HOLLYWOOD — Ascent Media Network Services has boosted four execs, led by William Doyle, who becomes VP-general manager of the Ascent Media Systems & Technology Services unit.In addition, William Davidson has been upped to VP engineering; Bob Dunbar was made VP of field operations; and Jim Lyons was named VP of technical operations. All three will report to Doyle, who reports to senior VP Tom Canavan. “Our recent surge of growth at Ascent Media Systems & Technology Services directly correlates with the positive contributions made by these four consummate professionals,” Canavan said. The division serves the satellite industry, broadcasters and cable-system distribution. Ascent, formerly Liberty Livewire, is owned by Liberty Media.