Telecom GSM Update Location Flow

Telecom GSM Update Location Flow :

1. When subscriber switch on the mobile, The Mobile station finds the near by MSC/VLR.
2.  MSC/VLR will do the MGT validation using MCC and MNC which is present in the IMSI. And sends the SAI request to HLR.
3. HLR sends the Triplets to MSC/VLR which consists RAND, SRES and KC.
4. MSC/VLR checking the received Triplets with their records. If its matching with their records, MSC/VLR sends the Update location request to HLR.
5. Then HLR sends the ISD to MSC/VLR which consists Supplementary services, Teleservices and Camel subscriber information.
6. After receiving ISD, MSC/VLR will send Return result ISD to HLR.
7. Now HLR will check Old MSC/VLR for Cancel location.
8. Old MSC/VLR sends the Cancel location acknowledgement to HLR.
9. Finally HLR sends the Update location response to the MSC/VLR. Mobile station will latch in network.