WTVE Reading (Pa.) and transmitter manufacturer Axcera
announced that they are testing the use of a single-frequency network (SFN),
which broadcasts the same signal from multiple transmitters to improve
reception, for mobile DTV using the new A/153 ATSC Mobile DTV standard. Axcera
said that the system, which began operating in August, was the first such
system to be deployed.
WTVE, a RNN affiliate which serves
Reading as well as Philadelphia,
Wilmington, Del.
and the Delaware River
Valley region, has
operated an SFN for its normal ATSC broadcasts since 2007. The system employs
eight synchronized transmitters to blanket the WTVE coverage area. To
demonstrate the effectiveness of multi-transmitter networks for Mobile DTV, the
station has worked with Axcera to convert the system to support the new ATSC
Mobile DTV standard, also referred to as ATSC M/H (Mobile/Handheld). Continued
testing of the system is planned into early 2010, after which the station will
share results with other broadcasters.
"Since handheld devices are
typically just a few feet off of the ground and can be moving at very high
speeds throughout the coverage area, Mobile DTV requires a much more dense
signal than broadcasting to home receivers," said WTVE GM Todd Stewart in a
statement. "ATSC M/H offers excellent performance in the mobile environment,
and combining this with DTS technology will allow us to ensure the best
coverage possible to our viewers."
The conversion to ATSC M/H and
testing was completed in cooperation with technology vendors Expway, Harmonic,
Kenwood and LG. The headend includes Harmonic's ProStream 4000 live
multi-screen transcoders and Expway's FastESG (electronic service guide)
system, feeding an Axcera ATSC M/H Preprocessor/MUX and DTxA2B distributed
transmission adapter. Each transmit site uses an Axcera "Axciter" intelligent
modulator with DTS slave and M/H post-processor functionality. Testing is being
done using professional and consumer receivers from Kenwood and LG.
The coverage analysis and DTS
system design was provided by the broadcast technology consulting firm Merrill
Weiss Group, LLC, which worked with WTVE back in 2007 to create its original
SFN. Transmission expert Weiss has consultedwith broadcasters in New York and elsewhere about using SFNs to improve
conventional DTV coverage .
"Since ubiquitous coverage is
critical for a successful mobile DTV service, we felt that we could leverage
our position as innovators of both ATSC M/H and DTS, along with the
capabilities of our valued partners, to promote the use of these ATSC-compliant
technologies and demonstrate the great opportunity they offer to broadcasters,"
said Axcera President David Neff in a statement.
