02.06.2009 08:24 AM
Originally featured on BroadcastEngineering.com
DTV delay flexibility adds complicating element to transition
The House passage of a bill Wednesday to delay the DTV transition until June 12 adds the wildcard of flexibility to the DTV playing deck. The bill, which the Senate previously passed and is expected to be signed by President Barack Obama, gives broadcasters permission to transition early.
That means a new element — the likely presence of some full-power analog stations during the 115 day extension — will be injected into the transmission equation. This was never envisioned nor planned for by those responsible for orchestrating the transition.
For the 1089 full-power stations already operating on their post-transition digital channel, the unexpected presence of continuing analog service on some channels is not a problem. Things get a little more complicated for two other groups of stations: those that have already pulled the plug on analog service and those moving from a pretransition DTV channel assignment to a different post-transition DTV assignment.
According to the commission, the FCC has granted requests or received notification from 143 stations to end analog service prior to Feb. 17. Additionally, 276 stations have told the FCC they intend to shut down analog operations by the original deadline. These stations must grapple with the question of turning analog back on or foregoing their plans to shut off analog. While doing so means added expense, the question may come down to weighing those operational expenses against the cost of losing over-the-air viewers who haven’t prepared.
From an engineering point of view, some of the stations moving from pre- to post-transition DTV assignments may have interference concerns if other stations in their market or adjacent markets continue analog service until June 12. A Feb. 3 letter from FCC acting-Chairman Michael Copps responding to inquiries from Reps. Joe Barton, R-TX, and Cliff Stearns, R-FL, states the commission will assess these situations on a case-by-case basis. According to the letter, “the commission’s Media Bureau [will] conduct an engineering analysis” and determine “that the move would not pose a risk of harmful interference to other existing analog or digital channels.”