Over the course of the past six months or so, a debate has swirled around DISH Network (NASDAQ:DISH). The company’s co-founder and board chairman Charlie Ergen has suggested the organization could build the infrastructure necessary to power an entire wireless telecom network for a modest $10 billion. The key, he explained, would be the utilization of software rather than hardware, which lowers upfront costs between 40% and 60%. Meanwhile, MoffettNathanson’s senior analyst Craig Moffett unofficially led a chorus of critics suggesting that estimate was alarmingly low. In his words, “The idea that DISH might spend $10 billion (their own estimate on previous conference calls) and then somehow be finished is, well, just silly.” Moffett underscored his assessment by adding: “Verizon spends $15 billion annually to maintain a network that they’ve already built.” The financial truth is likely somewhere in between. While $10 billion might underestimate DISH’s total cost of getting into the wireless business should Sprint and T-Mobile finally consummate their long-awaited union, virtualized networks rather than dedicated hardware with a relatively short lifespan probably does represent some degree of cost-savings. The problem is that roughly two-thirds of AT&T‘s (NYSE:T) wireless network is now virtualized, but the move hasn’t measurably lowered the telco’s total capital spending or operating costs.The shift hasn’t dramatically lowered operating expenses for AT&T’s mobility division either. The company spent 56.2% of Q3’s wireless revenue just to keep its network up and running, but that’s in line with operating expense levels we’ve seen since 2016.Ergen has also noted that existing wireless providers are still servicing legacy 3G and even 2G connections, and he’s right. Nevertheless, with three-fourths of its network now virtualized, one would have expected AT&T to at least show some sort of measurable savings by now.