WASHINGTON — New Internet access rules approved by federal regulators on Tuesday prohibit network operators from meddling with Web traffic into American homes but do not extend to the fast-growing market for smartphones and tablet computers.
The regulations passed the Federal Communications Commission along party lines, with two Democratic commissioners reluctantly siding with agency chairman Julius Genachowski in a 3-2 vote.
The rules seek to uphold a principle called net neutrality, under which Internet service providers are supposed to give equal treatment to all legal Web content on their networks. But the measure met with swift opposition Tuesday.
Republican lawmakers immediately promised to work to overthrow the rules, while analysts predicted that cable and telecom giants will file lawsuits challenging the FCC's authority to regulate the broadband market.
Genachowski, who had aggressively pushed for the rules for more than a year, did get the support of President Obama, who said the measure fulfilled a election campaign promise for net-neutrality regulations.
Under the rules, broadband providers are barred, for example, from blocking streaming videos from providers such as Netflix or slowing purchases from retailers such as Amazon. The rules leave open the possibility of network operators charging higher rates to websites, such as YouTube, for better delivery of content.
However, the rules for the most part do not apply to wireless carriers, which have increasingly become the main providers of Internet connections for smartphone users.
The exemption of wireless broadband provoked criticism from Genachowski's allies in the consumer groups that have long pushed for net-neutrality rules.
"The commission could have established clear rules that would give more protections to Internet users than the one approved today," said Gigi Sohn, president of the public interest group Public Knowledge. "Instead, these rules will be subject to manipulation by telephone and cable companies."
The FCC has justified its exemption of wireless broadband by noting that mobile technology is evolving quickly and that cellular networks have significant capacity limitations.