T-Mobile US agreed to pay a $40 million fine and follow a compliance plan after a Federal Communications Commission (FCC) investigation found the operator covered up rural call completion failures with false ring tones.

The investigation looked into complaints from rural operators and consumers that T-Mobile callers were unable to connect with customers of three rural operators in Wisconsin. Call delivery problems were also discovered in at least seven other rural areas.

Although T-Mobile told the FCC the problem had been solved, the commission found the operator was injecting false ring tones into a number of calls to make it sound like a call was going through when it was not. T-Mobile admitted to adding deceptive ring tones to hundreds of millions of calls and breaking FCC rules in doing so. The practice was banned by the commission in 2014.

The FCC noted false ring tones create a “misleading impression” a caller’s service provider is not at fault for the missed connection.

Rural broadband association NCTA applauded the verdict and called for “continued vigilance” to prevent rural call failures.

In a statement, FCC Commissioner Mignon Clyburn called T-Mobile’s practice “massively deceptive and harmful”, and blasted the settlement agreement for not including compensation for consumers. She also claimed her request to have the settlement come before the full commission body for a vote was ignored.

Connection move
The settlement announcement came as the FCC moved ahead with new measures to tackle the issue of rural call completion. The measures would require larger providers to monitor the performance of intermediate providers, and oblige those larger operators to establish a point of contact to address call completion issues.

However, the moves would also eliminate data reporting requirements for larger providers, claiming the commission had not found those reports to be useful since their implementation in 2013.

In February, President Donald Trump signed into law Congressional legislation to address rural call completion, which required intermediate providers to register with the FCC and adhere to service standards set out by the commission.