I am not really experienced with how the 3G/4G network work, but I know that SS7 have some security vulnerabilities, and Diameter protocol brought over some of the SS7 vulnerabilities.
So I would like to ask for example,if I am on a 4G/LTE network It is still technically possible to intercept any SMS being sent to me regardless of who, because of SS7 vulnerability(Just harder in this case)? or is it impossible now?
The protocol is insecure by definition as it needs to pass over a public open network for everything to operate flawlessly.
If you need private communications, use a secured web or email connection, or a call encryption app. Note however that call encryption needs to be set up on both sides and the key (password) should be transmitted securely over another channel (like email).
It is easy to intercept SMS and perform other attacks (e.g., determine location) against SS7/MAP networks if you have a Linux box connected to the SS7 network, or one of the spy tools rigged to attach to and attack the SS7/MAP architectures.
Please see this Q&A for more details -- SS7 exploit on the wiretapping part
