TV Technology - January 7, 2009 - (Page 21)

Special Report 21 Curve CONTINUED FROM PAGE 19 degree, to tailor the Nextel project to design and build that network.” EASE OF OPERATION trucks, the Nextel project showed up. We definitely KCNC chose NuComm Newscaster VT2 transdidn’t need any selling on going to digital. When mitters and CR6D receivers for much of their new we first got wind of this project we knew that if digital microwave system. this happened it was going to be awesome.” “The main selling point of the NuComm gear Buckland explained how KCNC took the oppor- was its ease of operation,” Jones said. “There were a tunity of the BAS relocation project to greatly enhance their microwave system. “We were able to design an enhanced system with the Sprint Nextel Dock Swap program. In this Dock Swap program, Nextel totaled up the value of equipment they had agreed to replace. Approximately 60 percent of it made sense in our new plan but we weren’t constrained in building a digital network exactly like our old analog network. We were able to accent that and do our own touch on a system of the future. “At a certain number of receive sites we were able to put a little additional money into it and we upgraded all of our trucks and a majority of our receive sites to operate not only in the 2 GHz band but in the 6.5 NSI Silhouette and Andrew antennas atop KCNC studio GHz band,” Buckland continued. “This was building in downtown Denver. good timing since in our market the 2 GHz band is overly congested. We had more receive number of preset buttons on the front panel of the antenna systems than we needed in our future sites transmitter. An engineer can set up these presets so instead of buying one for one for everything we and just tell an operator to press the appropriate had authorized under the Dock Swap program, we preset button.” Buckland added that NuComm offered KCNC a turned some of those dollars into 6.5 GHz operafree VSB option on all their gear if purchased tion at the sites we were working on.” Buckland said that because KCNC had a whole exclusively from the company. “VSB is more bandyear’s prior experience with digital backhauls, the width efficient, if less robust than COFDM and we station “now has the best backhaul network in plan to experiment with using VSB transmission for certain fixed link applications,” he said. market.” At presstime, Sprint Nextel planned to convert “Through our early experience,” he said, “we recognized some of the issues and were able, to a the Denver market in January. I KCNC Uses MER to Judge Signal Quality hroughout their early use of digital microwave, up with methods as we went along and I think that’s why KCNC discovered that measuring Modulation Error Nextel as an organization came and visited us early on Ratio (MER) was the preferred method for judging the because they knew we had fumbled our way through a quality of a digital microwave signal. lot of the early stuff and had come up with a reasonable “Initially we would punch up the MastCam on a truck, system for tuning in live shots digitally. Ideally it’s nice to point it at traffic and look for macro blocking,” said have a spectrum viewer and then also to have some qualKCNC Engineer Chris Jones. “We ity metrics that let you know you’re were trying to figure out what sort approaching the cliff. BER lets you of metric to use to gauge the qualknow you’ve fallen off the cliff but ity of a live shot. Bit Error Rate is MER lets you know you’re one of those things that sort of tells approaching it.” you what you already know. Your Initially KCNC used Tandberg pictures are frozen by the time you IRDs for monitoring. These IRDs see that your BER is shot. We were have a Web interface that provides trying to find a way to see that coman MER value. KCNC installed these microwave ing on, and through trial and error “The MER in the Web interface antennas atop Lookout Mountain, site and research we came across MER required refreshing; it wasn’t a of the station’s transmission facilities. as the best way to tune in a live dynamic meter,” Jones said. shot.” “We’ve been using that up until now when we got our Jones compared the process to FM in which the engi- new NSI gear which has constantly refreshing meters neer in the truck observes the waveform monitor and lis- that indicate both MER and Receive Signal Level [RSL].” tens to the audio until the chroma stops fluttering in order The NSI MC5 controller offers a GUI which displays to achieve a good shot. a bar graph of MER and RSL as derived from the digital “It’s pretty intuitive to tune in an FM live shot but that’s microwave receivers. not so for digital live shots,” he said. “We had to come Andy Morris T http://www.cobaltdigital.com http://www.cobaltdigital.com

Table of Contents Feed for the Digital Edition of TV Technology - January 7, 2009

TV Technology - January 7, 2009 NFL Enters a New Dimension Mobile DTV Looms Large in 2009 Contents A ‘Flexible Framework’ Doing More With Less ‘X’tra-Streamlined Finish Line in Sight for BAS Transition Ahead of the Relocation Curve DTV Transition Survival Guide ENG and the Lines of Communication DTV Transition Survival Guide Who Do We Really Work For? Obama to Expand Internet Access The Wizard Takes a Holiday The Solid-State Disk Revival To Light the Ear... or Not Hulu Gets It Right—the First Time User Reports—Video Servers & Recording/Controllers Reference Guide Product Showcase Classifieds Marketplace TV Tech Business

TV Technology - January 7, 2009

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