Some of these companies also cautioned that a free Wi-Fi service could interfere with existing cellular networks and television broadcasts.
Intel, whose chips are used in many of the devices that operate on cellular networks, fears that the new Wi-Fi service would crowd the airwaves. The company said it would rather the FCC use the airwaves from television stations to bolster high-speed cellular networks, known as 4G.
"We think that that spectrum would be most useful to the larger society and to broadband deployment if it were licensed," said Peter Pitsch, the executive director of communications for Intel. "As unlicensed, there would be a disincentive to invest in expensive networking equipment and provide users with optimal quality of service."
Cisco and other telecommunications equipment firms told the FCC that it needs to test the airwaves more for potential interference.
"Cisco strongly urges the commission to firmly retreat from the notion that it can predict, or should predict . . . how the unlicensed guard bands might be used," the networking giant wrote.
Supporters of the free-Wi-Fi plan say telecom equipment firms have long enjoyed lucrative relationships with cellular carriers and may not want to disrupt that model.
An FCC official added that there is little proof so far that the spectrum that could be used for public Wi-Fi systems would knock out broadcast and 4G wireless signals.
"We want our policy to be more end-user-centric and not carrier-centric. That's where there is a difference in opinion" with carriers and their partners, said a senior FCC official who spoke on the condition of anonymity because the proposal is still being considered by the five-member panel.
The lobbying from the cellular industry motivated longtime rivals Google and Microsoft to join forces to support the FCC's proposal. Both companies would benefit from a boom in new devices that could access the free Wi-Fi networks.