T-Mobile USA told the FCC that having an open network caused it severe overloading and network degradation, thanks to one incompetent Android developer.
The developer in question created an Instant Messaging application that drove traffic up by 1,200 per cent in one instance. As it became more popular, T-Mobile was obliged to offer technical support to the developer or risk the stability of its network. Now the mobile operator said it thinks that mandated net neutrality would prevent it from taking remedial action next time.
Fierce Wireless spotted the details, which were in a submission made to the FCC in January as part of T-Mobile's arguments that wireless should be exempted from any net neutrality legislation (pdf). The argument is based on the premise that wireless networks are more vulnerable than fixed networks, and thus should be afforded special protection.
"These signalling problems not only caused network overload problems that affected all T-Mobile broadband users in the area; it also ended up forcing T-Mobile’s UMTS radio vendors to reevaluate the architecture of their Radio Network Controllers to address this never-before-seen signalling issue."
The events described happened some time last year, and the argument is far from new, but it's interesting to hear that the issues have already manifested themselves. The problem here isn't the quantity of data, but the way in which the application was making use of it. T-Mobile isn't providing more details, but it seems likely the application was repeatedly setting up and tearing down IP connections, using each one for a very small amount of data and thus generating more signalling load than the base stations could manage.
This kind of thing is increasingly a problem as smartphones try to push battery life by shutting down data connections as quickly as possible, while the applications treat data connectivity as if it had no overhead - and thus make no attempt to aggregate traffic. Desktop applications can treat connectivity like that, resulting in a critical difference that T-Mobile reckons warrants an industry-wide exception to net neutrality.
T-Mobile's argument is that in this instance it was able contact the developer and help reduce the bandwidth being used, but next time it might not be so lucky. ®