By David Shepardson WASHINGTON (Reuters) - The U.S. Federal Communications Commission is moving forward to advance a new broadcasting standard that would improve television picture quality, allow better access to programs via mobile phones and let broadcasters turn on a television set to send emergency alerts. Republican FCC Chairman Ajit Pai said the commission will vote Feb. 23 on whether to grant initial approval on a rule to allow broadcasters to use the new standard on a voluntary basis. Pai had been urging this move for months last year while Democrats controlled the FCC.