How to calculate parameters AUTN, MAC in AKA?

Hi,
I would like to know how to calculate the values AUTN, MAC defined in
TS 33.102?

In other words, what does the functions the functions f1, f2, f3, f4,
f5 in the below formula teakn from TS 33.102 notify?

-a message authentication code MAC = f1K(SQN || RAND || AMF) where f1
is a message authentication function;
- an expected response XRES = f2K (RAND) where f2 is a (possibly
truncated) message authentication function;
- a cipher key CK = f3K (RAND) where f3 is a key generating function;
- an integrity key IK = f4K (RAND) where f4 is a key generating
function;
- an anonymity key AK = f5K (RAND) where f5 is a key generating
function or f5  0.
Finally the authentication token AUTN = SQN * AK || AMF || MAC is
constructed.


It would be very helpful if someone could clarify this.

Thanks,
Prakash

.