"Here’s how it worked. Whenever a phone couldn’t establish a connection with another phone, instead of remaining silent, the calling tone would start ringing in the caller’s ear. Logically, the person placing the call believes that the phone on the other side is actually ringing but nobody is picking up.

...

If you think that’s not that bad, imagine this: You’re driving through the middle of nowhere in Midwest Square State, U.S.A. Your car breaks down, your A/C is nonfunctional in the hot summer weather, and you call road assistance. The phone rings and rings, but nobody picks up. You call again. And again. It seems that everyone at road assistance must be out partying, or they just hate you. By the 27th call, you’d probably be mad enough to break the phone–all without realizing that your those rings were pure fiction, and you needed to move to find a better signal. And what if someone with you was injured, or a more serious emergency took place?"

it has nothing to do with signal strength. the fact that they were able to inject a fake ring tone, means that you were connected to the tower just fine.

the issue was that they couldn't connect the call to the other phone's telephone company and pretended it had reached it.

i.e. if you call overseas, you don't hear our ringtone, you hear whatever their ringtone is.

> the fact that they were able to inject a fake ring tone, means that you were connected to the tower just fine

Do we know this? The tone could have been injected by the device.

The arstechnica story (linked in another comment) clarifies that the ring tone was injected in T-Mobile servers for calls that went over a SIP backbone. So yes we know it was not in the user terminal.

I cannot believe that T-Mobile would remote 'Celebrite'/jailbreak/root a device just to add the necessary files and remote-execute a process to play an mp3 while the Phone-app has taken control. When the Phone-app is running, it automatically thwarts any other sound-using app (such as Spotify, Music, Skype, games)

Carriers have enormous control over devices. While we now know it didn't happen, they likely could have easily shipped a manipulated standard phone app since when a carrier gives out a device it is often running customized firmware with the carrier's logo on boot and preinstalled bloat ware like Spotify, Facebook or WPS Office (by my experience with branded os images for Sony Xperias).

The link in the article has a lot more info: https://arstechnica.com/information-technology/2018/04/t-mob...

The fastcodesign link doesn't really add anything except a story that's not quite accurate (saying it's the signal.. which is wrong).

Which was posted as https://news.ycombinator.com/item?id=16857864 .

I've experienced this before. It's really frustrating. You could kind of tell when it was happening because the timing of the ring was not quite right, and there would be this audible switch when the phone really started ringing. For some reason, it mostly seemed to happen when calling my brother.

I hope this fine means the end of this crappy behavior. I generally like T-Mobile.

This just links and poorly summarizes the much better article at https://arstechnica.com/information-technology/2018/04/t-mob... .

Which was posted as https://news.ycombinator.com/item?id=16857864 .

T-Mobile reported $40B in revenue for FY 2017, so this fine represents 00.1% of their total revenue. Is this sort of fine really going to deter them?

How big fine should be, according to you, to really deter them?

10~20% of "net" yearly income imho or instead of a fine, levy penalty tax rate like how credit works.

I don't get why they did this? Did they forget about busy tones? Or did they think people would prefer a ring tone that wasn't answered? I just don't get it, it didn't exactly feel malicious.

Perhaps unintentionally dangerous. But also very needlessly.

I guess this is related to bad implementation of using SIP for connecting call. I had similar experience with local telecom provider in Turkey, which is routing international calls over cheap SIP providers. Basically they are calling a SIP route, which you hear ringing, when it starts ringing other provider starting to initiate the call.

In this case I think the cell tower is not Tmobile’s, but they have agreement with the tower owner to route call to their SIP trunk.

>With Trump-appointed Ajit Pai in charge of the FCC, the treatment of telecomm companies probably won’t change any time soon.

Why not sprinkle a lil bit of politics there, eh?

> Why not

Maybe if it wasn't relevant to the story.

Pai being a former telco lobbyist, it seems pretty relevant.

Unnecessary and gratuitous dig at Trump and Ajit Pai at the end of the article, especially with no supporting evidence or explanation given.

No fan of Trump, but yea, just for SEO I think. Esp considering Obama had put him on the board to begin with, Trump only had him chair.

> Esp considering Obama had put him on the board to begin with

It should be noted that Obama was legally required to appoint a Republican to that slot, and took Mitch McConnell's recommendation.

Making him Chairman is an explicit vote of confidence far greater than "I have to pick someone I don't really like, might as well be this guy".

Ah yes, I remember when Obama was forced to select this guy during the great rebulican shortage.

I felt the dig at Pai was more warranted than the Trump one. But overall, neither added very much.