This week I'm focusing on NAB so articles on FCC actions this week will appear in next week's RF Report.

The words "Mobile DTV" showed up at this year's NAB Show, almost as much as "HDTV ready" did at previous NAB shows in sessions on TV production as well as at most transmitter and antenna manufacturers' exhibits. Working Mobile DTV receivers and USB stick tuners were demonstrated in several booths, sessions and suites. These receivers had a wide choice of channels to choose from.

DISH was broadcasting on a channel 56, a channel it won in the 700 MHz auction. The transmitter was located in the Harris booth at NAB and used a directional antenna pointed at the Hilton on the roof of the North Hall. DISH was transmitting 4 ATSC Mobile DTV program streams on it. Harris had channel 45 on the air with Mobile DTV at the Convention Center. Full power stations KBLR (DTV RF channel 40), KVCW (DTV RF channel 29) and KVMY (DTV RF channel 22) were transmitting ATSC Mobile DTV signals throughout the show. A low power DTV station was transmitting Mobile DTV, but I didn't see it on the receiver I had during the show.

As mentioned last week, I was working on the three-transmitter KBLR distributed transmission system, (DTS) for Telemundo station KBLR. As far as I know, this was the first public demonstration of a DTS carrying a Mobile DTV stream over the air.

KBLR transmitted 1080i HD at 14 Mbps on its main channel and two 500 Kbps mobile program streams with bandwidth to spare. The demonstration included the main KBLR transmitter at Black Mountain operating at 230 kW horizontally polarized and two vertically polarized transmitters. One of the vertically polarized transmitters was located on the top of the Stratosphere. The other was in the ATSC Mobile DTV booth in the Convention Center central hall. The KBLR demonstration included KBLR's programming as well as a special version of CNBC. CNBC was delivered to the KBLR studio on Fremont Street in Las Vegas over a video over IP link on the NBC LAN from New York using TV-IPS equipment.

A DISH uplink on the roof of the KBLR studio sent the Mobile DTV ASI signal to AMC-16. It was downlinked at KBLR's Black Mountain transmitter site and at the Convention Center. Rohde and Schwarz SX800 ATSC Mobile DTV exciters were used at all locations. The Stratosphere DTS transmitter received its signal over a digital microwave system from MRC. Triveni supplied the equipment needed to provide the signaling information required by the ATSC A/153 standard to the Rohde and Schwarz Mobile DTV multiplexer. LG provided the Pixtree USB tuner I used to check the Mobile DTV signals.

The DTS system worked! I'll have more details in a future RF Technology column. Walk around tests showed it provided a Mobile DTV signal in locations in the South Hall where the main KBLR signal wasn't receivable. I had a chance to check regular ATSC reception in the South Hall and found the DTS helped it as well.