Located in the Minneapolis/St. Paul market, Hubbard Broadcasting’s locally owned and operated flagship station KSTP-TV launched mobile DTV Oct. 14. The station is the first in its market to launch mobile DTV.
According to Hubbard Broadcasting President Rob Hubbard, the mobile DTV launch has been a success. “Broadcasters are excited about mobile DTV because the technology makes TV accessible in locations where normal reception was not possible,” he said. “It gives people the freedom to watch television while in motion, walking or riding the train.”
KSTP-TV chief engineer Dick Rice said that the station began serious discussions about launching mobile DTV a year or so ago and received approval to go ahead in midsummer 2010. “We had already done quite a bit of homework on what we needed to do for a launch, but we didn’t have specific equipment chosen,” he said. "The station was already the host forcentralized Triveni PSIP for the group, so it was somewhat important for us to stay with Triveni for the MDTV electronic signaling and that also guided to some degree the other manufacturer decisions as well."
The first step that KSTP-TV wanted to take was a transmitter upgrade to improve transmitter performance. Rice’s team installed the Axcera LDMOS solid-state amplifier add-on upgrade to its Harris Sigma IOT transmitter. “The Axcera LDMOS helps with the linearization of the transmitter for both ATSC and mobile and improved the signal-to-noise ratio of the transmitter dramatically,” Rice said. “Now, seeing the results, we think it was well worth doing.”
Once the transmitter upgrade was finished, Rice also wanted to implement statistical multiplexing to better fit the mobile DTV service into its bandwidth without a negative impact to the existing channels. “We installed the Harmonic Electra 8140 encoding/stat-mux system from HeartLand Video," Rice said. “Once the VBR encoding was operational to our liking, we gave it a couple of weeks on the air to make sure everything was working well before installing and launching the Axcera mobile DTV system Oct. 14."
“We’ve been pretty happy with the receivability of the mobile signal,” Rice said. “We’ve been impressed with how well we cover most of the Twin City Metro areas, but, as expected, there are some holes in the coverage area and we’re testing to find out where they are so we can come up with a plan on how to fill them.”
For now, the single mobile DTV channel is broadcasting a simulcast of the primary station, but KSTP will soon implement a program stream that includes additional local programming and older movies and TV shows from the This TV network.
“The biggest hurdle in the project was launching the statistical multiplex due to variable-bit rate encoding parameter incompatibilities with some viewer TVs, but we've overcome that,” Rice said. “Considering how new the mobile DTV technology is, it has worked very well.” With regard to how much it cost to add mobile DTV, KSTP does not release these figures, but Rice will say that it was “in line with what you read in the trades.”