T-Mobile has agreed to pay a $40 million fine over accusations that the company tried to cover up poor rural cell service with "false rings."

The settlement, announced Monday by the Federal Communications Commission, also requires T-Mobile (TMUS) to implement a "compliance plan" to improve address the issues. The company says it stopped using the false ring tones last January.

False ringtones are used to make is seem like someone isn't answering the phone when in fact the call was unable to go through. This means a person trying to call someone in a rural area with spotty coverage would hear multiple rings and assume the other party was just unable to answer.

Source:

http://money.cnn.com/2018/04/16/technology/t-mobile-false-ring/index.html