Hmmm,
As far as I am aware, SIFF has been in use for many years. I would refer you to its analysis following Operation Bright Star 1983. United States Rapid Deployment Joint Task Force (later Central Command). McDill AFB. Florida. Theres some papers about it on the net somewhere.
The recent developments you speak of, are, I think (and I only say think, as I am not an expert in this field), the change FROM localised IFF to satelitte based SIFF. The whole idea of using it via Satelite is so that the signal is a sorta strait up and down signal with minimal lateral spread. That way, the forces on the ground are not compromised.
It was the use of local high frequency conventional radio that compromised them. Radio could be RDF'd. Satcoms cant. Well, not in theory as far as I know, anyway.
Try Jane's Command and Communications yearbook.
www.Janes.com
As to who told me they were investigating its use in cabs, it was a guy called Adrian, I think. And I do believe he was from Autocab. But it was a while ago, and in general conversation, so I may have miss-heard J.