Phil Kurz /
01.26.2010 03:26 PM
Originally featured on BroadcastEngineering.com
CTV turns to new solution for live contribution of Olympic Torch Relay
Canadian national broadcaster CTV is using a new technology that identifies available cell phone bandwidth, encodes video to that bit rate and distributes outgoing video data across multiple cell phone connections to deliver live online and on-air video coverage of the Olympic Torch Relay winding its way across Canada.
The technology, the product of a Waterloo, Canada, startup Dejero, combines off-the-shelf components with proprietary software to manage data throughput and match it to available wireless channels. The as-of-yet unnamed product will work with existing cell phone service, WiFi connections, satellite data services, such as Inmarsat’s BGAN network, or next-generation wireless links, such as WiMAX and HSPA+ networks.
“The system is smart enough to figure out available bandwidth based on the environment it is in,” said company CTO Bogdan Frusina. On startup, the Dejero wireless ENG platform scans available wireless connections and sets a target bit rate for its MPEG-4 H.264 encoder based on available bandwidth. In a newsgathering environment, the unit would typically use 2Mb/s to deliver live SD feeds with less than one second of talk-back latency, he said. For the torch relay, CTV is using the Dejero solution at 1.5Mb/s, he added.
The solution, which fits in a Pelican case, addresses a problem broadcasters have faced when using wireless networks for live links — namely, the unpredictability of cellular networks that do not guarantee bandwidth. The Dejero technology offloads meeting the bandwidth requirement of video contribution from a single channel by splitting the data across multiple wireless channels — any one of which can dynamically vary based on the carrier. On the receive side, a Dejero server reassembles incoming data from multiple wireless channels and delivers two to four video outputs.
For the CTV application, the Canadian broadcaster is using a robotic camera mounted in a protective Plexiglas enclosure affixed to mobile home to cover the relay. An HD-SDI signal from the camera is ingested into the Dejero transmitter before being transmitted via various carriers back to CTV ENG rooms along the route. The Web-addressable transmitter can be instructed over the Internet to direct its calls to Dejero servers located at the various CTV ENG receive sites in proximity to the torch relay.
While CTV has used the Dejero technology to cover the relay since it began in Halifax in November 2009, the company plans to make its official public unveiling of the ENG contribution solution in April at the NAB Show in Las Vegas.
According to Frusina, the new technology can be used for contribution of HD content; however, achieving one-second talk back latency won't be likely until next-generation networks offering greater bandwidth become available.