I'd be surprised if the real number was even a net subsidy rather than a net tax. We impose all sorts of extra taxes and costs on the telecommunications that we do not impose on other industries. For example, state and local cable TV franchise fees alone (typically 5% of gross revenue) amount to $5-6 billion per year in the U.S. In comparison, the American Recovery and Reinvestment Act had $7 billion in telecommunications subsidies, and that was a one-time shot.
Then there is the economic deadweight loss created by implicit and explicit cross-subsidies. There is a 17-18% tax on telecommunications services.[1] That is not a net tax, because the money is redistributed within the industry, but it increases prices, which decreases demand, which causes a net deadweight loss. Then there is implicit cross-subsidies in the form of build-out requirements. In nearly every city, you are not permitted to only build out in the neighborhoods where you can count on having enough subscribers to recoup the cost of that part of the build. You have to build out everywhere. The end result is that prices go up in neighborhoods with more potential subscribers in order to subsidize the deployment to neighborhoods with fewer potential subscribers. Again, making the product more expensive decreases demand and imposes a deadweight loss.
The ideas behind these policies are mostly well-intentioned. We want as a society to provide connectivity to rural areas and poor neighborhoods. But the implementations are driven by politics rather than any attempt to achieve the desired end result in the most economically efficient way. We don't pay for SNAP benefits with a tax on supermarkets. We impose a general tax on everybody, to avoid distorting the economy in favor or against any particular industry.
[1] That tax pays for almost all the "subsidies" you hear telecom companies getting. It's like imposing an 17-18% tax on all smartphones, and giving the money to companies building cheap smart phones for poor people. Nobody would call that a "subsidy" to the smart phone industry (it's a cross-subsidy within the industry).