A newspaper article "Telecom in dark over cause of latest XT text fault " By TOM PULLAR-STRECKER - The Dominion Post,
http://www.stuff.co.nz/technology//3337572/Telecom-in-dark-over-cause-of-latest-XT-text-fault, blames the latest outage on school kids texting.
What rubbish.
Other systems like Telecoms CDMA network, Vodafone etc work ok at the times when there is an increase in kids texting. The problem is that Telecom built the XT Network on the cheap. They did not build it to handle the load they
knew it would get, they built it with the least amount of infrastructure they felt the could get away with. They did the same thing in the days of dialup internet, they spent heaps of money on advertising the service before adding the infrastructure to handle the increased load from any increase in customers. This meant that for a while dialup internet customers had problems connecting.
Eventually the may spend money on the network, but in the meantime customers have to put up with rubbish service. Telecom will end up losing a lot of customers and use this as an excuse to keep more control of the lines (broadband and landline phones) so they can overcharge their competitors for access to those lines.
There are other things that will be contributing to the problem as well, but Telecom not spending money on the network is most likely the root of it all. Which has its roots in the fact that Telecom decided to use a system almost no one else in the world uses instead of a system that has been working fine for decades,
the system Vodafone uses, because they are scared that using the same system would make it to easy for customers (if unhappy) to change mobile service provider.