Eleven months after AT&T Inc. announced its $48.5 billion deal for DirecTV that would create a substantially bigger pay-TV company than Comcast Corp., the deal seems to be cruising smoothly through Washington, while Comcast's $45 billion deal for Time Warner Cable Inc. has faced a public backlash. The deals - Comcast announced its in February and AT&T disclosed its in May - have been a surprising tale of two giant telecom mergers.