Thomson’s ATSC Mobile DTV Terrestrial Broadcast Technology from Grass Valley is based on the ATSC Mobile DTV Standard A/153 (approved October 15, 2009) and is backward compatible with legacy ATSC transmission systems, enabling stations to use their existing DTV channel and the mandated ATSC 8-VSB modulation scheme. The technology offers several significant technological advantages over other systems, including the use of M/H Block Coding to provide maximum capability for signal reception.
As the only supplier in the broadcast industry to provide equipment from image capture through RF transmission, Grass Valley leveraged years of experience and a broad product portfolio to develop a complete ATSC Mobile DTV system that is fully integrated and pre-configured to ensure real-world success.
“This is an exciting time for broadcasters looking to build out mobile video services,” said Richard Fiore, Senior Director for Transmissions and Mobility at Grass Valley. “Grass Valley has been very careful to develop a robust and reliable system that can be cost-effectively implemented in a very short amount of time.”
The basic equipment needed to begin broadcasting mobile video services via ATSC Mobile DTV includes program encoders, a multiplexer, an electronic services guide (ESG) server, and a compatible DTV transmission exciter. Each of these devices is now available in field-tested production models from Grass Valley.
ViBE Mobile TV Encoding
The ViBE Mobile TV encoder is a cost effective device that provides the necessary MPEG-4/H.264 video compression and HE-AAC audio compression. A single 1RU ViBE Mobile TV encoder chassis can hold up to four individual program encoders. ViBE is also available with statistical multiplexing allowing for maximum picture quality across all program streams/video contents in a given bandwidth.
Beyond the standard ATSC Mobile DTV encoder, Grass Valley offers Scalable Video Coding (SVC) on the Premium version of the Grass Valley ViBE Mobile TV platform. In addition to SVC, the Premium encoder features a unique Region of Interest (ROI) encoding system. ROI is a patented feature that automatically detects the visually interesting area of a picture and crops out the uninteresting areas. The ROI feature allows broadcasters to re-purpose “large screen” content for smaller displays associated with mobile and other handheld devices, further enhancing the user’s experience with the mobile content.
There are two ViBE Premium encoder platforms available that support SVC and ROI, depending on the number of program streams. For a basic system with a single program stream, the TNM-3264-P100 platform is supplied. If there is an intention to start with more than one program stream, the ViBE TNM-3264-P200 encoder supports up to 2 CIF or 4 QCIF channels in a single 1 RU chassis.
Critical Mobile DTV multiplexer (MUX) and IP encapsulator (IPE) functions are provided by the Grass Valley NetProcessor 9030 platform. The NetProcessor 9030 is available with a large variety of interfaces (DVB-ASI, GigE/IP, ATM, etc.) and handles IP data injection and bit rate management. In addition to MUX and IPE functions, the NetProcessor 9030 contains the Signaling Server for the generation of TPC, FIC, and SSC tables specified as part of the A/153 standard.
Broadcasters that already have deployed the standard Grass Valley ATSC 9030 NetProcessor can be software upgraded for compatibility with ATSC Mobile DTV services.
XMS™ Network Manager
The Grass Valley eXtensible Management System (XMS) is a robust client/server architecture that provides broadcasters a complete management solution for the mobile video headend system. The XMS server is a package of applications running on a PC or server, and XMS Clients are graphical user interfaces (GUIs) allowing remote access to user applications located on the XMS server. Several clients can access the server at the same time with updates from all clients reported in real time. The management of users’ rights ensures a safe, distributed access to the system, with partial scope if needed.
Mobile DTV Transmission
For the most part, any existing Thomson-branded DTV transmitter already in use is capable of broadcasting the ATSC Mobile DTV signal (ATSC A/153) with minor upgrades. The key component that will require attention when implementing ATSC Mobile DTV service is the exciter. Initially, DTV transmitters were shipped initially with MODAP (6 RU) and then later with ADAPT-IV (2 RU) 8-VSB exciter platforms. The ADAPT-IV exciter platform features embedded FPGA/Power PC cores that allow a simple software upgrade to handle the additional requirements of the ATSC Mobile DTV system.
Older MODAP exciters can be upgraded to the newer mobile DTV hardware platform.
The OMVC and Grass Valley
For the past 18 months, the Open Mobile Video Coalition (OMVC), a consortium of stations interested in mobile video service, has been testing ATSC-compatible, in-band digital television transmission technologies. Grass Valley recently participated in the OMVC’s conformance testing that was conducted in Q3 this year.
At various trade shows over the past two years, Grass Valley has staged live demonstrations of elements of its new ATSC Mobile DTV Terrestrial Broadcast Technology, including the use of scalable video codecs.
The X ATSC Mobile DTV system allows stations to distribute their local content to portable mobile devices, such as cell phones, laptop computers, and in-car entertainment systems. With a standard in place, the National Association of Broadcasters predicts that TV stations delivering content to mobile and handheld devices could generate more than $2 billion in annual revenue by 2012.