It's pretty clear that ebullient T-Mobile CEO John Legere is focused on taking it to AT&T and Verizon these days, and less concerned about the perception that the Magenta operator is in a fight for third place with Sprint.

On Thursday, T-Mobile US Inc. revealed that it is going unlimited from September 6 onwards in its latest "Un-Carrier" update. It will offer monthly customers unlimited data -- with video compression -- for $70 a month. Family plans will go unlimited at $40 per line. You can see more about the announcement here and learn about the Binge On video compression technology that has convinced T-Mobile it can go unlimited here.

T-Mobile has also stepped up its commitment to tablets. Customers can add a tablet to the unlimited plan for $20 a month.

Always willing to go after competitors in front of the press, Legere called AT&T Inc. (NYSE: T) and Verizon Communications Inc. (NYSE: VZ) "dumb and dumber" repeatedly on a press and analyst call Thursday, while Sprint was simply dubbed the much more mellow "yellow."

On the call, Legere predicted that the move to a simple unlimited structure will bring an "avalanche" of new customers to T-Mobile and he is clearly hoping that the plans will attract subscribers currently on AT&T and Verizon.

"Two of the three other carriers have no desire to do this," boasted Legere.

T-Mobile CTO Neville Ray doubled down a little later on the call. "There is no way on earth that Verizon and AT&T, with their overcrowded networks, can do what we're doing," Ray stated.

Legere, meanwhile, even suggested on the call that Sprint and T-Mobile don't need to take customers out of "each other's hide," indicating that he's more focused on the big two operators.

Ironic then, that Sprint reacted almost instantly to T-Mobile move with $100 a month for two lines of unlimited.

Whatever happens with the jockeying for customers between the two, T-Mobile will need to add capacity to its LTE network if Legere's predictions of a flood of new customers come to pass.

T-Mobile execs couldn't talk directly about the ongoing 600MHz auction, as there is a quiet period while the bidding is in process. Legere, however, has predicted that T-Mobile will be a big winner in the low-band auction. (See T-Mobile CEO: We'll be a 600MHz Auction Winner and Get Ready! FCC 600MHz Auction Bidding Starts May 31.)

Even if that is the case, that doesn't mean that T-Mobile will get to use that spectrum lickety-split when the auction eventually ends. It takes time -- sometimes measured in years! -- for the Federal Communications Commission (FCC) to transfer the spectrum to the carrier, and then time for the operator to start offering services on the radio waves.

Although, T-Mobile and the FCC appear to have worked on making the process of going from winning spectrum to turning on 4G services on the air faster. Recall that T-Mobile won mid-band AWS-3 spectrum at the end of January 2015, paying $1.77 billion for the additional bandwidth. (See FCC's Monster Auction Ends at $45B in Bids.)

"We intend to be the first carrier here in the US to light up AWS-3," Ray said on the call Thursday. If that happens in 2016 that's a lot faster than the usual three- to five-year process of turning new spectrum up in the US.

Nonetheless, Ray says that in order to add capacity to the operator's 4G LTE network straightaway, T-Mobile has now started to deploy 3-band carrier aggregation (3CA) -- a technique of combining radio channels to boost capacity -- and 4x4 MIMO, multiple antenna arrays at the cellsites that can boost data rates to subscribers. (See Sprint Plots Ramped-Up LTE for more on 3CA.)

— Dan Jones, Mobile Editor, Light Reading