Thanks Wader2. A bit more detail. On a job I'm doing, a certain British company is calling its SSR an IFF. I can't work out why and their answers haven't been compelling. However, it is capable of decoding Modes 1-5 (4, as I understand, it being a unique identifier and hence an IFF).
Anyway, that aside, can a controller provide any radar service without the SSR or is the height data essential to provide deconfliction?
Following on from that, if the SSR fails mid-games will the controller have to hand off all the guys he is working?