The work to develop a comprehensive standard for mobile and handheld services—known as ATSC Mobile DTV—has reached a milestone with publication of the A/153 Candidate Standard document set. ATSC Mobile DTV is being developed to support a variety of services including free (advertiser-supported) television and interactive services delivered in real-time, subscription-based TV, and file-based content download for playback at a later time. The standard can also be used for transmission of new data broadcasting services.

ATSC Mobile DTV is built around a highly robust transmission system based on vestigial sideband (VSB) modulation coupled with a flexible and extensible Internet Protocol (IP) based transport system, efficient MPEG AVC (ISO/IEC 14496-10 or ITU H.264) video, and HE AAC v2 audio (ISO/IEC 14496-3) coding. The ATSC Mobile DTV Candidate Standard describes the methodology for new services to be carried in digital broadcast channels along with current DTV services without any adverse impact on legacy receiving equipment.

In addition to live television, the ATSC Mobile DTV system provides a flexible Application Framework to enable new receiver capabilities. Receivers that make use of an optional Internet connection will enable new interactive television services, ranging from simple audience voting to the integration of Internet-based applications and transactions with television content.

Development of the ATSC Mobile DTV system was based on a strategic plan approved by the ATSC Board of Directors in October 2006. ATSC subsequently developed detailed system requirements and issued a request for Proposals (RFP) in May 2007. Work on the ATSC Mobile DTV system has been done within the Specialist Group on ATSC-Mobile/Handheld (TSG/S4), which is led by Mark Aitken of Sinclair Broadcast Group as Chair and Dan Borowicz of Ion Media as Vice-Chair. The major elements of the ATSC Mobile DTV system have been selected and documented. On November 25 the Technology and Standards Group (TSG) approved publication as a Candidate Standard.

The ATSC Mobile DTV Candidate Standard

A Candidate Standard (CS) is a specification that has received significant review within an ATSC specialist group. Advancement of a document to Candidate Standard is an explicit call to those outside of the related specialist group for implementation and technical feedback. This is the phase at which the specialist group is responsible for formally acquiring that experience or at least defining the expectations of implementation. The parent technology group (TSG) must approve advancement of a document to Candidate Standard status; this done by a ballot of voting members of the group.

Because the Candidate Standard phase is intended to gain real-world implementation experience, ATSC member companies are already working to make sure that the ATSC Mobile DTV system functions as intended, and to identify any elements that might require additional work.

When TSG votes to elevate a document to Candidate Standard, it also sets the period of time for the CS implementation phase. The CS period for ATSC Mobile DTV extends to May 20, 2009. A Candidate Standard may be revised during this period, giving the specialist group the ability to address any issues that are identified during trial implementations. Suggested laboratory tests and field tests on the system during the CS phase are documented in the test plans developed by ATSC. Testing organizations can request these plans from ATSC or develop their own.

The Open Mobile Video Coalition (OMVC) has announced plans to conduct field trials of the ATSC Mobile DTV system. The OMVC is an alliance of broadcasters whose mission is to accelerate the development of mobile digital television in the United States.

Rounding out the ecosystem for ATSC Mobile DTV devices and services, the Consumer Electronics Association has launched a complementary Special Interest Group for manufacturers interested in building products to the Candidate Standard.

Documentation

In a tip of the hat to the core ATSC DTV Standard—document A/53—the final ATSC Mobile DTV standard will be known as A/153. Like A/53, A/153 is modular in concept, with the specifications for each of the modules contained separate Parts. (See Figure 1.)

Figure 1 The overall A/153 documentation structure.

Schedule

The current work plan for ATSC Mobile DTV meets the often-stated U.S. broadcaster need to announce the availability of future mobile/portable/handheld services in the first quarter of 2009. If all goes as planned, TSG will be asked to approve a ballot on the ATSC Mobile DTV Proposed Standard by May 2009, with the ATSC process ending with final membership approval in Q3 of 2009.

The ATSC Mobile DTV Candidate Standard document set can be downloaded from the Candidate Standard page on the ATSC Web site: http://www.atsc.org.

Jerry Whitaker
VP, Standards Development
Advanced Television Systems Committee
202-872-9160
www.atsc.org