There’s a storm brewing in Mexico it would seem, as América Móvil unveiled its 2Q15 results and introduced a new policy for Mexico-US roaming for its Mexican subsidiary, Telcel.

Since AT&T introduced itself to the Mexican with its purchase of Iusacell in 2014, the North American market has begun to contract. AT&T quickly moved to introduce free cross-border calling for customers in January, a move which has seen rival players in each market respond in turn. T-Mobile recently announced it will be unleashing unlimited data, voice and messaging roaming between the US, Mexico and Canada as part of its unrelenting “uncarrier” strategy.

América Móvil’s quarterly announcement saw it unveil the “Sin Fronteras” campaign, making roaming between the US and Mexico a non-issue for customers, with cross-border data, voice and messaging all treated as though it local. The operator did concede that voice revenues have declined to less than one third of its total ten years ago – $9.2bn to $3bn – and Sin Fronteras could be a welcome move to help keep its mobile subscriber numbers ahead of its domestic rivals. According to Ovum’s WCIS, Telcel’s market share sits at around 69%, a dominant position which hasn’t been threatened for years – with only Movistar Mexico’s 22.6% of the market seeing any growth in recent times, gaining 4 percentage points since June 2013.

The telco also claimed it gained more than half a million mobile subscribers in Mexico in the second quarter of 2015, almost 300,000 of which were post-paid subs. América Móvil Mexican businesses, including Telmex, finished June with 72.6 million clients, growing 1.9% year-on-year. In total, it posted a year-on-year revenue decline of 2.4% due to a plummeting voice revenue stream – down 19.2% on fixed, 14.6% on mobile. Data revenues were up 2.9% on mobile and 4.4% on fixed platforms, while the telco’s second quarter EBITDA came in at 28.2 billion pesos, down 7.3% year-on-year.