AT&T Inc. (NYSE:T) has taken out full page ads in several big newspapers attacking T-Mobile for its service quality. The move demonstrates the rising temperature in the rivalry between the two companies. Last year the two companies were set to merge, but the Federal Trade Commission put an end to it.

AT&T logo

The newspaper ads claimed to “The truth about T-Mobile’s network compared to AT&T,” and contained comparisons between the two cell carriers. According to the advertisement, T-Mobile has “2x more dropped calls, 2x more failed calls, 50% slower download speeds.”

The advertisement, having appeared for one day only, is unlikely to change the market considerably, but it may lay the foundation for a new full campaign from AT&T. The T-Mobile response to the advertisement was almost jubilant. The company, which is the United States’ fourth largest carrier, is glad for the free publicity.

In a statement printed in Bloomberg, Chief Marketing Officer Mike Sievert said“Wow. Looks like we struck a chord. AT&T doth protest too much. Glad they’re spending their money to print our name.” T-Mobile is not standing down from the brewing rivalry, it appears to be embracing it instead.

An AT&T Inc. (NYSE:T) spokesperson, also talking to Bloomberg, said that the advertisement was a direct response to the T-Mobile advertising campaign that brags about the speed of its 4G network compared to competitors. Mar Siegel, commenting for AT&T said “T-Mobile’s advertising is a combination of misguided and just plain wrong.”

Siegel said that the ads were intended as “just a friendly reminder of the fact that independent third-party testing says AT&T’s network delivers faster speeds and fewer dropped calls than them.” Various studies have been carried out on network speeds, though some of the results don’t add up.

A Piper Jaffray study on 4G speeds found that AT&T scored second, behind Verizon Communications Inc. (NYSE:VZ). T-Mobile came fourth in that survey, just a shade behind Sprint Nextel Corporation (NYSE:S). 4G speed across the nation is a difficult number to calculate accurately, as evidenced by the glut of contradictory reports.

Neither firm appears to have been affected significantly by today’s advertisements. AT&T Inc. (NYSE:T) shares were up a small fraction at time of writing. So far in 2013, the company’s stock has risen by more than 6.5%.