Originally featured on BroadcastEngineering.com
Harris debuts new in-band mobile DTV system at NAB2007
Harris and LG Electronics this week debuted their MPH (Mobile-Pedestrian-Handheld) mobile in-band digital TV system, which allows broadcasters to transmit over-the-air broadcast signals to mobile devices as part of their existing 19.4Mb/s DTV channel allocation. The companies are holding a series of demonstrations of the system at this week’s NAB2007 show.
According to the companies, MPH streams would take up a minimal amount of the allocated DTV spectrum, letting broadcasters transmit one or more MPH channels to mobile devices as a value-added service while still continuing to broadcast their main broadcast SD and/or HD channels to fixed devices. The system is backward compatible with existing ATSC 8-VSB transmission and receiving equipment and fully compatible with the ATSC transmission standard, including PSIP data and the ATSC A/110 distributed transmitter standard.
MPH may prove to be a boon to broadcasters looking to launch mobile TV services based on repurposed local content. Because the MPH signal can be transmitted as part of a station’s regular DTV channel allocation, there is no need to piggyback on a wireless carrier’s network to transmit the signal. Furthermore, Harris and LG Electronics claim that broadcasters will not have to build a new transmitter for the service, as they can use their existing DTV transmitters to transmit the MPH signals, but they will have to purchase some new support equipment, such as encoders, multiplexers and modulators. Harris is currently developing such products, with a planned launch early next year.
For the NAB show, local Las Vegas FOX affiliate KVVU, in collaboration with Harris and LG Electronics, is transmitting two MPH channels along with its regular ATSC DTV signal to an antenna on top of a bus taking hourly tours around the city. Tour participants are able to see the reception capability of the MPH system while the bus is in transit, as well as that of KVVU’s regular DTV signal. Another demonstration, taking place in the Harris booth in the North Hall, will showcase MPH’s reliability in difficult reception environments through a lab simulation of such conditions. The companies are also showing videotaped results of the weeklong field test it conducted on the system with WBNS in Columbus, OH, at the ATSC DTV Hot Spot in the upper lobby of the South Hall.
During the WBNS trial, the station simultaneously transmitted its primary digital HDTV stream and two MHP channels in its allotted 19.4Mb/s DTV channel. A total of 4.4Mb/s were devoted to the MHP channels. According to Harris VP Jay Adrick, the signal was able to maintain its integrity even at speeds of up to 70m/h. Harris and LG Electronics are planning more tests of the system during this year.
For more information, visit www.broadcast.harris.com and www.lgusa.com.