Section: 4.7.4.1.5 Abnormal cases on the network side
Content: The following abnormal cases can be identified: a) Detach request received in a CSG cell for which the MS has no valid CSG subscription If the MS initiates a detach procedure in a CSG cell the CSG ID of which is not valid for the MS and the detach procedure is not due to "switch off", the network shall proceed as follows: - if the detach type is "IMSI detach" and the MS has a PDN connection for emergency bearer services active, the SGSN shall send a DETACH ACCEPT message and deactivate all non-emergency PDP contexts, if any, by initiating a PDP context deactivation procedure; - otherwise, the network shall initiate the detach procedure. The network shall send a DETACH REQUEST message including the GMM cause value #25 "not authorized for this CSG".