When I talk over 3G without a SIM, for which the only example I see is 911 emergency calling, is any encryption used? In other words, can a 3G eavesdropper understand any content of my 911 call? I assume the network provider (who provides the link from my phone to the 911 operator) can understand this content if they wanted to, but am curious about outside parties.
Additionally, does my phone somehow authenticate the 911 center? If not, does it at least authenticate the network provider selected for this emergency link?
(The above questions assume that no SIM is used. I do realize that SIM protocols themselves are not perfect, but am wondering how much weaker encyption and authentication becomes with no SIM.)