inject the WARN messages.

"We are very honored that PBS has chosen Sencore to play such a key role in delivering this vital service as part of the U.S. emergency alerting system," said Thomas Stingley, executive vice president, sales and marketing at Sencore. "With TDI 3000 units operating in local PBS member stations across the country, this installation is validation of Sencore's leadership position in delivering reliable, effective broadcast signal delivery technology."