Communications regulators on Tuesday will unveil a sweeping proposal to overhaul U.S. broadband policy. Their aim: to bring affordable, high-speed Internet connections to all Americans and make access much faster for people who already have broadband.

Yet it's not certain the Federal Communications Commission can find the funding, corporate support and legal clearance to carry out the entire vision of the plan.

Already, broadcasters oppose one key element of the proposal. That would seek to reclaim some airwaves now in the hands of TV stations and instead sell some of those frequencies to companies that deliver wireless Internet access. And the FCC also will be trying yet again to reform a program that subsidizes telephone service in poor and rural areas.