A new DTV-related standard approved by the Advanced Television Systems
Committee (ATSC) will make it easier for broadcasters to transmit electronic
program guides, closed-captioning and other data to consumer DTV and HDTV
The new standard, PMCP (Programming Metadata Communication Protocol),
complements a current DTV standard, PSIP (Program and System Information
Protocol). Properly implemented, PSIP allows transmission of program guides,
closed-captioning, audio information and virtual channel changing (letting
viewers tune to the traditional analog channel, say, WCBS New York, Ch. 2, and
“virtually” tune in to its digital assignment, Ch. 56).
Although TV stations nationwide have been dabbling in PSIP for six
years, they haven't been able to embrace it; the implementation is too
cumbersome. Its most attractive aspect, the electronic program guide (EPG),
requires someone at the station to manually input program information. It's
not only labor-intensive but error-prone. But a new related standard, PMCP,
makes it easier for every station to provide accurate EPG information.
According to ATSC President Mark Richer, “This support is critical for
digital TV, and broadcasters have been behind the cable and satellite providers
in offering those services.” As broadcasters embrace multicast services, like
NBC's WeatherPlus or ABC's ABC News Now, viewers will have access to
program-schedule information at the push of a button. Broadcasters see EPGs as
an important competitive feature, since cable and satellite delivers them.
PMCP arrives at a critical juncture.
The FCC is mandating that all DTV broadcasters transmit a minimum amount
of PSIP data come Feb. 1. PMCP will be used by traffic-system vendors,
guide-information services and other manufacturers to send their respective
data to the PSIP generator at the station.
Based on the programming language XML, it will automatically insert the
right information into the right fields on the programming guide. A program's
timing will be pulled from the traffic system; the content description, from
the guide service.
“Once PMCP is set up, the PSIP generator will automatically know what
channels are on-air,” says Graham Jones, director of communications
engineering for NAB and chair of T3/S1, the ATSC specialist group on PSIP.
“The system will know the long-term schedule or any last-minute
changes to ensure the electronic program guide is correct,” he added. Jones
oversaw the PMCP project, which took a year and involved such companies as CBS,
ABC, Decisionmark, Encoda, VCI and Triveni.
The FCC mandate gives broadcasters the option of transmitting EPG
information in minimum 12-hour chunks. But Art Allison, NAB senior engineer,
science and technology, warns stations about just doing the minimum: Because
DTV sets receive the PSIP data once a day, if viewers receive only the minimal
PSIP data, programming guide will be blank once the 12 hours end. Allison
recommends stations send out three days' worth of PSIP data daily so viewers
always have information available whenever they tune in.
Karyn Reid, regional account manager for traffic-system vendor VCI, has
been involved with PMCP for two years. The use of XML, the Internet programming
language that enables data to be easily passed between disparate systems, is
the key, she says, adding, “We're very excited about PMCP and see a real
future for XML-based databases.”
Although PMCP will enhance the roll-out quality of PSIP-based services,
it won't be available for station use until compliant products are introduced
at the NAB show, April 16-21, 2005.
Until then, vendors will be writing the programs and updates that will
make their existing products compatible with the system. Each vendor is
approaching the upgrade differently: Some charge a nominal fee for the upgrade;
others build it into new products.
Once the vendor interfaces are set up with the PSIP generator, the input
of PSIP data will be vastly improved.
The PSIP generator will pull in data—whether closed-captioning, EPG or
other related information—and push it into the DTV signal. The signal is then
broadcast and received by DTV and HDTV sets, where a PSIP receiver in the set
pulls in local broadcasters' program information and builds an electronic
program guide. Viewers just click a button marked “guide” or “info” on
With the hard work of creating a standard behind it, the industry now
turns to implementation. New standards are tricky, but Jones is confident that
this one will get traction quickly.
“We had a good selection of manufacturers,” Jones says, “and we
believe we're over the number needed to become an industry standard.”