Detach process (IMSI) refers to the process that MS informs the network that it is shiftingfrom working state to non-working state (usually a power-off process), or the SIM card isbeing taken out from MS. Upon receiving the notice from MS, the network knows that theIMSI subscriber is in non-working state. Therefore, if the MS is called, the call connectionwill be implemented.? IMSI attach process is opposite to detach process. It is the process that MS informs thenetwork it has entered the service area (usually a power-on process) or SIM card has beeninserted into MS. After entering service state again, MS will test whether the currentlocation area (LAI) is the same with the latest LAI recorded in MS. If yes, MS will start IMSIattach process. Otherwise MS will start location update process, upon receiving thelocation update or IMSI attach process, the network will indicate that this IMSI subscriberis in working state.Detach process (IMSI) refers to the process that MS informs the network that it is shiftingfrom working state to non-working state (usually a power-off process), or the SIM card isbeing taken out from MS. Upon receiving the notice from MS, the network knows that theIMSI subscriber is in non-working state. Therefore, if the MS is called, the call connectionwill be implemented.? IMSI attach process is opposite to detach process. It is the process that MS informs thenetwork it has entered the service area (usually a power-on process) or SIM card has beeninserted into MS. After entering service state again, MS will test whether the currentlocation area (LAI) is the same with the latest LAI recorded in MS. If yes, MS will start IMSIattach process. Otherwise MS will start location update process, upon receiving thelocation update or IMSI attach process, the network will indicate that this IMSI subscriberis in working state.