TV execs weren’t very reassured after FCC Chairman Julius Genachowski’s speech to the National Association of Broadcasters last week in Las Vegas, reports Broadcasting & Cable. Most are still concerned about a voluntary giveback of broadcast spectrum for the growing mobile-device market. Although the chairman has stressed that any spectrum reallocation wouldn’t be mandatory, NAB President Gordon Smith read in his keynote address from the FCC’s National Broadband Plan: “The government’s ability to reclaim, clear and re-auction spectrum is the ultimate backstop against market failure and is an appropriate tool when a voluntary process stalls entirely.” According to the plan, a trust fund created by proceeds from public broadcasting spectrum givebacks would be available to pubcasters that participate (Current, Feb. 8, 2010).