About UE support UMTS

Question

If network capability IE in attach request indicate that all the UMTS security functions are not support, can we comfirm that this UE is not support UMTS?
In other words, if UE support UMTS, is it possible that UE set all UMTS security not support in network capability IE when attach request?

Note: UMTS security is include integrity (UIA0~UIA7) and encryption(UEA0~UEA7)

and another question is that is it possible support encryption function but not support any integrity function?

Answer 1

It can be possible that. UE supports umts and does not support any security algo so UE can use null security algo . If core core/access network support null algo then ue can attend to nw.

Comments

But in 24.008 4.7.1.2a, it said "integrity protected signalling is mandatory for the GMM messages and SM messages once a valid UMTS security context exists and has been taken into use. For the network, integrity protected signalling is mandatory for the GMM messages and SM messages once authentication and ciphering procedure is initiated by the network." except emergency, I think it is mandatory for integrity. So if UE register LTE without emergency and indicate all UMTS security not support, does it mean that UE not support normal service in UMTS, but support emergency service? thank you for your reply.

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I think it is very strange that UE support UMTS, but just for emergency. Is there any UE like this in real world?

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I think this is not possible with commercial ue but test ue can have this configuration.