Following the lead set by its chief executive Dan Hesse, Sprint has been one of the most outspoken opponents of AT&T’s proposed $39 billion T-Mobile USA takeover. Hesse said the deal would “stifle innovation” and hurt U.S. wireless subscribers, and Sprint subsequently voiced its concerns formally on numerous occasions. Among AT&T’s main arguments are the deal’s potential to bring high-speed 4G LTE coverage to over 95% of the U.S. population, and the fact that it needs T-Mobile’s spectrum in order to curtail the massive strain on its network. In a new filing with the Federal Communications Commission on Monday, however, Sprint explained that AT&T’s acquisition is not necessary in order for the carrier to alleviate its network woes. Sprint contends that AT&T could increase its network capacity by more than 600% over the next three years simply by putting its current resources to better use. “AT&T could increase its capacity by developing its warehoused spectrum, accelerating its 4G network buildout, and implementing a more efficient network architecture,” Sprint said in a statement. But AT&T responded immediately by questioning Sprint’s knowledge on the subject considering the carrier outsources the management of its own network to Ericsson. “A company that has outsourced the management of its own network shouldn’t be giving advice to others,” an AT&T spokesman said.