Telecom executives worry that this role will force operators to miss out on the growing revenue that flows into smartphone applications, Internet gaming and other services, which all run on top of their networks. The concerns come as many carriers’ revenues — particularly in Europe, whose economy continues to stutter — have leveled off.

Some industry insiders also have expressed frustration that American tech giants like Google and Amazon, which have used complicated tax structures to reduce their global tax burdens, do not face the same levels of regulatory scrutiny as carriers. That includes the F.C.C.’s net neutrality decision last week, which will allow the agency to treat broadband Internet access as a public utility for regulatory purposes.

“We always pay taxes in Europe,” Pierre Louette, deputy chief executive at the French telecom operator Orange, told an industry conference late last year, in a jab at the Silicon Valley giants. “We can’t continue to be overregulated while they are not regulated.”

At the same time, several tech giants have gained footholds in areas traditionally dominated by the big telecom companies.

Google, for example, is introducing fiber-optic networks in several American cities, offering television and Internet services at speeds of up to one gigabit a second, 100 times as fast as the average Internet connection. The search giant is running other pilot projects in emerging markets, including Kampala, Uganda, to build Internet infrastructure not offered by local carriers.

And Facebook now competes head-on with traditional telecom players after acquiring WhatsApp, the Internet messaging service, last year for $19 billion. Along with Facebook Messenger, the company’s separate messaging service, Facebook now has hundreds of millions of mobile users who have shifted from traditional text messaging — a once highly lucrative revenue source for carriers — to free Internet messaging on their mobile devices.

“Operators only have themselves to blame,” said Steven Hartley, a telecom analyst at the research company Ovum in London. “They didn’t adapt to the mobile shifts in the industry. They can’t complain when others beat them to the punch.”