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Back in the late 2000s, 2009, a new Trans-SEO came in, Andy Biford, and he came over from England. He transitioned the TDC system over to something called Tetra. Tetra stands for Terrestrial Trunk Radio, and it's basically the European equivalent of P-25, which is a digital voice standard here. In basic terms, it's very secure. It uses a digital trunking standard that uses 4-slot TDMA, so it has 4 voice data paths per channel. Transit agencies like the TTC, they've grown to actually like it because it handles high volume data and voice simultaneously. It's great for train telemetry, subway operations, and all the other stuff, plus voice traffic going through it.