Section: 4.5.1.3.3 Paging response in Iu mode (Iu mode only)
Content: The network may initiate the paging procedure for CS services when the MS is IMSI attached for CS services. To initiate the procedure, the MM entity requests the RR sublayer to initiate paging (see 3GPP TS 25.331[ None ]  [23c], 3GPP TS 25.413[ UTRAN Iu interface Radio Access Network Application Part (RANAP) signalling ]  [19c] and 3GPP TS 44.118[ None ]  [111]) for CS services. At reception of a paging message, the RR sublayer in the MS shall deliver a paging indication to the MM sublayer if the paging was initiated by the MM entity in the network (see 3GPP TS 25.331[ None ]  [23c] and 3GPP TS 44.118[ None ]  [111]) and the MS shall stop the timer T3246, if running. The MS shall respond with the PAGING RESPONSE message defined in 3GPP TS 44.018[ None ]  [84], subclause 9.1.25. For reasons of backward compatibility the paging response shall use the RR protocol discriminator. If the MS receives a paging request for CS services during an ongoing MM procedure, and the MS has already requested the establishment of a radio connection, the MS shall ignore the paging request and the MS and the network shall continue the MM procedure.