LTE: what is the use of authentication privacy verification on the location request?

Question

According to the spec 29.172 (For Location services). Upon reception of PROVIDE SUBSCRIBER LOCATION REQUEST message, the MME shall perform authentication privacy verification on the location request.What is the use of performing authentication privacy verification when authentication has already been performed?

Answer 1

Location based service can be initiated by any entity of the network like UE, MME or GMLC(Gateway mobile location center).

In LTE MME node is responsible for authentication and security.
when MME receives "ROVIDE SUBSCRIBER LOCATION REQUEST" from GMLC then it need to verify that GMLC itself.

If you see when MME itself initiates to send "Subscriber Location Report". It need not be performed authentication privacy verification.

I am looking for more details from other users.