Section: 4.7.3.2 Combined GPRS attach procedure for GPRS and non-GPRS services
Content: The combined GPRS attach procedure is a GMM procedure used by a GPRS MS operating in MS operation modes A or B for IMSI attach for GPRS and non-GPRS services if the network operates in network operation mode I. If a GPRS MS operating in MS operation modes A or B is already attached for non-GPRS services by use of the MM specific IMSI attach procedure, but additionally wishes to perform an IMSI attach for GPRS services, the combined GPRS attach procedure shall also be used. The attach type information element shall indicate "combined GPRS/IMSI attach". In this case, the messages ATTACH ACCEPT, ATTACH COMPLETE, and ATTACH REJECT used by the combined GPRS attach procedure carry information for both the GPRS and the non-GPRS services. A GPRS MS in MS operation mode A shall perform the normal GPRS/IMSI attach procedure during an ongoing circuit-switched transaction.