In the remaining weeks of his tenure, Federal Communications Commission Chairman Kevin J. Martin will push for a free, no-porn wireless Internet network across the nation, according to the agency. Martin is expected to put his proposal for the free Internet network on the agency’s Dec. 18 meeting agenda despite criticism by wireless operators like T-Mobile, who say using the spectrum could interfere with their new high-speed data network. T-Mobile, a unit of Germany’s Deutsche Telecom, spent $4 billion for nearby spectrum and has disputed a report by the FCC that rejected the firm’s concerns of interference.