TSG-Core Network WG 1 meeting #5	Tdoc N1-99679
Oulu, 29th June – 1st July 1999	

Source:	TSG-N1
To:	TSG-R2, TSG-R3, SMG2-WPA
Title:	Liaison Statement on the Paging Response message categorization
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N1 is now studying the MM protocol. The discussion was raised whether Paging Response message, which was defined in the RR protocol in the GSM system, would be in the RRC protocol or in the MM protocol for UMTS.
N1 believes that there are benefits to include this in MM because of following points;
a)	If Paging Response is carried though Iu interface to MSC, it needs to be analysed by MSC.  This means that the MSC knows the format of an RRC message. According to basic principle of UMTS, RAN and CN are to be independent from each other therefore this procedure is against that principle.
b)	The issue of Paging Response categorisation is related to both RR and MM. If we are waiting for the simultaneous evolution both of RAN and CN, there is no chance to improve the protocol. The UTRAN specifications are being newly developed for UMTS giving the opportunity to separate these RR and MM dependencies.
c)	We may have more than one radio systems for UMTS. These should be independent from each other in terms of protocol structure and so on. However these radio access networks should provide the same Paging Response message to a UMTS Core Network.

Initial consideration in N1 have noted that modifications to redefine Paging Response message in MM protocol will impact dual mode (GSM/UMTS) terminals. It is also noted that introduction of MM Paging Response into GSM would introduce cross phase compatibility concerns that need careful consideration.

N1 would like to ask the experts of UTRAN and SMG2 if they see any impact on this issue.